key: cord-015354-yknwveyz
authors: nan
title: Abstracts_Poster presentations
date: 2007-09-18
journal: Eur J Nucl Med Mol Imaging
DOI: 10.1007/s00259-007-0544-9
sha: 
doc_id: 15354
cord_uid: yknwveyz

nan

T AM and T 1/2RV increasing. And vice versa in patients with T VM and T 1/2RV decreasing residual pulmonary hypertension was diagnosed. It may be explained on the one hand by residual imbalance in vascular tonus regulation, on the other hand by morphological changing in vascular wall. In inoperable patients (because of high risk of postoperative acute right ventricle failure) T AM and T 1/2RV decreasing predominated. In inoperable patients and in children with residual pulmonary hypertension we discovered mottled lung perfusion pattern that pointed either to local or diffuse circulatory disturbances. The expression of these symptoms was directly proportional to pulmonary artery pressure. Conclusion. The performing of perfusion lung scintigraphy and first pass radionuclide angiography with vasodilatators allows estimating right ventricle function and pulmonary microcirculation. It may be used for predicting of postoperative right ventricle function and pulmonary artery pressure normalization.

One of the main goals of whole body scintigraphy with radioactive iodine, performed after total thyroidectomy for differentiated thyroid carcinoma of follicular origin (DTCFO), is to quantify the residual tissue left, thus identifying the patients who need to be reoperated. To avoid the stunning effect, one may administer a low activity of 131I (e.g., 11, 1 MBq) or use other radiopharmaceuticals, in particular the 123I. Aim To compare scintigraphic imaging and cervical uptake of 123I and 99mTc in patients submitted to total thyroidectomy for DTCFO, in order to evaluate the suitability of 99mTc for the identification of patients whose volume of residual thyroid tissue constitutes an indication for a second surgical intervention. Materials and Methods Prospective study from 2005/08/04 to 2006/10/18 in 45 patients submitted to total thyroidectomy for DTCFO: 30 female and 15 male, aged 16-85 years (mean 51,16 ± 18,71 years). After withdrawal of levothyroxine, we obtained scintigraphic images and determined the cervical uptake of 123I 24 hours after oral administration of 11 MBq (300 μCi) of the radionuclide. Then, we proceeded to the i.v. administration of 296 MBq (8 mCi) of 99mTc, and, 20 minutes later, acquired scintigraphic images and calculated the cervical uptake of the radionuclide. We used a Siemens E-Cam DCR Dual head gamma camera, with medium-energy and low-energy high-resolution collimators for 123I and 99mTc respectively. Images of the activities to be administered as well as of the patient`s cervical region in anterior projection were acquired at 30 cm from the detector. Results All of the patients presented cervical uptake of 123I ranging from 0,21 to 37,2%, mean 6,17 ± 9,21. In 16 patients, who presented a very low or absent cervical uptake of 99mTc , a median 123I uptake of 1,1% (0,21-1,69%) was found. In 29 patients the cervical uptake of both radionuclides had a median value of 10,89 ±9,19 for 123I and 0,83 ± 0,62 for 99mTc, with an high correlation (R2 = 0,76). All the patients with a cervical uptake of 123I exceeding 12% presented a 99mTc cervical uptake above 1%. Conclusions A high correlation was found between the cervical uptake of 99mTc and 123I in patients submitted to total thyroidectomy for DTCFO. Cervical scintigraphy with 99mTc was shown to be useful in the identification of patients requiring repeat surgery for voluminous residual thyroid tissue.

Imaging a Breast Cancer With Tc99m MDP Scintigraphy S. I. Mihajlovska, 1954 , N. Kosturski, 1944 ; Clinical hospital, Bitola, THE FORMER YUGOSLAV REPUBLIC OF MACEDONIA.

The aim of the study was to assess the value of Tc99m MDP scintimammography in the detection of breast carcinoma. Fifty six patients (30-71 years, mean 49) were included into the study. There were 35 patients with diagnosed malignant lesions, 12 patients with mastectomy and 9 normal patients. All women were injected with 555-74MBq of Tc99m MDP and double phase (15 min. and 2 h.) breast imaging was made. Whole body scans and lateral views of both breast were obtained in prone position with elevated arms. Focal accumulation of MDP uptake in tumor localization was considered positive. Results: A clear uptake of Tc99m MDP was evident in 25 of 28 malignant lesions individuated (sensitivity 94.5 , specificity 100 %). No false positive results were observed. 11 out 12 patients presenting lymph node metastases (sensitivity 93.7 %). Radioactivity accumulations were detected on contralateral nonoperated gland in two of 12 patients who had masteclomy . For detection malignancy mammography, ultrasonography and biopsy were performed but they were negative. Definitive diagnosis were made base on the histopathologic results and showed malignant lesions. Our study suggests that scintimammography with Tc99m MDP seems to be a highly sensitive and specific method in the differentiation of breast lesions. This method can be added to routine presurgical bone scintigraphy as a diagnostic tool.

The aim of this study was to evaluate the results of early and late lymphoscintigraphy scan using medium sized particles of labeled human serum albumin (HSA) and to compare the results of preoperative imaging and intraoperative probe detector technique in localization and detection of SLNs in melanoma patients. Material and methods: Study enrolled 17 patients (9 male and 8 female, mean age 55 ±12 yr) with malignant skin melanoma. The localizations of the skin lesion were as follows: trunk 6, upper extremities 4, limbs 6 and head 1. The patients were given a total of 0.3 ml (37-74 MBq) 99mTc-HSA with the particle size of 200-600 nm (SENTISCINT-Mediradopharma, Hungary) in four to six small portions, intradermally, around the melanoma or on both sides of the scar after the making diagnostic excision. Dynamic lymphoscintigraphy was performed immediately after the tracer was injected, followed by early and late (12-18h) static scintigraphy. At the time of the surgery, blue dye was injected around the tumor at two to four sites, 10 minutes before surgery. During the surgery, a gamma probe (Europrobe, France) was used to localize sentinel lymph nodes. Results: A total of 25 SLNs were detected in 19 lymphatic basins in 17 patients on dynamic, early static and late lymphoscintigraphy. Ten patients were found to have 1 SLN, in 6 patients 2SLNs were detected, while in one patient 3SLNs were detected in one lyphatic basin. No additional SLN was detected on late static scintigraphy 18h after labelinig, and all SLNs localized preoperatively were found during the operation by collimated gamma probe detector, even 24h after labeling. Vital blue dye failed to color 5 SLN in 3 patients, and 2SLNs in patient in whom 3 SLNs were found by lymphoscintigraphy. Seven out of 17 patients had metastatic spreading in the lyphatic basins. The SLNs were positive in all patients with metastatic disease and were the only site of metastases in 6 out of 7 patients. Conclusion: The results of our study suggest that the use of medium sized colloidal particles should be preferred in a melanoma patient because SLNs could be detected early after radiopharmaceutical application but with prolonged selective concentration in the SLN, giving the surgeon enough time to make a surgery plan either for the same day or for the day after lymphoscintigraphy. The results demonstrated lymphatic mapping using lymphoscintigraphy as highly accurate method for staging melanoma patients. Conclusion: In our study, there was a significant correlation between the pattern of brain glucose metabolism and regional myocardial MIBG uptake. In particular, decreased cardiac MIBG uptake in inferior wall tends to correlate with hypometabolism in subcortical nucleus. Key Words: MIBG, heart, SPECT, FDG, brain, PET The treatment options for patients with follicular lymphoma have substantially improved recently, due to the development of radioinmunotherapy, which combines radiation and antibodies. The most important example is 90Y-Ibritumomab Tiuxetan (Zevalin®), which is specially indicated in relapsed and/or refractory follicular B-cell Non-Hodgkin Lymphoma (NHL). Aim: Show our experience in the use of Zevalin® in those patients with follicular lymphoma, whose previous treatments have failed. Material and Methods: Since April 2005 until February 2007 we have treated 17 patients (7 women and 10 men) with ages between 24 and 79 years old. All patients had to follow these criteria: follicular lymphoma, previous treatment with rituximab, platelet counts 100x109/L and bone marrow involvement 25%. The administered dose was 14.8MBq/kg if platelet counts 150x109/L, and of 11.1 MBq/kg if 150x109/L. 15 days post-treatment, the weekly clinical and analitical survey was done, until haematological recovery was confirmed. The evaluation of the therapeutic response was done after three months. Results: From the 17 patients studied, 2 died (11.8%), 1 because of the progression of the disease, the other due to heart failure. 4 had not yet been evaluated (23.5%) and from the remaining 11, 8 had a complete response (47.1%), 2 had a partial response (11.8%) and 1 had a stabilized status (5.9%). Toxicities were primarily haematologic and reversible, with non extrahaematologic toxicity observed. Conclusions: Based on our experience, the treatment of NHL with Zevalin® is useful and secure, due to the minimal secondary effects. The use in early stages of the follicular lymphoma could improve the therapeutical results. Aim: To evaluate the usefulness of 99mTc-Ciprofloxacin scintigraphy (CP) in patients with hip or knee arthroplasty and suspect of infection. Material and methods: Fifteen patients (9 women, 6 men) with a mean age of 71±10 years and clinical symptoms, haematological and/or 99mTc-HMPAO leukocyte scan suggestive of prosthetic infection were included. CP was performed at 1h, 4h and 24h alter intravenous injection of 370 MBq of 99mTc-Ciprofloxacin. Anterior and posterior views centred in the affected joint were performed in all patients. A conventional bone scan, 99mTc-HMPAO leukocyte scan and 99mTc-colloid scan were performed in all cases. The final diagnostic of arthroplasty infection was established by positive microbiologic analysis, macroscopic evidence of purulent material, or after visualization of more than 5 neutrophils in the periprosthetic tissue. Results: Diagnosis of arthroplasty infection was established in 9/15 cases (Coagulase-negative Staphylococcus (4), Aureus Staphylococcus (2), E. Coli (1) and polymicrobial agents in the remaining 2 cases). CP was able to correctly diagnose all cases of infection. CP images at 60' postinjection showed 2 false positive cases, and at 24h 1 false negative case was found. In one patient with knee prosthetic loosening without infection and intense inflammatory changes, CP was positive and then considered as a false positive case. On the other hand, 99mTc-HMPAO leukocyte scan was non-diagnostic in 2/9 cases of infection.Conclusions: CP is useful in the diagnosis of arthroplasty infection of the hip and knee. CP images obtained at 4h alter injection are recommended. Presence of synovitis may cause false positive images with CP in knee prostheses. Surgical removal of PGs is a difficult procedure especially when their localization is deeper than expected. The aim of the study was to evaluate the number of deeply situated PGs in relation to their right or left positioning. Materials and methods. In this retrospective study 415 consecutive patients who had a positive scan (350 with primary and 65 with secondary hyperparathyroidism) were included. A double phase sestamibi technique followed by a pertechnetate scan was used. Early right and left 30 degree oblique images were routinely obtained in order to evaluate the depth of the PGs. Findings were classified in to two groups based on the degree of change of the relative position of PGs and the thyroid gland (TG) in the oblique compared with the anterior image. Group I included PGs where the relative position of the PG and TG in the anterior an oblique images remained the same or changed only slightly. Those PGs were characterized as not deeply located. Group II included PGs that in oblique images the PG to TG distance was significantly increased and were characterized as deeply situated. The localization of the PGs was confirmed by the available surgical data. Results A total of 565 PGs were identified (65 upper right, 115 upper left, 202 lower right and 183 lower left). Group I included 58/65 upper right, 95/115 upper left, 163/202 lower right and 170/183 lower left (486 of the total 565 PGs). Group II included 7/65 upper right, 20/115 upper left, 39/202 lower right and 13/183 lower left (79 of the total 565 PGs). Upper left and lower right PGs were significantly more frequently located at a significant depth compared with the upper right and lower left sites (p<0.05 and p<0.01 respectively). Conclusion These results indicate that upper left and especially lower right PGs are more frequently deeply located; information which is useful for the procedure of surgical removal, mainly when preoperative imaging has not been performed. In recent years, picture archiving and communication systems (PACS) and electronic transfer of radiological images using the DICOM file standard has become more widely employed in diagnostic radiology. It seems to be likely that nuclear medicine will be integrated within such systems. On the other hand, many departments possess older equipment without digital output facilities. There is an increasing tendency to display and archive evaluated images ('Save-screens', printouts) on non-dedicated, inexpensive systems using file formats capable of data compression. This was the reason for examining the value of the JPEG format in this pilot study. Fifty scanned planar bitmap images of the most frequent scintigraphic examinations (thyroid, bone, myocardium, lungs, and kidneys) were compared with JPEG format at different data compressions by two blinded observers. The visualization of details, e.g. pathologic findings, is described for all these images as the visual appearance of the images and the storage capacity required. Relevant loss of clinical information did not occur up to compression factors of 0.75. A major decrease of subjective image quality was seen at compression factors > 0.90. Compared to bitmap files, the use of these factors reduced the storage capacity required by 98% at a (JPEG-related) compression factor of 0.50, and 99% at a compression factor of 0.90. Compared to the GIF format, a reduction by 4.0-5.7 could be achieved. Use of the JPEG format can therefore be recommended to save costs of image transfer or archiving of standard planar scans for nuclear medical evaluation.

The evaluation of genotoxic effect of gamma radiation in nuclear medicine workers to be used [1] . Material and Methods: In a previous work we recorded the personal whole-body dose values received by the workers over a period covering the starting of a PET unit (October, 2004) and the subsequent years until March, 2006 [1] . Then, we reported a substantial increase (167%) of the whole-body dose received by the technologists which was then related to the initial increasing number of PET exams. Following a clear evidence of this initial increase of whole-body dose to be related with the technologists contact with the patient during preparation to exam, a wholebody lead shielding, with a thickness higher than the tenth-value-layer (TVL) for 511 keV photons, was implemented for protection during patient handling and exam preparation. All the dosimetric measurements considered in this work were executed by the same personal dosimeter provider (NRPB, UK) . Results: After shielding started to be used by the technologists during PET patient handling, we observed a clear reduction of whole-body doses back to levels close to the ones observed before the PET implementation. Conclusion: The increased dose received by the technologists before shielding implementation can now be even more clearly related with the time needed to handle the PET patient at the exam and with the higher exposition rate constant of F-18 when compared with other isotopes used in Nuclear Medicine (namely Tc-99m). In conclusion, we can say that whole-body shielding is an affective way to reduce doses to the technologists during this stage of PET procedures. Besides shielding during patient preparation image acquisition, a remote control similar to the ones existing in a common gamma-camera could be also useful in the reduction of the doses. [1] J.A.M. Santos et al. Impact of FDG-PET in the occupational whole-body dose received by several professional groups in a Nuclear Medicine Department, Annual Congress of the EANM, Athens, 2006 (oral presentation, 198) Aim: The dose administered to the hands of nuclear technologists working with PETnuclides is a problem of concern ever since the introduction of PET as a routine examination in Nuclear Medicine. The dose to the hands can be monitored using ring TLD's. The aim of this study is to determine the accuracy and detection limits of extremity dosimetry using ring TLD's. Material and Methods: Two types of TLD's with different thicknesses, 0,0036 and 0,015 inch respectively, were used. The TLD's were exposed to ionising radiation using a 137Cs source. The TLD's were exposed to various doses under several angles. The use of 12 sets of TLD's, each consisting of 1 thick and 1 thin TLD, averaged out the effects of single TLD's. To improve statistics each exposure was repeated 3 times. A Perspex rod with a diameter of 20mm was used to simulate a human finger. After each exposure the TLD's were read out using a Harshaw 6600. Uncertainty analysis was used to determine detection limits and uncertainty intervals for both types of TLD's. Results: Analysis of the measured data shows that within the uncertainty intervals the measured dose matches the exposed dose. No significant angle dependence is found. The relative error in the measured dose is larger at smaller doses. This effect occurres in both types of TLD's. The effect was more pronounced in the thin TLD, yielding a higher detection limit for the thin TLD then for the thick TLD. The detection limits for the thin and thick TLD are 180 μ Sv and 34 μ Sv respectively. The main contribution to the uncertainty at low doses is the effect that manipulating a TLD induces an artificial dose during TLD read out. This effect probably scales with the volume/surface ratio of the TLD and the amount of manipulation, needed to get the TLD out of the ring, into the TLD reader. Conclusion: Due to its high detection limit, is the thin TLD, in contrast with the thick TLD, not suitable to be used for extremity dose monitoring in Nuclear Medicine. The detection limit of both TLD's can be improved by reducing the amount of manipulation, needed to put the TLD in the TLD reader, and to improve the protection against mechanical impacts. Both can be achieved by improving the construction of the ring. New experiments are conducted using an improved design of the ring. Aim: Despite international recommendations about the use of the SI units system [1] determined in 1978 by the CIPM (Comité International des Poids et Mesures), non-SI units in radiation physics and other fields of science are still in use today and included in scientific publications. Some of these, such as the roentgen (R), rad, rem and curie (Ci) are called traditional units and still temporarily acceptable by the SI system although its use has been discouraged and a cessation has already been proposed for the year 2000 by the CIRRPC. In Nuclear Medicine, these units have also been thoroughly used through the years. Nevertheless, SI units are slowly taking their place in the current clinical Nuclear Medicine practice and there is a general tendency for homogeneity towards its universal acceptance. However special care should be taken in this process. Discussion: Although the rad, rem and roentgen have already been almost universally replaced by their SI units, the curie is still widely used in parallel with the bequerel (Bq). The consequences, although minimal, can not be disregarded. Activity values tend still to be written as integer multiples of the milicurie (ex. 5 mCi, 20 mCi) in most of the Nuclear Medicine literature, even if a conversion is provided, resulting in awkward values of activity expressed in SI units, altering the number of precision digits, as seen in the above example, and leading to erroneous appreciation of measurement errors. For example when writing "3 mCi", it is implicit an error of 0.5 mCi (17%) while writing "3.0 mCi", an error of 0.05 mCi (1.7%) is assumed. On the other hand, when writing "111 MBq" instead of "3 mCi", we assume an error of 0.5 MBq, i.e. 0.45% (which is much less than the actual precision of a clinical purpose activimeter). Conclusion: Supplementary effort, besides simple conversion of traditional units into SI should be pursued. Significant digits number and the errors associated with them should be considered. The calculation of other important Nuclear Medicine physical quantities, such as the SUV in PET or activity per body mass, should also be written and thinked primarily in SI and optionally converted to traditional units and not vice-versa (ex. 0.1 GBq/Kg -3 mCi/Kg; 120 MBq/Kg -3.24 mCi/Kg). [ ECNC, in 2007 Guidelines for Radionuclide Imaging of Cardiac Function will be published by the same institutions. Methods and Results: 22 authors from several different European countries are collaborating and have written a draft of the new guidelines including the following sections: 1) Radiopharmaceuticals and dosimetry, 2) Acquisition of radionuclide ventriculography (first pass and planar and tomographic equilibrium ventriculography) as well as gated perfusion imaging, 3) Right ventricular EF, 4) Left ventricular (LV) EF, 5) LV volumes, 6) LV diastolic function, 7) LV regional function, 8) Physics and software, 9) Reference values, and 10) Clinical indications. Discussion and conclusion: The paramount principle is to write evidencebased guidelines, referring to original, peer-reviewed papers from international journals. However, such evidence is not always available. In lack of evidence for the best choice of performance of a procedure or indication, we emphasize the lack of evidence by expressions like "there is general consensus" or "most centres use" etc. The guidelines will be published in the EJNM with direct links from EANM, ECNC, and ESC, and they will be regularly updated.

Influence of Radiation Source Geometry on Determination of 111In and 90Y Activity of Radiofarmaceuticals P. Kolenc Peitl, P. Tomše, A. So an, M. Krošelj, T. Gmeiner Stopar; University Medical Centre Ljubljana, Ljubljana, SLOVENIA.

Aim: Measuring of the radioactivity of radiopharmaceuticals before injection to patient is essential in nuclear medicine. Measurements are performed by use of a dosecalibrator. To assure accurate readings quality control checks are performed and proper calibration factors used. Calibration factors are not only dependent on the type of the radionuclide but also on a number of other factors, including nature of the container and volume of the solution in it. The aim of our study was therefore estimation of the impact of these factors on radioactivity readings for 90Y and 111In in four different dose-calibrators before implementing radiotherapy with 90Y based radiopharmaceutical into routine use. Material and Methods: 90YCl3 and 111InCl3 solutions were gravimetrically dispensed in seven different containers (3, 10 and 20 mL vials and 1, 2, 5 and 10 mL syringes). In each container several dilutions of the parent solutions were performed. Mass, activity and time for each source geometry were recorded for all dose-calibrators (two VDC-405, Capintec and PTW). Measurements were background, time and mass corrected. Aliquotes of both parent solutions were calibrated in National Metrology Laboratory, Vienna, Austria (BEV). From our measurements and results from BEV correction factors (CF) and volume correction curves were determined. Results: 111In: Accurate results with ±5% precision for all source geometries in all vials were obtained using manufacturersupplied CF in both VDC-405 and Capintec calibrators. For PTW the uniform CF (0,75) was determined for all geometries in all types of vials. The uniform CF for each type of syringe was determined in each dose-calibrator: readings have to be reduced for up to 20% for VDC-405 and up to 30% for Capintec and PTW, depending on syringe. 90Y: The uniform CF for each type of syringe was determined in each dosecalibrator: readings have to be reduced for up to 10% for VDC-405, 20% for PTW and 30% for Capintec. In the vials the volume correction curves have to be used to increase readings for up to 20% in 15% in Capintec and to reduce readings 10 to 20% in PTW. Conclusion: Our results show that manufacturer-supplied CF without ckecking the influence of radiation source geometry cannot be blindly trusted. Ignoring this fact measurements can lead to errors reaching 30% in preparation and dispensing of 111In and 90Y radiopharmaceuticals. Aim: Bone grafting is essential modality for reconstruction of congenital and acquired bone defects. Our aim was to determine the viability of bone grafts by three phase bone scintigraphy with histopathological confirmation. Method: Two different grafting methods in 12 New Zealand rabbits were evaluated; Autogenous bone grafting and Demineralisation Bone Matrix (DBM) method, which has been developed to improve incorporation and formation of new bones. One centimeter square sized bone defects were made on the parietal bones of rabbits. The acquired bone defects on the left side were replaced by grafting the healthy parietal region from the right and the bone defects on the right side were replaced by using DBM grafts. At the second week; as early stage and in the sixth and twelfth weeks as late stages of the graft operation, dynamic three phase bone scans were performed. The rabbits had intravenous bolus injection of 20 mCi (185 MBq) Tc-99m HDP under anesthesia and the images were acquired with a pinhole collimator. Early and late stages of bilateral parietal regions were visually and quantitatively assessed with equal pixel region of interests (ROI). Visual assessments were scored from 0 to 3 (Zero as no uptake, 1 as mild, 2 as moderate and 3 as highest uptake). Results: Osteoblastic radioactivity uptake ratios were evaluated from 1 to 3 in all grafts and histopathologically those grafts were viable. Perfusion and blood pool images were similar in both bone grafts in all rabbits at all stages. In the quantitative assessment right parietal to occipital ROI and left parietal to occipital ratios were as follows; at the second week DBM 0.70±0,12, autogenous bone graft 0,76±0,16 (p= 0,08); at the sixth week DBM 0.66±0,85, autogenous bone graft 0, 62±0,65 (p=0,38) and at the twelfth week DBM 0.68±0,16, autogenous bone graft 0, 64±0,14( p=0,24) . In all phases of bone scintigraphy there was no visual or quantitative difference in statistically by between 2 grafting methods statistically (p<0.05). Conclusion: The determination of graft viability by three phase bone scintigraphy in both DBM and autogenous bone graft method is an in-vivo, sufficient, useful and cost-effective imaging modality. P01 -Monday, Oct. 15, 2007, 2: Aim: It is widely accepted that myocardial perfusion SPECT should be acquired with ecg-gating. With this technique additional information about the pump function of the left ventricle is gained. The purpose of this study was to evaluate the relationship between left ventricular stress and rest ejection fraction (EF) in myocardial perfusion SPECT and to analyse possible influencing factors. Material and Methods: In this study 50 consecutive patients from our outpatient clinic with a 2-day stress/rest protocol were enclosed. The patients consisted of 7 women and 43 men, with a mean age ± s.d. of 63.2 ± 10.3 years. In 45 patients a coronary heart illness was known. The stress was induced ergometric by bicycling in all patients. The SPECT acquisition was carried out 60 min after i.v-injection of Tc-99m-MIBI (stress-study) or after 90 min (rest-study) with a double headed gamma camera E.cam (Siemens). The reconstructed slices of the short heart axis were used for fully automatic determination of the left ventricular ejection fraction and assessment of semiquantitative segmental pathology scores through the software 4DM-SPECT (University of Michigan). Results: The matched EF-values of the stress and rest study showed a small, but significant difference in the paired t-test (p = 0.04). The average value for the stress EF (55.5%) lay about 2.5 percent points below the value of the rest EF (58.0%). In a regression analysis the decrease of the EF ( EF) between the stress and the rest study showed no dependency with age (p = 0.68), the summed stress pathology score (SSS) (p = 0.46) or the summed rest pathology score (SRS) (p = 0.27). However a significant increasing of the EF was found with the summed pathology difference scores (SDS) (p = 0.02) and a growing rest EF (p = 0.03). Conclusion: The stress EF was found to be significant lower then the rest EF. This indicates a stress induced injury of the heart still influencing the EF at the post stress acquisition time of the SPECT. Higher EF values correlated positively with stress-induced ischemia, according to the SDS score. In contrast a perfusion abnormality alone in rest (high SRS score) or stress (high SSS value) had no significant influence to the EF. The additional information gained with gated myocardial perfusion SPECT can contribute to the assessment of stress-induced stunning of the myocardial pump function.

Aim: In many institutions, the first line imaging modality for suspected pulmonary embolism is lung scintigraphy. The value of adding ventilation imaging and single photon emission computed tomography (SPECT) to the perfusion study is controversial. The prospective Acute Pulmonary Embolism 1 (APE 1) Trial is planned to include 500 patients suspected of pulmonary embolism. The aim is to determine if ventilation imaging and SPECT, as an adjunct to planar perfusion imaging, improves the interpretation of lung scintigraphy. This is a report from an initial pilot study.

Consecutive patients clinically suspected of pulmonary embolism entered the study. Within four hours we performed scintigraphic examinations and, if abnormal, pulmonary angiography which was considered the gold standard. Readings were done by expert physicians blinded to clinical data and other imaging modalities except the chest x-ray. Results: Of the 17 patients who entered the pilot study, two had normal scintigrams and in one case logistics failed. The results presented are from the remaining 14 patients, of whom six had pulmonary embolism and eight did not. Planar perfusion images correctly identified five patients with pulmonary embolism and five patients without, but failed to identify one patient with and three patients without pulmonary embolism. Perfusion SPECT and combined perfusion and ventilation imaging (both planar and SPECT) correctly identified all patients with pulmonary embolism and four patients without, but failed to identify four patients without pulmonary embolism. In the table below, the corresponding sensitivities and specificities are presented. Conclusion: The APE 1 pilot study showed no clear benefit from either ventilation imaging or SPECT, suggesting that planar perfusion imaging alone may be sufficient in suspected pulmonary embolism. However, the number of patients in the pilot study was small and definitive conclusions cannot be drawn until the results from the APE 1 Trial become available. The aim of the study was to compare myocardial blood flow (MBF) and coronary flow reserve (CFR) measured by positron emission tomography (PET) and the severity of coronary artery stenosis on coronary angiography. Methods: We studied 67 patients with angiographically proven coronary heart disease (CHD) with dynamic [13N]ammonia PET imaging at rest and after dipyridamole. MBF was calculated by firstpass extraction method. The coronary flow reserve (CFR) was defined as the ratio between the stress and the rest MBF. Results: MBF at rest did not differ between the patients with coronary atherosclerosis and the controls (70,56±15,7 mL/min/100g vs 74,2±14,6 mL/min/100g ns) with the exception of infarct-related regions where MBF at rest was significantly low (44,8±15,7 mL/min/100g, p<0,01). During hyperemia MBF significantly decreased in the regions supplied by diseased coronary vessels in the patients (99,57±32,1 mL/min/100g. vs 202,1±15,4 mL/min/100g., p<0,001). It was revealed a significant correlation between MBF during hyperemia and coronary artery stenosis degree (r= -0,79; p90% stenosis showed an attenuated response to dipyridamole (CFR = 1, 14±0, 18) . CFR was significantly low in regions supplied by arteries without significant stenoses in the patients vs the controls (2,2±0,54 vs 2,9±0,2; p<0,001) due to an influence of coronary heart disease risk factors: myocardial hypertrophy, smoking, diabetes mellitus. Conclusion: [13N]-ammonia PET imaging provides the valuable information about functional severity of coronary atherosclerosis. CFR impairment in regions without significant stenosis can be explained by an influence of coronary heart disease risk factors.

Silent ischemia elicited on resting post-nitrate gated-SPECT by a coronary steal mechanism is associated with short term outcomes in prior myocardial infarction G. Carboni, T. Castiello; Univ. Campus Bio-Medico, Roma, ITALY.

The value of post-nitrate cardiac gated SPECT (G-SPECT) in patients (pts) with prior myocardial (M) infarction (I) is still uncertain .Thirty-six such pts ,mean age 74+-10 years , 56% males , were thus studied by G-SPECT , at rest , after sublingual administration of 5 mg isosorbide dinitrate (N) and at controlled conditions ( baseline ) . Methods: In all pts , G-SPECT , (63 % with Thallium , 37 with % Mibi ) , was carried out on a dual-head gamma camera and ejection fraction (EF), extent and reversibility (R) of abnormal defects (ADs) were analyzed with Cedars-QGS-CEqual softwares. Extent of ADs after N administration was calculated as a percentage (%) of total LV pixels ( P ) and R as a % of the ADs . The ADs were considered significant when > than 10% P and concordant with regional hypokinesia on echocardiograpy . All pts were followed-up for cardiovascular events (CE) . Results: Overall pts , only 9 showed partial R of ADs . On a Cox regression model (Chi-Square = 6 , p < 0.01) , only R ( b = 1.4 , p < 0.01 ) was associated with the hazard of CE ( in 3 pts cardiac death , in 6 pts major CE ) but not with age, EF, CAD , prior CABG or PTCA , ( p = ns for all ) . Results did not change when data were adjusted for risk factors. On Kaplan-Meier curves , pts with R showed also lower event-free survival probability versus those without R ( 11% versus 63% at a 24 months follow-up ) , Log-rank test: p < 0.0007 , hazard ratio = 0.2 , 95% CI = 0.006 to 0.6 ) . Conclusions: In 25% ( 9/36) of pts under study , resting post-N G-SPECT elicited partial R of ADs ( residual M ischemia in prior MI ) in absence of any increase in M demand. A N-induced " coronary steal " from low flow coronary territories (infarct-related coronary artery) to non ischemic territories cannot be thus excluded . Such a paradoxical effect occurs silently and may identify M instability , predict short-term outcomes and imply concern for N chronic therapy in prior MI . The aim of this study was to compare the results of ejection fraction (EF) values and volumetric data derived from gated myocardial perfusion SPECT( g-SPECT) using both QGS (Siemens ICON) and 4D-MSPECT(4D) algorithms and to determine normal limits in patients with normal cardiac perfusion and function. Methods: One hundred and sixty-six consecutive patients (59 men, M, 107 female, FM, 53 ±10 years old) referred for the evaluation of suspected coronary heart disease ( CHD) using g-SPECT were included in the study. Inclusion criteria: Having normal cardiac perfusion and function; Exclusion criteria: Previous CHD, left bundle branch block, ischemia finding, Q or QS pattern in ECG and severe arrhythmia at rest .Modified Bruce protocol was performed in stress test. EF%, end-diastolic (EDV;ml) and end-systolic volumes (ESV; ml) and stress/ rest left ventricular cavity dilatation index (CDI) were calculated. Results: The mean values of overall EF, EDV and ESV in S and R were as follows. QGS: R-EF%=64. . In volume comparison, although there was high correlation (r=0.85-93) between the methods , the mean differences were significantly different (p<0.001). Conclusion: Ejection fraction limits in normal patients obtained in this study were in concordance with those of previously reported in the literature. EF values derived from 4D were significantly higher than those of QGS both in S and R g-SPECT and the methods do not prove to be interchangeable for EF calculation in normal patients. Key Words: Left ventricular ejection fraction, gated perfusion SPECT, normal limits Aim: Generator-produced rubidium-82 (82Rb) is of interest for centers lacking access to a cylotron. Quantitation of myocardial blood flow (MBF) has been performed with 82Rb using compartment-based models. However, reproducibility of such MBF quantitation with 82Rb is not known precisely. Material and Methods: Fourteen individuals (mean age 47±19y range 21-75y; 4W, 10M; including 10 volunteers and 4 patients with angiographically proved CAD) underwent dynamic PET imaging studies (21 frames) at rest and during adenosine stress (0.14mg/kg/min for 6 min) after injection of 1100MBq of 82Rb (Discovery LS, GEMS). After waiting period of 30min, the rest-adenosine stress sequence was repeated. MBF was determined using a 1-compartment model including a correction for flow-dependent extraction fraction of 82Rb (PMOD 2.80 analysis software, www.pmod.ch). Myocardial flow reserve (MFR) was defined by the ratio of stress/rest MBF. For comparison, paired t-test and Bland-Altman plots were used. Results: There was no difference in hemodynamic parameters between baseline and repeat measurements (rate-pressure product: 7.42E3±0.20E3 vs. 7.34E3±0.17E3 mmHg/min, p=0.70). One volunteer refused to undergo adenosine stress because of side effects. There was no significant difference between baseline and repeat studies regarding MBF at rest (0.84±0.18 vs. 0.87±0.19 ml/min/ml, p=0.45), during adenosine stress (2.50±0.84 vs. 2.43±0.99 ml/min/ml, p=0.49) or in MFR (3.07±0.79 vs. 2.80±0.81, p=0.14). The correlations between baseline and repeat studies were also excellent (rest: r2=0.97 y=1.02·x; adenosine: r2=0.98 y=0.98·x; MFR: r2=0.96 y=0.90·x) . Finally, overall agreement was very good on Bland-Altman plots with 26 out of 27 measurement pairs (96%) being within reference range for difference, without any systematic difference (p=0.72). Conclusion: These results demonstrate an excellent reproducibility of myocardial blood flow measurements with 82Rb at rest and under adenosine challenge. Aim: Diabetic patients develop coronary artery disease (CAD) more frequently and have a higher incidence myocardial infarction (MI) .CAD is also an important cause of mortality in patients with diabetes. Its early detection is fundamental to improve medical treatment. The aim of this work is to describe single-photon emission computed tomography myocardial perfusion imaging (SPECT MPI) findings in patients with diabetes mellitus type 2 (DMII) with atypical chest pain and analyze whether the presence of others risk factors are reliable predictors of positive scyntigraphy. Materials & methods: Authors interviewed all patients with DMII that underwent SPECT myocardial-perfusion with 99mTcMibi from December 2006 to March 2007 that had read and accepted informed consent. Method of inducing stress was infusion of dipyridamole in 68.3% cases and exercise loading in the others (31.7%). Ejection fraction (EF) was assessed by ECG-Gated technique. Patients that had reported previous heart infarction with or without revascularization intervention were excluded. Results: Authors interviewed 41 diabetic patients who underwent SPECT MPI during this period. 68.3% were women, ages ranging from 40 to 76 years old (mean value=59.8). It was found perfusion abnormalities in 15 patients (36.6%); 14 exams showed reversible defects and 1 of them had irreversible lesion. 40% of the abnormal exams showed only one lesion; 40% showed two compromised walls and 20% showed 3 walls affected. Ejection fraction ranged from 35 to 75% (median=58). Concerning to risk factors, 33 patients (80.5%) affirmed being sedentary, 25 patients (61%) were overweight, 10 patients (24.4%) were smokers, 17 patients (41,5%) had hyperlipidemia and 23 patients (56,1%) reported positive family history of CVD. Authors also assessed whether the presence of risk factors would be correlated to a positive exam. No statistical correlation was individually significant: smoking (p=0,130) and sedentatariness (p=0,687) both analized with exact Fisher' test; and overweight (p=0,923), hyperlipidemia (p=0,067), and positive family history (p=0,702) , assessed with qui-square test. Conclusion: Frequency of perfusion abnormalities in diabetic patients with atypical chest pain was high (36.6%).This data suggests that occult CAD is common among asymptomatic and poorly symptomatic patients with diabetes. Perfusions abnormalities in these patients by means of SPECT MPI could provide incremental information about silent CAD. Individualy, risk factors for CAD had not statiscaly significant correlation with a positive SPECT MPI in this study, probably due to the small population surveyed.

Early primary percutaneous coronary intervention (PCI) is a very effective technique in the treatment of the acute myocardial infarction (AMI), since it allows the recanalization of the affected coronary vessel. Objective: The aim of the study was to evaluate the extension of saved myocardium defined as the difference of perfusion score pre and post PCI. Patients and methods: 13 patients with AMI and ST segment elevation were studied prospectively (3 women, mean-age: 63.6 ± 14.1 years) . Two gated-SPECT detections were acquired after 99mTc-MIBI injection in all cases. The first injection before PCI and the other after it (15.22 ± 9.02 days), following the habitual methodology. The initial acquisition was carried out at the exit of the Catheterization Lab in 12 patients (70.83 ± 13.01 minutes) and after seven hours of stay in the Coronary Unit in 1 patient. The quantitative automatic valuation of the 17 segments was performed by the software QPS (Cedars). Pre and post PCI (SSS, SRS) score, the difference of the score (SDS) and the percentage of extension (SS%, SR% and SD%) was evaluated. According to the coronary angiography the dilated arteries were 10 Left Anterior Descending Arteries (LAD) and 3 Right Coronary Arteries (RC). In 12 patients the revascularization was angiographycally effective. Results: In 2 patients there was not significant difference between pre and post SPECT quantification (1 not effective revascularization and 1 with large AMI). In the rest of patients salvaged myocardium is showed. SSS shows the pre-dilatation deffect, SRS shows the residual deffect (AMI) and SDS shows the saved myocardium. Conclusions: The myocardial perfusion quantification by gated-SPECT allows a precise valuation of the saved myocardium by primary PCI in the AMI.

Side effects in 3723 patients undergoing myocardial perfusion imaging in one centre.

Medicine, Aarhus University Hospital, Skejby, Aarhus, DENMARK.

Aim: To analyse the frequency of side effects in stress myocardial perfusion imaging (MPI) related to gender, age, referral diagnosis and type of stress. Material and methods: We included 3723 consecutive patients referred for MPI in the period June 2003 -December 2006 (3½ years). Bicycle stress was first choice (14%). Patients who could not perform the test or were treated with betablockade were stressed with adenosine in combination with a minor work load when possible (55%) otherwiseand in case of left bundle branch block -adenosine was injected at rest (23%). Dobutamine was used in patients with severe chronic obstructive lung disease or atrioventricular block (8%). Results: The investigation included 1836 men and 1887 women aged 5 to 95 years (mean of 62 years). The women were on average 1.3 years older. The patients suffered from ischemic heart disease (IHD) (32%) or were suspect to IHD (67%). Side effects: Only164 patients (4.4%) had side effects. The most frequent side effects were: Atrioventricular blockade (1.9%), bronchospasme (0.8%) and "other unspecified side effects" (1%). Rare side effects were arrhythmias (0.35%), AMI/unstable angina (0.30%) and syncope (0.24%). No patients died. Uncomplicated angina and well-known subjective symptoms to pharmacological stress and work load were not registered. Patients stressed with bicycle had seldom side effects (1.3%), whereas frequency was about 5% after adenosine and dobutamine stress but with differences in type of side effects. There was a higher prevalence of side effects in women (57 vs. 43%), especially for AMI /unstable angina (91%) and other unspecified side effects (67%). Only syncope was more frequent among men (78%). The frequency of side effects increased with age from 1.9% in the thirties to 6.3 % in the eighties. Patients referred with known or suspected IHD had the same frequency of side effects. Conclusion: During a 3½ year period 3723 patients were examined with stress MPI. No one died and only 4.4% had side effects apart from angina and wellknown subjective symptoms to pharmacological stress and work load. Less than 1% had arrhythmias, AMI /unstable angina or syncope. The prevalence was higher during pharmacologic stress than work load. The prevalence was more frequent in women and increased with age. Cardiovascular disease is the leading cause of death among patients with type 2 diabetes, myocardial ischemia being frequently silent. Coronary artery disease detection is challenging in women due to a variety of factors. Aim Our purpose is twofold: to investigate the association of silent ischemia and diabetes in women; and determine the sensitivity of myocardial perfusion gated SPECT in these patients. Material and Methods Poststress and resting gated SPECT was performed in 60 women (39 with type 2 diabetes and 21 nondiabetic) with suspected coronary artery disease. 28 of the diabetic patients underwent coronary angiography within 3.7 months. Mean age was 67.5 years. A 2-day stress/rest protocol was used with 99mTctetrofosmin and pharmacologic stress (adenosine:56, dobutamine:4). Perfusion analysis was semiquantitative based on a 20 segment model determining the summed stress store (SSS) and the summed difference score (SDS). The SSS<4 was defined as a normal scan, SSS: 4 to 13 as moderate and SSS>13 as severe ischemia, respectively. The SDS < 2 was considered no ischemia, SDS: 2 to 7 moderate and SDS>7 severe ischemia, respectively. Poststress LVEF was considered normal if > 45%. Results P<0.05 SDS detected ischemia more frequently is diabetic versus nondiabetic patients. Results of coronary angiography were positive with good vessel-territory correspondence in 26 patients. Two patients had false negative myocardial gated SPECT yielding a sensitivity of 92.8%. Clinical presentation, age (65 vs 67.8), stress agent and risk factores (arterial hypertension, dyslipemia and smoking) were not different between nondiabetic and diabetic patients. There is no statistically significant difference between both groups in age variable. Conclusion Female patients with type 2 diabetes present more severe ischemia than nondiabetic patients of similar conditions and clearly benefit from early coronary angiography. Diabetes is considered a Coronary Artery Disease (CAD) risk equivalent with the evidence of an increased mortality rate in diabetic patients. CAD is often silent and when it becomes clinically manifest it is in an advanced state. However, there is a wide variation in prevalence of CAD in diabetes, possibly related to the presence of additional risk factors. Aim of the study was to prospectively assess the usefulness of myocardial perfusion SPECT (MPS) in asymptomatic diabetic patients and occult CAD in comparison with traditional risk factors. Methodology: Among 402 patients, 105 pts with diabetes mellitus (7 type I; 98 type II) and high likelihood of CAD underwent rest-stress MPS with 99mTc-Tetrofosmin and a 20-segments scoring model was used for SPECT analysis. A summed stress score (SSS) >4 indicated abnormal MPS, SSS 4-8 a mild, SSS >8-13 a moderate and SSS >13 a severe perfusion defect. Multiple risk factors and clinical predictors like duration of diabetes, presence of peripheral vascular disease, dyslipidemia, hypertension, active smoke, family history of CAD or diabetes and Body Mass Index, were analysed. Results: According to the SPECT results, patients were classified in: Group A (56 pts with normal MPS), and Group B (12 pts with reversible, 23 pts with mixed, 14 with fixed perfusion defects). Moderate or large stress defects occurred in 13 and 17 pts, respectively. The analysis of the presence of CAD risk factors or the association of two of these was not statistically significant (Table 1) . Conclusion: MPS is effecting in detect occult CAD and silent myocardial infarction in asymptomatic patients with diabetes mellitus while the usual risk factor analysis or the association of 2 or more of these, are inadequate to predict the presence of CAD in this population. 

Effects of cardiac resynchronization therapy: evaluation by first-pass radionuclide angiography and multiple gated equilibrium blood pool scintigraphy S. Minin, V. Chernov, E. Makarova, G. Savenkova, Y. Lishmanov; Institute of Cardiology, Tomsk, RUSSIAN FEDERATION.

Background: Cardiac resynchronization therapy (CRT) reduces symptoms and improves left ventricular function in many patients with heart failure due to left ventricular systolic dysfunction and cardiac dyssynchrony. But changes of pulmonary and central haemodynamics after CRT are not clear. Aim: To evaluate of chronic CRT effect on pulmonary and central haemodynamics as well as on left ventricular ejection fraction (LVEF) in patients with severe heart failure. Material and methods: The study involved 15 patients (M/F: 11/4, mean age: 52+4.9 years). We studied scheduled for implantation of a CRT device based on conventional criteria (NYHA class III or IV, LVEF <35%, left bundle-branch block and QRS duration >120 ms). Two patients had ischemic and 10 patients had idiopathic dilated cardiomyopathy. First-pass radionuclide angiography (FPRA) and multiple gated equilibrium blood pool scintigraphy (MUGA) were performed before and 1 month after CRT. Results: Our data show a significant clinical benefit of CRT (NYHA class change from 3.3+0.6 to 2.1+0.7; p=0.01). We found significant increase in cardiac output from 3.7±1.2 to 4.3±1.1 ml/min (p=0.004), stroke volume from 52.1±18.8 to 64.4±17.6 ml (p=0.02), cardiac index from 1.9±0.6 to 2.2±0.5 ml/min/m2 (p=0.009) and stroke index from 26.8±9.8 to 32.1±9.9 ml/m2 (p=0.03). Also increase in LVEF from 26.6±8.3 to 31.9±8.3% (p=0.02) was shown. All patients after CRT had improvement in pulmonary haemodynamics: the time of radionuclide bolus transit thought arterial section of lung (Tam) and time of radionuclide bolus transit from right to left ventricles (Tlung) decrease from 7.95±3.3 to 6.25±2.5 sec (p=0.01) and from 16.9±6.45 to 13.8±5.6 sec (p=0.01), respectively. Conclusion: Our results suggest that CRT improved of pulmonary and central haemodynamics as well as of left ventricular contractility in patients with severe heart failure. FPRA and MUGA are useful methods fore monitoring of CRT effect. Aim The aim of this study was to investigate whether early myocardial Tetrofosmin imaging (T1, 15 min after injection) provided additional information in detecting coronary artery disease with respect to standard delayed scan (T2, 45-60 min).

One-hundred and twenty patients (100 male, 20 female, mean age 61+/-10 yrs, range 23-83) with anginal symptoms underwent single or two-day stress-rest Tetrofosmin Gated SPECT. In all conditions, T1 an T2 were obtained after stress and at rest with the same gamma cameras and using the same acquisition parameters. Combines myocardial perfusion/function analysis was performed on a 20segment model using QPS/QGS software (Cedar Sinai). Coronary angiography was obtained within one month in all patients and stenosis > 50% at quantitative analysis was considered significant. Results Among clinical and nuclear variables, univariate predictors of coronary artery disease included: gender; previous myocardial infarction; previous PTCA/CABG; T1 and T2 summed stress, rest and difference scores, T1 and T2 post-stress and rest wall motion scores; T1 and T2 post-stress and rest EF, T1 and T2 EF. Multivariate logistic analysis of the most predictive and not correlated variables revealed previous myocardial infarction, T1 summed difference score and T1 EF as the most important predictors of significant coronary artery disease (p<0.001). According to ROC curves analysis, the optimal cut-off to identify coronary artery disease was 2 for T1 summed difference score providing a global diagnostic accuracy of 0.81 (sensitivity: 0.75; specificity: 0.77). Moreover, ROC analysis showed that a reduction in T1 EF after stress >2% was the optimal cut-off to identify patients with coronary artery disease (sensitivity: 0.80; specificity: 0.77; accuracy: 0.84). The combination of T1 summed difference score and T1 EF resulted in a significant increase in the global chi-square for prediction of significant coronary artery disease (30.82 vs 67.90; p<0.001). Conclusions Our data suggested that early 15 minutes Tetrofosmin gated SPECT is superior to standard delayed 45-60 minutes imaging providing indexes of both perfusion and function highly predictive of coronary artery disease. serum levels of CRP, creatine kinase (CK), creatine kinase MB fraction (CK-MB) and troponin I of 560 patients with ACS of high-risk, were measured on admission and every 6 hours for 48 hours. Patients were evaluated with stress/rest 99mTc-tetrofosmin gSPECT before discharge or up to one month after ACS. Patients have been divided in group 1. Acute ST elevation myocardial infarction (STEMI) without history of prior myocardial infarction (pMI) (18,8%), 2. STEMI and pMI (2,6%), 3. Non-ST-elevation acute myocardial infarction (NSTEMI) without pMI (18,8%), 4. NSTEMI and pMI (11,8%), 5. Unstable angina (UA) without pMI (28,9%) 6. UA and pMI (19, 1%) . Infarct size was measured by myocardial perfusion defects in SPECT ("bull eye"); LVEFr by gated SPECT and the left ventricular dysfunction in stress was evaluated by the ratio of ventricular volume stress/rest >1,2 or when the stress LVEF was significantly lower than the LVEF at rest (more than 5 percent). Results: The serum levels of CRP on admission were similar in all 6 groups. The pCPR, CK, CK-MB and troponin I levels were significantly related to infarct size determined by SPECT in all the groups, except in the patients with UA without pMI. The pCRP levels were significantly related to MN size (p = 0,0001), with a tendency to more infarct zone in the patients with pMI. Higher pCRP (> 3mg/l) were related to infarct zone > 18% of left ventricular myocardium (p=0,001). pCRP levels were not related to myocardial ischemia in either groups (p=0,55). The maximum CPR levels were found in patients with lower LVEFr (p=0,008). Left ventricular dysfunction was not related to pCRP levels (p=0,67). Conclusion: The high levels of C Reactive Protein are related to extension of myocardial necrosis and low left ventricular ejection fraction at rest, determined by gated SPECT irrespective of clinical form of acute coronary syndrome, but they are not related with stress-induced systolic left ventricular dysfunction of ischemic origin. The aim of the study was to assess (1) diagnostic accuracy of myocardial perfusion SPECT (MPS) with low-dose CT attenuation correction (AC), and (2) the risk of concomitant correction artifacts (CA). Methods: AC has been clinically validated in 95 patients with coronary artery disease (CAD) verified by coronarography (group A). CA were studied in 25 patients with normal MPS finding (group B). In both groups, gated stress MPS has been performed with 99mTc-tetrofosmin using hybrid dual-head gamma camera with low-dose CT (GE Infinia-Hawkeye). Rest MPS was performed only in the group A. For data processing, 4D-MSPECT programme was used. AC was applied using CT attenuation maps. In both groups of patients, perfusion defects were compared in emission scans with and without AC. Quality of SPECT/CT registration was assessed visually. Results: In the group A without AC, perfusion defects on inferior wall were found in 57 of 95 patients. With AC, 9/57 (16%) of these defects completely disappeared. In comparison with coronarography, specificity of findings in the territory of the right coronary artery (ACD) increased by 13% from 84 to 97%. In the group B without AC, no perfusion defect was found in any of 25 patients. With AC, perfusion defects appeared in the anterior wall and in the apex in 16/25 (64%) patients. In these patients, apparent SPECT/CT misregistration was found. In 9/25 patients without perfusion defects on AC scans, SPECT/CT registration was good. Conclusions: Considering perfusion defects in the teritory of ACD, AC improved specificity of MPS. In this area, no correction artifacts were found in any patient. In the anterior wall and in the apex, high frequency of correction artifacts reduced the value of AC unless the reality of the perfusion defect was supported by registration of emission and transmission scans. In order to optimise the diagnostic accuracy of AC MPS, simultaneous assessment of emission scans with and without AC and inspection of the fused SPECT/CT images remains necessary. Background: WBR is an iterative method for resolution recovery. It is designed to simultaneously suppress noise and improve image resolution and is optimised for short gated cardiac perfusion acquisitions. We have demonstrated in previous studies that the WBR technology applied to cardiac perfusion scans doesn't influence functional and perfusion parameters. Considering that transient ischaemic dilation (TID) is believed to be also an important parameter for CAD severity, the aim of this study is to compare the TID indexes obtained from the two reconstruction SPECT methods (FBP/WBR). Methods: 100 patients (pts) were studied: 29 women and 71 men. Mean age: 62±11 years old. 51 with past AMI. After pharmacological stress test, pts went through a double stress SPECT acquisition. The first acquisition used 30 views, 40s/view with 2 detectors at 90º and images were reconstructed by FBP. The second acquisition used 60 views, 10 s/view, and images were treated by WBR. The 200 studies were analysed and processed with Cedars-Sinai software. Perfusion scores (SSS and SDS) and functional parameters (LVEF, EDV, ESV, SMS, STS) were obtained. TID index resulted from the ungated LV stress and rest volumes ratio (USV and URV). We considered abnormal values of TID index >= 1.25.For statistical analysis, we used paired Student t-test to compare FBP and WBR TID indexes. We also determined the correlation coefficient (CC) between TID and LVEF, EDV, ESV, scores and ungated volumes) Results: Global paired t test for WBR and FBP TID indexes showed p<0.05. There were only 7/100 high TID for WBR and 5/100 for FBP. From these high TID, only one had a normal perfusion scan. The others had necrotic and ischaemic lesions. Although 67 pts had perfusion scans showing CAD lesions, only 6 (9%) showed a high TID index on FBP and 5 (7%) on WBR. Conclusions: This study showed that TID index determination isn't influenced by the reconstruction method (FBP/WBR). In neither techniques (FBP or WBR), did TID index show a good correlation to LVEF, EDV, ESV, to the ungated volumes or to any score (SSS, SDS, SMS, STS).The low incidence of significant TID in patients with known CAD is also of concern. P19 Scintigraphic and hemodynamic pattern of diabetic patients with and without cardiac autonomic neuropathy undergoing adenosine stress myocardial perfusion scintigraphy P. Keinrath 1 , F. Gürel 2 , R. Weitgasser 2 , C. Pirich 1 ; 1 Nuklearmedizin und Endokrinologie, Salzburg, AUSTRIA, 2 Innere Medizin I, Salzburg, AUSTRIA.

Myocardial perfusion scintigraphy (MPS) is recommend for cardiac risk assessment in diabetic patients. In many countries, however, there is no agreement on diabetic patient selection for MPS. Recent studies have demonstrated an attenuated heart rate response in diabetics during dypirdamole MPS (Lee et al. J Nucl. Cardiol. 2001) representing a subgroup with presumably increased cardiac risk. Methods: We aimed to investigate whether this effect could be also found in adenosine stress MPS in diabetics with or without cardiac autonomic neuropathy (CAN). CAN was diagnosed by the VAGUS 2000 programme ( beat to beat variation, valsalva test, 30:15 ratio and orthostasis test). 67 patients with a mean age of 65 ± 2 years with diabetes underwent adenosine stress MPS (42 pts without and 25 pts with CAN). Patients were asymptomatic or had episodes of atypical chest pain, but a negative physical exercise test. Results: Mean ejection fraction was 59 ± 13 % in CAN positive and 61% ± 12 in group CAN negative subjects. MPS was classified as abnormal in 12% ( 5 patients) without CAN and in 24% (6 patients) with NP, respectively (n.s.) Mean stress defect scores were 4 ± 5 in patients with CAN and 2 ± 4 in patients without CAN (n.s.) . Baseline heart rate (CAN negative pts: 73 ± 13, CAN positive pts 69 ± 12) and maximum heart rate (CAN negative pts: 91± 16, CAN positive pts 86 ± 14) as well as absolute or relative heart rate increase were not different in CAN negative or positive diabetics, either. Conclusion: In this study in diabetics hemodynamic to response adenosine was not different between patients with and without CAN. There was not difference in scintigraphic outcome between subjects with or without CAN, either. Our data suggest that the presence or absence of CAN does not yield information on cardiac risk stratification comparable to the well validated information given by scintigraphic parameters, alone. Purpose of study: A reverse redistribution (RR) pattern is described with Technetium (Tc-99M) myocardial perfusion stress (MPS) imaging. The aim of this study was to determine if there was an angiographic correlation of the finding of a RR pattern on Tc-99-m MPS imaging. Method: We reviewed 2923 consecutive Tc-99 m tetrofosmin SPECT stress studies over a 5 year period. 111 patients (3.8%) were found to have a RR pattern, of which 36 patients had undergone coronary angiography within 12 months. Correlation was sought between RR pattern and location of angiographic stenoses, The effect of reversible perfusion defect (RD) or a fixed defect (FD) in addition to RR pattern on angiographic findings was also determined. Results: Of 111 patients, RR pattern occurred anterior in 32, lateral in 6, inferior in 46 with 27 having RR in more than 1 territory. Of the patients who had angiography 16/36 (44%) had normal coronary angiograms, 5/36 had 1 vessel disease (VD), 8/36 had 2VD and 7/36 had 3VD. Of the 36 studies 7 patients had RR pattern involving more than one coronary territory. Stenosis location correlated poorly with RR pattern (LAD/Anterior 5/10, Cx/Lateral 3/9, and RCA/Inferior 11/22). In 7 cases, there was a RR pattern without RD or FD, of which 4 cases had normal angiographic findings,1 had angiographic disease not correlating with the RR pattern and 2 had angiographic disease correlating with the RR pattern. In 12 cases, there was a RR pattern together with RD or FD but normal angiography. In the remaining 17 cases (47%), there was angiographic disease with evidence of RR pattern with RD and/ or a FD as well but correlation with coronary territory was poor (as given above). Conclusion: (1) RR pattern alone should not be used to make a decision to proceed to angiography. (2) RR pattern does not reliably correlate with the location of significant coronary artery stenosis (3) RR pattern in addition to RD or FD does not influence angiographic findings.

Correlation of myocardial perfusion single photon emission computed tomography with coronary artery calcium score in coronary artery disease -An Indian perspective.

S. Simon, I. Muthukrishnan, P. Nagwani, H. R. Kulkarni; Apollo Hospitals, Chennai, INDIA.

Objectives: The consequences of atherosclerosis can be detected by coronary artery calcium score (CACS) and stress induced myocardial ischemia on myocardial perfusion single photon emission computed tomography (MPS). We assessed the relationship between stress induced myocardial ischemia on MPS and magnitude by 64 slice computed tomography (CT) in patients undergoing both tests. Methods: Our study included 77 patients with no earlier history of coronary artery disease (CAD) of both sexes ( males 63, females 14) in age group of 34-69 years. Our patients were referred by cardiologists after they underwent CACS. Of these 45 patients (58%) presented with symptoms which included chest pain (non anginal, anginal, atypical) presence or absence of shortness of breath, and rest (42%) were asymptomatic. For each patient coronary risk factors were noted. All these patients underwent CACS and rest and stress MPS one day protocol with Tc99m sestamibi within 7 days. According to the CACS patients were divided into groups A ( 0-100 CACS ), group B (100 and above CACS ), group C ( group A with symptoms), group D (group B with symptoms). Results: Myocardial perfusion study was positive for inducible ischemia in 28% in group A ( n=47), 67% in group B (n=30), 34% in group C ( n=32), 85% in group D (n=13). From these we observe that the incidence of ischemic MPS is more with increasing CACS (P=0.02), in patients with symptoms (p=0.003) which are statistically significant. And also it is noted that more frequency of inducible ischemia in patients who presented with symptoms irrespective of CACS who are at short term risk. In negative MPS CACS may be useful in long term risk stratification in finding out subclinical atherosclerosis. Conclusion: The general perception is that the CACS is a good tool for long term risk stratification but it may be applicable to those patients with no significant risk factors. When there are risk factors MPS is a better indicator for risk stratification for CAD irrespective of CACS. Further studies incorporating prognostic follow up is required. Objective: Peripheral arterial disease (PAD) is frequently associated with significant coronary artery disease (CAD) and cardiovascular morbidity/mortality. However, there is a paucity of studies disclosing the prevalence of CAD by stress Tc99m Sestamibi myocardial perfusion imaging tomography (SPECT) and the effects of atherogenic risk factors (ARF) on abnormal myocardial perfusion. We thus investigated the prevalence of silent CAD and the impact of other ARF in hypertensive (HT) patients (pts) with PAD vs those without PAD and no known CAD. Material and Methods: We investigated 993 treated HT pts without known CAD; 476 men, 517 women aged 66.3 ±10.1 years. All pts underwent stress and rest dipyridamole stress SPECT imaging that were analysed blindly by 2 experienced observers. Other ARF were also evaluated. It is important to note that, of these 993 pts, 398 or 40.1% had type 2 diabetes mellitus. Results: We found that PAD was present in 307 pts or 30.9% of our studied population. Moreover, overall silent myocardial ischemia was observed by SPECT in 205 (20.7%) of the HT pts. Of note, the frequency of silent CAD increased from 20.7% to 30.3% in pts with PAD (p=0.009;RR:1.46). Analysis of ARF indicated that pts with PAD were more closely associated with male gender (p<0.0001), hypercholesterolemia (p=0.009) and smoking (p<0.0001) as compared with pts without PAD. Most importantly, silent CAD was further increased in HT pts with PAD affected by type 2 diabetes mellitus (DM) (p<0.0001;RR:1.90). Indeed, the prevalence of silent CAD increased from 20.7% in HT pts to 39.4% in HT pts with DM plus PAD. Conclusion: In this large scale population of high risk treated HT pts, the prevalence of silent myocardial ischemia is significantly greater in HT pts with PAD. Furthermore, the prevalence of silent CAD increased significantly in DM pts. These findings should be clinically relevant in order to select HT pts who are the most suitable candidates for silent CAD who require intensive medical or surgical intervention. Objectives: Coronary artery disease (CAD) is a major complication of type 2 diabetes mellitus. Because CAD is often asymptomatic and the disease can be controlled through screening programs, myocardial perfusion scintigraphy may be the best practical way to accomplish this on a larger scale. The aim of our study was to screen the silent coronary artery disease in type 2 diabetic patients by perfusion myocardial scintigraphy. We also analyzed the risk factors that might be related to CAD in type 2 diabetes mellitus (T2DM) patients with no classical cardiac ischemic symptoms. Methods: Gated single-photon emission computed tomography was performed using a same day stress/rest protocol with Tc-99m Sestamibi. We screened a total of 75 patients: 38 diabetic patients without evidence of CAD and 37 diabetic patients with evidence of CAD . Gender, patients' age, known diabetes duration, smoking status, HbA1C, the presence of WHO-metabolic syndrome defined hypertension and level of cholesterol and triglycerides were examined in order to access relationship to CAD in diabetic patients. Results: A semi-quantitative visual interpretation was made using short axis, horizontal, and vertical long axis myocardial tomograms and a five grade (0-4) scoring system in 20-segmental model. A study was judged abnormal if the sum of stress scores (SSS) was 4. Two groups of patients were compared: group A (38 patients) without clinical evidence of cardiac disease and group B (37 patients) with clinical evidence of cardiac disease. Compared with group B patients (we excluded patients with combination of reversible and fixed defects), group A patients tended to have fewer perfusion reversible changes by visual analysis (t-4,817, p< 0,001), as well as by SSS test (p= 0.001). Correlation coefficient has been sign among visual analysis and sum stress scores (C = 0.510) . Thirty-eight asymptomatic patients with normal resting ECG (group A) were examined by stress/rest myocardial perfusion scinigraphy with Tc-99m sestamibi. Fifteen patients (39%) considered to have positive test or significant myocardial ischemia. Twenty-three showed no significant ischemic lesion (p <0.007). Diabetes duration of 7.9 years was associated with silent CAD (CI: 1.96;5.05), Tryglicerides and HbA1C were significantly associated with asymptomatic CAD as well. (p<0.05 and p< 0.02). Conclusions: A considerable proportion of T2DM patients have silent CAD (39%). The patients with diabetes duration seven years and more should be screened routinely for the presence of CAD as well as the patients with high level of HbA1C. M. L. De Rimini 1 , M. Catalano 1 , S. Comenale Pinto 2 , R. Ancona 2 , P. Caso 2 , R. Merenda 2 , A. Scalzone 2 , P. Muto 1 ; 1 Nuclear Medicine AORN Monaldi, Naples, ITALY, 2 Non Invasive Cardiology, AORN Monaldi, Naples, ITALY.

Diastolic function (DF) abnormalities can be an early sign of cardiomyopathy in diabetic (DM) patients (pts) with no coronary artery disease (CAD) or systolic (Sy) left ventricular (LV) dysfunction. Echocardiography (Echo) with Doppler measurements of transmitral and transtricuspidal flow and myocardial (M) tissue Doppler (DTI), Strain (S) and Strain rate (SR) can evaluate DF. Aim: to evaluate early D dysfunction in DM pts without documented CAD. Methods: we studied 30 male pts: 15 non-DM and 15 DM, mean age: 54±7. Selection criteria were: no history of CAD or hypertension and normal perfusion at stress/rest (Str/R) M-GSPECT (SSS/SDS 4). QGS quantified LV Sy (EF; RWM; RWT) and D (PFR/EDVs; TTPF) F. Echo System Seven GE, equipped with TVI function, calculated LV/RV Sy and DF, pulmonary artery wedge pressure (PCWP), by E/Ea and left and right atrial (LA/RA) peak Sy tissue S and SR in 4 and 2 chambers view, at the level of the apical segment of the septal, lateral, anterior and inferior LA walls, and RA free wall. Pulsed Doppler and DTI studied early (E) and late (A) D wave velocity, ratio E/A, deceleration time (DecT); L-R isovolumic relaxation time (IVRT) and Pulsed Doppler of pulmonary vein flow. Results: At Echo: significantly higher prevalence of abnormal D mitral (ratio E/A=0,83 vs 1,2) and tricuspidal (ratio E/A=0,85 vs 1,4) flow patterns and a longer mitral valve DecT (245 versus 195 msec) was observed in DM vs non-DM pts. Although no differences were found in LA/RA diameters and volumes, the M atrial S and SR were found to be significantly (p=0,002) lower for atrial septum, RA free wall and LA anterior wall in DM pts in respect of controls. No differences were found in DM and non-DM pts for Sy function: EF=60% vs 64%, IVRT (91 vs 90 msec), propagation velocity of transmitral flow during early ventricular filling (Vp=78,93 vs 80,12 cm/sec) and PCWP (11, 87 vs 10, 21 mmHg) . Similarly at GSPECT: Str/R PFR/EDVs mean value = 2.8/2.34 in DM and 3.6/3.14 in non-DM pts (p=0,002); rest TPFR was longer in DM pts (203 ± 45ms) than in non-DM pts (172 ± 23ms), with preserved Sy function (LVEF= 60 ±5% / 57±5%) in all pts. Conclusions: GSPECT can assess Str/R DF; impaired PFR/EDVs, TPFR, LA/RA S and SR in DM pts with no hypertension or CAD and preserved LV-Sy function can suggest an earlier functional effect of a specific DM cardiomyopathy independently of CAD. Würzburg, Würzburg, GERMANY, 2 St. Antonius Ziekenhuis, Nieuwegein, THE NETHERLANDS, 3 

Objectives: For quantitative comparison of myocardial perfusion SPECT scans (MPS), the 17-segment model conventionally used for clinical analysis has an undesirably low resolution, resulting in numerical obfuscation of extreme differences in small areas. The objective of this study was to establish a segment model that allows for detailed quantitative comparisons of MPS and compare this to the 17segment model. Methods: A 68-segment model was defined by quartering each segment of the 17-segment model. Both models were applied to 6 Tl-201 and 6 Tc-99m repeated phantom MPS, 20 repeated Tl-201 and 20 repeated Tc-99m-sestamibi patient MPS from an ethical board-approved study. Mean segmental counts-per-pixel values for the 17-and 68-segment model were calculated based on 460 data-points extracted from MPS using the MunichHeart software. For each segment the difference between repeated scans was calculated. Spiral profiles for the difference per segment between scans were then generated. Results: Tl-201: The overall variation between repeated phantom MPS was 2.3% (95% CI: -0.7 to 5.4 %) for the 17 segment model. For the 68-segment model this was 4.5% (95% CI: 0.4 to 8.6%). For patient scans overall variation was -5.0 % (95% CI: -4.0 to -6.0%) for the 17-segment model and -6.1% (95% CI: -7.3 to -4.8%) for the 68-segment model. Tc-99m: The overall variation between repeated phantom MPS was 0.9 % (95% CI: -1.6 to 3.3%) for the 17 segment model. For the 68-segment model this was 2.9% (95% CI: -2.2 to 6.4%). For patient scans overall variation was -1.6% (95% CI: -4.3 to 1.0 %) for the 17 segment model and -5.2% (95% CI: -6.4 to -4.1%). Spiral profiles: Comparing the spiral profiles for the 17-and 68-segment model showed that the 68-segment model showed higher extreme deviations than the 17-segment model. Regions of variability could be identified in more detail than in the 17 segment model. Conclusion: The 68-segment model allows for more detailed analysis of differences than the 17-segment model when comparing MPS quantitatively. Research support: Supported financially by Tyco Healthcare. Würzburg, Würzburg, GERMANY, 2 St. Antonius Ziekenhuis, Nieuwegein, THE NETHERLANDS, 3 Utrecht University, Utrecht, THE NETHERLANDS, 4 Tyco Healthcare B.V., Petten, THE NETHERLANDS, 5 UMC Utrecht, Utrecht, THE NETHERLANDS.

Objectives: Simultaneous acquisition of a Tl-201 rest myocardial perfusion SPECT (MPS) and a Tc-99m-sestamibi labelled stress MPS is a much sought-after procedure in nuclear cardiology. Before this procedure can be applied clinically, Tl-201 rest-MPS before and after an exercise test need to be compared for equality. For interpretation of this comparison, the normal variation between two repeated MPS needs to be known. The objective of this study was establishing a normal range for the variation between repeated rest Tl-201 and repeated stress Tc-99m-sestamibi MPS. Methods: Ethical board approval was obtained. In 20 patients repeated Tl-201 rest-MPS and in 20 patients repeated post-stress Tc-99m-sestamibi MPS was performed. Also 6 repeated anthropomorphic thorax phantom MPS were obtained for both isotopes. Quantitative analysis of mean counts-per-pixel for each segment in a 17segment model was done using the MunichHeart program. Subsequently, statistical methods were used to calculate a normal range of variation. Visual analysis was performed by 2 independent observers scoring each of the repeated 17 segments for each patient on a scale of 0-4. Results: Tl-201: The overall variation between repeated phantom MPS was 2.3% (95% confidence interval (CI): -0.7 to 5.4 %). For patient scans this was -5.0 % (95% CI: -4.0 to -6.0). Observer 1 scored 6.4% of segments differently between repeated scans; observer 2 did so in 8.8% of segments. The observers disagreed in 3.7% of segments. The differences were not clinically significant. Tc-99m: The overall variation between repeated phantom MPS was 0.9 % (95% CI: -1.6 to 3.3%). For patient scans this was -1.6% (95% CI: -4.3 to 1.0 %). Observer 1 scored 2.9% of segments differently between repeated scans; observer 2 did so in 3.2% of segments. The observers disagreed in 3.1% of segments. The differences were not clinically significant. Overall: The mean difference per segment for repeated phantom SPECT scans did not differ significantly between the Tl-201 and Tc-99m tests (paired t-test, p=0.24) , and were significantly correlated (Pearsons' r = 0.70, p = 0.002). The mean difference per segment for repeated patient SPECT scans differed significantly between the Tl-201 and Tc-99m patients (paired t-test, p=0.025) Conclusion: On average, Tl-201 and Tc-99m-sestamibi MPS show only minor variation when repeated; a normal range of variation between scans was calculated. The difference between Tl-201 phantom-and patient-MPS indicates a biological source of variation in patients. Research support: Supported financially by Tyco Healthcare Aim: To study the prevalence of Ischemic heart disease (IHD) in patients with Diabetes mellitus who are asymptomatic for IHD with myocardial perfusion study (MPS) . Materials and Methods: This retrospective study included 62 patients known for Diabetes Mellitus of more than 5 years duration of both sexes with or without additional risk factors for IHD but without any clinical evidence of IHD. Patients were selected from the group referred by the cardiologists for myocardial perfusion Single Photon Emission Computed Tomography (SPECT). Patients with known IHD were not included in this study. Age matched asymptomatic non-diabetics [n = 21] without risk factors for IHD were evaluated with myocardial perfusion SPECT as controls. These patients were subjected to a rest and stress Technitium-99m Sestamibi myocardial perfusion SPECT. The images were interpreted as fixed perfusion defects, inducible ischemia or both. Twenty-two patients with inducible ischemia underwent coronary angiography. These results were correlated with glycosylated hemoglobin {HbA1c}; duration of Diabetes; and presence of additional risk factors for IHD -Hypertension [BP>140/90], Hyperlipidemia [Total cholesterol > 240 mg/dl, LDL > 160 mg/dl, HDL < 35 mg/dl], Obesity [Body mass index > 25 kg/ sq. m], Smoking, and a family history of premature IHD. Results: Significant perfusion abnormalities were found in 45 out of the 62 patients [75 %] and 3 out of the 21 [14%] controls. Hence CAD was 5 [relative ratio] times more prevalent in diabetics than in controls. In 45 patients, the extent of myocardial ischemia or perfusion defects increased with duration of diabetes and with poor glycemic control [Elevated HbA1c] statistically significant with [p = 0.04]. Nine out of 22 patients [41%] who underwent angiography had significant perfusion abnormalities in MPS but without significant coronary stenoses [< 70%]. The correlation of MPS with coronary angiogram showed a sensitivity and specificity of 100% and 59% respectively. Conclusion: Due to autonomic dysfunction in Diabetes Mellitus, chest pain is uncommon in spite of the underlying "silent" myocardial ischemia, warranting a thorough cardiac evaluation. MPS is a sensitive modality for screening of subclinical IHD in Diabetics. . perfusion of 73.1%, 76.9% and 72.7% in the segments with severe, moderate and mild perfusion defects respectively. Pre-operative rest MPS showed 409/720 hypo-perfused segments with 74 (18.1%) segments with severely decreased perfusion, 161 (39.4%) segments with moderately and 174 (42.45%) with mildly decreased perfusion. After revascularization, perfusion in these segments was improved in 39.2%, 82.6% and 91.95% respectively. There was no change in 60.8% of segments with severely decreased perfusion. Conclusion: The positive effect of CABG surgery in the area of severely hypoperfused segments on rest MPS was not observed in more than in 60% of segments. Segments with severely decreased perfusion showed fixed defects normally associated with myocardial infarction. However the significant improvement in myocardial perfusion after CABG was demonstrated in segments of moderate and mild perfusion defects. Myocardial perfusion scintigraphy with Tc99m Sestamibi provides useful information for assessment of coronary artery bypass surgery and prognosis of revascularization in patients with ischemic heart disease.

The role of captopril renal scintigraphy for the qualification to the PTA of the stenosed renal artery.

M. Kostkiewicz 1 , T. Przewlocki 1 , D. Rzeznik 2 , W. Szot 1 , A. Kablak-Ziembicka 1 , W. Jarosz 1 , W. Tracz 1 ; 1 John Pauil II Hospital, Dept of Nuclear Medicine, Krakow, POLAND, 2 John Pauil II Hospital, Dept of Nulcear Medicine, Krakow, POLAND.

Stenosis of renal artery is the most common cause of secondary hypertension and renal insufficiency. Renal perfusion imaging (RPI) with ACE inhibitors is well acknowledged study in diagnosis of these diseases. Percutaneous transluminal angioplasty (PTA) of stenosed arteries is currently one of methods of treatment in this group of patients, however, there are no effective methods of noninvasive control in those subjects and indications for PTA still remain unclear. Methods The group of patient studied comprised of 24 people (14 males and 10 females, mean age 61.04_+ 8, 72) with ischemic heart disease, referred for PTA, in whom angiography revealed stenosis of one or both renal arteries. All the patients had RPI with ACE inhibitors performed with 2-days protocol with minimum 48 hours between the first and second study -initially and 3 months after PTA. The values of GFR, time to peak of renographic curve (Tmax), renal perfusion images, value of renal inflow and shape of renographic curves were analyzed. Two independent observers were evaluating data in aim to refer the patient for PTA. 3-grade scale was used: 1 -stenosis not significant or normal images, 2 -borderline stenosis, 3 -significant stenosis. The data obtained were compared with ultrasonographic studies. RPI was repeated after 3 months to evaluate late outcome of treatment and probability of recurrent stenosis. Results. In studied group of patients left renal artery stenosis was found in 13 pts, right in 9 pts and bilateral in 2 pts. PTA proved to be successfully performed in all those pts. In 2 pts recurrent stenosis was found and subsequent PTA was performed. In 2 pts, despite successful PTA, no improvement in renal function was found in control study. Those pts had low GFR values (below 20 ml/min.) together with nephrectomic type of renographic curve. Scintigraphic image was consistent with angiographic localization of renal artery stenosis. In 2 pts, despite the presence of significant stenosis the scintigraphic images were normal. Conclusions RPI with ACE inhibitor is substantially efficient study in referring pts for PTA and evaluation of late results. In case of severely impaired renal function the RPI should be the reason for postponing the PTA. KBN 2PO5BO1528 Aim: Coronary revascularisation is effective in many patients with stable angina pectoris. However, in some patients symptoms may persist or even progress, probably because of persisting regional hypoperfusion. We examined the rates of unchanged or worsened perfusion two years after coronary revascularisation. Material and Methods: A prospective series of 139 patients (30 females) with a mean age of 60.3 ± 8.0 years underwent coronary revascularisation for stable angina pectoris. Myocardial perfusion scintigraphy (MPS) was performed before angiography and two years later. The decision of invasive management was based exclusively upon patient history and angiographic findings since the result of MPS was kept secret. The MPS studies were reviewed to determine if a change, e.g., from a reversible to a mixed defect or from a mixed to a fixed defect was due to improvement (i.e., smaller defect) or deterioration (i.e., larger defect or decreased reversibility at unchanged defect size). Results: Before revascularisation, the rates of normal perfusion or of reversible, mixed, or fixed defects were 17% (24/139), 53% (74/139), 23% (32/139), and 6% (9/139), respectively. Two years following revascularisation, improvement in perfusion was noted in 0% (0/24), 77% (57/74), 38% (12/32), and 0% (0/9) of these groups, respectively, summing up to improvement in 50% of the entire study population (69/139). Perfusion remained unchanged in 41% (57/139) corresponding to 79% (19/24), 19% (14/74), 47% (15/32), and 100% (9/9) of patients with initially normal perfusion, or reversible, mixed, or fixed defects, respectively. In the remaining 9% (13/139) of patients there was a worsening of perfusion. Worsening of perfusion was deemed serious in only 3 of the 13 patients with a worsened perfusion. Conclusion: Two years following revascularisation, the relationship between improvement, no change, or a deterioration in myocardial perfusion was in stable angina pectoris patients approximately 5:4:1. Serious deterioration was a seldom event. Improvement was noted exclusively in the patients with reversible or fixed perfusion defects suggesting that preoperative MPS might potentially improve the overall result of coronary revascularisation by straining off patients with normal perfusion or fixed perfusion defects.

F. Marranzano 1 , M. Caruso 1 , C. Privitera 1 , G. Privitera 1 , G. Rapisarda 2 , A. La Rosa 2 , S. Gusmano 2 ; 1 Dip. Immagini Az.Osp.Un. OVE, Catania, ITALY, 2 UOC Cardiologia Az.Osp.Un. OVE, Catania, ITALY.

Aim To determine the clinical features of myocardial perfusion imaging in a novel heart syndrome with transient left ventricular apical ballooning( AB) , but without coronary artery stenosis, that mimics acute myocardial infarction. Several case studies of AB, so called takotsubo cardiomyopathy ( TM), have been reported. TM is characterized by angina-like precordial pain and ST-segment elevation and limited release of cardiac enzymes. Sometimes appears with dyspnea or syncope. The catheterization procedure shows normal coronary arteries, and apical dyskinesia is observed on contrast ventriculography. The incidence of this syndrome is not clear but it develops predominantly in elderly women. Case Report We present the case of a 78 year-old woman arrived to the emergency department of our institution 1 hour after emotional stress ; symptoms began with angina and dyspnea at rest . The electrocardiogram on admission showed small progression of the first vector and STsegment elevation in leads V1 to V6, with a moderate increase in levels of cardiac serum markers (CK , CK-MB, and troponin I ). On physical examination, she had a pulse of 70 beats/min and her blood pressure was 130/80 mm Hg. Two-dimensional echocardiography showed left ventricular dilatation with preserved systolic function in the basal segments; the midventricular segments and the apical segments were dyskinetic. The diagnosis of acute anterior myocardial infarction was established, and thrombolysis was performed by use of recombinant tissue plasminogen activator. Partial signs of reperfusion were observed , with reduction of ST-segment elevation. Four hours after the initial symptoms appeared acute rest-sestamibi myocardial perfusion G -SPECT was perfomed. Results Acute Rest-G-SPECT showed perfusion defects on the septal, anterior, and apical walls . By use of gated SPECT, it was possible to assess myocardial dyskinesia of the anterior wall and apex. Coronary artery study revelead no significant stenosis of main epicardial vessels . One month later a stress-rest G-SPECT study ( two days maximal exercise protocols) showed no perfusion defects, and the wall motion abnormalities had disappeared, with completely normal heart function. Conclusion We report a case of severe, reversible myocardial perfusion defects and left ventricular wall motion dysfunction , seen on gated SPECT , compatible with TM , in patient with normal coronary angiograms and dyskinesia on contrast ventriculography.G-SPECT is therefore a useful method for the diagnosis and follow-up of TM because it is a noninvasive imaging technique that shows the complete reversibility of this entity.

Clinical utility of myocardial stress-rest perfusion scintigraphy with Adenosine in elderly patients with diabetes mellitus. G. P. Gerasimou, T. Aggelopoulou, A. Revela, E. Dedousi, G. Liaros, E. Papanastasiou, A. Siountas, K. Psarrakos, S. Chatzimiltiadis, S. Gavriilidis, A. Psarrakou; AHEPA University Hospital, Thessaloniki, GREECE.

Coronary artery disease (CAD) in elderly patients with diabetes mellitus (DM) is often characterized by occult or absent symptoms. These patients are not able to achieve an acceptable level of ergometric exercise. This study has as purpose to assess the diagnostic value of stress/rest radionuclide myocardial perfusion scintigraphy (RMS) with Adenosine (ADN) in patients with DM, older than 60 years, with a low clinical prevalence of CAD. Materials and methods: Fifty-six patients (18 females) with DM (mean age 67.6+6.8), with equivocal symptoms of CAD are enrolled in the study. All patients underwent pharmacological intervention with ADN at a dose of 140μg/kg/min in 6min under ECG inspection and 260MBq of Tc99m-tetrofosmin (TF) were injected at the 3rd min of ADN infusion and stress study was taking place 20min post TF injection. Four hours after pharmacological test, rest study was performed 30min post iv injection of 740MBq of TF. Coronary angiography (CA) has been performed to all patients. Results: The left ventricle of the patients was divided into 9 segments (apex and apical plus basal segment of the anterior, lateral, inferior wall and interventricular septum). A segment was considered as abnormal, if the counts revealed were less than 75% compared to the data of normal population. In CA, a stenosis was considered significant when it exceeded 60% of a vessel's lumen or accordingly to the fraction flow reserve. In 12 of the patients stress/rest radionuclide TF test has been considered within normal limits. In these patients CA revealed a stenosis of the coronary vessels in one of the patients, in one of the coronary vessels. In the remaining 44 patients, reversible myocardial ischemia has been mentioned to 60 out of a total of 396 segments, whilst findings compatible with myocardial infarction have been reported to 2 of these patients, numbering 3 additional segments of the left ventricle. CA has been considered as abnormal in 40 of these patients, with total occlusion of the coronary arteries in both patients with myocardial infarction as mentioned to RMS. According to these results, the sensitivity of RMS has been considered as high as 97.5%, whilst specificity was at the level of 73.3%. Conclusions: In elderly patients with DM, presenting silent myocardial ischemia, RMS with ADN challenge, is a sensitive tool in the diagnosis of CAD.

Purpose: Some authors reported that a reduced I-123 BMIPP uptake in the myocardium in patients with HCM, and the reduction of I-123 BMIPP related to the myocardial abnormalities. We hypothesized that the abnormality of fatty acid uptake and metabolism may occur before it can be visually recognized on SPECT images in patients with HCM. A distribution volume (Vd) of I-123 BMIPP could be useful for detecting such abnormality of myocardial fatty acid metabolism. The purpose of this study was to investigate Vd of I-123 BMIPP in myocardium through a compartment model analysis in patients with HCM. Methods: Twenty-eight normal controls and 30 patients with HCM were studied. I-123 BMIPP and Tc-99m tetrofosmin SPECT were performed. According to the literaturere, the uptake of Tc-99m tetrofosmin and I-123 BMIPP are preserved in very early phase of HCM. In moderately advanced phase of HCM, the uptake of I-123 BMIPP is reduced, but the uptake of Tc-99m tetrofosmin is preserved. In severely advanced phase, the uptake of Tc-99m tetrofosmin is also reduced. Based on these results, we defined early HCM as normal uptake of Tc-99m tetrofosmin and I-123 BMIPP, moderately advanced HCM as normal uptake of Tc-99m tetrofosmin and decreased uptake of I-123 BMIPP, and severely advanced HCM as decreased Tc-99m tetrofosmin and I-123 BMIPP. Moreover, all the myocardium was divided into 13 segments. Finally, these 390 segments of HCM were categorized into early, moderately and severely advanced HCM segments. By using the timeactivity curves, we analyzed BMIPP pharmacokinetics through a 2-compartment model. We defined k1 and k2 as influx and outflux rate constant between blood and reversible component, k3 as specific uptake rate constant between reversible and irreversible compartments. Additionally, we calculated k1/k2 as Vd. Results: The results were summarized in the table. The Vd of I-123 BMIPP was gradually decreased with progression of HCM, and there was statistically significant difference between normal and each HCM group (P < 0.005 in each group). Conclusion: Vd of I-123 BMIPP might be useful index to evaluate the progression of HCM. However, uptake of I-123 BMIPP was not reduced in early HCM group at least with visual qualitative approach. These results indicated that a mathematical compartment model analysis might be useful to detect subtle change of fatty acid metabolism in patients with HCM, and not only for identification of HCM in very early stage, but also for evaluation of the progression of HCM. Aim: 99mTc-sestamibi (MIBI) shows good retention in normal myocardium after the initial uptake. But, the washout is sometimes observed in ischemic hearts. These suggest the possibility that the washout rate of MIBI would be a useful indicator of myocardial damages or dysfunction. This experimental study evaluated the MIBI washout by hypoxic myocardial damage using electrically paced isolated rat hearts. Methods: Isolated rat hearts were electrically paced at 300 beat/min and were perfused with oxygen-saturated Krebs-Henseleit solution of constant flow of 6ml/min. Heart rate and left ventricular pressure (LVP) were measured. After MIBI (15 to 25 MBq) was infused for 5 minutes, MIBI washout was observed in the following two groups: the control group that was continuously perfused with oxygen saturated solution for 60 minutes and the hypoxic group that was perfused with oxygensaturated solution for 30min followed by nitrogen-saturated solution including glucose. Cases of irreversibly damaged hearts were excluded. Radioactivity in the heart was continuously measured using a gamma camera equipped with pin-hole collimator. MIBI washout rate was evaluated by the slope of time-activity curve (TAC) for ROI of whole heart. Results: The mean MIBI uptake in the isolated heart was 10.5±1.6 %/added dose. In the control group, MIBI showed good retention with a very gentle slope of TAC (-0.17±0.08%/min). In the hypoxic group, the slope of TAC was significantly increased (-1.37±0.57%/min). Under hypoxic condition, LVP was reduced first, and then the diastolic pressure (DP) was elevated. The change of TAC slope simultaneously occurred with the rise of DP, not at the initiation of the hypoxic condition. Carbonyl cyanide-m-chloro phenylhydrazone (CCCP), a mitochondrial uncoupler, induced similar increase of the slope of TAC under the same condition, suggesting that the MIBI washout induced by the reversible hypoxic damage observed here was implicated in mitochondrial function. Conclusion: The myocardial washout rate of MIBI can be a useful marker of myocardial viability. Aim: Initial clinical studies have shown that bone marrow progenitor cells had beneficial effect on the healing process after myocardial infarction. The aim of the present study was to evaluate the effects of intracoronary infused bone marrow derived progenitor cells (CD34+) on regional myocardial viability and perfusion by [18F]FDG PET and [99mTc]MIBI SPECT in patients with first episode of acute myocardial infarction. Materials and methods: 7 patients were treated by percutaneous revascularisation and stenting of the occluded artery; 6 left anterior descending (LAD), 1 right coronary artery (RCA). All patients received intracoronary infusion of autologous CD34+ bone marrow stem cells 12±1 days after the revascularisation. All patients underwent FDG-PET and MIBI-SPECT before transplantation and 6 months afterwards during follow-up. For quantitative evaluation of myocardial [18F]FDG and [99mTc]MIBI uptake a ventricular segmentation scheme (16 segments) was applied. Mean signal intensities (MSI) of the segments assigned to the LAD/RCA distribution were callculated for each patient. Results: PET studies showed a highly significant increase of the MSI in the infarct area from 56.6±11.8% to 72.2±13% (p=0.007). No statistically significant differences were found in myocardial [99mTc]MIBI uptake before (52.8±10.3%) and after (59.0±15.9%) stem cell translpantation(p=0.152) Conclusion: Our results indicate that local intracoronary CD34+ progenitor cell therapy results in a significant increase in myocardial viability of the infarct zone. Aim In patients with previous myocardial infarction, the relationship among viability, ischemia, volume overload and systolic dysfunction is still unclear. Methods We studied 90 patients (age 64±10 yrs, 75 male) with previous myocardial infarction (27 anterior, 45 inferior, 18 lateral). All patients underwent a single day rest postnitrate/stress Tetrofosmin G-SPECT study. G-SPECT analysis was performed using QGS/QPS protocols. Viability was scored according to a Summed Rest Score (SRS) <3 (mostly viable), 7-4 (partially viable), and >8 (mostly necrotic). In each category, Summed Difference Score (SDS) provided the presence (SDS>4, Group 1) or the absence (Group 2) of myocardial ischemia. Results According to SRS, 38 patients showed mostly viable, 22 partially viable and 30 mostly necrotic myocardium. In patients with mostly viable myocardium, mean resting LVEF resulted lower in G1 than in G2 patients (50±8% vs 58±10%, p<0.01) and significantly changed following exercise only in G1 (from 50±8% to 48±7%, p=0.02). Mean resting EDV was higher in G1 than in G2 (p<0.02) and did not change following exercise in both groups (p=ns). Delta SMS (resting SMS -exercise SMS) resulted significantly lower in G1 than in G2 patients (-4.4±3.8 vs -0.9±5.0, p<0.001) , suggesting the presence of exercise induced regional stunning. In patients with partially viable myocardium, mean resting LVEF was lower in G1 than in G2 patients (39±5% vs 46±4%, p<0.005) and significantly changed following exercise only in the presence of myocardial ischemia (G1, from 39±5% to 36±5%, p=0.05). Mean resting EDV was higher in G1 than in G2 patients (p<0.01) and did not change following exercise in both groups (p=ns). Again, delta SMS resulted significantly lower in G1 than in G2 patients (-4 .8±7.2 vs 3.7±4.0, p<0.01). In patients with mostly necrotic myocardium, mean resting LVEF resulted similar between G1 and G2 (36±11% vs 30±9%, p=ns) and did not change following exercise (p=ns). Similarly, mean resting EDVs were 159±40 mL and 188±58 mL (p=ns) in G1 and G2 patients and did not change following exercise (p=ns). Delta SMS resulted similar between G1 and G2 patients (-0.6±5.4 vs -3.9±7.6, p=ns) . Conclusions In patients with previous MI, EF decreases and EDV increases proportionally to the amount of scarred myocardium. At any level of tissue viability, transient ischemia has an additional role in determining the degree of resting systolic dysfunction and volume overload. Repetitive episodes of ischemia during daily activity could modulate the extension of scar and the time course of LV dysfunction. Several studies have indicated that contrast-enhanced magnetic resonance imaging (CMR) enables the visualization of infarction and reperfusion.So far there are only a few reports comparing CMR with SPECT early after AMI.The aim was to compare Tl-201 rest(R)-redistribution(RD) perfusion SPECT results with CMR in patients early after AMI. Methods:Twenty-nine patients (21 males,8 females;62±11 yrs) with recent AMI were studied.Within 6 days after AMI, the patients were performed Tl-201 R-RD perfusion SPECT using 4 mCi activity.CMR was carried out 5-20 minutes after 0,15 mmol/kg of iv.Gadobutrol injection.Myocardial perfusion and contrast enhancement was analyzed using a 17 segment model.Myocardial perfusion was scored in Tl-201 SPECT as follows:0=normal (70%-100% maximal myocardial activity(mma), 1= 69-50% mma, 2= 49-30% mma ,3=29-10% mma and 4=<10% mma ;Myocardial contrast enhancement on CMR images was graded as:0=no contrast enhancement, 1=hyperenhancement of 0-25% of the wall thickness(WT) 2=hyperenhancement of 26-50 % of the WT, 3=hyperenhancement of 51-75 % of WT and 4=hyperenhancement of 76-100 % of WT.In CMR the existence of microvascular obstruction(MO) was also evaluated.Total segment scores(TSS) in R,RD and CMR for each patient were calculated by summing of 17 segment score values. Results:The mean TTS values were calculated as: R-TSS=15±10.8,RD-TSS=14.2±10.9 and CMR-TSS=22.5± 10.6.The mean differences between R-RD Tl-201 and CMR were significant(p=0.000); CMR-TSS values > R and RD-TTS in 23/29 patients. In 24/29 patients, MO was observed.In 2/24 patients with MO, perfusion was normal in R-RD Tl-201 (R and RD-TTS=0, CMR-TSS= 19).In 2/ 5 patients without MO,R-RD Tl-201 perfusion findings were normal (R and RD-TTS= 0; CMR-TTS=3 and 4),1/5 patients had R-TTS =O, RD-TTS= 2 and CMR-TTS=14.In the analysis of a total of 493 segments, poor agreement was found between CMR versus R and RD results (kappa=0.24 ve 0.27).According to coronary artery territories the agreement between the segments were: LAD: CMR -R, RD (kappa= 0.26 and 0.30), RCA:CMR-R,RD (kappa=0. 15 and 0.17), LCX: CMR-R, RD (kappa= 0.28 and 0.28). Conclusion:A poor segmental agreement was observed between CMR and Tl-201 R-RD study. The segments in RCA territory showed the worst agreement comparing to LAD and LCX. CMR detected infarcted areas larger in 80% of patients. This was compatible with related literature including histopathology. Possible explanations for overestimation in CMR, early after AMI include an altered washout characteristics of the contrast medium in the ischemically injured but viable myocardium. Follow up studies after revascularization are needed to obtain reliable results in identifying accurate viable and necrotic tissues. 

In patients with previous myocardial infarction evaluation of myocardial viability and global left ventricular ejection fraction (EF) may provide clinically useful diagnostic and prognostic information. Gated SPECT imaging allows simultaneous assessment of myocardial viability (according to extent of perfusion defect and preserved wall thickening) and function (left ventricular EF). The aim of the study was to compare myocardial perfusion and global EF in patients with previous myocardial infarction (MI) before and after angioplasty. Materials and Methods: Study group consisted of 25 patients (mean age 53±8 year, 21 male) with previous myocardial infarction (before 3.6±6 months) and single vessel coronary artery disease (17 LAD, 4 LCx and 4 RCA). All patients underwent coronary angioplasty and stenting of infarct related coronary artery. To evaluate myocardial perfusion and function we performed rest ECG gated MIBI acquisition after nitroglycerin administration. Left ventricular EF was calculated from gated SPECT data by commercially available software 4D-MSPECT. Myocardial perfusion abnormalities were expressed as defect extent in per cent of entire left ventricle. Myocardial region was considered as viable when systolic wall thickening was present and MIBI uptake was 50% of peak myocardial activity. Perfusion and function were evaluated before and 3-13 months after stenting. Results: According to myocardial perfusion and preserved systolic wall thickening the patients were divided in two groups: group I consisted of 16 patients with viable segments after MI and group II of 9 patients with non-viable segments. The mean left ventricular EF in group I was higher than in group II (60±9% vs. 39±7%, p<0.05) and perfusion abnormalities were grater in group II than in group I (41±13% vs. 25±15%, p<0.05). After successful angioplasty and stent implantation in group I global LVEF slightly increased (60±9vs 63± 9%, p>0.05) and perfusion abnormalities significantly decreased (25±15% vs. 18±14%, p<0.05). On the contrary, in group II there was no significant improvement of LVEF (39±7% vs. 43±8%, p>0.05). Perfusion abnormalities were larger after angioplasty, although without statistically significance (4l±13% vs. 42±11%, p>0.05 age 65.4 ± 8 years submitted for evaluation of viability with 99mTc-sestamibi using rest-nitrate protocol with GSPECT and RNV. Eighteen pts. had repeated studies at six months for assessment of therapy, so a total of 47 pairs of studies were obtained. Gated SPECT was performed between 45 and 75 min after administration of 99mTcsestamibi (14 MBq/k) at rest, using 8 frames per cardiac cycle, 2x zoom factor and no beat rejection. RNV was performed 48 hours later with labeled RBCs in left anterior oblique projection, 16 frames per cardiac cycle, 2x zoom factor, and 20% window beat rejection. Patients with complete arrhythmia or with ectopic beats >20% of total beats were not included for analysis. EDV, ESV and LVEF were determined using the QGS (Cedars-Sinai) software package for GSPECT Aim Coronary artery disease (CAD) shows higher incidence in diabetics than in nondiabetic population and is more advanced at diagnosis. The prognosis of CAD is less favorable in patients with diabetes than in nondiabetics. Postinfarction mortality is higher in diabetics. The available data suggest that occult CAD is a comon finding among asymptomatic diabetics. Stress/rest myocardial perfusion imaging (MPI) could be a useful, noninvasive procedure with diagnostic and prognostic roles. Methods Study population of 306 patients, 122 of them presented diabetes mellitus. Clinical follow-up of 11-20months, for confirmed cardiac deaths, non-fatal myocardial infarction and others adverse cardiac events (ACE) MPI was performed after administration of 740 MBq Tc99m-tetrofosmine in stress and 925 MBq in rest (2 day protocol). Some patients also underwent radionuclide ventriculography and coronary angiography. The obtained images were categorized as normal or abnormal: reversible, fixed or mixed myocardial perfusion defects, severity and anatomic location (right, descending and circumflex coronary artery). Results Aim: Due to the aging of population and high frequency of obesity, the prevalence of type II diabetes mellitus (DM) is increasing rapidly in Western nations and the associated coronary artery disease (CAD) is nowadays the leading cause of death in diabetic subjects. The purpose of this study was to evaluate the long-term prognostic value of gated-SPECT myocardial perfusion imaging (gMPI) for the occurrence of cardiovascular events in patients with DM. Materials and methods: A cohort of 184 consecutive patients (76 women and 108 men, mean age 64±7 years), with at least a five-year history of DM were enrolled in this study. The population was clinically classified according to history of CAD and chest pain into high-(n=78) and low-risk (n=106) groups. All subjects underwent clinically indicated rest/stress Tc-99m sestamibi gMPI with physical exercise (n=117) or dipyridamole (n=67). To determine the prognostic value of gMPI the first endpoint was major acute cardiac events (cardiac death or non-fatal myocardial infarction) and the second endpoint was the revascularization rate. Patients data were analysed using both Kaplan-Meier event-free survival curves and Cox multivariate analyses. Results: Follow-up was completed in all patients with a median period of 2.8 years (1.9-3.5 ). The prevalence of abnormal gMPI was 56% (n=103) with reversible defects occurring in 35% (n=64), fixed defects in 6% (n=11) and mixed defects in 15% (n=28). Patients with a normal gMPI had neither cardiac death, nor myocardial infarction, independently of a history of CAD or chest pain. Among the independent predictors of cardiac death and myocardial infarction, the strongest was abnormal gMPI (p<0.0001), followed by history of CAD (Hazard Ratio (HR)=15.9; p=0.0001) and inability to exercise (HR=7.7; p=0.02). Patients with normal gMPI had a revascularisation rate of 2.5% during the follow-up period, significantly lower than subjects with abnormal gMPI (21.1%). Compared to normal gMPI, cardiovascular events increased 6.1 fold for reversible defects, 9.3 fold for fixed defects and 22.6 fold for the association of both defects. Conclusion: DM patients with normal gMPI seem to have an excellent prognosis independently of history of CAD. On the opposite, an abnormal gMPI led to a more than 6-fold increase in cardiovascular events. This study outlines the additional value of gMPI in predicting cardiovascular events and risk-stratifying DM patients even if larger prospective trials are mandatory to confirm these findings and to assess their potential impact in clinical settings. The detection of myocardial ischemia in patients with preexisting left bundle branch block (LBBB) remains problematic. Myocardial perfusion scintigraphy (MPS) with Dipyridamole is the preferred non-invasive diagnostic modality for this group of patients. Materials and Methods: Seventy six patients with preexisting LBBB underwent sestamibi perfusion imaging with dipyridamole infusion protocol (0.56 mg/kg). Stress and rest SPECT studies were acquired using single head ECAM (Siemens) and double head Toshiba GCA-7200A gamma cameras. Images were interpreted by consensus of two experienced observers and classified as, low risk group (normal MPS, small reversible/small fixed defect) and high-risk group (a large severe fixed or reversible defect and dilated LV cavity). 76 patients with mean age of 53±10 years (range=39-72 years) were included in the study. These patients were followed up for 24 months ± 8 months and occurrences of hard cardiac events (MI or cardiac death) were asked by telephones. Results: Out of 76 patients 52 had low-risk scans (68%) and 24 had high-risk scans (32%). In low risk group cardiac deaths were observed in 1/52 (1.9%) and non-fatal MIs were seen in 2/52 (3.8%). In high-risk scans, 5 suffered cardiac death (20.8%) and non-fatal MIs in 3 (12.5%). Over all survival rate was 98.1% in the low-risk group compared with 79.16% in the high-risk group with a significant difference (p=0.0338). Conversely, the negative predictive value of a normal myocardial perfusion scintigraphy for the occurrence of death was 100%. Conclusion: Myocardial perfusion imaging with dipyridamole stress provides important prognostic information in patients with left bundle-branch block, which is incremental to clinical assessment.

Aim; Revascularisation of occluded coronary arteries and bypass grafts with insertion of drug coated and non drug coated [bare metal] stents has become the preferred choice of treatment in recent years for patients with multivessel coronary artery disease [CAD] .Our aim was to evaluate the role of gated SPECT [GSPECT] in patients who underwent multivessel PTCA /stents. Materials and Methods: We evaluated 41 patients[32 males,9 females, mean age 53yrs] referred with chest pain 6-24 months after PTCA/stent procedure in multiple coronary vessels including bypass grafts.All patients underwent two day stress/rest technetium-99m-tetrofosmin myocardial perfusion gated SPECT [GSPECT] [2] [3] [4] [5] [6] .Coronary angiography showed instent restenosis in 7 patients and progressive CAD in 5 patients with patent stents.9 patients were treated with redo PTCA/stent and 3 had CABG .No myocardial event was seen at 10-12 months follow-up. 9[22%] patients were considered normal [SDS 0-1] .Coronary angiography showed partial instent restenosis in 3 of these patients. No adverse myocardial events were seen in these patients at 10-12 months followup. 5[12%] patients had fixed defects and event free follow-up .Conclusion:Our study shows that technetium-99m-tetrofosmin myocardial perfusion GSPECT can be used as a powerful prognostic tool in patients who were treated with multivessel PTCA/ stents Aim: Extension and severity of myocardial scar may condition short and long term efficacy of autologous stem cell treatment. Methods: Five male patients (mean age 56 ± 3 yrs) with previous myocardial infarction, multivessel coronary artery disease underwent 10 to 23 intramyocardial 0,1 ml injections of autologous stem cell in scarred myocardium concomitant with off-pump coronary artery bypass grafting. After open heart surgery, stem area was mapped on a 3D heart model by a cardiologist and a cardiac surgeon and transferred to the 20-segment model used for scintigraphic analysis. Delivery area was chosen according to: 1) dominance of scar; 2) akinesis; 3) ungraftability of the tributary coronary artery. 99mTc Tetrofosmin Gated SPECT (370 MBq, 64 views in a 180 degrees orbit, double head gamma camera) was performed at rest before, 10 weeks and four years after treatment with the same camera and acquisition parameters. Severity of scar was quantified as number of standard deviations below matched normals according to QPS protocol (GE Health Care) in 20 segments. In the same segments regional wall thickening was quantified by QGS protocol (GE Health Care). Results: Ten weeks after the implantation, Gated SPECT showed an improved regional perfusion in stem area in 2 patients in whom the reduction of scar was 32% and 61%, respectively. One patient showed a further reduction of 10% after four years. 3 patients who did not improve regional perfusion both at short and long term follow-up showed a more extensive scar area and an impairment in regional wall motion before surgery. Conclusion: In patients with previous myocardial infarction and multivessel coronary artery disease undergoing stem cell treatment in ungraftable areas, reperfusion was higher in those segments with more viability and less akinesis. Results observed at 10 weeks were confirmed by Gated SPECT at long term follow-up. Gated SPECT appears to be an optimal tool to assess short-and long term effect of stem cell treatment on regional blood flow and function. Background: There is a lack of validation and standardization of acquisition parameters for myocardial 123I-metaiodobenzylguanidine (MIBG). This lack of standardization hampers large scale implementation of 123I-MIBG parameters in chronic heart failure (CHF). Methods and Results: In a retrospective multi-center study 123I-MIBG planar scintigrams obtained on 290 CHF patients (82% male; 58% dilated cardiomyopathy; NYHA>I) were reanalyzed to determine the late heart-tomediastinum ratio (H/M). There was a large variation in acquisition parameters. Multivariate forward stepwise regression showed that a significant proportion (31%, p<0.001) of the variation in late H/M could be explained by a model containing patient related variables and acquisition parameters. Left ventricular ejection fraction (p<0.001), type of collimation (p<0.001), acquisition duration (p=0.001), NYHA class (p=0.028) and age (p=0.034) were independent predictors of late H/M. Conclusions: Acquisitions parameters are independent contributors to semi-quantitative measurements of cardiac 123I-MIBG uptake. Improved standardization of cardiac 123I-MIBG imaging parameters would contribute to increased clinical applicability for this procedure. Objectives: For investigating the effects of suppression of myocardial sympathetic innervation on the myocardial adrenergic activity and norepinephrine transporter (NET) density, the study undertaken 123I -Metaiodobenzyl Guanidine (MIBG) myocardial imaging and and myocardial NET immunohistochemistry in Sprague-Dawley (SD) rats following surgical sympathectomy (SX) at superior cervical ganglia. Methods: Twelve 12-wk-old male SD rats were included in this study, 4 rats were subjected to right-sided surgical SX (RSX group), 4 rats were subjected to left-sided surgical SX (LSX), and another 4 rats were subjects to sham operation for control (C group) . All rats were undertaken myocardial imaging within 48 hours following operation. 123I-MIBG myocardial images were performed for the early and delayed imaging using a gamma camera (Picker Prism 1000 XP) equipped with a 2-mm pinhole collimator. The heart-to-mediastinum count ratios (H/M) of the 15-min initial imaging and the 4-h delayed imaging were determined, then the myocardial washout rate (MWO) was determined for being a marker of uptake-1 activity. Following 123I-MIBG myocardial imaging, the rats were sacrificed and the isolated hearts were collected for NET immunohistochemistry. Results: The results demonstrated the early MIBG H/M of RSX rats were lower than that of control rats (H/M: 1.91+0.15 in RSX; 2.96+0.15 in control rats, p < 0.05), whereas H/M in LSX rats were similar to control rats (H/M: 2.59+0.19 in LSX; p= NS vs. control rats). The MWO of control rats were higher than that of SX rats; whereas the LSX rats were higher than that of RSX rats (control rats: 0.67+0.10, vs. RSX: 0.29+0.08; p < 0.01; LSX 0.46+0.05,p < 0.05 vs. control rats). The myocardial NET immunohistochemistry revealed the density in RSX rats were higher than in LSX rats, whereas the NET density in LSX were higher than that of control rats. Conclusion: Based on the above findings, we suggest myocardial sympathetic dennervation will develop following right-sided sympathectomy, which will accompanied by compensated uptake-1 system on presynaptic nerve endings of postganglionic neuron, demonstrated by lowered MWO and increased NET density.

Role of I123-MIBG cardiac scintigraphy in differential diagnosis between Alzheimer's and Lewy bodies dementia E. M. Covelli, P. Sullo, G. Mazzarella, M. Salzillo, G. Vitale, G. Belfiore; S. Anna e S. Sebastiano Hospital, Caserta, ITALY.

Purpose: Lewy Bodies are abnormal structures in the mid-brain: microscopic protein deposits found in nerve cells that disrupt the brain's normal functioning. Lewy Body disease (LBD) is the second cause of dementia in older adults caused by abnormal structures in the brain. LBD diagnosis can be difficult because many of the symptoms are similar to Alzheimer's disease (AD), and cerebral perfusive tomography is always non conclusive. I123-metaiodobenzylguanidine (I123-MIBG) is a radioiodinated analogue of noradrenaline. I123-MIBG scintigraphy is a non-invasive and safe diagnostic tool to assess and evaluate cardiac sympathetic innervation. The aim of this study is to evaluate the cardiac sympathetic innervation by I123-MIBG scintigraphy in patients with clinically demential symptoms and inconclusive Tc99m-ECD perfusive tomography in order to help the differential diagnosis between LBD and AD. Methods: Fourteen patients (9F, 5M; mean age 67±16 years) with suggestive dementia symptoms underwent cerebral Tc99m-ECD tomography and cardiac I123-MIBG scintigraphy. Cerebral perfusive tomography was performed one hour after Tc99m-ECD (740 MBq) injection and qualitative analysis was used for diagnosis. Cardiac I123-MIBG scintigraphy was carried out in all patients within one week and planar scintigraphic images were acquired 4 hours after I123-MIBG (111 MBq e.v.) administration. Semiquantitative analysis was also performed calculating delayed (4 hours) heart to mediastinum count-ratio (H/M) by drawing regions of interest (ROIs) over the upper mediastinum and whole heart to confirm diagnosis. Results: All patients submitted to cerebral Tc99m-ECD tomography presented severely reduced tracer uptake suggestive to dementia but we observed a different cardiac innervation pattern between AD and LBD patients. In fact, cardiac I123-MIBG scintigraphy showed normal uptake (delayed H/M: 1.92±0.16) in eight patients diagnosed as having AD and abnormal reduced cardiac tracer accumulation (delayed H/M: 1.27±0.22, p<0.05) in remaining six LBD patients. Conclusions: A significant decrease of cardiac MIBG accumulation indicating a relevant degeneration of myocardial sympathetic neurons in LBD patients was detected. Therefore, these preliminary data suggest that cardiac I123-MIBG scintigraphy may be useful in the differential diagnosis between AD and LBD especially when cerebral Tc99m-ECD tomography is not conclusive and it can be considered a suitable and helpful tool in the management of patients with dementia syndromes.

A new iterative reconstruction algorithm (WBR™) has been recently proposed for cardiac SPECT. The WBR™ technology, based on accurate modelling of the emission-detection process, was designed to reduce noise improving lesion detectability without affecting the image resolution. Few data exist on the comparison between filtered back-projection (FBP) and this new algorithm in a clinical setting. Aim. The aim of this study was to compare the performance of FBP and WBR™ in the clinical arena. Methods. A group of 18 pts, with different cardiac pathology, scheduled for a stress-rest SPECT were studied. A two-day 99mTc-Sestamibi protocol was used. All pts performed standard ECG-gated SPECT acquisitions with a dual-head@90° camera, with a time/frame of 20 sec. Immediately after the conclusion of the acquisition, a second ECG-gated acquisition was performed at half-time/frame (10sec). Standard-time SPECT was reconstructed with a conventional FBP (Butterworth, 0.4, 10); half-time SPECT was reconstructed with WBR™. Tracer uptake was blinded evaluated by two experienced observers in 17 segments with a 4point scoring system (from 0=normal to 4=absent). Discrepancies were resolved by consensus. Summed stress scores (SSS) and summed rest scores (SRS) were calculated. LV EF were automatically calculated with QGS. Results. No significant differences were observed in SSS and SRS between half-time WBR™ SPECT (21.5 and 21.0, respectively) and standard-time FBP SPECT (22.1, and 20.7, respectively, NS) . LV EF on rest acquisitions was also comparable (43.6% on half-time SPECT vs 44.2% on standard-time SPECT, NS). LV EF on post-stress studies in half-time SPECT (40.3%) was lower than standard-time SPECT (46.7%), although not statistically significant. Conclusions. Visual analysis of half-time/frame SPECT reconstructed with the new algorithm WBR™, was comparable to that of a standard time/frame SPECT acquisition reconstructed with conventional FBP. Differences in the time elapsed from the end of the stress test and the SPECT acquisition could be involved to explain the differences of LVEF between the two post-stress studies. Results from the present study do not necessarily apply to SPECT studies employing an reduced activity of injected tracer, and further studies are needed. Aim: Present devices used for gated SPECT MPI may be incapable to identify the R wave as a proper triggering signal in patients with a pacemaker, mainly with dualchamber stimulation. The aim of our study was to assess in how many such patients the use of R wave fail and to test the usefulness of pulse wave as an alternative. Material and methods: We evaluated a group of 22 pts with pacemaker referred to our department for stress MPI. There were 11 m and 11 f, mean age 71 y (52-82). Two data sets were acquired at rest, the first set synchronized with R wave and the second set with pulse wave. CEqualTM and QGSTM software were used for processing. We compared ejection fraction (EF), end-diastolic and end-systolic volumes (EDV, ESV). Paired t-test and correlation were used for comparison. Results: We were unable to get good data in 3/22 (13.6%) pts using synchronization with the R wave. In all of them the data synchronized with the pulse wave were acceptable for processing. In the whole group, the mean EF, EDV and ESV calculated using the R wave for triggering were 0.50 (0.21-0.75), 79 (43-155) and 39 (14-95) respectively, using the pulse wave 0.49 (0.16-0.73), 89 (49-156) and 46 (15-89) respectively, p=0.485 for EF, p=0.004 for EDV and p=0.002 for ESV. Correlation for EF was 0.363 (p=0.096), for EDV 0.884 and for ESV 0.921 (p = 0.000 for both correlations). Conclusion: There is a significant number of pts with pacemaker in whom the use of the R wave does not allow to evaluate parameters of the heart function (13.6% in our group). We believe that the use of the pulse wave is the only alternative in such pts. Quantitative data correlate highly with the data calculated with ECG trigger.

The relation between Helicobacter Pylori infection and cardiac syndrome X;A novel study Objectives: Cardiac syndrome X (CSX) is characterized by an angina pectoris and/or presence of positive none-invasive test (exercise tolerance test or myocardial perfusion scan) accompanied with normal coronary angiogram. Several mechanisms such as ischemia, inflammation and endothelial dysfunction have been suggested. This study was carried out to assess the possible role of helicobacter pylori (HP) in this syndrome. Methods: HP infection was distinguished by urea breath test (UBT) in patients with CSX, and compared with two sex-and age-matched control groups. UBT classified as; negative, intermediate, positive for H. pylori. Statistical analysis was carried out using ANOVA and T tests. A P-values of 0.05 or less were considered to be significant. Results: each group consisted of 30 patients with a mean age of 53.30 ± 5.90 [SD] years, 55.80 ± 8.49 years, and 51.80 ± 8.72 years in CSX, CAD and healthy control respectively. Fifty percent (15) of CSX patients had positive result, while none of two control groups had the same results (p-value= 0.005). The negative and intermediate results were not statistically significant in three groups. Conclusion: With respect to the high occurrence of HP infection and likely contributory effect of inflammation in subjects with CSX, potential role of HP infection in the pathogenesis of CSX is proposed. However well planned clinical trials are required to validate this initial result.

The interpretation of medical images by inexperienced physicians would theoretically be improved with a second opinion of a more experienced colleague or by a decision support system. In the present study we evaluate the performance and interobserver variability between inexperienced as well as experienced physicians and a decision support system regarding classification of myocardial infarction and ischemia. Method: Seven physicians, all specialists in nuclear medicine but with varying experience, participated and were compared with the CARE decision support system. Each of the physicians interpreted 98 patients with gated myocardial perfusion scintigraphy (MPS) First a preliminary interpretation was made without the advice from the decision support system. The image was then processed by the computer and within seconds the physician received the advice from the decision support system and the interpretation and report was finalized. Result: The sensitivity regarding interpretation of ischemia increased with 6 % (p<0.001) for the whole group with the help of a decision support system, both for inexperienced, 8% (p<0.001) and experienced physicians, 4% (p=0.006). The increase in sensitivity was larger in the anterior and inferior areas of the heart. Conclusion: In the present study a second opinion from a decision support system increased the precision of physicians interpreting nuclear images, both for inexperienced as well as experienced physicians. A decision support system based on artificial intelligence is always available and can give advice regarding presence of infarction or reversible ischemia with the same precision as an experienced physician. 

A new iterative reconstruction algorithm (WBR™) has been recently proposed for cardiac SPECT. The WBR™ technology, based on accurate modelling of the emission-detection process, was designed to reduce noise improving lesion detectability without affecting the image resolution. Few data exist on the comparison between filtered back-projection (FBP) and this new algorithm. Aim. The aim of this study was to compare the performance of FBP and WBR™. Methods. An antropomorphic phantom was acquired with a dual head@90° camera, equipped with a LEHR collimator. A solution of 99mTcO4-was used to fill the different regions of the phantom: 2 MBq for both right ventricles and heart cavity. Two different activities were used to fill the heart wall: 20.3 MBq (comparable to the activity usually obtained in clinical setting; standard dose) and 10.1 MBq (half-dose). A cold lesion was simulated in anterior, septal, posterior, and lateral region with a 5 cubic cm cold disk inserted in the cardiac wall. For each wall activity and the different lesions, two sets of acquisitions were recorded: one at 20sec/frames (standard time) and one at 10sec/frame (half time). Each SPECT was reconstructed with conventional FBP (Butterworth, 0.4, 10) and with WBR™; a circular ROI was drawn on the short-axis slice better displaying the lesion. An activity-vs-angular position histogram (circumferential profile) was obtained and the FWHM was calculated for each lesion. Results. The average FWHM in half-time/standard dose (59.2 degrees) and halfdose/standard time (55.3 degrees) WBR™ SPECT were comparable to that of standard time/standard dose FBP SPECT (60.2 degrees). However, the FWHM in half time/half dose WBR™ SPECT (71.1 degrees) was worst than standard time/standard dose FBP SPECT. Conclusions. The new iterative reconstruction algorithm WBR™ compared well in respect to conventional FBP SPECT, allowing half-time or halfactivity studies. However, further studies are needed to verify the potential clinical application of this method.

Fanbeam Reconstruction using an iterative Algorithm including 3D-collimator modell S280 O. S. Grosser 1 , T. Prautzsch 2 , G. Ebel 2 , M. Seemann 1 , J. Ricke 1 ; 1 Radiology und Nuclear Medicine, Universitaetsklinikum Magdeburg, Magdeburg, GERMANY, 2 Scivis, Goettingen, GERMANY.

Aim: Fanbeam Geometry improves resolution and sensitivity imaging small volumes and small Field-of-Views. Reconstruction of volume data from Fanbeam projections is usually performed using filtered back-projection algorithm (FBP). This procedure considers the imaging geometry, but attenuation and collimator characteristics are ignored. To improve imaging quality we performed reconstruction using an 3D-itertiv reconstruction algorithm for Fanbeam geometry. The algorithm incorporates the distance and location dependent point spread function of the collimator and attenuation of the object. Material and Methods: Examinations were performed using an e.cam variable (Siemens Medical Solutions) gamma camera with Fanbeam collimators. For this system the location dependent point spread function for different distances to the collimator front and for different positions orthogonal to the focus line were estimated. A 3D-system model is derived. It is used for iterative reconstruction with GMA (Geometric Mean Algorithm). We performed SPECT with a Jaszcsak-Phantom with different count rates (high/low) and different numbers of projection angles (n=120, 60 and 30). Data were reconstructed using a clinical established FBP including Chang's attenuation correction and with an iterative algorithm using a contour based attenuation correction. Furthermore the reconstructed data were examined for image quality and artifacts. SPECT homogeneity and resolution of solid spheres with different diameters were estimated. Additionally line profiles, resolution and contrast were examined. Results: The visual image quality of GMA reconstructed data is significant improved compared to images reconstructed by FBP. In addition iterative reconstructed images show an better signal-noise-ratio SNR (GMA: 9.9; FBP: 6.3; p=0.05) and a significant higher contrast in small solid spheres. FBP shows typical extra corporal artefacts. These artefacts are not to notice in images reconstructed with GMA. Conclusion: Utilization of iterative Fanbeam reconstruction including a 3D-collimator model results compared to standard FBP to an improved image quality, significant higher SNR and an increased contrast. Using the iterative algorithm is connected with an acceptable time involved. 

The main obstacle of FBP is the noise otherwise it is the best technique of tomographic reconstruction. Determining the best filter and the proper degree of smoothing can help to ensure the most accurate diagnosis. Unfortunately there have been significant discrepancies in selection of proper filter and adjustment of the filter parameters to individual cases. The purpose of this study was to define an optimal parameter for the tomographic reconstruction procedure in routine single photon emission tomography (SPECT) studies. In this study Hoffman Brain Phantom is modified in such a way that only software capability is evaluated. The phantom is composed of several independent slice that can be imaged individually (planar) or in 3-D composition (SPECT). Method and Materials: The designed phantom was filled with water containing 99mTc. Dual head Mediso gamma camera SPECT system, equipped LEHR and LEGP parallel hole collimators was used. Energy window was set at ±20% of photo peak. Planar image of the slices were acquired separately at 0-10 cm from the collimator face collecting 107 counts. Tomographic image was performed using the phantom in 3D position. A total of 128 projection images with 128×128 matrix were acquired over 360°. The time per view was 10 and 20 sec. Planar images were used as reference ideal image for each corresponding reconstructed slice images. All the SPECT images were reconstructed using 6800 different filtering conditions. The quality of reconstructed images was evaluated by comparing the reconstructed images with the reference image using the universal image quality index (UIQI). Results: At all count density no significant difference observed between Metz and Wiener (), however the difference between these two and other filters was quite significant (P<0.001). The optimum filtering condition was significantly related to the count density (signal to noise ration) of the data. The results of this study are summarized the Tabel-1. Finally, all of the acquisition studies regardless of counts or collimator, that the mean of UIQI was the most for wiener filter in comparison with the other filters. Discussion: The data from this study suggests that the Hanning and Hamming are the weakest of the seven filter types tested. This is due to response of Hanning and Hamming filters at the low frequencies. Based on the results of this study, Wiener filter provided best image quality. Aim: Gated myocardial perfusion scintigraphy is an efficient tool to simultaneously assess myocardial perfusion, wall motion, left ventricular volumes and ejection fraction (LVEF). Filtered back projection (FBP) is often used for tomographic reconstruction, as this method can efficiently determine the transaxial slices. In a previous study we have investigated the effects of the applied smoothing filters on the measured volumes and ejection fractions. It turned out that the smaller volumes were underestimated, also resulting in an overestimation of the LVEF for small hearts. Iterative reconstruction techniques like OSEM perform better in low signal-to-noise ratio studies. So, we can apply filters with a higher cut-off frequency, which in turn may result in better estimates of the smaller volumes. In this study we have investigated the differences in measured volumes after FBP and OSEM reconstruction. Methods: 44 studies (Ex/Re) from 29 patients were selected. All studies were reconstructed with FBP using an order 9 Butterworth filter with fixed cut-off frequency equal to 0.27. The first 22 studies were also reconstructed using OSEM. By increasing the cut-off frequency of the filter from 0.18 to 0.30, a single frequency for all 22 studies was selected above which the LVEF was not changing anymore. In a former study this method was also applied to select the optimum cut-off frequency for FBP reconstructed studies. Next all studies were reconstructed using both, FBP and OSEM, each method with their optimum cut-off frequency. A standard software package (Germano) was used to determine the left ventricular volumes. FBP and OSEM results were compared on a study by study basis. Results: The optimum cutoff frequency for OSEM turned out to be equal to 0.24 (0.26 for FBP). The comparisons of the volume measurements as well as the LVEF are shown in the Table. A good correlation was found between the two reconstruction methods. Both, ESV and EDV volumes determined after OSEM turned out to be somewhat larger than those calculated from the FBP reconstructed studies, especially for the smaller LV volumes. LVEF in turn, was found to be lower for OSEM compared to FBP with differences ranging from -4% to +12%. Aim: Erdheim-Chester disease (ECD) is a rare multisystem, non-Langerhans form of histiocytosis of unknown origin. It involves multiple organs and typically causes symmetrical osteosclerosis of the long bones. We describe 2 patients with histologically proven ECD whose PET/CT showed vascular lesions. Materiel and Methods: Case 1 is a 52-year-old man operated for aortic regurgitation with a bicuspid aortic valve. Spumous histiocytes were found in samples collected during surgery. A thoraco-abdominal CT showed an infiltration of main thoracic and abdominal arteries, and a perisplenic and perirenal fibrosis. Bone scintigraphy showed symmetrical increased uptake of the long bones. Case 2 is a 41-year-old woman who had a history of weight loss and a severe biologic inflammation. A thoraco-abdominal CT scan revealed infiltration of the mediastinum, subrenal abdominal aorta and the superior mesenteric artery. Bone scintigraphy did not reveal any abnormalities. The 2 patients underwent a 18F-FDG PET/CT for evaluation of the extent of the disease. Results: Case 1: FDG PET imaging showed a marked hypermetabolism within the vascular lesions seen on the CT scan, with a more important FDG activity on the thoracic vascular lesions. There was no abnormal FDG uptake on the long bones. On the other hand, increased FDG uptake was observed on two dorsal vertebrae which was proved to be an extra-medullary meningioma. PET imaging failed to depict perirenal and perisplenic fibrosis. Case 2: FDG PET showed only 3 hypermetabolic foci: one on the level of the left pulmonary artery and the 2 others of the superior mesenteric artery and the subrenal abdominal aorta. There was no abnormal FDG uptake on the skeleton. Conclusion: FDG PET can detect extra skeletal lesions such as vascular involvement. In our cases, skeletal lesions were not depicted. This could be explained by effective treatment, since FDG PET was performed under chemotherapy.

In ECD, FDG PET may be used for evaluation of the extent of the disease and the assessment of the response to therapy, but more further studies are needed.

The Prevalence of Coronary Steal in Dipyridamoleinduced Myocardial Perfusion Scintigraphy: The Philippine Heart Center Experience R. B. Matias; Philippine Heart Center, Quezon City, PHILIPPINES.

To determine the prevalence of coronary steal in patients undergoing Dipyridamoleinduced Myocardial Perfusion Scan (MPS) in the nuclear medicine division of PHC To identify the subsequent MPS abnormality in patients who developed coronary steal during dipyridamole induction. To determine if there is an association between MPS abnormality and coronary steal. Coronary steal is caused by redistribution of flow away from collateral-dependent myocardium following coronary vasodilatation. Although coronary steal has been well described in canine studies, there are more limited observations of the absolute magnitude of coronary steal in humans and its relationship to clinical signs of myocardial ischemia. There is controversy whether chest pain and ECG changes with coronary vasodilation represent true myocardial ischemia because of coronary steal. Dipyridamole (Dipy) is often used as an alternative to exercise in the detection of coronary artery disease by radionuclide techniques that produce selective vasodilatation of normal coronary arteries, predominantly in the small, resistance vessels of the coronary bed. Method: 795 patients from January 1, 2003 to December 31, 2006 who developed chest pain with respective ECG changes after induction of Dipy during MPS procedure were included in the study. ECG changes include ST segment depression or elevation of > 1mV in 1 or more leads. Perfusion abnormalities include evidence of inducible ischemia (mild, moderate or severe), fibrosis or scar and infarcts. Normal perfusion scan pertains to those with no definite evidence of ischemia and defects which are due to soft tissue attenuation. 

A. Hughes; Royal Preston Hospital, Preston, UNITED KINGDOM.

Aim Gated SPECT is a well established technique that allows simultaneous assessment of the perfusion and function of the left ventricle (LV). Both global and regional LV function can be assessed using this technique and analysis of regional wall motion and thickening can help to identify viable myocardium and eliminate attenuation artefacts. Most centres use an acquisition protocol that divides the cardiac cycle into 8 frames. Temporal resolution can be improved by using 16 frames per cycle, but there will be a loss in the signal-to-noise ratio if the duration of the study is not increased. The aim of this study was to compare regional wall motion and thickening scores derived from gated SPECT using 8 and 16 frames per cycle.

Thirty-four female patients with normal perfusion and function were imaged on a Philips Forte JetStream gamma camera. Gated datasets with 8 and 16 frames per cycle were acquired simultaneously one hour after treadmill exercise. All data were filtered using a 2-dimensional Butterworth filter and reconstructed using filtered backprojection. Regional wall motion and thickening scores were computed for a 20-segment model of the LV using the Cedars-Sinai QGS software. Results Wall thickening scores for the 16-frame datasets were consistently higher by 15-20% throughout the myocardium. Additionally, there was a significant increase in circumferential variation in thickening in the mid and distal portions of the LV, with the anterior and antero-lateral segments exhibiting the largest differences. Wall motion scores were ~12% higher for the 16-frame data except in the septal wall, where the scores were comparable. Comparing motion and thickening scores of patients with known functional defects with data from the normal patient group did not reveal an increased sensitivity of one technique over the other. Conclusion The acquisition and processing of gated SPECT studies using 16 frames per cycle is feasible on modern imaging systems. Although there is an increase in temporal resolution over data acquired using 8 frames per cycle, resulting in differences to the normal ranges, there does not appear to be an improvement in the detection of functional abnormalities. Aim: Brain Natriuretic Peptide (BNP) is a neuro-hormone representing a marker of heart impairment. Female patients undergoing radiotherapy for left breast cancer may develop cardiac impairment. To evaluate this potential heart damage, BNP was measured in women treated by left breast radiotherapy. Methods: Twenty-four women with left breast carcinoma undergoing breast conservative surgery and radiotherapy (single dose 2 Gy; total dose 50 Gy followed by boost of 10 Gy on tumour bed) underwent BNP measurement, echocardiography and electrocardiogram at baseline (1 week before treatment) and 1 (2nd evaluation), 6 (3rd evaluation) and 12 (4th evaluation) months after radiotherapy. Four patients were also evaluated 24 months after radiotherapy, because the study is still in progress. Aim: The aim of the study was to compare LV dyssynchrony assessment by gated myocardial perfusion SPECT (GMPS) and tissue Doppler imaging (TDI). Background: Recently, it has been demonstrated that left ventricular (LV) dyssynchrony is an important predictor of response to cardiac resynchronization therapy (CRT); dyssynchrony is predominantly assessed by TDI with echocardiography. Information on LV dyssynchrony can also be provided by GMPS with phase analysis of regional LV maximal count changes throughout the cardiac cycle which tracks the onset of LV thickening. Methods: In 75 patients with heart failure, depressed LV function and wide QRS complex, GMPS and 2D echocardiography, including TDI, were performed as part of clinical screening for eligibility for CRT. Clinical status was evaluated using NYHA classification, 6-minute walk distance and quality-of-life score. Different parameters (histogram bandwidth, phase standard deviation (SD), histogram skewness and histogram kurtosis) of LV dyssynchrony were assessed from GMPS and compared with LV dyssynchrony on TDI using Pearson's correlation analyses. Results: Histogram bandwidth and phase SD correlated well with LV dyssynchrony assessed with TDI (r=0.89, P<0.0001 and r=0.80, P<0.0001 respectively). Histogram skewness and kurtosis correlated less well with LV dyssynchrony on TDI (r=-0.52, P<0.0001 and r=-0.45, P<0.0001 respectively). Conclusion: LV dyssynchrony assessed from GMPS correlated well with dyssynchrony assessed by TDI; histogram bandwidth and phase SD showed the best correlation with LV dyssynchrony on TDI. These parameters appear most optimal for assessment of LV dyssynchrony with GMPS. Outcome studies after CRT are needed to further validate the use of GMPS for assessment of LV dyssynchrony. Aim. Using radionuclide methods to study the correlation between the disturbances of central hemodynamics and the renal functional activity in patients with heart failure. Material and methods. Thirty seven patients (median age was 52,43 ± 1,29 years) with coronary artery disease (CAD) and heart failure (HF) of NYHA class II or III were examined using radionuclide renoscintigraphy and radiocardiopulmonography. Parameters of cardio-pulmonary hemodynamics and renal function were estimated. Results. We observed the damage of most of cardio-pulmonary hemodynamics parameters in all patients. That indicated the reduction of contractive activity of the left and right heart ventricles with pulmonary hypertension development. The disturbances of renal function were note in 73% of pts with HF and included the decrease of glomerular filtration rate and/or the increase of parenchymal clearance of 99mTc-DTPA. Using multiple linear regression analysis significant positive correlations were detected of the damages of renal filtration and evacuatory parameters with the decrease of cardiac minute volume, cardiac index and efficiency factor of circulation. Therefore the decrease of cardiac output is one of the basic factors of renal dysfunction pathogenesis in patients with HF. Furthermore were detected significant negative correlations between the disturbance of pulmonary circulation and the decrease of glomerular filtration rate. Conclusion. The radionuclide methods are available for the evaluation of influence of hemodynamics disturbances on renal function in pts with HF. Aim To explain our experience with GBPS, the obtained measurements of right and left ventricular ejection fraction (RVEF and LVEF) from GBPS and corresponding values determined by equilibrium imaging, due to ERV is the standard technique used to evaluate ejection fraction. To assess the reproducibility and reliability, the advantages and limitations of both thechniques. Materials and Methods 31 patients underwent GBPS and ERV. There were 26 females and 5 males, with a range age between 39 to 84 years, who had risk of cardiotoxicity induced by chemotherapy (this is the most frequent indication to evaluate FVEF), except the younger patient, who presented congenital cardiopathy, and the two older men, who presented cardiac failure. Imaging was performed 10 min after administration of 925 MBq 99m Tclabelled blood cells, acquiring SPECT with ECG gating. Next a planar image was acquired, about 30 min after injection. The data were processed using QUBE algorithm on a Segami workstation by a physician specialist in nuclear medicine and processed again to assess intraobserver reproducibility. A second operator reconstructed and processed the same studies, to assess interobserver reproducibility. Bland-Altman analysis was applied. Results The mean of LVEF's values obtained with GBPS was 73.10, versus 66.03 from ERV. For RVEF was 53.10 with GBPS and 55.41 with ERV. The intraobserver reproducibility of LVEF and RVEF was higher for ERV than GBPS in both observers (in the best of cases, the limits of agreement ±2SD calculated using Bland-Altman analysis were -0.13±7.1 for GBPS vs. 0.03±3.32 for ERV from LVEF, and 0.71±9.12 for GBPS vs. 0.26±3.46 for ERV from RVEF). The interobserver reproducibility presented less differences between both techniques. LVEF and RVEF obtained from GBPS were compared with those from ERV using Bland-Altman analysis. The mean difference was 7.07 with DS 4.46 from LVEF and -1.76 with DS 7.31 from RVEF. Processing of data obtained with ERV for RVEF was unsuccessful in 4 patients, in this cases GBPS was very useful to estimate RVEF. Conclusions GBPS presented a intra-inter-observer reproducibility slightly lower than ERV. This technique provides values of LVEF higher than ERV (approximately 7%), but RVEF's values were very similar to obtained with ERV. In cases that RVEF is especially difficult to estimate with ERV, GBPS is very usefull. Aim: The aim of the study was to identify myocardial viability by 99mTc-Tetrofosmine (rest and nitrate) in patients with ischemic left ventricular aneurysm. Material and Methods: The study involved 15 patients (men) aged 41 -63 with stable angina of the II-IV NYHA classes, chronic left ventricular aneurysm, all of them had a history of 1-3 previous transmural myocardial infarction. All patients before operation were underwent 99mTc-Tetrofosmine myocardial SPECT according to protocol "nitrate-test (10 mg of sublingual isosorbide dinitrate) -rest". All patients underwent coronary artery bypass surgery (ABS) and aneurysmectomy by Dore. After operation patients in 4 weeks were underwent 99mTc-Tetrofosmine myocardial SPECT only rest. Analyse was performed by dividing the left ventricle into 16 segments for SPECT. Result: 240 segments of left ventricle were analyzed on 99mTc-Tetrofosmine SPECT. After 99mTc-Tetrofosmine nitrate-test the amount of aperfusion sectors decreased in 11% in comparison with rest. After the surgery, we found that the amount of aperfusion segments was 13%; the amount of normal perfusion segments was 63%. We analyzed 90 perfusion scans and 1080 myocardium segments for assessment size of the perfusion defect. Average the perfusion defect before operation in 99mTc-Tetrofosmine SPECT rest was 37.4±12.9%. After 99mTc-Tetrofosmine nitrate-test it decreased to 25,3±13,7% (P<0.05). After the surgery it was 23.1±10.5%. We found significant difference in intensity of accumulation 99mTc-Tetrofosmine in the perfusion defect on rest and nitrate-test (P<0.05). Conclusions: 99mTc-Tetrofosmine SPECT by protocol rest -nitrate -rest is useful techniques for the identification of viable myocardium and to predict functional recovery after revascularisation in patients with ischemic left ventricular aneurysm.

Diagnostic value of gated SPECT myocardial perfusion imaging using thallium-201 in patients with latent coronary artery disease H. Shi, Y. Gu, W. Liu, W. Zhu; Zhongshan Hospital, Fudan University, Shanghai, CHINA.

Aims: To investigate the diagnostic value of SPECT myocardial perfusion imaging using thallium-201 for the patient likelihood of latent coronary artery disease. Materials and Methods: Fifty-two asymptomatic aircrews with positive results of exercise treadmill test underwent dipyridamole pharmaceutical stress and rest SPECT myocardial perfusion imaging using thallium-201. Patients with myocardial perfusion imaging positive findings accepted coronary artery angiography. Patients with myocardial perfusion imaging negative findings were followed up till five years. Results: Twenty-four patients showed positive results in myocardial perfusion imaging and twenty two of them detected coronary artery stenoses with more than 50% luminal narrowing by coronary artery angiography and two of them were negative results in coronary artery angiography. Twenty eight patients showed normal in myocardial perfusion imaging and no cardiac events happened in the following five years after myocardial perfusion imaging performed. Conclusion: SPECT Myocardial perfusion imaging using thallium-201 is very useful method for detecting latent coronary artery disease, especially for negative predictive value. And its diagnostic accuracy is much higher than exercise treadmill test.

Association of Left Ventricular Functional Parameters Measured by Gated Single Photon Emission Tomography and by Two-Dimensional Echocardiography C. Groselj, 19481 , B. Simonic, 19731 , B. Groselj, 19832 ; 1 University Medical Center, Ljubljana, SLOVENIA, 2 Medical Faculty, Ljubljana, SLOVENIA.

Introduction LVEF, EDV and ESV are good clinical indicators of left ventricular function and volumes, routinely measured by echocardiography (ECHOC). In former decade the Emory Cardiac Tool Box (ECTB) was developed, a toll for assessing left ventricular function and volumes from gated SPECT myocardial perfusion scintigraphy (GSPECT). GSPECT myocardial function assessment provides an important incremental information. Aim of the Study The aim of the present study was to validate the accuracy of the ECTB in assessing LVEF, EDV and ESV from GSPECT using ECHOC as a reference values. Patients and Methods 44 consecutive patients, 29 males and 15 females; mean age 63+/-12 y, range 39 -87 y, with suspected or known coronary artery disease were examined using 99mTc-MIBI GSPECT (8 gates/cardiac cycle) 60 min after tracer injection at stress. The GSPET data were reconstructed using an automatic algorithm employing filtered back projection (FBP) and further analyzed by Emory cardiac (EC) toolbox. All patients underwent two-dimensional (2D) M-mode ECHOC in the same diagnostic evaluation. The results of both methods were compared. Aim To determine if an average residual activity could be assumed for stress and rest Myoview administrations. Method An audit of residual activity in the syringe following Myoview administrations for myocardial perfusion imaging was conducted at Guy's and St Thomas' (GSTT) and the Royal Free Hospital (RFH). Residual activities for both stress and rest administrations were measured. Myoview was administered using 2ml Terumo syringes and 2ml Braun Injekt syringes at GSTT, and 3ml BD Luer-lok syringes and a y-tap extension set at RFH. Stress activities were administered via a 3-way tap (GSTT) and y-tap extension set (RFH). Rest activities were directly injected into a vein. Results At GSTT 40 residuals for rest studies and 43 residuals for stress studies were collected using Terumo syringes. 13 residuals for stress studies were collected during a trial of Braun Injekt syringes. At the RFH 26 residuals for stress studies and 13 residuals for rest studies were collected. The residual activities from GSTT, using the Terumo and Injekt syringes follow a normal distribution for both stress and rest administrations, and there was no dependence of residual activity on time of injection. There was a statistically significant difference in residuals between technologists for stress injections but not rest injections. The mean stress residual using Terumo syringes (86.26MBq), is significantly higher (p = <0.001) than the mean rest residual of 53.90MBq. The mean stress residual for Braun Injekt syringes of 28.62MBq was significantly lower than the mean for Terumo syringes of 86.26MBq (p=<0.001). The mean stress residual using the y-tap extension of 65.89MBq was significantly lower than the stress administration with Terumo syringes (p=0.041). There was no significant difference between the rest and stress residual activities at the RFH (p=0.409). Conclusion: The significant difference between stress and rest residual activities was attributed to increased difficulty flushing the syringe during the stressing procedure, compared to direct injection. The significant difference between the stress residuals using the Terumo and y-tap extension set but not between the rest residuals demonstrates that the stressing method using a y-tap extension reduces the residual activity and is not due to technologist working practices. Due to the overall large variation of residuals assuming a single average residual activity may not be good practice. However, residual activities were significantly reduced using the Injekt syringes and the y-tap extension set. Using Injekt syringes would reduce the residual of rest injections as well as stress injections.

The value of radionuclide methods in patients with suspicious chronic myocarditis. , 7 -complained about chest pain and dyspnea, 12 had myocardial conduction disorders. Echocardiography showed abnormalities at 28 patients: hypokinesia (total or local) at al cases, mitral valve prolapse -in 6 cases. Abnormalities of laboratory indexes were found at 5 patients (increasing of erythrocyte sedimentation rate, levels of AST and KFK). All patients underwent SPECT with 99mTc-HMPAO-leucocytes at 20 hours post injection, following by gated-SPECT with 99mTc-MIBI at the rest condition. Both scintigrams were then combined, using Fusion Display application, to define more exactly the localization of 99mTc-HMPAO-leucocytes uptake in the heart. The presence, character and magnitude of perfusion defects, ejection fraction (EF) of left ventricle (LV), motion and thickening extent were also estimated. Results: Perfusion defects were detected at 31 cases, with average size -10,3±3,57% (max -16%), which localized in ventricular septum, anterior or inferior wall of the LV. (7). The viability of labelled stem cells was tested by flow cytometry with propidium iodure (FACScan® Becton Dickinson™). The proliferation capacity was tested by cell culture on specific media (RPMI-based cell media). After determination of optimal dose, we made an intramyocardial injection of labelled stem cells on a healthy rabbit. A SPECT scintigraphy was then performed with static acquisitions at 24 and 48h after injection. Results: The labelling efficiency was good for all samples with an average rate of 67% (52-85%). The viability was 91.6% of living cells (no significant difference with control groups). The labelling with 1.85 MBq did not interfere on the proliferation whereas the higher activities, 3.7 or 7.4 MBq, stopped proliferation. The lowest dose does not disturb the viability and proliferation of stem cells and allows SPECT scintigraphy until at least 48h after intramyocardial injection of labelled stem cells on animal. Conclusion: The labelling of rabbit bone marrow stem cells was successfully performed with Indium-111 oxine. Thus, we can follow stem cell therapy by SPECT scintigraphy without affecting cell viability or proliferation.

The usefulness of an 18F-FDG PET/CT image obtained at 2 hours after intravenous 18F-FDG injection in detecting aortic 18F-FDG uptake compared to that obtained at 1 hour after injection Aim: Atherosclerosis is an immune inflammatory disease. Increased macrophage metabolism is seen in active atherosclerotic plaque inflammation. 18F-FDG concentrates in those lesions and many studies have reported clinically and experimentally regarding the 18F-FDG images of atherosclerotic plaque inflammation.

Most of the studies used PET or PET/CT images obtained at about 1 hour after intravenous 18F-FDG injection (as an early image), but to our knowledge there have been no reports using PET or PET/CT images obtained at 2 hours after injection (as a delayed image). Therefore we investigated the usefulness of the delayed PET/CT images in detecting aortic 18F-FDG uptake comparing with the early images.

Forty-one patients were participated in this study who were referred for tumor staging or seeking recurrence or metastatic lesions using FDG-PET/CT. We reviewed the early and delayed images visually for the presence of aortic 18F-FDG uptake. Aortic 18F-FDG uptake was evaluated visually by dividing into the following 5 sections: (1) ascending aorta, (2) aortic arch, (3) thoracic descending aorta, (4) upper abdominal aorta and (5) lower abdominal aorta. We also examined the degree of aortic blood-pool 18F-FDG activity. Results: The delayed image showed decreased blood-pool 18F-FDG activity in all lesions of the aorta. The number of aortic 18F-FDG uptake seen in the early image, the number of uptakes seen in the delayed image and the number of obtained clear visualizations in the delayed image of each section were as follows: (1); 30, 31 and 18, (2) ; 27, 28 and 13, (3); 15, 15 and 9, (4); 4, 4 and 3, (5); 3, 2 and 2, respectively. Conclusion: This presentation illustrates the change in the aortic 18F-FDG uptake over time and the usefulness of delayed PET/CT images. About half of the aortic 18F-FDG uptake lesions in the delayed image showed clear visualization compared to the early image. The reasons were thought to be not only decreasing the blood-pool 18F-FDG activity but also increasing the aortic 18F-FDG uptake itself in the delayed image. Aim: To measure the equivalent doses of radiation to medical staff performing 13NH3 myocardial perfusion PET scan. Methods: The study was conducted in 2006 during 17 PET examinations. Nine examinations were performed on patients with severe ischaemic heart disease and consisted of two PET scans (one rest and one dipyridamole pharmacological stress scan), and eight examinations were performed on asymptomatic HIV patients and consisted of three PET scans (one rest, one cold pressor stress and one dipyridamole pharmacological stress scan). An electronic dosimeter was placed on the chest, and highly sensitive thermoluminescent dosimeters (TLD) were placed on the right index finger and the right wrist of the two technologists and the physician, performing the examinations. When examinations consisted of two scans (2S), the primary technologist (T1) withdrew 13NH3 from the production facility and performed injection of the tracer into the patient. The second technologist (T2) nursed and observed the patient during the whole scan, and the physician (P) monitored and observed the patient during the pharmacologic stress. When examinations consisted of three scans (3S), the roles were the same, but the physician additionally held the left leg of the patient in 0ºC water and coached the patient through the cold pressor testing. Results: When performing two scans, the mean equivalent doses to the index finger were 387 μSv, 5 μSv and 5 μSv, and the mean equivalent doses to the wrist were 91 μSv, 3 μSv and 1 μSv for T1, T2 and P respectively. When performing three scans, the mean equivalent doses to the index finger were 453 μSv, 3 μSv and 7 μSv, and the mean equivalent doses to the wrist were 138 μSv, 0 μSv and 0 μSv for T1, T2 and P respectively. The mean equivalent doses to the chest when performing two scans measured by electronic dosimeter were 10±0.6 μSv for T1 (p=0.026 vs. 3S and p<0.001 vs. B2 and P), 4±0.5 μSv for T2 (p=0.01 vs. P) and 2±0.4 μSv for P and when performing three scans, 13±0.8 μSv, 3±0.4 μSv and 4±0.4 μSv for T1, T2 and P respectively. Conclusion: Mean equivalent dose is less than 1 ‰ of the current one year dose limit for the most exposed member of the medical staff when performing a myocardial perfusion examination with three 13NH3 PET scans. Equivalent dose is dependant on work function and scan regimen as well as patient morbidity.

The role of 18F -FDG PET in the diagnosis of large vessel vasculitis Purpose: Physiological accumulation of FDG into salivary glands often causes false positive findings in diagnosing head and neck lesions. It has been reported that some amount of radioactivity were excreted into saliva, therefore gargling before PET scanning has been investigated for improving the image quality in this region, however the actual efficacy of it is still unknown. In this study, we assessed the efficacy of lemon stimulation for encourage secretion of radioactivity in saliva to obtain images with higher quality. Methods and Materials: Thirty normal subjects were examined FDG PET before and after lemon stimulus. Region of interests of salivary glands, oral cavity and soft tissue were determined according to anatomical margins of them using fusion image with CT, and SUVs were measured.

Radioactivities in saliva before and after lemon stimulation were also measured by a curiemeter. Results: The SUVs of salivary glands were shown in table 1( PG: parotid gland, SMG: submandibular gland, SLG: sublingual gland ). There were no significant differences between before and after lemon stimulation. In addition, radioactivity in saliva after lemon stimulation was 3.64+/-4.83 microCi in 10mL of gargling water which was as low level of radioactivity as that of background (0.360+/-0.476 microCi/ml). Conclusions: Although low level of radioactivity was present in saliva after injection of FDG, excretion of it was not influenced by lemon stimulation in normal subjects. Therefore, alternative imaging methods need to be developed for reduction of physiological accumulation of FDG into salivary glands and for improving image quality in the area of oral cavity. 

Aim. Diffusion weighted MR imaging is a technique allowing to grade non-invasively the tumour cellularity, basing on the principle that molecules in living tissues routinely undergo random (Brownian) motion. ADC (Apparent Diffusion Coefficient) is a value describing microscopic water diffusibility in presence of factors restricting diffusion within tissue (cell membranes, viscosity). Our aim was to investigate the existence of a relationship between metabolic activity as measured by 18FDG PET and water diffusivity as evaluated by Apparent Diffusion Coefficients (ADC) in brain tumours. Methods. Gadolinium-enhanced fast spoiled gradient echo (Gd-FSPGR), diffusion weighted magnetic resonance imaging (DWI) with ADC maps and 18FDG PET were performed in 13 patients (2 glioblastoma multiforme, 1 astrocytoma, 10 brain metastases) with 16 tumour lesions. ADC and 18FDG PET images were coregistered with enhanced FSPGR images to identify tumour sites. Spherical 3D tumour and contralateral control region of interest (ROIs) of the same geometric parameters were drawn on FSPGR, ADC and PET images, using Gd-FSPGR as target for statistical parametric mapping with fused localization of ADC and PET (by using MRIcro). PET and ADC ratios of the tumour and control ROI were obtained and linear regression analysis was carried out. Results. A significant correlation was not shown between PET and ADC ratios in all lesions studied; plotting ratios, if PET values were greater than 2.5, ADC data were below 4, while if ADC indices were greater than 4, PET ratios were below 2.5. A significant correlation (r2 = 0.5506, p = 0.0350) was found between PET and ADC findings in 8 lesions, having PET and ADC ratios lower than 4. Conclusions. Our data, although preliminary, show that a relationship might exist if PET and ADC present low ratios. This could be due to the fact that in high cellularity areas, structures and cell membranes could increase impedence to water diffusion, causing decreased ADC values and increased 18FDG uptake, while areas with low cellularity, i.e. necrotic areas, present increased ADC and reduced 18FDG uptake. Aim: According to literature, 18F-fluoroethyl-L-tyrosine (FET) was found to be a new valuable PET tracer to image brain tumors. Particularly, FET uptake was higher in recurrent gliomas than in radiation injuries, whereas CT and MRI showed a limited specificity in differentiating between post-therapeutic unspecific changes and neoplastic lesions. In this study we evaluated the contribution of FET PET/CT in the diagnosis of tumor recurrence in patients with gliomas undergoing multimodal treatment or radiosurgery. Methods: the study included 24 patients with glioma (primary grading: 17=WHO grade IV, 5= grade III, 2= grade II) who showed neuroradiological findings suspected for tumor relapse after multimodal treatment (20 patients) and GliaSite Radiation Therapy using radioactive iodine 125-I-Iotrex (4 patients). Brain PET/CT scans (Discovery LS PET/CT scanner, GE Healthcare, Milwaukee, WI, USA) were performed 30 min after injection of 160-360 MBq of 18Ffluoroethyl-L-tyrosine (IASON Labormedizin GesmbH & Co. KG Graz-Seisberg, Austria) using 3D mode acquisitions in 20/24 cases and 2D acquisitions in 4/24 The FET uptake in the most active part of the lesion was quantified by the standardized uptake value (SUVmax) and lesion-to-brain ratio (SUVmax/BG). Brain lesions with a SUVmax/BG of at least 1.5 were interpreted as probable recurrent disease. previously undergone breast cancer surgery and sentinel node biopsy and, when indicated, axilla lymphadenectomy, were enrolled. A sCT scan was already performed in these patients when they came to our Institution for PET/CT scanning. We compared sites and number of sCT-diagnosed relapses with PET/CT results. Results.

In 10/50 patients (pts) (20%) sCT scanning showed relapses not observed by PET/CT; in 6 of these pts metastases observed in sCT scans were located in liver or lungs. In other 4 pts metastases sites were axillary or mediastinal lymph node chains. In 7/50 pts (14%) PET/CT results were coparable to sCT ones. 8/50 pts (16%) had negative sCT scanning, while PET/CT revealed widespread bone or lymph nodes metastases. Finally in 25/50 PTs (50%) PET scans showed unclear meaning high metabolic activity bone and lymph nodes areas; while in the same pts sCT imaging revealed different sites of relapses as in lungs. Conclusion. PET/CT seems to have higher sensitivity and positive predictive value than sCT in detecting lymph node and bone relapses; sCT appears more reliable than PET/CT to reveal lung or liver metastases.

Comparison of 99m Aim. Breast carcinoma express the Na+/I-symporter and may -albeit not a routine procedure -be imaged with 123iodide (123I) and 99mtechnetium-pertechnetate (99mTcO4-) scintigraphy. Objective of our prospective study was the comparison of 99mTcO4--and 123I-SPECT with FDG-PET in patients suspicious for breast cancer. Methods and Patients. Twenty-nine untreated patients suspicious for breast carcinoma were prospectively examined with thorax SPECT with 99mTcO4-(n=19) or 123I (n=10), respectively, and FDG-PET (n=29) prior to biopsy. Tumor-to-background ratios (TBR) were calculated for SPECT findings. Mean and maximum SUV were calculated for PET findings. Findings were compared in an intra-individual lesion-tolesion analysis. Results. In 28/29 patients, malignancy was verified with histopathology. In imaging the primary tumor, sensitivities of 99mTcO4--SPECT, 123I-SPECT and FDG-PET were 63%, 67% and 89%, respectively. TBR mean was 2.3±0.9 in 99mTcO4--SPECT and 2.7±1.1 in 123I-SPECT. In FDG-PET, mean tumor SUV was 4.1±4 and maximum tumor SUV was 5.4±5.1. In contrast to FDG-PET, 99mTcO4--SPECT was not sufficient in imaging nodal and distant metastases in the thorax, and 123I-SPECT failed in imaging lymph node infiltrations. Distant metastases were not present in patients of the 123I group, and the value of 123I-SPECT was not evaluated. Conclusion. In contrast to FDG-PET, 99mTcO4--and 123I-SPECT are not sufficient in imaging breast carcinoma in clinical practice. showed an overall accuracy of 94%, with sensitivity and specificity of 97% and 71% respectively. Conversely, dual-time point PET-CT showed an overall accuracy of 83%, for lesions with an SUVmax 2.5 and/or with a positive SUVmax, with sensitivity and specificity of 80% and 100%, respectively vs 66%, 60% (both, p<0.001) and 100% (p=n.s.) of single-time point PET-CT. In addition, on PET-CT, malignant lesions showed an increase in FDG uptake between time point 1 and 2, with a %SUV of 12±25. Conversely, benign lesions showed either no change or a decrease in SUVmax between time point 1 and 2, with a % SUV max of 20±8 (p < 0.001). Discussion. MRI shows higher sensitivity compared to PET-CT in disclosing breast malignancy. Dual-time point improves PET-CT accuracy in patients with suspicious breast malignancy over single point PET-CT. On PET-CT examination there is increasing uptake of FDG over time in breast tumor, conversely, benign lesions show a decrease in FDG uptake over time. These changes in SUVs over time might be considered a reliable parameter that can be used to differentiate benign from malignant lesions of the breast, on PET-CT examination. Aim : To evaluate the significance of early and late delayed image in the lesion that SUV is over 2.5. Material and Methods : 96 cases suspected malignancy obtained three-phase (64±10min, 110±12, 232±24 after FDG injection) PET/CT scan. The maximum SUV value in three phase were recorded as SUV1,SUV2,SUV3. Retention index of each lesion in two delayed phase were calculated according to the following formula: RI1=(SUV2-SUV1)/SUV1*100%.RI2=(SUV3-SUV1)/SUV1*100%. The diagnostic value of two delayed images was compared through ROC curve. The most proper cut-off value of RI in two different delayed phases was established. Results : 160/200 lesions were malignancy, 40/200 lesions were benign, that were proven by pathology, clinical, laboratory and radiological examination. SUV1 in each lesion was over 2.5. RI1,RI2 in malignancy were 12.6%±16.0%,11.1%±21.4%, the correlation coefficient was 0.65(P=0.0001). RI1,RI2 in benign lesion were 10.0%±28.6%,8.7%±4.3%, the correlation coefficient was 0.60(P=0.0001). Through analysis of ROC curve, the area under ROC curve in early delayed image was 0.62 ±0.05(Null hypothesis: true area = 0.5, P<0.05), when RI =1%, the maximum Youden's index was 0.219, the diagnostic sensitivity, specificity and accuracy was 81.9%,40.0%,73.5%. The area under ROC curve in late delayed image was 0.57 ±0.06 (Null hypothesis: true area = 0.5,P>0.05), that suggest late delayed image has no diagnostic value. Conclusions : The retention index of two delayed phase in benign and malignant lesion have good relativity. The diagnostic value of early delayed image is higher than late delayed image. When RI was 1% in early delayed image, it has maximum diagnostic efficiency. The aim of the study is to evaluate the use of PET-CT for detection of mediastinal lymph node (MLN) metastases from preoperatory staging of non small cell lung cancer in order to avoid mediastinoscopy before surgery. Material and Method We studied 84 patients (p), 5 out of them were women, between 44-83 years old (medium of 66 years). We used a GE Discovery LS equipment to realize the PET-CT studies after the administration of 370 MBq of 18F-FDG and multislide CT without iv contrast. We analized histologically the primary tumour and mediastinal lymph nodes in all patients by means of mediastinoscopy or thoracotomy. We determined tumour staging and the standard uptake value (SUV) of the tumour and mediastinal lymph nodes with activity above vascular pool. Results Primary tumour location: Hilium 14p, right lower lobe 15 p, left lower lobe 5, lingula 2p, medium lobe 2p, right upper lobe 21 and left upper lobe 25. Hystological analyse of primary tumour: Adenoesquamous carcinoma 43 p, adenocarcinoma 26 p, large cell carcinoma 8 p , bronchioloalveolar 1 p and others 5 p. Differentiation grades: Indiferentiated 3,1%, low 37,5%, moderate 33%, high 6,3% and non valuable 15%. SUV T 1 = 7,78 (17-3,2) ; SUV T2 = 11,4 (25-3); SUV T3 = 13,6(19-10); SUV T4 = 16,3 (24-11). Staging: IA 12 p; IB 34 p; IIA 3 p; s IIB 18 p; IIIA 12 p, IIIB 4 p and IV 1 p.

Detection of mediastinal metastases: Sensitivity: 0.71, specificity: 0.93, PPV: 0.66; NPV: 0.94 and diagnostic accuracy: 0.89. The false-positive PET-CT scan were 2 carcinoma abcessed, 1 fibrohistiocitosis and 2 inespecific adenitis . False negative scan in 3 p with subcarinal mediastinal station afectation milimetric nodal size.

The hight NPV of PET-CT can avoid mediastinoscopy. But it must be considered that a positive or negative PET-CT does not assess or exclude malignancy in mediastinal nodes. Aim: PET is a useful technique in the staging of non small-cell lung cancer (NSCLC). Although there is a wide experience with FDG-PET and CT, the introduction of PET/CT deserves to investigate its role in the context of diagnostic CT as a routine technique for NSCLC staging. The aim of this study was to compare the contribution of FDG-PET/CT and diagnostic CT in the staging of NSCLC. Material and methods: Sixty-six patients with NSCLC, 52 male and 14 female were studied, (average age of 62 years). All patients underwent a FDG-PET/CT and a CT, in 1-month interval. The findings of both techniques were compared, and the final diagnosis was made by histological findings, clinical follow up, and response to therapy. Results: FDG-PET/CT and CT findings were concordant in 16 of the 66 patients (24%). In 15 of them, the same lesions were identified. In 50 of the 66 patients (76%), the results disagreed. Thus, in 34 of the 50 discordant patients (66%), the FDG-PET/CT showed a greater involvement than CT, related to the extension of lymph node involvement in 23 patients (2 false positives) and to the number of metastasis in 15 (2 false positives).

In 13 of the 50 discordant patients, the FDG-PET/CT showed a smaller involvement than CT: less lymph nodes in 7 (10%) and less metastasis in 6 (9%). Therefore, in 1/50 patients FDG-PET/CT and CT showed differences in location of the involved lymph node region. Staging was modified by FDG-PET/CT in 41/66 (61%): it was increased in 28 (42%) (3 false positives) and diminished in 13 (19%). In 21 patients (31%), FDG-PET/CT modified the therapeutic setting, avoiding surgery in 15 (22%), discarding adrenal metastasis in 3 (4.5%), and diminishing the lymph node extension in 3 (4,5%) patients. Objective: Diffusion-weighted MRI is known to provide images seemingly similar to those of FDG-PET. In the present study, we examined and compared lung cancer cases using FDG-PET/CT and DWIBS (diffusion-weighted MRI) on the same day.

[Subjects] We examined 21 lesions that were confirmed to be lung cancer with lymph node metastasis based on biopsies in addition to one pulmonary hamartoma lesion in 13 patients who underwent follow-ups longer than 6 months. The mean lesion size was 20.8±9.4 mm (range: 10-45 mm). Materials and Methods: After 5-hour fasting, FDG was intravenously injected at a dose of 3.7 MBq/kg and then its distribution was analyzed using Discovery ST Elite System (GE) one hour later. DWIBS was performed to the consented patients, immediately prior to PET analysis, by taking images (slice thickness = 6 mm, b-factor = 1000) with a single shot EPI method using a 8-ch body array coil with SIGNA EXCITE 1.5T (GE). Both images were visually evaluated. The tracer accumulation in the liver and the signals in the spinal cord were considered to be positive for PET, DWIBS, respectively. Results: Twenty (95.2%) of the 21 malignant lesions were positive on FDG-PET/CT, whereas 19 lesions (90.5%) were positive on DWIBS. There were no significant differences between the two modalities (p = 0.565). The benign pulmonary hamartoma was negative on PET, but positive on DWIBS. Pulmonary adenocarcinoma (12.6 mm) in the right upper lobe showed false-negative findings on PET, but CT scanning of this node indicated suspicious pulmonary adenocarcinoma. In addition, left pulmonary hilar lymph node metastasis (15 mm) associated with left upper lobe cancer and pulmonary adenocarcinoma (12 mm) in the right upper lobe showed false-negative findings on DWIBS. Conclusion: Both PET and DWIBS detected malignant lesions almost the same level. However, DWIBS is less efficient in differentiating malignant lesions from benign lesions because DWIBS showed benign lesions such as pulmonary hamartoma as positive.

by-lesion analysis. The vertebrae were the most frequently involved bones (23/70 = 32.8%), followed by ribs (16/70 = 22.8%), and pelvic bones (15/70 = 21.4%). SUV values of the metastatic foci range from 2.1 to 26.1 (mean 6.3; median 5.5). The CT patterns were classified into four groups: osteolytic (21/70 = 30.0%); osteoblastic (18/70 = 25.7%), mixed (17/70 = 24.3%) and invisible type (13/70 = 18.6%). Osteolytic and invisible skeletal metastases showed higher value of FDG uptake than osteoblastic (the difference were statistically significant, P < 0.0001) and mixed lesions (the difference were statistically borderline, P = 0.0615). Conclusion: Our preliminary data shows that [18F]FDG-PET/CT provides a powerful combination of functional and morphologic information allowing an accurate characterization of bone metastases in lung cancer in terms of both metabolism and structural changes. , SUVmax, and SUVmean were calculated for each adrenal lesion. Moreover, FDG adrenal uptake was compared with radioactivity of aorta, liver, and spleen by calculating the adrenal lesion-to-aorta, the adrenal lesion-toliver, and the adrenal lesion-to-spleen SUV ratio. Standard of reference for confirming the definitive nature of the adrenal lesions was either histophatology or clinical/imaging follow-up data. The value of [18F]FDG-PET/CT imaging was assessed by using independent t tests and receiving operating characteristic analysis (ROC). Results: Of the 29 lesions, 8 turned out to be malignant based on subsequent growth (n = 6) or histophatology (n = 2), while 21 were benign based on stability for 6 months (n =19) or histopathologic analysis (n = 2). There was a statistically significant difference in HU and SUV between benign and malignant masses (P < 0.0001), while the difference in size was not statistically significant (P = 0.09). The cutoff values derived from ROC analysis for best discriminating malignant from benign lesions were as follows: SUVmax of 4.6 (AUC = 1.00, sensitivity = 100%, specificity = 100%, PPV = 100%, and NPV of 100%), HU of 21 (AUC = 0.976, sensitivity = 100%, specificity = 90.5%, PPV = 77.8%,and NPV of 100%), and a adrenal lesion-liver SUV ratio of 2.2 (AUC = 1.00, sensitivity = 100%, specificity = 100%, PPV = 100%,and NPV of 100% Purpose: Positron Emission Tomography (PET) is a radioisotope imaging method for obtaining information of organs and metabolisms within the human body. One of the most important criteria for quality-PET images is a high contrast value. Injection doses and scan durations have important effects on the contrast of PET images, especially for the overweight patients. In this study, we have investigated the impact of injection doses and scan durations on the spatial resolution of the PET images within the lung lesions with diameters 0.6, 1.0, 1.6 and 2.4 cm consecutively. Material and Method: For the study, a whole body phantom was designed considering a standard adult human body of average weight of 100 kg. The lung-lesions were filled with different an activity-concentration as 4, 8 and 16 times more than that of lung-tissue background. Seventy-two transaxial PET images were acquired with combinations of 3, 4, 5, 6, 7, 8 MBq/kg injected doses and 2, 3, 4, 5 min/bed scan durations using a Siemens Biograph HI-RES PET/CT. Results: It was found that the visibility and contrast value of lung lesions increased with the increasing of injection doses and scan duration. Two minutes scan duration for a bed position is not sufficient to localize a lesion with 0.6 cm diameter with all injection doses. Apart from this, all scan durations and injection doses used in this study are sufficient to detect the lesion of 2.4 cm diameter. Conclusion: We concluded that minimum contrast value for the visibility of a lung tumor PET image is 3 and 5 min/bed scan duration and 8 MBq/kg injection dose are sufficient to detect the lung lesion used in this study. Objective: Pulmonary nodules associated with low or absent flourodeoxyglucose (FDG) tracer activity on FDG PET can generally be managed conservatively after consideration of multiple clinical parameters and risk factors. In some instances, patients with such pulmonary nodules have hilar and mediastinal lymph nodes with definite abnormal FDG uptake, confounding study interpretation and patient management. We hypothesized that a high level of FDG uptake in hilar or mediastinal lymph nodes, in the setting of a pulmonary nodule with low or absent FDG uptake, is due to benign inflammatory processes. Methods: A total of 1520 PET-CT reports were reviewed and twenty-seven studies with discordant pulmonary nodule and hilar or mediastinal lymph node metabolism were identified. Discordance was defined by an SUV ratio of lymph nodes to nodule of greater than 2.0. The SUV (standardized uptake) values (average values, not corrected for lean body mass, and measured at 90-120 minutes post FDG administration) were calculated from filtered back projection images, and ratios were then calculated based on those SUV values. A retrospective chart review was performed on the cases that met the study criteria and the follow-up (biopsy or follow up imaging) was documented. Patients with a known diagnosis of malignancy or sarcoidosis were not included in the study. Results: The SUV values for the nodules ranged from 0.6-3.2, with a mean of 1.8. The SUV values for the lymph nodes ranged from 4.3-9.3, with a mean of 6.8. In 6 of twenty-seven patients biopsy found histologic findings of necrotizing granulomas or histoplasmosis. In 12 of the twenty-seven patients, follow-up imaging revealed the hilar or mediastinal lymph nodes had decreased in size or remained stable. The remaining nine patients have yet to be followed up. Conclusion: In patients undergoing FDG PET for evaluation of a pulmonary nodule, a nodule with low or absent glucose metabolism can likely be managed conservatively, even when there is definite associated abnormal glucose metabolism in hilar or mediastinal lymph nodes.

18F-FDG Uptake of N2 Lymph Nodes and Primary Tumor on PET: Clinical Significance in Stage IIIA N2 Non-small-cell Lung cancer

Purpose: This study evaluated the potential role of 18F-fluoro-2-deoxy-glucose (FDG) uptake by primary tumors and N2 nodes on positron emission tomography (PET) in patients with stage IIIA N2 non-small-cell lung cancer (NSCLC). Experimental Design: We analyzed PET scans of 57 NSCLC patients who received surgical resection and proved pathologically to have stage IIIA N2 disease between January 2000 and April 2005. On each patient's PET scan, FDG uptake by the primary tumor and N2 nodes were evaluated using the maximum standardized uptake value (SUV). The highest SUV of the N2 nodes in each patient was used for analysis.

The SUV of the node was affected by histology (P = 0.012). Whereas a different survival outcome was not observed according to the SUV of the primary tumor (P = 0.875), the SUV of the node ( median vs. > median) was associated with survival (P = 0.034). Patients with a low ratio of the node SUV to the primary tumor SUV ( median) showed better survival than those with a high SUV ratio (> median) (P = 0.024). In the multivariate analysis, the T stage (P = 0.002) and ratio of the node SUV to the primary tumor SUV (P = 0.045), adjusted for the size of the N2 node ( 1 cm vs. > 1 cm), remained significant prognostic factors. Conclusion: These results suggest that FDG uptake by the N2 node, especially relative to the uptake by the primary tumor, may predict survival of patients with stage IIIA N2 NSCLC.

Accuracy of dual-phase FDG PET for diagnosis of pulmonary nodule with initial SUV less than 2.5 C. Chen, B. Lee, W. Yao, P. Wu, C. Chu, N. Chiu; National Cheng Kung University Medical Center, Tainan, TAIWAN.

Aim: 18F-FDG PET is a very useful tool for the evaluation of pulmonary lesions with high sensitivity and specificity when using cutoff standard uptake value (SUV) of 2.5. However, false results may occur, such as in bronchioalveolar carcinoma or inflammatory foci. Studies indicated the usefulness of delayed PET images to improve accuracy. Our study aimed to clarify the efficiency of delayed PET in pulmonary nodules with initial SUV less than 2.5. Material and Methods: We collected dualphase FDG PET studies, imaging at 1hr and 2 hr post-injection, that showed pulmonary lesions with initial SUV less than 2.5. Those with final pathological reports were recruited for further analysis. We analyzed the difference in SUVs, retention index (RI) (%) (ie. subtracting the 1 hr SUV from the 2 hr SUV and dividing by the 1 hr SUV), and rate of further increase of SUV between benign and malignant pulmonary lesions. Results: Totally 24 lesions, in 20 patients, were recruited. Ten, including nine of granulomatous inflammation, were benign and 14 were malignant. For the benign lesions, the average SUV on 1 hr and 2 hr images were 1.79 (range: 1.1 to 2.3) and 1.97 (range: 1.0 to 2.4), respectively. For the malignant lesions, the average SUV on 1 hr and 2 hr images were 1.55 (range: 0.8 to 2.3) and 1.77 (range: 0.9 to 3.4), respectively. Further increases of SUV on delayed 2 hr images were observed in 7 of the 10 benign (70.0%) and 9 of the 14 malignant lesions (64.3%). No significant differences in SUV, RI, rate of further increase of SUV were found between the benign and malignant pulmonary lesions. Conclusion: Further increases of FDG uptake on delayed PET images occur not only in malignant lesions but also in benign lesions, such as granulomatous inflammation. Therefore, delayed FDG PET is not useful for differentiating benign and malignant pulmonary nodules with initial SUV less than 2.5, especially in the epidemic area of granulomatous diseases.

IRMET SpA, Torino, ITALY, 2 Università di Torino, dipartimento di Scienze Cliniche e Biologiche, ASO S. Luigi, Orbassano, Torino, ITALY.

Introduction. The role of FDG PET/CT in the management of patients with non small cell lung cancer has been widely investigated in the recent years and its usefulness has been proved in the initial diagnosis, staging, restaging in case of suspected recurrence and radiotherapy planning. Our aim was to evaluate the accuracy of PET/CT with FDG in the preoperative mediastinal nodal staging of NSCLC with histological results as gold standard. Materials and Methods. 60 patients (37 men, 23 women, mean age 65) with early clinical stage NSCLC were included. All of them were preoperatively studied with clinical evaluation, whole body c.e. CT, whole body FDG-PET/CT, fibrobronchoscopy. All patients underwent surgery. PET mediastinal nodal findings were compared with histo-pathological ones; these latter were used as the reference standard. Statistical evaluation was performed on per-nodal-station. Sensitivity, specificity, positive and negative predictive value and accuracy of PET were calculated. Results. PET correctly classified 314 out of the 339 lymph nodes histologically evaluated, with an accuracy of 92.6%. In particular, PET correctly evidenced 11 malignant nodes out of 31, and 303 non malignant nodes out of 308. So, sensitivity and specificity resulted 35.5% and 98.4%, respectively. In the remaining 25 nodes, we had 5 false positive (all reactive hyperplasia) and 20 false negative nodes (in all cases, the node diameter was inferior to 18x13mm), with positive and negative predictive value of 68.8% and 93.8%, respectively. Conclusions. Our study, in concordance with the literature data, demonstrate that FDG-PET/CT has high specificity, but low sensitivity in mediastinal nodal staging. 

In patients with non small cell lung cancer (NSCLC), pre-operative assessment with FDG PET/CT provides accurate TNM staging resulting in improved management plans. Assessment of the visceral pleura is important since visceral pleural disease changes tumour staging from T1 to T2, hence from stage IA to IB, which reduces post operative 5 year survival from 80 to 60%. Although orthogonal planes are available, attention is often focused on the axial and coronal planes when PET/CT data is analysed. The aim of the study was to assess the impact of additionally reviewing images in the sagittal plane to assess visceral pleural involvement. Method 59 consecutive patients who had PET/CT for NSCLC staging were reviewed. We assessed the effect of analysis of the sagittal plane in determining extension of the tumour onto interlobar fissures, and so by implication involvement of visceral pleura. Results PET/CT identified 13 patients with T2 disease. In 6, T2 disease was diagnosed by size criteria, or extension onto the fissure on axial PET /CT. 7/59 patients (11.9%) were upstaged from T1 to T2 by diagnosis of extension onto the fissure not diagnosed prior to sagittal plane review. In 1 patient multiple lumbar vertebral collapses due to osteoporosis was diagnosed on sagittal plane images. Conclusion Review of the sagittal plane on PET/CT images especially when the primary tumour is in the vicinity of an interlobar fissure can improve accuracy of T staging, and thus provide important prognostic information. Background: Accurate staging of small-cell lung cancer (SCLC) is critical for patient treatment and prognosis. The most common staging system adopted from the Veterans Affairs Research Service Lung Group includes two stages, limited-stage disease is defined as tumor confined to one hemithorax and the regional lymph nodes, whereas extensive-stage disease is defined as disease beyond these bounds. Patients with limited-stage disease are offered combination chemotherapy and concurrent thoracic radiation therapy. Patients with extensive-stage disease are offered combination chemotherapy without thoracic irradiation.

[18F]Fluoro-2-deoxy-D-glucose (FDG) positron emission tomography (PET) scan is widely used for the staging evaluation of non small cell lung cancer, however, its use in small cell lung cancer (SCLC) remains investigational. The aim of this study was to evaluate FDG PET for SCLC staging and to determine the impact of PET on treatment planning. Patients and Methods: From February 2005 to March 2007, we prospectively performed pretreatment FDG-PET on 29 patients, with SCLC who also underwent a conventional staging. Tumor-nodemetastasis system staging was assigned for each patient, with and without PET information and modification of treatment planning was assessed. Results: FDG-PET demonstrated findings consistent with extensive-stage SCLC in fifteen of 29 patients. FDG-PET correctly upstaged nine (31%) of 29 patients to extensive-stage disease. PET correctly identified tumor in each SCLC mass (primary or nodal) that was suspected on computed tomography (CT) imaging, thus giving a lesion-based sensitivity relative to CT of 100%. PET identified unsuspected bone metastasis for eleven patients, hepatic lesions for 7 patients and 5 in others sites. FDG-PET correctly downstaged one (3%) of 29 patients to limited-stage disease who had a adrenal mass in CT and negative in PET confirmed by histology. Treatment was modified for ten patients (34 %), 9 patients underwent only chemotherapy and one had both chemo and radiotherapy.Conclusion: FDG-PET has high sensitivity for SCLC and appears to be of value for initial staging and treatment planning. Aim: Non small cell lung cancer (NSCLC) is the leading cause of cancer mortality in both females and males. Some studies have linked tumor glucose metabolism as evidenced by F-18 FDG PET to survival but these study populations were heterogeneous. We aimed to assess whether tumor glucose metabolism is related to tumor size, disease stage and tumor histology in patients treated with radiation therapy and curative intent. Material and Methods: 87 patients (71 males and 16 females, mean age: 67 years) underwent 3D conformal radiation therapy. All patients underwent pre-treatment staging with F-18 FDG PET (PET-CT) and were evaluated by the assessment of tumor size in two dimensions, maximum SUV (SUVmax), and tumor histology. Eighty-one patients were clinically staged by TNM (T1 n = 19, T2 n = 37, T3 n = 20 and T4 n = 5). In 77 out of 87 patients the tumor was histologically analysed (squamous cell carcinomas = 48, adenocarcinomas = 18, large cell carcinomas = 4, non-small-cell-lung-cancer = 7). Results: In non-parametric analysis tumor metabolism as measured by SUVmax was associated with tumor stage( r = 0.507, p < 0.01). SUVmax was related to 2-D tumor size in patients with NSCLC (r = 0.440, p < 0.05). This relation was stronger in patients with adenocarcinoma (r = 0.603, p < 0.05) than in patients with squamous cell cancer (r = 0.403, p < 0.05). Multivariate analysis indicated that up to 20 % of SUV variability could be explained by tumor size. Conclusion: In NSCLC some relation exists between disease stage, primary tumor size and SUVmax as an indicator of glucose metabolism. However, it is notable that tumor histology has substantial impact on these relations.

Correlation between Staging 18FDG-PET, some Cell Cycle Markers and Survival in Lung Cancer.

A. Sanchez-Salmon 1 , I. Aim: A great part of the patients with lung cancer have spread disease at the diagnosis. 18FDG Positron Emission Tomography (18FDG-PET) is recommended for staging these patients in order to avoid unnecessary surgery in advanced disease. We report the evaluation of the relation between the SUVmax (" standardized uptake value ") of the PET, cell cycle markers and the patients' survival in lung cancer patients. Material and Methods: there were 85 patients (76 men and 9 women) studied, with an average of 65 years old and a range of 39-87 years old. In the histological evaluation 41 cases were squamous, 26 adenocarcinoma (including 7 bronquioloalveolar), 10 undifferentiated, 5 oat cell, and 3 neuroendocrine tumours. Five patients were in stage IA, 15 in IB, 1 in IIA, 10 in IIB, 13 in IIA, 20 in IIIB and 21 in IV. The follow-up ranged between 1 and 92 months. The inmunohistochemical study was realized by 2 blocks of tissue microarrays using the EnVision (DAKO) system. Results: An association between the SUV and the negativity for the D3 cyclin (p=0.022 and p16 (p=0.035) was found. There is also a positive correlation between the SUV and the index of proliferation (MIB-1) as well as between the SUV and the 1a inducible factor inducible by hypoxia (HIF-1a) expression but both of them did not reach significance. The of the SUV maximum values associated with the age and with the squamous histology. There was found no correlation of the SUV neither with the TNM nor with the survival. Conclusions: 1. 18FDG-PET is very useful method for staging lung cancer. 2. 18FDG-PET is associated with different biological characteristics of the tumours 3. In our experience, it does not seem to be a good survival marker . Background: The diagnostic and therapeutic management of different lung nodules in a single patient is challenging. The nature can be benign, as hamartoma, or malignant, as primary cancer or metastases. Despite a high number of researchers and proposal for diagnostic work-up have been published accurate differentiation of benign from malignant lesions remains unsolved. Aim of our study is to assess whatever integration of morphologic and metabolic imaging can help in the differential diagnosis between malignant and benign lung nodules in patients bearing multiple lung nodules. Aim: 18F-FDG PET is widely accepted for evaluating patients with lymphoma; the role of PET in paediatric patients is still debated. Aim of our study was to assess the usefulness of 18F-FDG PET imaging in paediatric Hodgkin (HD) and Non-Hodgkin (NHL) lymphoma. Materials and methods: 19 paediatric subjects (11males, 8 females; mean age 12years, range 5-12 years) with malignant lymphoma (9HD, 10NHL) were enrolled in the study. 18F-FDG PET was performed following standard procedures (5,3MBq/kg of FDG were injected iv in the 6hours fastened patient, image acquisition was performed after one hour uptake). Overall 45 PET scans were carried out, 7 at lymphoma presentation and 38 during follow-up. PET results were compared with conventional imaging (CI) information (MR and/or CT) and with clinical followup; in all cases at least one contemporary imaging method was available, as well as 10 months follow-up. Results: Out of 45 scans, PET findings were consistent with clinical follow-up and other CI data in 43 cases (15 true positive, 28 true negative results) with an overall sensibility and sensitivity of 100% and 93% respectively. The remaining two cases resulted falsely positive, and in one subject this was due to prominent thymic uptake. Considering all scans, PET was more accurate then conventional imaging in the assessment of children with lymphoma, identifying active disease in 2 CI negative scans and in 4 CI inconclusive cases and excluding the presence of lymphoma in 3 CI inconclusive and 1 CI positive scans. Conclusions: our data show the usefulness of 18F-FDG PET to accurately evaluate children with lymphoma. The presence of hyperplastic thymus in one case may have accounted for inaccurate PET reading, although in other 6 cases prominent thymic uptake did not affect PET reporting. A recent report has emphasized the number of false positive PET findings in children: our data do not support this observation. Nonetheless particular care has to be paid when reporting PET scans carried out in paediatric patients.

Purpose: In this retrospective study we aimed to assess the clinical impact of PET/CT imaging on staging and management of both Hodgkin disease (HD) and nonHodgkin lymphoma (NHL). The results are also compared with the CT imaging findings. Materials and Methods: A total of 30 patients with newly diagnosed lymphoma were included in the study. There were 20 HDs and 10 NHLs. The age range was 16-78 with a mean age 38.4 years. Each patient was undergone whole body PET/CT examination with low dose CT acquisition by administrating only oral contrast in addition to establish full diagnostic CT examinations of cervical, chest and abdominopelvic regions. PET/CT scanning from the skull base to the upper thigh was performed using a dedicated PET/CT scanner (Siemens Biograph 6 HI-REZ LSO), only when the patient's blood glucose level did not exceed 150 mg/dl. The interval of PET/CT and CT was 3 weeks at maximum. The findings suggesting for disease involvement obtained from the both modalities were recorded on a data sheet according to their topographic localization. The diagnostic certainty of two modalities was made according to clinician's final decision mainly based on clinical follow-up status of the patients. Results: A total of 113 disease sites in 30 patients were recorded according to final clinical decision. Of these, 107 sites were revealed by PET/CT, but only 80 were shown by CT. Two modalities were agreed in 74 sites. Thirtythree sites were demonstrated only by PET/CT, which caused upstaging in 8 (27%) patients. Whereas CT found 6 sites despite of negative PET/CT, which did not caused upstaging of the disease in any patient. In 6 of the 8 patients in whom PET/CT upstaged disease, treatment strategy was changed to the more aggressive protocols. Conclusion: FDG PET/CT has a very important contribution in the initial staging of lymphomas, by changing the treatment strategy in a considerable percentage of the patients. According to our opinion CT appears to have a minimal role in initial staging beyond of PET/CT scanning and can be omitted in routine clinical settings.

High negative predictive value of midtreatment FDG-PET/CT in response assessment of malignant lymphoma. Aim 18F-FDG-Positron Emission Tomography/Computed Tomography (PET/CT) is currently used in staging/restaging and in the definitive evaluation of response to therapy of Hodgkin Disease (HD) and aggressive non-Hodgkin lymphoma (NHL). In fact, this functional imaging modality allows an accurate evaluation of disease extension as well as a metabolic characterisation of residual masses after chemo and/or radiotherapy. The use of 18F-FDG PET/CT for response assessment during treatment is still under debate: midtreatment scan seems to be predictive of final response to therapy, however its role and prognostic value remains to be proved. In our study we evaluated the predictive value of interim PET/CT scan in patients with HD and aggressive NHL, compared to the final therapy response. Materials and methods 87 consecutive patients (43 male, 44 female; mean age±SD: 44±13 ys) were staged by 18F-FDG-PET/CT (PET-1), whole body CT and bone marrow biopsy for HD (n=53) and aggressive NHL (n=34). All of them underwent interim PET/CT (PET-2) after 2-4 cycles of chemotherapy, and final restaging with whole body CT and PET scan (PET-3) at the end of the treatment. Results HD: 40 out of 53 patients had a negative PET-2 scan. At the end of the treatment, 38 of them (95%) presented complete response, while 2, partial response. The remaining 13 patients were positive at PET-2. At the end of the treatment, 6 (46%) of them were in complete response, while 7 (54%) had partial response. NHL: 23 out of 34 patients had a negative PET-2 scan. At the end of the treatment, all of them had complete response. The remaining 11 patients presented a positive PET-2 scan. At the end of the treatment, 4 (36%) of them were in complete response, while 7 (64%) had partial response. Conclusions Our data confirm that interim PET/CT scan has a very high negative predictive value, both in HD and aggressive NHL (95% and 100%, respectively). Further studies are needed to demonstrate how this information can affect patient management and patient outcome. Aim We performed a systematic review of the literature to analyze positron emission tomography with 18F-fluorodeoxiglucose (FDG-PET) as a diagnostic tool in the evaluation of lymphomas response to chemotherapy or immunotherapy in terms of diagnostic accuracy and clinical usefulness. Methods and material Bibliographic search was performed between July-August 2006, with a date limit consensus established in 1999. We used MEDLINE, EMBASE and CancerGov, as bibliographic primary fonts adopting in each case the most convenient searching strategy, adopting free vocabulary to specific thesaurus. Cochrane library and other health technology agencies data bases were also reviewed. The methodology quality assessment of every article was determined by the QUADAS questionnaire. The software tools use to manage all extracted data were Reference Manager 10.0, SPSS 13.0 and Epidat 3.1. Results The number of primary article localized was 407. Two independent reviewers performed screening of all references, and the final number of articles selected to be analyzed was 10. Despite of the differences among equipment, no difference in patient's preparation and studies acquisition were found. All studies consider visual qualitative analysis as part of the evaluation, and only four did semiquantitative analysis using standard uptake value (SUV). Six of ten studies performed FDG-PET scans in Hodgkin lymphoma at the end of the treatment. Global results of sensitivity, specificity, positive predictive value, negative predictive value and accuracy correspond 90.0% [95%CI, , 73.1-74.1] . Work in progress to evaluate the possibility of develops meta-analyses of diagnostic test. Conclusion Despite of the small number of studies and the heterogeneity of the different population, it is important to emphasized the global results of negative predictive value of the FDG-PET in both Hodgkin and non-Hodgkin lymphomas and also at the different early and late response evaluation. Study supported by the quality plan of the Spanish National Health Service. 28 months after FDG-PET) despite of additional therapy. Two patients were noted as false-positive. In four patients only slightly increased FDG uptake was observed (equivocal findings). Conclusions: FDG PET enables reliable prognosis in short and long-term follow-up of patients with HD and NHL , especially in patients without pathological uptake of FDG. False positive FDG uptake seems to be a problem. No one of our 15 FDG negative patients relapsed. Our results show that FDG negative patients usually have good prognosis and stay in complete remission for a long time. Therefore, results of PET are predictive of immediate success of therapy as well as of disease-free survival. Negative PET scan is an important contribution in the management of these patients due to its prognostic value and may reassure patients and their doctors that disease is not active.

The bone lesions (BL) in Hodgkin's disease (HD) are rare (1 to 4%) in the initial staging but have to be detected for a more aggressive treatment. BL are explored mainly by the invasive unilateral bone marrow biopsy (BMB), insufficient compared with the bilateral one. The aim of this study is to evaluate the agreement between bone positive FDG-PET, bone CT and MRI for rachis BL detection in HD, before and during chemotherapy. Material and Methods: 4 patients (mean age 28 ± 6 years, 2 men) with HD histologically proven and with FDG-avid lesions in the bone were analysed. Only one suffered from lumbar pain. All underwent unilateral BMB, bone CT, and then MRI of axial skeleton at the time of first staging. All those imaging exams were repeated for early interim evaluation (after 4 cycles of chemotherapy) and 1 month after the end of treatment (after 8 cycles). Each lesion was defined by its localization, the intensity of its signal: T1, T2 on MRI, bone destruction with CT by a neuroradiologist, FDG uptake with maximum standardized uptake value by a nuclear physician. Results: The BMB was positive only in 2 cases. A total of 37 lesions were visualized on initial staging FDG-PET (average SUVmax 3,1±1,7) and 32 on MRI. On bone CT, only 4 of 32 lesions were detected. For 6 of 37 lesions, FDG-PET presented a vertebra hypofixation corresponding to a massive infiltration on MRI. The localization of BL on FDG-PET and MRI was well correlated except for patient4 (kappa=0,89 ; 0,58 ; 0,70 ; 0,21 respectively for patients 1 to 4). Indeed for this patient, a mismatch was noted between a homogeneous intense uptake of the thoracic rachis without pathological signal on MRI at the same level. We concluded to a falsepositive FDG-PET by bone marrow hyperplasia. At mid and end of treatment, the FDG-PET became relatively normal whereas MRI showed healing pattern on several vertebrae. On the follow-up, one patient recurred on mediastinal lymph node without BL. Conclusion: FDG-PET and MRI were the most accurate imaging modalities for BL in this context, complementary, especially in the whole spine assessment. FDG-PET allowed a better wholebody analysis and was enough sensitive to detect BL, including vertebra hypofixation. During treatment, bone FDG-PET became negative earlier than MRI. The MRI remained more precise for the small BL individualization. Objective: Because of anatomic changes after operation, detecting recurrent tumor is difficult in post-operative stomach cancer patients, especially in patients with paucity of intra-abdominal fat tissues. This study aimed to compare FDG PET/CT and enhanced CT in the detection of recurrent tumor according to body mass index (BMI) and anatomic regions. Materials and Methods: Total of 77 patients who had PET/CT and enhanced CT within 1 month of each other, and diagnosed with recurrence were included. 17 cases were pathologically confirmed and 60 diagnosed clinically. We classified the patients into 4 groups according to the BMI (kg/m2): group I <18.5; group II 18.5 ~ 22.9; group III 23.0 ~ 24.9; and group IV >25.0. We compared PET/CT and enhanced CT findings by the anatomical sites: anastomosis site or stump; lymph node (LN); seeding nodules; bowel wall; and solid organ. Result: Five patients had only extraperitoneal lesions, and one had diffuse ascites without a focal lesion. 3 cases were false negative in both PET/CT and enhanced CT. Excluding these 9 cases, we compared the findings of PET/CT and enhanced CT. In group I (n=23), PET/CT found 25 LN lesions, 21 seeding nodules and 2 foci of bowel wall thickening, while CT found 20 LN lesions, 17 seeding nodules, 11 foci of bowel wall thickening. In group II (n=34), 54 LN lesions, and 23 seeding nodules were discovered on PET/CT. And 40 LN lesions, 11 seeding nodules, and 7 foci of bowel wall thickening were detected. Conclusions: FDG PET/CT may be more useful than enhanced CT in detection of metastatic lymph nodes and seeding nodules in patients with low BMI (groups I and II). However in cases with seeding metastasis presenting as bowel wall thickening, enhanced CT could be more useful. Aim: Gastrointestinal tumors can be detected incidentally by FDG-PET. Even though measurement of standard uptake value (SUV) has been proposed to determine the nature of these tumors, the method has been criticized. Because dual-time point FDG imaging was reported to increase accuracy of FDG PET, we conducted this study to analyze the use of SUV and delayed FDG imaging in the evaluation of gastrointestinal tumors. Material and Methods: Gastrointestinal tumors with dual-time point FDG imaging were collected. Images were acquired at 1 hr and 2 hr post-injection. Those with final pathological results were enrolled. We recorded the 1 hr and 2 hr SUV of the lesions for further analysis. Results: There were ten benign and fourteen malignant gastrointestinal lesions enrolled in this study. Average 1 hr and 2 hr SUV of the benign lesions were 3.72 (SD: 1.11) and 4.18 (SD: 1.52), respectively. Average 1 hr and 2 hr SUV of the malignant lesions were 6.19 (SD: 1.95) and 7.62 (SD: 2.35), respectively. For differentiation of benign and malignant lesions, best accuracy (accuracy: 0.71, sensitivity: 0.71, specificity: 0.70) could be obtained by using criteria of initial SUV higher than 4 and further increase of delayed SUV higher than 10%. Conclusion: Delayed imaging can improve the accuracy of FDG-PET in differentiating benign and malignant gastrointestinal lesions. However, the accuracy is not high.

Evaluation of liver metastases from colo-rectal cancer after chemotherapy: FDG PET seems not to improve CT sensitivity M. Rodari, C. Carnaghi, C. Tronconi, L. Rimassa, F. R. Lutman, G. Ciocia, A. Chiti; Istituto Clinico Humanitas, Rozzano -Milano, ITALY.

Aim: Neoadjuvant chemotherapy has been successfully used to treat patients with colorectal liver metastases. Selection of those patients who can benefit from surgical resection after chemotherapy still poses a significant clinical problem. FDG PET is a useful tool in the assessment of liver metastases from colo-rectal cancer, but few data are available on its sensitivity after chemotherapy. We aimed to assess FDG PET and CT in the pre surgical evaluation of patients bearing liver metastases. Materials and Methods: Data from patients with liver metastases from colo-rectal cancer treated with chemotherapy, evaluated with FDG PET and contrast enhanced CT scan at the end of treatment were retrospectively reviewed. Nineteen patients (12 males, 7 females; median age 61 years; range 41-79) were evaluated. Chemotherapy regimens were: FOLFOX (14 patients), FOLFIRI (3 patients), other (2 patients). Median time between end of chemotherapy and CT was 3.4 weeks, between end of chemotherapy and PET 5.9 weeks and between end of chemotherapy and surgery 9.9 weeks. All patients underwent surgery and had pathological confirmation of liver lesions. Nine patients underwent segmentectomy, 2 wedge resection, 5 right hepatectomy and 3 explorative laparotomy with liver biopsies. Results: Data from 19 patients were evaluated and 65 liver lesions were confirmed by pathology. Results on a perlesion basis shown a sensitivity of 62% for PET and 70% for CT. A complete agreement between PET or CT and histology was documented in 5 and 3 patients, respectively. PET sensitivity increases for lesions larger than 1 cm (74% vs 18%). Conclusions: Our results suggest that PET and CT scan have sub-optimal sensitivity in the evaluation of colo-rectal liver lesions after neo-adjuvant chemotherapy, particularly for lesions <1 cm. The combined use of the two imaging techniques seems not to significantly increase the sensitivity of CT alone. Introduction: The basic of PET/CT by use of 18F-fluorodeoxyglucose (FDG) is significantly increased glucose metabolism in the malignant neoplasm cells. The FDG metabolism depends on many factors such as: histopathology and presence of other factors which increase FDG metabolism. Knowledge about the FDG metabolism in the stomach cancer cells' is not clear and some types of cancer are not avid in this type of diagnostics. Aim: The evaluation of the FDG metabolism of pathological lesions in gastric cancer patients according to its histopatological type. Material & Methods: Retrospective analysis of the PET/CT results of 55 patients (16 women, 39 men, mean age 58,3) suffered from stomach cancer. The study population consists of 20 patients with the primary stomach cancer and 35 patients with confirmed recurrence. There were 35 tubular adenocarcinoma, 16 mucinous adenocarcinoma and 19 low differentiated stomach cancers. PET/CT studies were performed on the BIOGRAPH LSO 60 min after iv. of 5 mBq/kg FDG. Standard uptake value -SUV was calculated. PET/CT results and mean values of SUV were calculated for the each histopathological type of stomach cancer. Results: Lesions with pathological increase of FDG metabolism were fund in 29 patients (82,8%) with tubular adenocarcinoma, (mean SUV 10,3± 6,1), 4 (25%) patients with mucinous adenocarcinoma (mean SUV 4,1±1,8) and 16 (84,2%) patients with low differenciated stomach cancer (mean SUV 11,2 ± 5,1) False negative results were found in 12 patients with mucionous adenocarcinoma, 5 with tubular adenocarcinoma ( low differenciated -G3) and 4 with low differentiated cancer. Conclusions: 1. Higher differentiated tubular adenocarcinomas and low differentiated stomach cancers are characterized by the highest FDG metabolism. 2. Mucinous adenocarcinomas is characterized by the low level of FDG metabolism. 3. Histopatological type of stomach cancer must be taken into consideration during setting of indication to the PET/CT study.

Polyps: A Feasibility Study P. Mainenti 1 , B. Salvatore 2 , C. Sirignano 1 , T. De Falco 3 , A. Speranza 1 , G. Fiumara 3 , F. Ricci 3 , L. Evangelista 3 , L. Pace 3 , M. Salvatore 3 ; 1 IBB-CNR, Naples, ITALY, 2 AOU "Federico II", Naples, ITALY, 3 Department of Diagnostic Imaging, University "Federico II", Naples, ITALY.

Aim: To evaluate: 1) the feasibility of PET/CT colonography (PET/CTc) in patients with colo-rectal polyps; 2) the impact of metabolic information on CTc findings and the added value of morphologic to functional information in the characterization of focal colorectal uptakes. Materials and methods: Ten patients with colo-rectal polyps underwent PET/CTc previous colo-rectal air insufflation and just after therapeutic conventional colonoscopy (CC). A radiologist and a nuclear medicine physician analysed the PET/CTc images. The grade of overlapping of morphologic and metabolic information in the colon-rectum was evaluated. Sensitivity and specificity for colo-rectal polyps of PET, CT and PET/CT were calculated. Results: 17 polypoid lesions were identified at CC: 6 < 5 mm, 6 between 6 and 9 mm, 5 > 10 mm (4 hyperplastic polyps, 11 tubular adenomas, 1 adenocarcinoma and 1 submucosal lipoma). The overlapping of morphologic and metabolic information was excellent in 17 scans, good in 2 and moderate in 1. PET/CTc showed a sensitivity of 91% for lesions > 6 mm and a specificity of 100%. The metabolic information did not allow to disclose any further polyp missed on CTc. The morphologic information permitted to classify correctly all 8 focal radiotracer uptakes. Conclusions: PET/CTc is a feasible study. Adding a colonographic protocol to PET/CT images seems to allow characterizing correctly all colo-rectal focal radiotracer uptakes. The metabolic information does not seems to increase the accuracy of CTc. Aim. Metastases of colon cancer are often diagnosed in an advanced stage. In patients with this kind of neoplasm, PET with [F-18] fluorodeoxyglucose (FDG) is more sensitive and specific than the CT for detection of metastases. The CEA level is used for monitoring the cancer but without anatomical localization of the lesions. The aim of this study was the retrospective assessment of the value of the PET/CT and CT in the diagnostics of the group of patients with an increased CEA level. Material & Methods In the time between March 2003 and April 2005, 326 studies were made to diagnose colon cancer . We selected 32 patients referred to the PET-CT study with an increased CEA marker level who were being diagnosed for colon cancer with complete information about CT with contrast media. PET studies were made by using the Siemens Biograf LSO scanner according to typical PET protocol. We compared the results of the particular methods of diagnostics, performing patient to patient analysis. Results: In 4 cases (14,1%)PET/CT and CT gave consistent results. There was 3 patients (9,38%)with negative results of PET/CT and CT . There were 5 negative PET/CT results ( 15,63%) and 29 CT negative results(90,63%). In 26 patients PET/CT positive results(81,25%) corresponded with the negative CT results. In 2 patients (6,25%)CT positive results corresponded with the negative PET/CT results. Mean CEA level in this group of patients was 28,84 ng/ml. Conclusion: PET/CT was found to be the more valuable than CT tool for detecting colon cancer metastases in the group of patients with increased level of CEA, additionally giving exact information about their localization. There is a need to conduct a prospective study to assess the value of the PET/CT in the diagnostics of colon cancer in connection with histopathology. Introduction. Although the FDG-PET is indispensable in the follow-up of Colo-Rectal Carcinoma (CRC) when recurrence suspicion exists (elevation of markers and/or findings in structural image), is not defined the role that can suppose its inclusion in the systematic follow-up of these patients. The aim of this work is to analyze the impact that can suppose the incorporation of the FDG-PET in the systematic management of CRC patients without suspicion of tumour recurrence. Population and Methods. From a cohort of 43 patients with CRC, a total of 32 (mean age 66,83 +/-14,2 years; 14 rectum, 9 sigma, 9 colon) were followed-up during two years by simultaneous use of FDG-PET and Structural Image (mainly US and CT) evaluated in blinded conditions. Results. FDG-PET was considered negative in 25/32 patients, without findings in the structural image. In 7/32 (21,8%) cases FDG-PET showed not suspected tumour recurrence, without findings in the structural images in 4 of them (4/7/32; 57%/0,12%). Dissemination of was determined as hepatic metastases (3), pulmonary metastases (2), retroperitoneal lymph node (2) and mesenteric implants (2) . That is, FDG-PET showed unsuspected tumour disease in 21,8% of patients, 57% of them free of significant structural changes. Conclusions. Even though the little number of patients, our series suggests that the inclusion of the FDG-PET in the systematic follow-up of the treated CRC patients can improve their clinical management. Aim. Primary carcinoma of the gallbladder is a rare malignancy which is very difficult to diagnose and characterizes an extremely poor prognosis,. Using FDG PET/CT we can obtain functional and morphological images of the entire body The aim of the study is a retrospective evaluation of PET/CT in patients with gallbladder carcinoma incidentally detected during cholecystectomy. Material and Methods. Between March 2003 and December 2006 PET/CT was performed on 13 patients (10 women, 3 men; age 55,9 yrs ) with gallbladder carcinoma detected incidentally after cholecystectomy. The PET/CT was performed with a Biograph LSO 60 minutes after an intravenous administration of 5 MBq/kg FDG. Results. PET/CT scanning presented lesions of increased FDG metabolisms in 10 patients. In 6 patients liver metastases, 5 hilus of the liver , 3 site of the gallbladder removal, 3 postoperative scar metastases, 3 metastases in lymph nodes of the abdominal cavity, 3 lymph nodes of the retroperitoneal space metastases, 1 omentum metastases were found. All were true positive. There were true negative results in the remaining 3 patients. Conclusions. 1. PET/CT by FDG is a useful method in gallbladder cancer patient diagnostics. 2. PET/CT enables the diagnostics of the residual tumors, recurrence and distant metastases of the gallbladder carcinoma..

Background It is known that F-18 FDG PET has a low sensitivity in the detection of hepatocellular carcinoma (HCC). We prospectively compared C-11 acetate PET results to those of F-18 FDG PET in patients with HCCs. Methods We prospectively analysed four patients (M:F=3:1, Age Range:48-64) with histopathologically or clinically confirmed HCCs underwent C-11 acetate PET and F-18 FDG PET. Whole body C-11 acetate PET was performed 10 min after injection of 555 MBq of C-11 acetate. F-18 FDG PET was done within 2 day before or after C-11 acetate PET. Results A total of 22 HCC lesions were confirmed histopathologically or clinically. F-18 FDG PET detected only 8 lesions of them whereas C-11 acetate PET detected 12 lesions. Two false positive lesions were found on both PETs, respectively. Conclusion Although the number of patients was very small, C-11 acetate PET may be complementary to F-18 FDG PET and useful in imaging of HCC. Further studies including more patients are needed.

Comparison of hepatic FDG uptake between Japanese people with and without metabolic syndrome Objectives: Liver demonstrates heterogeneous FDG uptake pattern and sometimes shows abnormally increased uptake even though there is no malignant tissue. Recently, FDG uptake in liver was correlated with fasting plasma glucose, reported. Over the past 2 decades, there has been a dramatic increase in the number of subjects with the metabolic syndrome in Japan as well as in Western countries. The International Diabetes Federation defines metabolic syndrome as the presence of central obesity plus any two of the following three factors (fasting plasma glucose, lipid deviation and blood pressure). Therefore, we evaluated the significance of hepatic FDG uptake associated with metabolic syndrome and hepatic enzymes.

Methods: Sixty one patients (40 men and 21 women; age range, 28-80 years; mean age, 54.8 years) underwent whole-body FDG-PET imaging for cancer screening. Patients with sever hepatic disease had been excluded. All patients were instructed to fast for at least 5 h before the intravenous injection of FDG. PET image was obtained 1 hour after injection of 3.7MBq/kg of F-18 FDG with PET camera. The FDG uptake in liver was analyzed semiquantitativly using ROI on transaxial image at umbilical level and we compared mean standardized uptake value (SUV) between normal and metabolic syndrome group, based on waist circumference, raised triglyceride level, reduced HDL cholesterol, raised blood pressure, and raised fasting plasma glucose. We also evaluated effects of fasting plasma glucose and hepatic enzymes, i.e., aspirate aminotransferase (AST), alanine aminotransferase (ALT) and -glutamyl trasopeptidase ( -GT) on hepatic FDG uptake. Results: The average of hepatic SUV in abnormal groups of blood glucose level, lipid deviation and blood pressure was significantly higher than that of normal group, respectively (blood glucose level; 2.25±0.22 vs 2.06±0.36 (p<0.05), lipid deviation; 2.21±0.37 vs 2.00±0.29 (p<0.01), and blood pressure; 2.17±0.32 vs 2.00±0.35 (p<0.05). There was much more significantly high hepatic FDG uptake in metabolic syndrome group than normal group (2.30±0.30 vs 1.99±0.33, p<0.0001). On the other, hepatic FDG uptake of abnormal AST, ALT and -GT groups showed no significant difference from normal groups. Conclusions: There was significantly high hepatic FDG uptake in metabolic syndrome group than normal group. This result suggests that we need careful interpretation of the liver in a case of metabolic syndrome. Aim: Contrast materials with high iodine concentration have been found to improve parenchymal enhancement on CT imaging. However, intravenous contrast materials (CM) may cause artifacts on PET/CT when using the CT data for PET attenuation correction. The aim of this retrospective clinical study was to assess the feasibility to use a highly concentrated contrast material (HCCM) containing 400 mg iodine/mL in PET/CT imaging. Intravascular and parenchymal enhancement, potential CT and PET artifacts, and the accuracy of PET tracer quantification were assessed and compared to a lower concentrated CM containing 300 mg iodine/mL (LCCM). Material and Methods: 60 whole-body FDG-PET/CT-scans of oncologic patients were investigated: 30 patients each with hypervascularized and non-hypervascularized tumors underwent FDG-PET/CT with either an application of HCCM or LCCM. CT enhancement (Hounsfield Units) and tracer uptake (maximal standardized uptake value, SUVmax) were measured at 16 defined positions in different vessels and parenchyma. The quality of CT enhancement, the extent of potential CT and PET artifacts as well as the quality of tumor delineation were defined on a 4-point-scale. The influence of PET artifacts on clinical interpretation was defined. Mann-Whitney-Wilcoxon-Test was performed to evaluate statistically significant differences (p<0.05). Results: In patients with hypervascularized tumors, HCCM led to significantly higher CT enhancement in 11/16 positions compared with LCCM. In patients with nonhypervascularized tumors, HCCM provided significantly higher CT enhancement in 6/16 positions. No significant differences using HCCM and LCCM were found both for hypervascularized as for non hypervascularized tumors with regard to the quality of CT artifacts, to the SUVmax, to the quality of PET artifacts, the quality of tumor delineation on CT, and the quality of tumor delineation on PET. No statistically significant difference was detected between HCCM or LCCM concerning the influence of PET artifacts on clinical image interpretation. Conclusion: HCCM leads to a stronger contrast enhancement on CT images than LCCM without causing more artifacts on CT or PET. The application of HCCM is feasible in hybrid PET/CT and should be considered in patients with hypervascularized tumors. Aim: is to determine the clinical utility of 18-FDG PET/CT in follow-up of patients with malignant melanoma. Materials and methods: we studied 68 patients in followup after surgery, having AJCC stage III melanoma and contrast-enhanced computed tomography (CT) total body negative. In all patients a whole body (legs included) PET/CT scan was performed after an intravenous injection of 444-518 MBq of 18F-FDG in normoglucemia conditions. Images were evaluated by 2 nuclear physicians. Results: of the 68 PET/CT scans 24 showed 56 sites of active disease: 26 limph nodes (10 axillary, 2 parasternal, 2 supraclavicular, 6 external iliac, 4 bronchopulmonary, 2 paratracheal), 2 suprarenal gland, 2 bone, 22 subcutaneous and 4 skin. All PET/CT findings were confirmed by histology or clinical evolution; PET/CT caused changes of treatments. Conclusion: in our study PET/CT is superior to CT scan in detecting lymph nodes, skin and subcutaneous metastases. As everybody knows: the early detection of resecable melanoma metastases with early treatment decreases the risk of recurrence and increases survival. Aim. To value PET/CT scanning sensibility and specificity compared with those of standard CT (sCT) in staging lymph nodes, liver, bone and other organs metastases in patients (pts) with malignant melanoma (MM). Patients and Methods. Between September 2006 and March 2007, 17 pts, age 31-62 years, mean 44, were enrolled. All pts were previously submitted to surgery to remove MM, sentinel node and, when indicated, other regional lymph nodes. A sCT scan was already performed in these pts when they came to our Institution for PET/CT scanning. We compared sites and number of sCT-diagnosed relapses with PET/CT results. Results. In 1/17 (6%) pts sCT scanning showed a cerebellar relapse not observed by PET/CT. In 9/17 (53%) pts PET/CT results were comparable to sCT ones; 1 of these pts had a lung relapse, 7 hadn't metastases, 1 had an ovarian mass which was described as an ovarian cyst by sCT, while PET/CT wasn't able to define it as malignant or benignant lesion. 5/17 (29%) pts had negative sCT scanning, while PET/CT revealed bone or lymph nodes metastases; in 1 of these pts there were widespread metastases. Finally in 2/17 (12%) pts PET scans showed high metabolic activity lymph nodes, while in the same pts sCT imaging revealed different sites of relapses, above all liver. Conclusion. PET/CT and sCT seem to have, in staging or restaging of MM, the same sensibility in discovering lung metastases, while PET/CT sensibility is higher than sCT one relative to bone or lymph nodes relapses. PET/CT sensibility appears lower in detecting liver involvement. sCT shows more specificity than PET/CT in describing cerebellar and ovarian lesions. Aim: Ovarian cancer is the leading cause of death as concerns gynecological cancer in the western countries. The difficulty in the detection of recurrence and the bad prognosis of the disease is well known. This study was designed to determine the value of 18 FDG PET/CT compared to MRI and CT, in the evaluation of recurrence disease. Material-Methods: 30 patients went through 18 FDG PET/CT examinations (SIEMENS Biograph LSO) from June 2004 -March 2007. The injected radioactivity dose for all scans was between 340 -410 MBq (9-11 mCi). All of them had ovarian cancer and underwent the PET/CT for restaging. Mean age was 53.6 ±12.2 years. In women with ovarian cancer, 26 were subjected to CT scans (Group A) and 8 to MRI (Group B) for disease reevaluation just before PET/CT evaluation. Results: 20/30 patients had positive PET/CT scan (SUV 4.9 ± 2.3), 13/26 patients had positive CT while 7/8 had positive MRI. Group A: 7/26 patients (26,9%) had match findings in PET/CT and CT scans (6 cases negative results and 1 case positive result) PET/CT scan outbalanced CT in 9/26 patient cases (34.6%) -(mainly in extra pelvic disease). In 7 cases with negative CT, PET/CT was positive (26.9%). In 1/3 patients with negative PET/CT, CT was positive and 2 of them had non diagnostic CT. Group B: In 2/8 patients (25%) we had match findings in PET/CT and MRI as well. In 1/8 patients (12.5%) we had MRI (+) and PET/CT (-) while another one had MRI (-) and PET/CT (+). The critical point is that in 4/8 patients with MRI (+) and PET/CT (+), PET/CT outbalanced MRI (mainly in extra pelvic disease).In 8 patients with tumor markers, 6 of them had elevated serum Ca 125 and 2 had normal Ca 125 levels. In 5/6 women with elevated serum Ca 125 PET/CT was observed (+) and in 1/6 PET/CT was (-). In the 2 cases with normal Ca 125 level we found PET/CT (+). Conclusion: According to the results of this study PET/CT scan presents a plain superiority in effectiveness over the CT scan. 18-FDG PET/CT may detect recurrent ovarian cancer more accurate than MRI. Also 18-FDG PET/CT is a very promising technique compared to raising levels of tumor markers. Introduction: Only sporadic data support the use of labelled-choline as oncological probe to monitor the PCa response to treatment in patients. Aim: To evaluate early modifications of 18F-methyl-choline (18F-Ch) uptake in an animal model of prostate cancer (LNCAP xenograft on Balb-C nude mice). Material and methods: Hormonosensitive prostate cancer xenografts were obtained in the back legs of athymic nude mice by subcutaneous injection of 6-10 LNCaP cells suspended in a solution of RPMI 1640 medium and Matrigel®. Animals were kept in appropriate facilities until tumour size reached 0.5-1 ml. Mice were then treated twice a week by intra-peritoneal administration of docetaxel (8mg/Kg). Sequential 18F-Ch animal PET acquisitions (105_to_120 min after ip injection) were performed basically and in the course of treatment of eight mice, to observe tumour metabolic changes after 2-3 cures and 5 cures of docetaxel. Because some animals died after the fifth cure of docetaxel, not enough data were available to perform further statistical analysis. Results: Tumor xenograft volumes continued to rise during the first cures of chemotherapy but tumour growth significantly slowed down afterwards. Before tumour growth stabilization, 18F-Choline PET revealed a decrease in tumour metabolism characterized by a significant fall (P=0.016) of both SUVmean (-43%) and SUVmax (-46%) in comparison with initial values. A transitory stabilization of tracer amount in tumours (%ID/ml) was also noted. Nevertheless, this observation was restricted to the induction phase, while later PET studies (after 5 or more cures) demonstrated a slight increase of semi-quantitative parameters in parallel to a tumor size regrowth, suggesting a docetaxel failure in the tumour proliferation control. Conclusion: These preliminary data show that docetaxel treatment inducted a rapid decrease of semiquantitative index of 18F-Choline uptake in LNCap xenograft tumours. Nevertheless, these observations are limited in time due to the suboptimal control of tumour growth by chemotherapy in these small animal series. Purpose: We studied dynamic pelvic imaging followed by whole body 18Ffluorocholine PET/CT imaging for the assessment of salvage radiotherapy in prostate cancer patients presenting either biochemical recurrence or suspicion of residual disease. Methods: We evaluated 40 patients with a persistent >0,1ng/ml or elevating PSA (median 3.41; range 0.23-37.7), 20 after radical prostatectomy combined or not with radiotherapy and 20 after radiotherapy commonly with additional hormonotherapy. Systematically all patients underwent early dynamic pelvic imaging within the first 10 minutes after intravenous injection of 300MBq 18F-fluorocholine, followed by total body PET/CT scan (Siemens Sensation 16 or 64). Late pelvic imaging after 40 minutes was performed in 23 patients. Fused PET/CT images were interpreted visually by 2 observers. Correlation was made with other imaging modalities including endorectal MRI (19 patients) and bone scintigraphy (18 patients). First results: Overall, 30 of the 40 patients showed positive PET/CT for local or distant recurrence, 2 were equivocal and 8 negative. When classified according to site, 22 were positive for local recurrence, 6 equivocal and 12 negative. Loco-regional lymph nodes were positive or equivocal in 5 patients. Of the 9 patients with positive PET/CT findings for distant sites, 3 were positive for lymph node, 5 for bone and 2 for adrenal metastases. When classified according to PSA levels, 3 patients were equivocal and 4 negative in range 1ng/ml, 2 positive and 4 negatives in range >1 to 2ng/ml, and 25 positive and 2 ambiguous in range >2ng/ml. Subsequently 16 patients underwent salvage radiotherapy with the radiation field centred according to PET/CT findings as well as other imaging modalities. Conclusion: Dynamic and late 18Ffluorocholine PET/CT imaging was advantageous in assessing loco-regional recurrence of prostate cancer. 25/27 patients with PSA >2ng/ml had positive PET/CT findings. Consequently, salvage radiotherapy field could be better defined. Further evaluation of the accuracy of this technique in the detection of recurrence using quantitative criteria as well as long term follow-up is underway. Aim: PET/CT using 18F-Choline (FCH) was found to be valuable in the detection of prostate cancer recurrence even at lower PSA levels. We evaluated the possible use of FCH PET/CT in early re-staging of prostate cancer relapse with regard to the degree of glandular differentiation of the primary prostate tumor [Gleason score(GS)]. Methods: 147 patients who had well/moderately differentiated primary prostate tumors (GS </=7) and were at low-risk for recurrence, and 92 more patients who had poorly differentiated primary prostate cancer (GS>7) and were at high-risk for recurrence underwent a whole body PET/CT scan at > 60 min after injection of 4.0 MBq/kg of FCH (IASON Labormedizin GesmbH & Co. KG Graz-Seisberg, Austria) because of rising PSA (> 0.1 ng/ml) after initial therapy (prostatectomy n= 145, radiotherapy n= 45, hormone therapy alone n= 49). 44(48%) patients with GS>7 and 33(20%) patients with GS </=7 were under adjuvant hormonal therapy at the time of examination. Focal high uptake of FCH was rated (visual interpretation) as probable recurrent disease. Corresponding images of CT from PET/CT (Discovery LS PET/CT scanner, GE Healthcare, Milwaukee, WI, USA) were also used to achieve the diagnosis. Results: prostate cancer recurrence was confirmed in all but one FCH positive case in the clinical course. No FCH negative patient had prostate cancer relapse from the clinically available data during a 6 month follow-up . FCH PET/CT detected recurrent disease in 69/92(75%) high-risk patients (local recurrences n=17, distant recurrences n=52) and in 72/147(49%) low-risk patients (local recurrences n=24, distant recurrences n=48). Among them, 37 high-risk patients and 17 low-risk patients were under hormonal therapy. Median PSA in FCH positive cases was 7.35 and 8.77 ng/ml for high-risk and low-risk patients respectively; median PSA in FCH negative cases was 0.74 and 0.76 ng/ml for high-risk and low-risk, respectively. FCH PET/CT obtained true positive findings even at lower PSA levels (< 4.01 ng/ml) in many (24/47) cases with GS>7 (median PSA 0.9 ng/ml, range 0.11-3.49) but in only few (14/82) cases with GS</=7 (median PSA 2.5 ng/ml, range 0.3-4.0). 15(35%) high-risk patients as well as 15(26%) low-risk patients developed recurrence in the first years after therapy. All recurrences (local n=7, distant n=23) were identified by FCH PET/CT, and for 21 patients PET/CT was the only test showing recurrent disease. Conclusion: FCH PET/CT is proven as feasible in early detection of prostate cancer relapse, especially in those with poorly differentiated primary prostate cancer. Introduction: Retroperitoneal (RP) lymph nodes represent the regional lymphatic drainage in germinative testicular tumors. These lymph nodes often remain enlarged even following chemotherapy (CHT), while the histopathological findings in resected lymph nodes consist of fibrotic tissue (48%), teratoma (37%), or other viable tumor cells (15%). Aim: Evaluation of the benefit of 18F-FDG PET in prediction of the viability of the RP masses via comparison of PET positive or PET negative findings in patients following curative CHT plus RP residue resection. Patients and Methods: From September 2003 through June 2006 (33 months) a total of 501 PET scans were performed in 482 patients with germinative testicular tumors. The presented study group includes 18 patients after CHT, in which the RP masses were resected within an average of 90 days following the PET scan. The patient age ranged from 18 to 39 years (average 27.6 years, median 26.8). The tumors included 3 seminomas and 15 non-seminomas. Results: The PET scan results subdivided the RP masses into PET positive (n = 5, activity of the lesion higher than the referential activity of the liver), and PET negative (n = 13). In the PET positive subgroup the resection confirmed persisting tumor tissue in 3 cases, while false PET positive results were recorded in 2 patients with inflammatory changes within fibrosis (in both seminoma and nonseminoma). Fibrotic changes were correctly detected via PET in 2 patients with seminomas. The negative PET scans in 11 patients with non-seminoma proved problematic due to eventual histopathological findings of teratocarcinoma micrometastases (1x), mature teratoma (4x) as well as fibrotic changes (6x). Conclusion: In case of seminomas the fibrotic residual masses were detected correctly. We have recorded false PET positivity due to inflammatory changes in fibrotic tissue in various histological tumor types. Our data suggest limited capability of PET to differentiate residual fibrotic masses from mature teratoma in case of nonseminomas (both findings can appear as PET negative). Support: IGA MZCR Grant NR 8342-3/2005. Aim: The incidence of testicular cancer has increased three-fold over the last decades, with the highest incidence being in European countries. A relatively new method 18FDG PET/CT, might be useful to overcome the diagnostic problems in re-staging testicular carcinoma. This study was designed to determine the value of 18FDG PET/CT compared to MRI and CT, in the evaluation of recurrence disease and postchemotherapy residual mass in testicular carcinoma. Material -Methods: We examined 39 patients who underwent whole-body PET/CT (SIEMENS Biograph LSO) scans with 2-deoxy -2-[F8F]fluoro-D-glucose (FDG). The injected radioactivity dose for all scans was between 340-410 MBq (9-11mCi). All of the patients had history of testicular carcinoma and underwent the PET/CT for re-staging. Mean age 29,5 ± 6,8 years. In men with testicular carcinoma, 37 were subjected to CT scans (Group A) and 10 to MRI (Group B) for disease reevaluation just before PET/CT reevaluation. Results: 16/39 patients had positive PET/CT scan (SUV 7,6 ± 7,4), 24/37 patients had positive CT while 6/10 had positive MRI. Group A: 13/37 patients (35,1%) had match findings in PET/CT and CT scans (11 cases negative results and 2 cases positive results). In 12 cases with positive CT, PET was negative (32,4%) while in 2 cases with negative CT, PET was positive (5,4%). In 10/37 patients we had mismatch findings between PET/CT and CT (in 6 patients, PET/CT scan outbalanced CT, while in 4 cases we had the opposite result). Group B: In 3/10 patients (30%) match findings observed between MRI and PET/CT scan (2 cases negative results and 1 case positive result). 3/10 patients (30%) had MRI (+) and PET/CT (-) while 2/10 patients (20%) had MRI (-) and PET/CT (+). In 2/10 patients (20%) with MRI (+) and PET/CT (+), PET/CT outbalanced MRI. In 21 men with tumor markers, 10 of them had elevated blood levels. 6/10 patients with abnormal tumor markers had positive

PET/CT scan, while 4/10 patients had negative PET/CT (all cases with elevated AFP levels). On the other hand in 11 patients with normal tumor markers 9 of them had negative PET/CT and 2 positive PET/CT scan. Conclusion: These preliminary results demonstrate that 18FDG PET/CT was superior to conventional techniques in restaging patients with testicular carcinoma. 18FDG PET/CT was a sensitive and reliable modality for detection of residual viable tumor in these patients. Aim: Primary extragonadal germ cell tumors (ExGCTs) account for nearly 5% of all GCTs and are characterized by a poor prognosis. Radical post-chemotherapy surgery of residual masses represents the standard of care. In case of residual viable tumor or teratoma, complete resection may be curative. However, when only necrosis is found, patients will be exposed to surgery-related morbidity and mortality without any survival benefit. No reliable factors predictive of the presence of viable tumor or teratoma in residual masses are available yet. FDG-PET has been successfully used for staging primary gonadal GCT, but its role in the management of residual masses form GCTs has not yet defined. We aimed to assess FDG-PET as a tool to detect residual tumor after chemotherapy. Materials and Methods: We evaluated 6 consecutive patients with ExGCTs (mean age 39 years, range 29-62), who underwent residual surgery following standard platinum and etoposide based chemotherapy. Four patients had primary mediastinal location, 2 peritoneal. Four patients had a non seminomatous tumor, 2 had seminoma. Three patients were metastatic at the time of first diagnosis. Four out of 6 patients were classified as poor prognosis (PP) according to the IGCCCG. The 2 patients with good prognosis (GP) had 3 cycles of chemotherapy, the others had 4 cycles.. All patients had FDG-PET, following standard procedures, at the end of chemotherapy and before undergoing residual surgery. FDG-PET results were compared with pathological findings. Results: After chemo the four PP patients were classified as in Partial Response, the 2 GP as Complete Response. The mean tumor shrinkage on CT was 54%. A correlation between FDG-PET and pathological finding was found in all cases: two patients with positive PET had viable tumor in postsurgical specimen, while 4 patients with negative PET had necrosis or fibrosis. Conclusion: Following chemotherapy for ExGCTs, complete surgery of residual masses remains the recommended standard of care since it may be curative in an approximately half of patients with residual viable tumor or teratoma. Among other clinical factors a positive FDG-PET might help to identify patients at higher risk for residual disease. In these patients, complete surgery may be suggested even in centimetric residual disease. FDG-PET may also help to address surgery to active lesions in patients with thoracic and abdominal disease. Introduction and Aim: Multiple myeloma (MM), malignant B cell and plasma cell disorder, involves the skeleton in more than 60% at diagnosis. Conventional and radionuclide methods are routinely used to evaluate these lesions. Recently, FDG PET/CT has been introduced to the field. In this study, our aim was evaluate the accuracy of FDG PET in detecting myeloma lesions and its influence on patient's management comparing with clinical, radiological and bone scintigraphic findings. Materials and methods: 34 pts (10F, 24 M) were evaluated; group I had 26 patients (8F, 18M; aged 32-83 years) with MM, group II had 4 pts (1F, 3M; aged 35-72 years) with solitary plasmocytoma and group III had 4 patients (1F, 3M; aged 37-60 years) with monoclonal gammopathy. Mean follow up period was 18,1±17,6 months. In group I, 2 pts were referred for evaluation of extent of disease before bone marrow transplantation (BMT) and 1 pt referred for assesment of BMT response, 7 pts had pain and referred for assesment of the extent of disease, and other pts with no complaints referred for follow up. In group 2 and 3, PET/CT was performed to evaluate the extention of disease. The results of whole body bone scintigraphy (WBS), radiographs, and MRI or CT imaging modalities as well as the clinical course at the same period were used to compare with FDG PET/CT results. Results: The results are summarized in this table. Conclusion: PET/CT scan is helpful to evaluate MM pts. It appears to be more sensitive than other radiologic and scintigraphic examination for the detection of lytic bone lesions. However, it may not be sufficient for detection and differentiation of small lesions and diffuse marrow involvement. In this study, 2/34 pts had negative PET/CT and positive bone lesions. It was thought that the combination of PET/CT and other radiological and scintigraphical examination might be more succesfull than PET alone. Since PET investigation was performed mostly during active disease evaluation of its impact on survival, response was not avalaible. It is also important to emphasize the disadvantages of PET/CT in myeloma treatment, steroid related hyperglycemia, early vertebrate operations the frequently performed cause false positivity. However, we took precautions to delay imaging untill 3 months following surgery and avoding imaging during glucose intolerance. PET/CT has the applicability to whole body imaging which is hard to apply to MRI and results with better resolution compared to whole body MRI. , lymphoma (n=8),hepatoma(n=5), prostatic carcinoma(n=5), gastric cancer(n=4),esophageal carcinoma(n=3), multiple myeloma (n=3), thyroid cancer (n=2), osteosarcoma (n=2), renal carcinoma (n=1),unknown primary origin (n=2);11 nonmalignant cases ingcluding:osteoporosis(n=7),bone tuberculosis(n=2), inflammation (n=1), hyperparathyroidism (n=1).In 51 of 58 malignant cases 18F-FDG PET/CT showed tracer accumulations corresponding to etiologic diagnosis .The sensitivity of 18F-FDG PET/CT was 51/58(87.9%).The false negative rate of 18F-FDG PET/CT was 7/58(12.1%).In 4 0f 11 nonmalignant cases 18F-FDG PET/CT showed abnormal tracer accumulations . The specificity was 7/11(63.6%).The false positive rate of 18F-FDG PET/CT was 4/11(36.4%). Conclusion: Whole body 18F-FDG PET/CT is a valuable tool in etiologic diagnosis of suspected BD,the diagnostic accuracy could be more improved combinding with CT ,MRI appearance and clinical informations. Aim: The aim of this retrospective study was to evaluate the potential additional diagnostic role of 18F-FDG PET/CT imaging for the detection of unknown primary origing cancer (CUP). Materials and methods: The study population consisted of 61 consecutive patients (37 men, mean age: 61 ± 6.8 years old) with suspected CUP, tumoral markers abnormalities and/or paraneoplasic syndromes. An 18F-FDG PET/CT was performed in all patients population. All acquired images were assesed by a nuclear medicine with experience in PET and PET/CT and a radiologist physician. Results: The initial evaluation of patients showed two differents findings: 1. Patients with macroscopic lesions: presence of masses and lymphoadenophatiesmostly supraclavicular -in 25 patients (41%) and liver and bone metastases in 10 patients (16%). 2. Patients without macroscopic lesions: high serum levels of tumour markers in 16 patients (26%) and paraneoplasic syndromes in 5 cases (8%). PET-CT results were: normal test in 11 patients, non-specific features in 10 patients and hypermetabolic lesions sugestive of malignancy (SUV > 3) in 40 patients. Primary tumor was sugested in 36 patients and re-stage of neoplasm was performed in 83%. PET/CT was abnormal in all patients of the group with macroscopic lesions, except in one case. In the second group, PET/CT was suggested of malignancy in only of 38% of patients. Conclusion: PET/CT identified primary tumour in 68% of patients with suspected CUP, showing a better accuracy than other imaging techniques. In our study the diagnostic accuracy of PET/CT was higher than previously described in literature (24-40%). However, the main limitation of this technique is the low ability to detect metastatic occult primary tumors in patients without macroscopic lesions. Objectives: To provide accurate preoperative localization of parathyroid adenomas (PA) and to facilitate minimally invasive surgical approach to PA, as opposed to open cervicotomy and bilateral neck exploration. Methods: For the same patients SPECT and MRI scans were acquired with fiducial skin markers (FSMs) placed on patient's thorax and neck. SPECT scans were obtained using: (i) 1 mCi of Tc-99m pertechnetate; (ii) 15 min. and (iii) 120 min. after administration of 30 mCi of Tc-99m sestamibi. MRI was acquired with a 3T magnet using T2-weighted spin-echo sequences. A deformable finite element model (FEM) has been implemented for accurate nonrigid registration and fusion of SPECT and MRI images. In this model FSMs are used to sample 3D image deformation between SPECT and MRI. In this method the intermodality displacements of the corresponding FSMs observed in SPECT and MRI are determined, then FEM is used to distribute the FSMs displacements linearly over the entire volume, followed by creation of a warped MR image registered with the SPECT image and by MRI and SPECT volume fusion. A commercial ANSYS FEM software was used for FEM calculations along with our own programs for 3D image warping and fusion. Results: We verified correct anatomical intermodal registration of the fused SPECT/MRI images using organs with known high uptake of radiopharmaceuticals. The target registration error not exceeded 4 mm. Conclusions: Our nonrigid registration and fusion method allowed creation of a detailed anatomic map of the neck and thorax from MRI accurately combined with a functional 3D map from SPECT for improved preoperative localization of the parathyroid adenomas. Aim: We describe our experience with 68Ga-DOTATOC PET imaging in neuroendocrine and neuroectodermal tumours as compared to 111In-Octreotide, 123I-MIBG and cross sectional imaging over a two year period. Material and Method: Thirty-three patients (13F, 20M) with a variety of neuroendocrine and neuroectodermal tumours underwent 68Ga-DOTATOC PET imaging. The mean administered activity was 150MBq. The number of lesions, intensity of uptake and overall quality of the images were compared with 111octreotide or 123MIBG (performed within 3 months in 80% of cases) and radiological investigations such as CT, MRI and angiography (performed within 3 months in 77% of cases). Results: Five patients (15%) had additional lesions on the 68Ga-DOTATOC scan compared with other nuclear medicine imaging. In two of these patients the 68Ga-DOTATOC scan showed the lesions more clearly than the 111In-octreotide scan due to better resolution. In 4/33 (12%) patients, 111In-octreotide or 123I-MIBG demonstrated more lesions than the 68Ga-DOTATOC scan. Of these cases, 3/5 were in patients with benign phaeochromocytomas. In 6/33 (18%) patients all scintigraphic tests were negative when radiological investigations including angiography demonstrated lesions. Conclusion: 68Ga-DOTATOC PET has an emerging role in detecting a wide range of neuroendocrine and neuroectodermal tumours. It shows better resolution and demonstrates extra lesions compared to 111In-octreotide and 123I-MIBG. In has lower sensitivity than 123I-MIBG for benign phaeochromocytoma but higher sensitivity in malignant neuroectodermal tumours. The multi-modality approach remains essential as 18% of these tumours were only detected with anatomical imaging. The increasing use of PET-CT should improve the sensitivity of this technique. Breast cancer is the most frequent tumour in women. It would be very useful to identify patients responders to neo-adjuvant treatment from not responders. Aim: The aim of this study was to systematically review the literature regarding the value of FDG-PET and PET-CT in the assesment of treatement respond after neo-adjuvant theraphy. Materials and Methods: Systematic review of the literature, searching relevant studies in MEDLINE and CANCERLIT. For the selection of the studies we applied inclusion and exclusion criteria that had been previously set. Two independent reviewers assessed the methodological quality of each selected study (Flynn criteria) and the eficacy diagnostic level (Fryback). Most relevant data and statistic results were obtained from each study. Results: 63 studies were found in the primary search. After aplying inclusion and exclusion criteria, four studies were selected. In three of these four studies the metodological quality was modarately low (C group) ; all the studies were in level II of diagnostic eficacy. With a statistical analysis , 0.91 Sensitivity, 0.5 Specificity and 0.85 Accuracy were obtained. Most of the authors agree in the necessity of perform some PET studies during neoadjuvant treatment. Most authors also agree that it would be suitable to use a semicuantitative analysis using "standardized uptake value" (SUV) from assessment the response. The threshold value for differentiation responders and no-responders is different depending on the study. Conclusions: Recent studies suggest that FDG-PET may identify patients responders to neo-adjuvant therapy earlier then other conventional imaging modalities. It is still not clear when to perform PET studies or which is the appropriate threshold value for differentiation responders and not-responders. Finally, further prospective investigations on a larger number of patients need to be performed. Objectives: Paragangliomas are usually slowly growing, somatostatin receptor (SSTR)-expressing, benign tumours of the head and neck region. However, they can also be locally invasive and cause bone destruction and dysfunction of cranial nerves. Up to 10 % of paragangliomas are malignant and may metastasize, leading to distant lesions. Therefore, accurate whole body tumour screening is important. The aim of this study was to assess the accuracy in detection of SSTR-positive lesions derived from paragangliomas by 68Ga-DOTA-Tyr3-Octreotide (DOTA-TOC) PET/CT or 68Ga-DOTA-TOC PET/MRI fusion. Methods/patients: In this study, the clinical value of SSTR imaging with 68Ga-DOTA-TOC PET was assessed in 9 patients (4 male and 5 female, age ranged from 27 to 74). Seven patients underwent whole body imaging with 68Ga-DOTA-TOC PET, and in 2 patients cerebral 68Ga-DOTA-TOC PET imaging was done. Each patient received 150 MBq 68Ga-DOTA-TOC, images were obtained 60-90 minutes post i.v.-injection. Combination of morphologic and functional imaging was done by PET/CT or PET/MRI, providing more accurate information in staging and restaging. The interpretation of CT and PET scans was done independently. Results: Of the 9 investigated patients with paragangliomas 2 patients showed true-negative and 7 true-positive results. All known lesions were also shown by PET. Additionally 3 unknown bone lesions were detected in a patient with metastatic disease. Because of the high SSTR-expression in one patient with local recurrence of invasive paraganglioma, treatment with the SSTR-analog 177Lu-DOTA-TATE was initiated, since no other therapeutic options were available. Over one year six therapeutic cycles with an overall dose of 32,7 GBq were performed, without severe side effects. In the follow up one year after first treatment by 68Ga-DOTA-TOC PET/CT, minor response was observed. Conclusion: 68Ga-DOTA-TOC PET provides accurate information concerning extension and localisation of paraganglioma lesions for initial diagnosis, for selection and for follow up after radionuclide-peptidetherapy. Furthermore, our data indicate that whole body imaging with 68Ga-DOTA-TOC PET might be useful to delineate distant and small metastases of paragangliomas. . Fourteen patients had more than one FDOPA-PET examination (between 2 to 6). Forty examinations were performed without combined CT and 36 (since July 2004) with combined CT. The impact of FDOPA PET was evaluated, on a per-patient basis, thanks to a questionnaire filled in by the referring physician and the pertinence of the induced decisions was assessed thanks to the follow-up data. Results: -Carcinoid tumour of the small bowel: 22 of 23 patients were evaluable. An impact of FDOPA-PET was reported in 11 of them (rate: 50%), corresponding to an adequate decision in all patients (major therapeutic changes in 5 patients, minor therapeutic changes in 4 patients and orientation of biopsies or complementary imaging in 2 patients). Among the 40 examinations performed in these 22 patients, 6 examinations were true-negative (TN), 33 were true-positive (TP) and only one was false-negative (FN) (residual tumour measuring 3 mm, responsible for clinical symptoms). -Non-carcinoid digestive tumours: 21 of 29 patients were evaluable. An impact of FDOPA-PET was reported in 4 of them (rate 19%), corresponding to an adequate decision in 2 patients (decision of surgery and decision of medical therapy) and a non-pertinent decision in 2 patients (inappropriate cancellation of surgery and futile complementary exploration of a questionable focus of FDOPA uptake). The 22 examinations performed in these 21 patients corresponded to 6 TP, 4 TN, 1 FP and 11 FN results. Conclusion: The overall rate of change in patient management was 35%, with a significant difference between the rate in carcinoid and in non-carcinoid tumours (50% vs. 19%, p < 0.04). FDOPA-PET appeared to be a major tool for the management of carcinoid digestive tumours with excellent diagnostic performances and induced pertinent changes in the management of patients at a rate similar to that of FDG-PET in other malignancies. Background: FDG PET has a role to evaluate the response to molecular targeting therapy with imatinib mesyilate against gastrointestinal stromal tumor. Metabolic response assessed by FDG PET is earlier than morphological changes determined by CT or MRI. The assessment of early response to the molecular targeting therapy has a clinical significance in terms of evaluating effectiveness and determining alternative therapy based on the possibility of ineffectiveness in the early stage of the expensive therapy. Purpose: We have conducted preliminary study of FDG PET to assess early response to the chemotherapy with gefitinib to non-small cell lung cancer (NSCLC). Materials and Methods: Four patients with advanced NSCLC who have measurable lesion and epidermal growth factor receptor mutation, and were scheduled for gefitinib therapy were evaluated. The study was approved by the institutional review board and all the patients gave informed consent. FDG PET was done prior to, 2 days and 4-6 weeks after the commencement of the therapy. PET was performed after injection of 5-6 MBq/kg FDG by 2D acquisition using a dedicated whole-body PET scanner (SET2400W, Shimadzu, Japan). Transmission data was acquired simultaneously with emission data using the external source. Uptake of FDG in the tumor was evaluated by the semiquantitative evaluation using standardized uptake value (SUV). Outcome of patients was correlated with the changes in the size of the tumor and the SUV. Results: Conventional response evaluation with CT revealed that two of four patients showed partial response (PR) and the others showed stable disease (SD) with minor response. Progression free survival (PFS) of the two PR patients was 12.9 and 12.5 months. PFS of two patients with SD was 14.9 and 4.5 months. FDG PET showed decrease in FDG uptake (58.1% and 47.2% of initial study) in SD patients as well as in PR patients. Conclusion: FDG PET could represent early response to gefitinib and have a role to estimate prognosis even in patients with SD which is evaluated by conventional CT. Aim: Dynamic PET studies with 18F-FDG were performed in patients with advanced Non-small Cell Lung Cancer (NSCLC) who received palliative chemotherapy to evaluate the impact of full kinetic analysis and assess its value with regard to short ot long survival. Methods: The evaluation includes 42 metastatic lesions in 14 patients with NSCLC. All patients received a combined chemotherapeutic protocol consisting of vinorelbin and oxaliplatin. The survival data served as reference for the PET data. All patients were examined prior to onset of chemotherapy and on day 15-21 after onset of the first cycle. The following parameters were retrieved from the dynamic PET studies: SUV, fractal dimension (FD), two compartment model with computation of k1, k2, k3, k4 (unit: 1/min), the fractional blood volume (VB) and the FDG-influx according to Patlak was calculated using the formula (k1 x k3) / (k2 + k3). We used a two group classification, namely a short and long term survival group based on the median survival time (193 days) as a cutoff. A support vector machines (SVM) analysis was used for classification of the two a priori defined groups. Results: The observed survival times varied from 40 to 392 days with a median survival time of 193 days. Most kinetic parameters demonstrated only small changes, mostly declining after one cycle. The change in all kinetic parameters did not correlate to the survival based classification.The change in SUV was significant between the first and second study (p=0.006) but without an impact on the prediction of short ot long survival. SVM based analysis revealed the highest correct classification rate (CCR) between short and long survival for the combination of SUV and influx of the first study and SUV, influx, k2, k4 of the second study with a CCR of 95.2 %. Conclusion: The results demonstrate, that a full kinetic analysis of the 18F-FDG kinetics in NSCLC is helpful for the classification into short or long survival and may be used to identify those patients who may benefit from this palliative chemotherapeutic protocol. Aim: (a) To evaluate the efficacy of FDG PET in the early prediction of chemotherapy effect on human testicular cancer xenografts; (b) To determine the optimal delay between chemotherapy administration and FDG imaging. Material and Methods: Animal model Eight 4 week-old male nude rats bearing subcutaneous human embryonal carcinoma xenografts (n=6 per animal) were treated with a single dose of cisplatin. A control animal received saline serum. PET imaging SA-PET imaging (Phillips Mosaic system) was performed 3.5 hours after injection of 15-45 MBq of FDG in the tail vein. FDG uptake was evaluated with tumour/background ratio (T/B ratio). Animals were imaged at day 0 (baseline examination), day 2, day 4 and day 7. Immunochemistry At each point, 2 rats were sacrificed for immunochemistry studies which comprised cell proliferation (cyclin A), apoptosis (cleaved caspase 3), and macrophagic infiltrate (anti-CD 68). Whole slice quantification (pixit® software) was used for comparison with SA-PET data. Results: SA-PET imaging FDG uptake in rats who received cisplatin showed a biphasic evolution: Initially, a peak was observed at day 2, with T/B ratios (10.21 +/-1.87) higher than those observed at day 0 (7.25+/-1.63), p<0.0001. Secondly, a decrease was seen from day 2 to day 4, although T/B ratios at day 4 were still higher than those at day 0. The decrease of FDG uptake became statistically significant at day 7 (p<0.0001). In the untreated rat images, tumours demonstrated an increase of FDG uptake at day 2 (far lower than that observed in treated animals) then remained stable. Immunochemistry A significant increase of apoptosis was observed at day 4 (29.4 +/-24.3; p=0.012) and day 7 (23.8 +/-13.8; p=0.001) in comparison with day 0 (11.8 +/-8.9). A transient increase in cell proliferation was observed at day 4 (72.8 +/-24.9 ; p=0.003) in comparison with day 0 (39.2 +/-26.3), and was followed by a decrease at day 7 (16 +/-14.5 ; p=0.008). Macrophage infiltrate, a well known cause of false positive findings, remained low when 18 FDG uptake was increased after chemotherapy. Conclusion: FDG PET may be useful in the early evaluation of treatment in patients with testicular cancer. A very early increased FDG uptake precedes a transient increase in cell proliferation but does not reveal refractory disease. Additional studies investigating the effect of chemotherapy type, dose and schedule are currently underway in our laboratory. Purpose. The purpose of this study was to analyze the diagnostic accuracy of PET and PET/CT in the evaluation of treatment response, both analyzing early response to treatment (ERT) after a few cycles of chemotherapy, and after having completed the treatment (AHCT), in patients with Hodgkin disease (HD) and non-Hodgkin lymphomas (NHL). Methods. We performed a systematic review of the literature, searching MEDLINE and EMBASE databases for studies published until December 2006. We included articles that evaluated PET and PET/CT in patients with lymphoma after treatment (ERT and AHCT). The eligibility was based in articles with sufficient data for calculate parameters of diagnostic accuracy, with separated analysis in HD and NHL. We calculated values of sensitivity (Se), specificity (Sp), positive probability rate (PPR) and diagnostic odds ratio (DOR). Results. We selected 28 studies for analysis. The diagnostic parameters for ERT in PET and PET/CT in patients with HD were: Se of 0.813 ( Recent studies have demonstrated the effective use of Imatinib mesylate for the unresectable, metastatic or recurrent GIST. The aim of this study was to evaluate the role of 18F FDG PET/CT in GIST patients treated with Imatinib mesylate. Material and Methods: Eight consecutive patients with GIST proven by surgery (3 stomach, 2 small bowel, 1 small bowel and peritoneum, and 2 rectum) underwent thirteen 18F FDG PET/CT imaging after the start of Imatinib mesylate therapy (400 mg/day or greater if disease progression). Patients were overnight fasting and had normal blood glucose levels. PET/CT was acquired 69-90 minutes after the intravenous injection of 370-555 MBq of 18F FDG. Iterative reconstruction algorithms were applied and PET images were corrected for attenuation on the basis of CT data. A visual analysis of images was performed. Standardized uptake value (SUV) was calculated for each lesion. In the 3 patients who underwent serial FDG PET/CT imaging, the therapy response was assessed according to the RECIST criteria for CT and EORTC recommendations for PET. Results were confirmed by clinical follow-up, radiographic findings or histological analysis. Results: Five patients were therapy-responders. The response was complete in 3, 2 of them had abdominal lymph nodes and the other, peritoneal implants. The remaining 2 patients had a partial response showing persistent FDG uptake in lung (1) and in liver metastases and lymph nodes (1). This latter patient showed a complete response increasing the Imatinib mesylate dosage to 600 mg/day. One patient had a disease progression showing new hepatic lesions on FDG PET/CT; a partial response was documented (a decrease of SUV in two liver lesions) after a left hepatectomy and an increase of dosage to 800 mg/day. Two patients were no-responders. One patient had an unresectable pelvic GIST and the other multiple peritoneal implants. Both patients died in a 2-6 months period after FDG PET/CT. Conclusion: Tumor response to Imatinib mesylate should be assessed by FDG PET/CT. FDG PET/CT imaging identified the degree of therapy response with a clinical impact on the management of patients with GIST.

of 3 doses that mimics maximum tolerated dose (MTD) used clinically. The body weight of each mouse and the size of tumor implants were monitored throughout the experiment. The mice were scanned with 18F-FDG on days 7, 10, 14, 17 and 21 post tumor inoculation using high-sensitivity projection imaging (PPIS-4800, Hamamatsu) with 18F-FDG for monitoring the anti-tumor effect of CTX. The results of PPIS imaging was compared to those of microPET imaging (R4, Concorde). Result: CTX treatment resulted in growth inhibition of the CT-26 tumor and a decreased of the body weight of the mice as compared to the untreated controls. Both the highsensitivity projection and microPET 18F-FDG imaging modality are equally effective in monitoring the CTX-induced tumor growth changes. Conclusion: Our results demonstrated that PPIS imaging modality is as effective as microPET in the monitoring of the tumor response to CTX chemotherapy. These results suggest that the high-throughout screening imaging system may be employed for evaluating new anticancer drug using murine tumor models. Aim: aim of the study was to evaluate the usefulness of 18FFDG-PET/CT in patients (pts) with lower rectal cancer treated with neoadjuvant chemo-radiotherapy (CRT).

Fifty-five pts were enrolled in the study. All patients had known rectal cancer located within 5 cm from the anal verge. The pts characteristics were: 30 men, 25 women, mean age 65 (35-81). Stage: 4 pts (uT2N-M0), 17 pts (uT3N-M0), 20 pts (uT3N+M0), 8 pts (uT3NxM0), 3 pts (uT4N0M0), 3 pts (uT4NXM0). Chemotherapy consisted of a weekly schedule of oxaliplatin (OXA) and 5-fluorouracil (5FU) or 5FU alone. Radiotherapy started the same day as ChT and was delivered up to a dose of 50.4 Gy in daily fractions of 1.8 Gy. Rectal surgery was performed 6-8 weeks after the end of neoadjuvant treatment. FDG-PET/CT was performed at staging and 6-7 weeks after the end of CRT. Pathological examination of surgical specimens included the tumor regression grade (TRG) evaluation according to Mandard. Pts were followed up for 6 -36 months. SUVmax pre and post CRT was measured in the site of the primary lesion. Results: Twenty-nine pts were considered as complete pathological responders (GROUP 1: 10 TRG1 -19 TRG2). Twenty-six pts were classified as pathological non responders (GROUP2: 19 TRG3 -7 TRG 4). The mean SUVmax decrease compared to the baseline was 82% (range -42% to -100%) in GROUP1 and 80% in GROUP2 (range -49% to -100%). The mean value of SUVmax post CRT in GROUP 1 and 2 was respectively 2 and 2.7. In GROUP 1 pre therapy SUVmax mean value was 9.5, while in GROUP 2 was 13.6. Interestingly, pts with TRG 4 showed a pre therapy SUVmax mean value of 26 while pts with TRG 1 showed a pre therapy SUVmax mean value of 11 (p < 0.05). Conclusion: In our series of patients no correlation was found between metabolic response (SUVmax decrement) and pathological response (TRG). However a correlation was found between pre-therapy SUVmax value and pathological response (TRG1 vs TRG4). Aim: To evaluate the FDG metabolism in patients (pts.) with high risk soft-tissue sarcomas receiving an induction or neoadjuvant chemotherapy. The treatment effect was assessed with regard to the prediction of therapy outcome. Methods: The ongoing evaluation includes 25 patients with high grade soft-tissue sarcoma with different histologies. 14 pts. received an induction chemotherapy consisting of adriamycin 75 mg/m2/day 1 and ifosfamide 1500 mg/m2/day 1-4 (AI-G regimen, six cycles) prior to peripheral blood stem cell transplantation, and 11 pts. were treated with pre-operative chemotherapy consisting of etoposide 125 mg/m2/day 1+4, ifosfamide 1500 mg/m2/day 1-4 and doxorubicin 50 mg/m2/day 1 (EIA regimen, 4 cycles). Pts. were examined prior to onset of therapy and after completion of the first cycle of AI-G and after two cycles of EIA chemotherapy, respectively. The restaging data of 20 patients (13 pts with AI-G and 7 patients with EIA treatment) served for reference. Restaging was performed using CT and/or MRI after six cycles of AI-G or four cycles of EIA chemotherapy. Results: Restaging data are available in 20 pts. According to RECIST criteria, clinical outcome was as follows: 1 pt. showed no evidence of disease (NED), 6 partial remissions (PR), 5 stable diseases (SD), and 8 pts. progressive disease (PD). Due to the small number of pts., we dichotomized the data in pts. with NED/PR (n = 7) and pts. with SD/PD (n = 13). Median SUV prior therapy was 4.0 SUV in comparison to 3.6 SUV after chemotherapy. Median influx was 0.034 prior to chemotherapy in comparison to 0.036 following therapy. Most kinetic parameters showed only small changes, only VB declined after one cycle. We used discriminant analysisto classify the patients into responders and non-responders. DA revealed a correct classification rate of 85 % using all kinetic data of the baseline study and 91 % using all kinetic data of the second study. Conclusions: On the basis of these results, kinetic FDG data are helpful for the prediction of chemo-sensitivity in patients with high risk sarcomas.

18F-FDG PET/CT monitoring of tumor response to chemotherapy: does 18F-FDG imaging can be used as a chemosensitivity testing method? S. Song, G. Huang; Renji Hospital, Shanghai Jiaotong University, Shanghai, CHINA.

Aim: The aim of this study was to determine if FDG-PET/CT can be used as an in vivo individual chemosensitivity testing method, especially in those who underwent chemotherapy at the begining. Material and Methods: Fourteen VX2 xenografts bearing New Zealand rabbits with total of 27 tumors in axillary fossa close to anterior wall were randomly divided into control group(n=4) and cisplatin chemotherapy group(n=10). The tumors were 15-20mm in size. In treatment group FDG-PET/CT images were obtained before administration CDDP(PETt1),during treatment (40min after administration CDDP PETt2),1d(PETt3),7d(PETt4) and 14d(PETt5) after chemotherapy. In control group FDG-PET/CT were obtained every 3 days from the first imaging to 40days of total 6 PET/CT imaging since the rabbit were inoculation VX2 tumor. Results: Mean SUVmax ( 55-60min after injection )of the control group were increased steadily, which were 6.25±2.92 (PETc1), 9.97±0.91(PETc2), 10.47±1.31 (PETc3), 9.02±2.40(PETc4), 9.39±1.57(PETc5) and 11.36±1.41(PETc6) respectively. In CDDP treatment group, according to the degree of SUVmax decrease on PETt1 and PETt2, we divided the xenografts into a responder group (partial response + stable disease, n = 6) and a nonresponder group (progressive disease, n = 4). We use the (PETt1-PETt2)/ PETt1 degree>25% as the criteria of response. The retention index and T/M ratios showed marked changes at the time point of PETt2 in the responder group, although the tumors did not show any significant change in volume at that time. Paraffin section stained with haematoxylin and eosin of sections showed that the number of viable tumor cells in the responder group decreased at 7 days, and peaked at 14 days. Necrotic cells and fibrotic tissue were observed after CDDP treatment of 7and 14days. The decrease of FDG uptake in responder group on PETt2 was an early marker that the individual was sensitive to CDDP, and correlated well to 14days pathology results. In non-responder group there were no significant changes in pathology results compared with control group. Conclusions: Early evaluation by FDG-PET/CT, especially during CDDP administration is useful. The decrease of FDG uptake was an in vivo biomarker to predict later pathology result. The study included 38 patients diagnosed and treated of NMLC. FDG-PET/CT was done 4 and 6 weeks after chemoteraphy and/or radioteraphy respectively. Pre-treatment staging was done with the addition of FDG-PET/CT in 18 patients, and only by CT in 20. The images were evaluated by visual and semiquantitative analysis and the results were compared with CT findings. Final diagnosis was based on the information obtained from clinical records. A good therapeutic response (GR) was achieved in 23 patients, no changes (NC) in 5, and progression of the disease (PR) in 10. Results: FDG-PET/CT and CT findings agreed in 12 of the 38 patients (32%) and disagreed in 26 (68%), 16 with GR, 1 with NC and 9 with PR. In 14 of the 26, FDG-PET/CT revealed more lesions than CT (5 in GR, 1 in NC and 8 in PR), showing a more extensive nodal disease in 8, extra-nodal metastatic disease in 5 and local growth in one. In 3 of the 26 patients with discordant findings (11%), all with GR, FDG-PET/CT rule out tumoral disease suspected by CT findings. In 12 patients CT studies were non-diagnostic (9 with GR and 3 with PR), and in 3 of them FDG-PET/CT rule out disease, in 4 confirm it. Overall, FDG-PET/CT was definitive to establish the final diagnosis in 11 of the 23 with GR (48%), in one of the 5 with NC, and in 9 of the 10 with PR (90%). Interestingly, regarding the employment of PET/CT at staging, of the 18 in whom it was applied, 15 showed GR; however of the 20 in whom staging was based only in CT, only 8 showed GR unlike 10 who showed PR. Conclusion: The results demonstrate the value of FDG-PET/CT and confirm that it must be included in the assessment of the response of treatment of NMLC. In addition to clarify non-diagnostic CT scans, revealed a considerable number of unsuspected tumoral lesions. Moreover, when FDG-PET/CT is employed for the initial staging a better therapeutic response is obtained. . 26 males and 4 females. They were of post solid organ transplantation namely heart (n=12), lung (n=1), liver (n=14), and kidney(n=3) that were performed from September 1989 until October 2005. They were for staging purposes (n=13), and as follow up assessment( n=17), post therapy. The biopsy procedure and tissue samples were obtained prior to the PET CT scan. The results of a total 50 PET CT were compared with conventional imaging (US, CT, MR), both of which imaging were done about the same time. Results: 29 cases were confirmed PTLD by histopathological diagnosis. 9 patients developed PTLD early(less than 12 months)and 20 patients developed late (12 months and later) after transplant. The mean time to onset is 60.6 months. PTLD histological subtypes revealed Malignant lymphoma,(ML) in 20 cases, Polymorphic Lymphoproliferative disorder (PLD) in 6 cases, Multiple Myeloma (MM) in 2 cases. In 1 patient, diagnostic histology type was not available. 9 cases involved only the lymph nodes and 20 cases involved extranodal. In 46/50 examination, PET CT and Conventional imaging were concordant. In comparison to conventional imaging, The PET CT study results showed lower sensitivity (76.9 % vs 80%) but similar specificity(100% vs 100%). The overall accuracy of PET in diagnosis and follow-up is almost similar to conventional imaging ( 86.4 % vs 87 %). Conclusion: This study suggest PET CT is an accurate diagnostic tool in staging and follow-up of PTLD patients. However, reconfirmation with histology of all positive findings remains mandatory. It is also a useful modality in patients with impaired renal function as a result of chronic immunosuppressive treatment. As no contrast medium is necessary, contrast related nephrotoxicity in PTLD patients is avoided. Further study is recommended before implementing PET CT as a routine diagnostic tool in suspected cases of PTLD following solid organ transplantation.

Keywords: Aim: 18F-FDG PET is increasingly used in radiotherapy planning. The aim of this study was to evaluate from a retrospective study the feasibility of using 18F-FDG PET/CT to detect and delineate the target volumes in advanced NSCLC. This implementation into radiation treatment planning has required strong collaboration between radiation oncologists and nuclear physicians. Patients and Methods: From April 2005 and October 2006, were enrolled for radical radiation therapy staging 17 patients with unresectable NSCLC (13 males and 4 females; mean age 61.2 years), performance status >70% (Karnofsky), 12 squamous cell carcinoma, 4 adenocarcinoma and 1 large cell carcinoma, stage III (n=12), stage IV (n=5). Whole body PET/CT (Biograph Sensation 16 Siemens) was performed after 60 min from the injection i.v. of 370 MBq 18F-FDG, followed by PET/TC scan of the ROI on bed for radiotherapy. GTVs were determinated and based on the PET data. Results: After FDG PET/TC, 14 out of 17 pts were judged to be potentially eligible for curative treatment; 13 out of 14 pts underwent concurrent chemotherapy, 2 out of 14 pts performed successive surgery (in one of these a focal thyroid uptake of FDG were investigated and malignant lesion were demonstrated by cytological analysis -papillary cancer-). 3 out of 17 pts FDG PET/TC detected distant metastases (controlateral lung, adrenal and bone); in this pts was given palliative therapy. Mean rate of radiation was 63Gy (50-74). GTV was changed in all pts (decreased in 8 pts and increased in 6 pts). 10 out of 14 pts had mild toxic effects (6 oesophagitis, 3 cough, 3 dyspnoea); 3 out of 14 pts moderate toxic effects (1 oesophagitis, 2 dyspnoea). All pts were followed for at least 6 months; 8 pts presented relapse (2 with local and 6 with distant recurrences), 2 pts were in stable disease and 3 pts were in complete remission (median time of 14 months: range 6-20). One patient died post-treatment. Conclusion: Our data, even if obtained in a short number of pts, seems to confirm that FDG PET/TC could add information to precisely identify the GTV in advanced NSCLC so as to obtain a better local control of disease. The technique of tumor contour definition by FDG PET/CT lead to substantially different volumes, especially in pts with necrotic or colliquative areas in the tumor mass. As we know from literature PET significantly altered the GTV or CTV in 44%, therefore all patients underwent a whole-body PET scan after a CT scan. The CT images provided morphological volumetric information, and in a second step, the corresponding PET images were overlaid to define the effective target volume. The images were exported off-line via an internal network to an RT simulator. We consider definitive follow-up after two years from treatment or in case of patient death's. The dose range is 40÷66 Gy, with a mean of 50,3 Gy. Five patients have a negative PET, so the RT field was the whole mediastinal area to prevent prospective micro metastases. In all the others cases we have considered the PET area as the GTV for RT. Results: Nine patient were excluded from the study owing to change in the disease stage subsequent to the PET/CT study, 2 SCLC and 7 NSCLC. Among the remaining 67 patients, we have definitive follow-up for 44 pz (66%) and temporary follow-up for the others . We verified 10 (15%) Not Evident Disease, 34 (51%) sistemic progression or diffused metastases, 13 (19%) stationary disease and 10 (15%) with relapses in the RT field or in the neighboring. Conclusion: FDG-PET is a highly sensitive imaging modality that offers better visualisation of local and locoregional tumour extension. This study lead to the conclusion that the use of PET/CT in radiotherapy planning allows a better patient management and gives comforting results about relapses in field.

The Assessment of the Radioimmunotheraphy with It is important to assess the therapeutic response in refractory or relapsing lymphoma patients before progression of disease. Therefore, we intended to find out the optimal timing for assessing the treatment response of the 131I-rituximab in patients with refractory NHL using 18F-FDG-PET/CT (PET). Methods: Twenty-eight patients with NHL (DLBL in 10, MCL in 6, MZBCL in 3, FL in 3, MALT in 1) refractory to previous chemotherapy (5 to 22 cycle, median: 9 cycle) were enrolled. PET was performed at pretreatment, and 5 days, 30 days, and 60-90 days after 131I-rituximab. We compared pre and post-treatment PET with 5 parameters; mean SUV, maximum SUV (SUVmax), volume of interest (VOI) of lesions, total metabolic volume VOLsum) and adjusted metabolic volume (SUV*VOLsum). We correlated the decrement (%) of individual PET parameters calculated by ROC curves with the clinical assessment of the treatment of 3 months after 131I-rituximab. Results: Clinical assessments for the 131I-rituximab were CR in 2, PR in 3, SD in 8 and PD in 10. Area under the curve of the calculated decrements of each PET at 5, 30, and 60-90 days after 131I-rituximab were 0.667, 0.838 and 0.780 for SUVmax, and 0.633, 0.853 and 0.800 for SUV*VOLsum. There were statistically significant differences in the PET parameter decrements on 30 days after 131I-rituximab (p<0.05). Moreover, there was tendency of disease progression in the 60~90 days PET parameters. Conclusion:

The assessment for the treatment of 131I-rituximab in patients with refractory NHL using PET was recommended at 30 days after treatment. Second dose of 131Irituximab was recommend within 60~90 days before progression of disease. Aim: CT images provides additional anatomical information for PET/CT study. However, the role of contrast medium in PET/CT is still controversy. In this study, we demonstrate the results and our experience by using CT contrast medium enhancement in FDG PET/CT examination. Material and Methods: Between Dec. 2005 and Apr. 2007, 802 FDG PET/CT studies were performed on 730 patients. Patients whose images had either insufficient anatomic information or equivocal findings in FDG PET/CT were included in the study. Subsequently we performed delayed imaging without and with intravenous contrast medium. The impact of contrast medium was assigned a value on a 5-point probability scale. Results: During this period, 142 FDG PET/CT delayed studies with contrast medium enhancement in 138 patients were recruited for the study. Among these scans with contrast medium enhancement, malignancy of the digestive system (70/142, 49%) is the most frequently required for this procedure, especially in colorectal cancer (40/70, 57%). In fact, contrast medium technique was useful for delineating the boundary of tumor and its surround tissues, evaluating vascular invasion of the tumor, and determining the vascularity of suspected lesions. There was mild adverse effect occurred in 1 patients with skin rash and 2 patients with extravasating contrast medium. Conclusion: An additional imaging with contrast medium enhancement in FDG PET/CT study may provide useful information in cases with insufficient anatomic information or equivocal findings. The relatively side effect for contrast medium is acceptable in this study. Introduction: The accumulation in the stomach and colon often pesters nuclear medicine physicians with the interpretation as to whether " normal or not " because 18F-FDG frequently accumulates not only in the abnormal lesion like malignant tumor but also in the normal stomach and intestines. The purpose of this study is to assess the ability of scopolamine butylbromide that inhibits the periatalsis to reduce the physiologic uptakes in the stomach and colon. Methods: We studied 148 people who had a checkup for cancer using PET/CT. All people are less than fifty years old and mean age was 41.3±6.03 (25 to 49). Fifty-four people were female and ninety-four people were male. We administered an intravenous drip injection of isotonic sodium chloride solution including scopolamine butylbromide of 20mg to 66 people in this study for 30 minutes. The drip was started at five minutes before the injection of 18F-FDG. We categorized the degree of 18F-FDG uptake in the stomach and along the colon into four grades according to the following scale: Grade 0: no visible uptake; Grade 1: lower than in the liver; Grade 2: similar to the liver; Grade 3: higher than in the liver. Also, we measured SUV in the stomach (circle ROI, 10mm in diameter) and counted the number of nodular uptakes in the colon that is higher than in the liver per man. Results: The mean Grade of stomach in the injection group (1.11±0.75SD) was significantly lower than that in the non-injection group (1.94±0.91SD) (p<0.0001). Also, the mean Grade of colon in the injection group (0.88±0.83SD) was significantly lower than that in the non-injection group (1.26±0.91SD) (p=0.010). The SUV in the stomach averaged 2.68±0.70SD in the injection group, and 3.26±0.75 in the non drip injection group. The averaged SUV in the drip injection group was significantly lower than that in the non drip injection group (p<0.0001).The number of nodular uptakes in the colon (0.15±0.40SD) in the injection group was lower than that in the noninjection group (0.37±0.96SD), but the significant difference was not found (p=0.066). Conclusion: Our results indicate that the intravenous drip injection of scopolamine butylbromide can reduce the physiologic uptake in the gastrointestinal tract, especially in the stomach. Aim: To detect malignant tumors PET images are usually obtained about 1 hour after intravenous administration of FDG, but FDG uptake by malignancies is often greater in delayed scans than in early scans. We investigated malignancies that were only detected on delayed scans and showed no FDG uptake on early scans. Materials: Two PET specialists judged the FDG-PET images of 48 lesions in 46 patients (33 men and 13 women with a mean age of 64.8 ± 10.6 years), which showed no uptake on early scans and abnormal uptake on delayed scans. These lesions were shown to be malignant by histology in 13 cases, by follow up in 21 cases, and by other methods in 14 cases. Methods: PET images were obtained from 50 to 70 minutes (early scans) and from 110 to 130 minutes (delayed scans) after administration of FDG following 5 hours of fasting. The ROI was set on the sites of abnormal FDG uptake on delayed scans and the corresponding area on early scans, after which the SUV max of each ROI and the rate of increase were calculated. Results: The 48 lesions included 13 metastatic liver tumors, 6 metastatic lung tumors, 6 metastatic mediastinal lymph nodes, 9 abdominal lymph nodes, 4 prostate cancers, 2 cases of peritoneal dissemination, 2 primary lung cancers, 2 bladder cancers, 1 esophageal cancer, 1 mesothelioma, 1 hepatoma, and 1 cholangioma. The SUV max values for the early scans and delayed scans were 2.54 ± 0.42 and 3.23 ± 0.64, respectively, while the rate of increase was 28.2 ± 5.4. Discussion: Among the 48 lesions, the most common was metastatic liver tumors, presumably because FDG uptake by these lesions increased over time and normal liver uptake decreased. The second most frequent diagnosis was metastatic mediastinal lymph nodes, also presumably because FDG uptake by these lesions increased over time and mediastinal background uptake decreased. Four prostate cancers and 2 bladder cancers were detected on delayed scans because bladder uptake was markedly decreased on these scans. The other lesions were too small for abnormal uptake to be detected on early scans. Conclusion: Examination of a delayed scan is extremely useful for detecting malignant tumors that do not show FDG uptake on the early scan, especially lesions surrounded by high background activity, such as those in the liver, mediastinum and bladder.

FDG uptake in cold and heat treated MCF-7 cells, comparison with cell viability, apoptosis, and tumor marker changes C. Zhang, X. Sun, J. Liu, P. Liu, G. Huang; Renji Hospital, Shanghai Jiaotong University, Shanghai, CHINA.

Aim: To investigate the FDG uptake changes in cold and hyperthermia therapy and its correlation with cell viability, apoptosis and tumor marker changes. Material and Methods : An in vitro cultured breast adenocarcinoma cell line, MCF-7, was divided into 5 groups. Hyperthermia group: cell was treated in 43degree centigrade 30 min. Hypothermia group: cell was treated in 0degree centigrade 30 min. Hypo-and hyperthermia group: cell was treated in 0 degree centigrade 30 min and 43 degree centigrade 30 min. chemotherapy group: cell was treated with 21 microgram Cisplatin for 6 hours. And Control group: cell was untreated. The levels 18F-labelled FDG uptake, a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide viability assay, flow cytometry assay and tumor markers (CA153,CA125) were detected at 24 hour and 48 hour. Results : The change of 18F-FDG uptake is early than tumor marker (which came out at the 48h) under our study conditions. In treated MCF-7 cells, the levels of 18F-labelled FDG uptake were significantly lower than control group. The levels of 18F-FDG uptake depression were well correlated with cell viability and apoptosis data. Conclusions : FDG uptake is sensitive and well correlated with cell viability and apoptosis assay, and can be used for early response monitoring in hypoand hyperthermia therapy. Purpose: To prospectively analyse the relevance of PET/CT in the clinical management (benign disease/malignancy, initial staging, re-staging) of the primary pleural malignancy (PPM). Methods: 23 consecutive patients (33-76 y.o., median 57 y.o.; 18 m, 5 f) with pleural disease were included. All of them underwent a wholebody PET/CT investigation (Discovery LS, GE Healthcare) with standard dose (0.125MBq FDG/kg). 30 studies were reviewed. PET/CT findings were assessed according to The TNM International Mesothelioma Interest Group clasification. The clinical indications were: suspected PPM (group A: n=6); initial staging of primary malignant mesothelioma (PMM) (group B: n=12); re-staging following therapy (group C: n=11) and assessment of recurrence (group D: n=1). For clinical management and to establish prognosis the following subgroups were compared: T1-T3 vs T4, N0-N1 vs N2-N3 y M0 vs M1. Imaging findings were correlated with surgical and histopathologic staging in all patients. Results: In group A (n=6) malignancy was excluded in 4/6 patients and confirmed in 2/6 cases, thus avoiding multiple invasive procedures and speeding up diagnosis. In group B (n=12) PMM was staged as: epithelioid (n=8), sarcomatoid (n=2) y (n=2) was unknown. It was located on the right-sided (n=9) and left-sided (n=3) pleura. Eight studies diagnosed irresectable disease: T4 (toracic wall/mediastinum infiltration) in 4/8 ; N2 (mediastinal adenopathy) in 2/8 and M1 in 2/8. Globally PET/CT diagnosed 6/11 patients (54%) with extensive disease significantly modifying their clinical management. In group C 11 studies were performed to assess response to therapy: chemotherapy (n=8): 3/8 with stable disease and 3/8 with disease progression, 1/8 with partial response and 1/8 had no previous study for comparison; surgery (n=2): 1 to assess incomplete surgery (decortication) showed residual disease and 1 without evidence of recurrence; surgery and chemotherapy (n=1) without evidence of recurrence. PET/CT showed unknown metastasis in two patients and a synchronic unknown malignancy (synchronic squamous cell carcinoma in the contralateral lung) which was confirmed by pathology. Conclusions: PET/CT is a non-invasive multimodality imaging technique with significant relevance in the clinical management of the primary pleural malignancy.

Estimation of optimal kinetic model and prediction of pathological diagnosis of anterior mediastinal tumor using 11C-acetate dynamic PET study Aim: Recent studies indicated that 11C-acetate (AC) may be a complementary tracer in PET imaging of thymomas. But, kinetics of AC in tumor tissue is not completely elucidated, and it is unknown which kinetic model (KM) is most optimal. The aim of this study is to evaluate which KM is most optimal for analyzing AC dynamics in thymoma tissue, and whether Dynamic AC-PET Study can predict pathological diagnosis of mediastinal tumors using this "most optimal" KM. Methods: Dynamic AC-PET Studies were performed for suspected thymic tumor with anterior mediastinal mass on chest CT scan. (In addition, static AC-PET scans and FDG-PET studies were also performed just after dynamic AC-PET studies.) We assumed candidates of four KMs as follows:

We analyzed 10 datasets of cases diagnosed pathologically (3 thymomas of type A/AB, 4 thymomas of type B2/C, and 3 thymic cysts) from August 2005 until December 2006, applying to these (A)-(D) KMs, and calculated Akaike Informational Criterion (AIC) of each KM, and determined which KM is most optimal, based on values of AIC. Furthermore, we analyzed 10 datasets again using this "most optimal" KM, and estimated parameters, and compared with pathological diagnoses. Results: AICs of (A) 2C-2P KM became smallest in all 10 datasets, and it seemed to be "most optimal" among 4 KMs. Using 2C-2P KM, we estimated Rate Constants (K1, k2) and Blood Volume and calculated Metabolic Rate (MR) defined as K1/k2 In 3 thymomas of WHO type A/AB, MRs were more than 1.0 (K1>k2), and in the remaining 7 tumors, MRs were less than 1.0 (K1 < k2). 7 cases with thymomas (Type A/AB/B2/C) were successfully detected by static AC-PET scan, but 2 cases among 7 thymomas were false negative by FDG-PET. 3 cases with thymic cysts demonstrated neither AC nor FDG uptake. Conclusion: This study indicated that 2C-2P KM may be "most optimal" for pharmacokinetic analysis of AC in anterior mediastinal tumors, and MR obtained by Dynamic AC-PET studymay be useful for discriminating between Type A/AB thymomas and thymic cysts, or Type A/AB thymomas and more aggressive histology, as well as static AC-PET scan. Objective: A potential false-positive FDG PET interpretation in oncologic imaging is FDG-uptake in brown adipose tissue. The purpose of this exhibit is to demonstrate the characteristic as well as the atypical locations and appearance of hypermetabolic brown adipose tissue in the neck, thorax, and abdomen. Methods: Twenty-one patients (16 female, 5 male; age range, 8-64 year-old) with brown adipose tissue on PET/CT studies were documented out of approximately 500 scans. Lesions were defined as brown adipose tissue by increased FDG metabolism corresponding to fat density tissue on CT scan. Results: There were two cases of hibernoma, two cases of lipomatous hypertrophy of the interatrial septum and the reminder seventeen cases of brown fat were identified in neck, supraclavicular, superior mediastinal, perinephric and retroperitoneal regions. Hibernoma is a benign neoplasm presenting as a focal lipomatous mass indistinguishable by conventional imaging from a lipoma with increased FDG metabolic activity of brown adipose tissue. Lipomatous hypertrophy of the interatrial septum is characterized by excessive deposition of fatty tissue in the interatrial septum. The typical appearance of brown fat in the neck appeared as bilateral curvilinear areas of FDG activity with extension into the supraclavicular regions. Mediastinal fat demonstrated focal activity in the mediastinum and mapped to the adipose tissue surrounding the large vessels. Perinephric fat illustrated curvilinear or focal activity corresponding to the perinephric adipose tissue surrounding the upper pole of the kidneys. Retroperitoneal fat demonstrated focal activity mapped to adipose tissue. Conclusion: Hypermetabolic brown adipose tissue can be misinterpreted as adenopathy or malignant mass in the setting of known primary malignancy. Knowledge of this potential pitfall and precise localization with CT are important in preventing misinterpretation as malignancy. male), 2528 consecutive FDG whole-body scans were obtained with a PET/CT scanner. Scanning was performed using the Discovery LS PET/CT scanner (General Electric Medical Systems). Patients were fasted at least 6 h before the PET acquisition. Intravenous injection of 55.5MBq/kg of 18F-FDG was followed by a tracer uptake phase of about 60 min, during which the patients sat in a quiet room without talking. Imaging parameters were as follows for an acquisition at 5-7 bed positions: 140 kV, 120mAs, 0.8s per CT rotation, a pitch of 6, a table speed of 22.5 mm/s, 722.5mm coverage, and a 31.9s acquisition time. All PET/CT scans were examined retrospectively by 1 observer on an interactive display using fusion software (Xeleris; General Electric Medical Systems). Results: Twenty-five patients (7 male and 18 female) of the 2528 scans (0.99%) demonstrated brown fat uptake. The incidence rate was 2.20% in scans of female patients and 0.42% in scans of male patients. Patients with brown fat uptake were younger than patients without (35.3±13y vs.53.6±14y, P<0.01). Although there was no significant difference in BMI between patients with brown fat uptake, they tended to be thinner (BMI, 20.4±2 vs. 23.2±5, P>0.05). BMI was 19.6±2 for male patients and 20.8±2 for female patients with brown fat uptake (P>0.05). When comparing the monthly incidence rate from April to October, the incidence was highest from November to March in the whole group of patients (1.68% vs. 0.48%, P<0.01). Conclusions: FDG uptake in brown fat occurs particularly in female, younger patients and those with lower BMI values. The incidence of brown fat is clearly increased during the cooler period of the year. Aim:The aim of the study was to evaluate the feasibility as well as the agreement between Tl-201 and Tc-99m MIBI in brain SPECT for the differentiation of brain lymphoma and toxoplasma encephalitis -a distinction which is not always possible by routine CT or MRI. Methods:We studied 21 female patients with acquired immunodeficiency syndrome during a 13-month period who had intracranial lesions on CT or MRI. Dual isotope Tl-201 and Tc-99m MIBI brain SPECT was performed in order to obtain simultaneous acquisition. We calculated uptake ratios by drawing ROI around each lesion as well as in the opposite side. We compared our findings with pathologic data and clinical follow up. Results:Of the 21 patients studied, 12 had intense focal uptake in the lesion(s). 11/12 had either biopsy -or autopsy-proven lymphoma (11 true positive). One patient with purulent infection had focal uptake (1 false positive). 9 patients with negative scans had toxoplasma encephalitis on clinical follow up (9 true negative). Tl-201 and Tc-99m MIBI SPECT tally with each otherwith MIBI slightly prevailing -as far as it concerns the lesion-to-normal tissue uptake ratios which were higher for sestamibi compared with those of Tl-201. Conclusions:1. Patients with AIDS having intracranial mass on CT or MRI may benefit from Tl-201 or Tc-99m MIBI SPECT in order to distinguish lymphoma and toxoplasmosis. 2. Tl-201 and Tc-99m MIBI may give similar results. 

Meningiomas account for about 30% of all intracranial tumors. Although grade I meningiomas have a benign clinical course, malignant ones are associated with 50-80% recurrence rate and less than 2 years median survival. Evaluation of their proliferation rate is useful for assessing their biological behavior, with implications in patient prognosis. SPECT by various radiotracers can metabolically characterize intracranial tumors. We evaluated whether 99mTc-Tetrofosmin (TF) uptake in meningiomas correlates with cellular proliferative activity and with tumor grade. Materials & Methods: 15 consecutive cases with diagnosed meningioma (4 males, 11 females; mean age 62.3 years) were enrolled. Brain SPECT by TF had been performed within a week prior to surgical excision. In the excised tumor specimens we assessed the Ki-67 index by the MIB-1 immunostaining method, reflecting cellular proliferation and aggressiveness. TF uptake was assessed visually and semiquantitatively, by calculating the lesion-to-normal (L/N) uptake ratio. Pearson bivariate correlation analysis was performed between the level of tracer uptake (as expressed by the L/N ratio) and Ki-67 expression and tumor grade. Statistical significance was set at p < 0.05. Results: 12/15 patients were diagnosed with typical benign meningiomas and 3/15 had malignant meningiomas. Intensity of TF uptake in the region corresponding to the CT/MRI findings ranged from faint to profound. A significant correlation was found between both TF uptake and tumor grade (r = 0.834, p < 0.001) and between TF uptake and Ki-67 expression (r = 0.702, p = 0.004). Conclusion: This pilot study implies that TF brain SPECT could prove useful in differentiating benign from malignant meningiomas and is a potential indicator of their proliferative activity.

Comparison of brain SPECT with Tc99m-MIBI and CTscan in discriminating of radiation necrosis and brain tumor recurrence S. Dabiri Oskouie 1 , M. Amiri 2 ; 1 Tabriz University of medical scienses, Tabriz, IRAN (ISLAMIC REPUBLIC OF), 2 Babol University of medical scienses, Babol, IRAN (ISLAMIC REPUBLIC OF).

Aim: Tc99m-MIBI has been proposed for use as an imaging agent for various tumors, including brain neoplastic lesions. In spite of many advances in diagnosis and therapy, brain tumors still represent a serious challenge for clinicians. After radiotherapy, deterioreting clinical status can be due to either radiation necrosis or recurrent tumor. Computed tomography and magnetic resonance imaging offer imperfect discrimination of radiation necrosis and tumor recurrence. The aim of this study is to compare Tc99m-MIBI scan and CT-scan results in this group of patients. Material and Methods: Twenty six patients (14 male, 12 female, mean age of 37 years) with primary brain tumors and deterioration of clinical status after radiotherapy were enrolled in this study. Tc99m-MIBI brain SPECT was performed 10 minutes and 3 hours after IV injection of 740 MBq (20mCi) Tc99m-MIBI. Images were obtained with ADAC dual head camera. Transverse, coronal, and sagital views were reconstructed. Images were visually assessed. Results: Focal Tc99m-MIBI was observed in 14 patients. Eight of these patients expired within 6 months. Biopsy of 3 patients in this group confirmed tumor recurrence. CT-scan was positive in 7 patients and the rest had equivocal or negative results. Of 12 patients with negative Tc99m-MIBI scan, only 2 patients died during 6 months follow-up. Six of these patients had positive, five had equivocal and one had negative CT-scan. CT-scan results didn't correlate with survival rate. Conclusion: Patients with negative MIBI scan showed higher 6 months survival rate ( 83.3% ) compared to patients with positive MIBI scan ( 42.8% ). Focal uptake on Tc99m-MIBI scan is probably due to recurrent tumor. It can be concluded that brain SPECT with Tc99m-MIBI is a useful method for discriminating radiation necrosis from tumor recurrence in patients following brain radiotherapy. Aim: The differentiation between tumor recurrence and radiation necrosis remains a challenge. These entities have discrete treatment options and prognosis. Radiation necrosis can occur between 6 months to few years after irradiation, i.e. the same period during which recurrence is most frequent. In many cases morphologic brain imaging by CT/MRI is unable to distinguish between these two pathological entities. Although glioma cell line studies substantiated a plausible imaging superiority of 99mTc-Tetrofosmin (TF) over other tumor-seeking radiopharmaceuticals, little has been reported on its in vivo imaging properties.We sought to evaluate the usefulness of TF brain tomography in distinguishing glioma recurrence from radiation necrosis. Materials & Methods: 11 brain tumor patients (7 males, 4 females; mean age 50.1 years) were prospectivelly enrolled in the study. The initial diagnosis had been glioblastoma multiforme (4 cases), anaplastic astrocytoma (1), anaplastic oligodendroglioma (3), grade II astrocytoma (2), and low-grade oligodendroglioma (1) . All patients had been operated upon and then received adjuvant external-beam radiotherapy (total dose 60 Gy; no residual tumor on CT/MRI), while 8 of them also received temozolomide-based adjuvant chemotherapy. In all cases neurologic symptomatology relapsed in a mean period of 25 months, arousing suspicion of tumor recurrence. CT/MRI could not differentiate between recurrence and post-irradiation necrosis, so TF SPECT was performed. The level of tracer uptake (as expressed by the lesion-to-normal brain [L/N] uptake ratio) was compared between radionecrosis and recurrence by the two-sided Mann Whitney U non-parametric test. Statistical significance was set at p < 0.05. Results: In 8/11 cases an abnormally increased tracer uptake appeared in the region that CT and/or MRI indicated as suspicious; in half recurrence was confirmed histologically after surgery, while in the other 4 by growth of the lesion over a 6-month follow-up period and clinical deterioration. The remaining 3/11 patients had faint uptake in the suspicious region, compatible with radiation injury; these lesions remained morphologically unaltered over a mean 12month follow-up period, with no clinical deterioration in patient's condition, a course most likely favoring the diagnosis of radiation injury. Statistical analysis verified that tumor recurrence had significantly higher TF uptake, as compared to radionecrosis (p = 0.014). Conclusion: Metabolic brain imaging by TF could offer useful information in the workup of treated brain tumors, where radiomorphologic (CT/MRI) findings are inconclusive between recurrence and radionecrosis. Aim: Distinquishing neoplastic from nonneoplastic intracerebral hemorrhage (ICH) constitutes a common challenging problem since on standard neuroradiologic imaging neoplasms can be hidden behind an intracerebral hematoma, while some hemorrhagic nonneoplastic lesions may mimic neoplasms. CT and MRI cannot always distinguish between neoplastic and nonneoplastic hemorrhage due to considerable overlap of findings. In contrast to neoplastic ICHs, nonneoplastic ones display faint radiotracer uptake and only several days (>7) after the onset of the episode. Accurate diagnosis is therefore critical in providing optimal patient care. We evaluated the usefulness of brain SPECT by the tumor-seeking tracer 99mTc-Tetrofosmin (TF) in diagnosing hemorrhagic brain tumors among patients with nontraumatic intracerebral hematomas. Materials & Methods: Ten patients (3 males, 7 females; mean age 64.0 years) diagnosed with spontaneous intracerebral hematoma on CT/MRI were prospectively enrolled in the study. All underwent TF brain SPECT within a mean period of 3 days after onset of symptoms. Imaging was performed early (10 min) post-injection. Surgery was performed in 4/10 within a week; in the remaining 6/10 the diagnosis was based on a 'wait-and-see' policy of clinical and morphologic (CT/MRI) follow-up. Results: Faint or absent TF uptake in the region corresponding to the CT/MRI findings was found in 9 cases, while only 1 displayed significant tracer accumulation.

The latter patient and 3 of those with negative SPECT underwent surgery, which revealed an underlying tumor (glioblastoma) solely in the patient with positive SPECT. The 6 hemorrhage cases lacking TF uptake that were not operated upon demonstrated a diminution in the lesion size on CT/MRI follow-up and clinical improvement, thus considered as representing non-neoplastic intracerebral hematomas. Conclusion: TF could prove useful in the early noninvasive assessment of nontraumatic brain hematomas, allowing differentiation between neoplastic and nonneoplastic intraparenchymal cerebral hemorrhage. #

Investigation of Pediatric Brain Tumours using Combined 111Indium-Octreotide /99mTechnetium-DTPA Brain Scintigraphy G. Dabasi 1 , I. Szilvási 2 , P. Hauser 3 , M. Garami 3 , D. Schuler 3 , A. Doros 1 , J. Járay 1 ; 1 Semmelweis University Transplantational and Surgical Clinic, Budapest, HUNGARY, 2 Semmelweis University Department of Nuclear Medicine, Budapest, HUNGARY, 3 Semmelweis Univ. 2 .Dept. of Pediatrics, Budapest, HUNGARY.

Brain tumours are the most frequent pediatric solid tumours.Some of them (especially medulloblastomas) express somatostatin receptors (SSR). In-111-octreotide scintigraphy (OS) can visualize SSR expression of various types of tumours. Increased octreotide uptake might be non-specific due to impaired blood-brain-barrier (BBB). Conventional brain scintigraphy (BS) with 99mTc-DTPA assess integrity of the BBB. Aim of our study was to evaluate OS for differential diagnosis of pediatric brain tumours using a double-tracer technique. Patients and Methods: 56 children with brain tumours were studied. 31 patients had medulloblastoma, 25 patients had different types of brain tumours: glioblastoma, ependymoma, astrocytoma, primitive neuroectodermal tumour (PNET) and cerebral metastasis of Ewing sarcoma. Diagnosis was based on histopathology and conventional radiological investigations. All patients underwent CS using Tc-99m-DTPA and OS with In-111-octreotide on the next day.Tumour to background ratios (T/BG) were measured at 60 minutes of the DTPA and at 24 hr of the octreotide scans. T/BG on OS was compared to T/BG on BS. Only tumours with T/BG on OS higher than on BS were defined as SSR positive. Results. 27 cases (48,2%) were SSR positive:16 medulloblastomas, 4 ependymomas, 4 astrocytomas, 3 glioblastomas. 29 patients had lower T/BG on OS than on BS. In this group 19 (33,9%) patients had no uptake of octreotide in the tumour region defined by DTPA scan. Diagnoses of these tumours were: 1 astrocytoma, 3 ependymomas and 12 medulloblastomas and in 3 PNET . In 10 (16,9%) patients moderate uptake of octreotide was seen, but T/BG on OS was lower than T/BG on BS. Diagnoses were:1 glioblastoma, 1 astrocytoma, 2 ependymomas, 1 metastasis of Ewing sarcoma, 3 medulloblatomas and 2 PNET. Conclusions: OS has not proved to be useful for differental diagnosis of pediatric brain tumours. SSR expression defined by higher T/BG ratio on OS than on BS is not specific for medulloblastoma. In our opinion somatostatin analogue and/or targeted radiation therapy is indicated only in patients with specific octreotide uptake, i.e. with higher T/BG on OS than on BS. This combined scintigraphic approach can be used to evaluate therapy of pediatric brain tumours with SSR expression. Although Magnetic Resonance Imaging (MRI) is an excellent tool to diagnose brain tumors, the functional information is limited. On the other hand 99mTc-MIBI brain SPECT is considered a useful tool in the management of brain tumors. Aim: 99mTc-MIBI tumor uptake is related to histological grading, cellular proliferation index and prognosis. Our aim was to evaluate 99mTc-MIBI brain SPECT and MRI studies efficacy in the differential diagnosis between recurrence of malignant gliomas and glioblastomas and the local modification after radiotherapy. Material and methods: Eight patients with suspected recurrence after surgical removal of a glioma (2 low grade and 6 high grade), 6-12 months before study and treated with radiotherapy were investigated. For brain SPECT -740MBq of 99mTc-MIBI were i.v. injected to each patient 15 minutes before image acquisition by a dual-head gamma camera. Gd-DTPA enhanced T1 and T2 weighted MRI studies were carried out in every patient within 3 days before 99mTc-MIBI SPECT. The ratio between the tumor ROI on a slice with maximum uptake and a mirrored control ROI was calculated and if >2 it was considered pathological. Results: SPECT and MRI studies well correlated being both positive for recurrence in 5 patients as confirmed by biopsy, while both negative in 2 patients, considered as having radiation effects (evaluate by clinical follow up). One patient with negative SPECT was operated being severely symptomatic and the biopsy was positive for low grade tumor. Combined sensitivity was 83,3%, specifity 100%, NPV 66% and PPV 100% Conclusion: 99mTc-MIBI brain SPECT and MRI studies provide high specifity of detection of relapses of gliomas and glioblastomas and also the most adequate anatomic depiction of extent of tumor process. Clinical follow up of these patients is underway to assess correlation of metabolic response to clinical response. Aim: The aim of this study was to assess the incremental diagnostic value of 131I SPECT/CT fusion imaging compared with conventional 131I planar scintigraphy in patients with thyroid carcinoma. Materials and Methods: Seventy-nine patients with thyroid carcinoma underwent 131I SPECT/CT and 131I planar imaging 3-7 days after administration of either a therapeutic dose (n=64) or a diagnostic dose of 131I (n= 15). Reconstruction of fusion images were performed by using external markers placed at 3 locations on each patient's skin to mark the same geometric plane and combining SPECT and CT images on a workstation. Without knowing the clinical information of the patients, 2 nuclear medicine physicians interpreted first 131I planar images and then 131I SPECT/CT fusion images. 131I SPECT/CT fusion imaging was considered to have an incremental diagnostic value when it demonstrated different but precise localisation from the 131I planar scintigraphy. Results: As compared with the conventional 131I planar scintigraphy, 131I SPECT/CT fusion imaging had an overall incremental diagnostic value in 34.2% (27/79) of patients, with more lesions detected in 55.6% (15/27) of patients. The undetected activity at the thyroid bed was demonstrated in 7.6% (6/79) of patients, 5 of whom had markedly elevated serum thyroglobulin level. The percentage of the detection of unsuspected lung metastases, bone metastases, and lymph node metastases were 1.3% (1/79), 1.3% (1/79), and 7.6% (6/79) of patients. The previously considered lymph node metastases were excluded in 7.6% (6/79) of patients. Conclusion: 131I SPECT/CT fusion imaging had an incremental diagnostic value over conventional 131I planar scintigraphy in patients with thyroid carcinoma for precise localisation of lesions and improved interpretation, which led to more appropriate patient management.

Optimal time for 131I post-treatment whole body scan: comparison between 2-day scan and 7-day scan after treatment C. Somboonporn, K. Roysri; Nuclear Medicine Division, Department of Radiology, Faculty of Medicine, Khon Kaen University, Khon Kaen, THAILAND.

Objective: 131I post-treatment whole body scan (WBS) is a widely accepted test in identifying the presence of thyroid remnant and the extent of functioning metastases in well-differentiated thyroid carcinoma (WDTC) patients. Sensitivity in detecting lesions depends on image quality and the amount of 131I taken up by the lesions. Although the scan is conventionally performed 4-7 days after 131I administration, optimal scanning time, however, that gives the best detection rate has not been well established. Therefore, we compare the sensitivity of lesion detection between the scan performed on the day of discharge from the hospital (day-2 scan) and that performed 7 days after treatment (day-7 scan) on the same patient basis. Material and method: 131I post-treatment WBS was prospectively studied in 37 patients (28 female and 9 male, mean age 44.7 + 14.2 years) treated with high-dose 131I therapy from November 2006 until January 2007 in our Nuclear Medicine Division. Both day-2 scan and day-7 scan were performed in every patient and the scans were interpreted by two nuclear medicine physicians with consensus. The number, location and grading of uptake (0 = no abnormal uptake, 1 = minimally increased but abnormal uptake, 2 = clearly seen abnormal uptake) by each lesion were compared between the two types of scan. Results: Three patients were negative by both scan types, whereas 34 patients had at least one lesion seen in either day-2 or day-7 scan. The two scans were concordant in terms of the number of lesion detection in 52 from the overall detected 65 lesions (80%). Day-7 scan found 11 lesions (7 in the neck, 3 in the lung, 1 in the mediastinum) not visualized in day-2 scan. Day-2 scan revealed 2 lesions not seen in day-7 scan of 2 patients; both of them were in the mediastinum. Eleven lesions in 9 patients having abnormal uptake had increase in uptake grade in day-7 scan compared with day-2 scan. Two patients with elevated serum thyroglobulin disclosed a cervical lesion that had not been seen in both pre-treatment scan and day-2 scan. Two patients showed more metastatic lesions in bone and mediastinum in day-7 scan which were not seen in day-2 scan. Conclusion: 131I post-treatment WBS performed 7 days after treatment is better than the scan performed 2 days after treatment because it yields higher lesion detection rate. Hence, it provides more accurate staging, risk stratification and better management plan in WDTC patients.

Value of post-treatment 131I SPECT/low dose CT on the management of patients with thyroid cancer K. Taborska, K. Michalova, P. Racek, P. Vlcek; Clinic of Nuclear Medicine and Endocrinology, the 2 ndMedical School of Charles University and Faculty Hospital Motol, Prague, CZECH REPUBLIC.

Accurate assessment of inconclusive foci on whole body 131I scan after radioiodine therapy is important for treatment planning. Due to lack of anatomic landmarks it is not always to evaluate correct site involvement or sometimes distinguish metastatic spread from physiologic uptake without further examination such as ultrasound, CT or MRI. Aim of our work was to analyse usefulness of 131I SPECT/low dose CT after radioiodine therapy when unexpected or new unknown areas with accumulation of 131I were found on post-treatment whole body scans. Material and methods: 19 patients (15 females, 5 males, age 20-83 years) with thyroid cancer at various stage of their disease were examined between August 2006 and March 2007. Planar scintigrams were performed with Sophy DSTXi (GE ) within four to six days after administration of 3,7-7,4 GBq 131I, SPECT/low dose CT examination was acquired with Symbia T (Siemens) at the same or next day. Results: Precise localization was obtained in all evaluated regions. SPECT/low dose CT images improved characterization of equivocal foci of 131I uptake as definitely benign in 2 patients. Additional morphologic imaging was recommended in 2 patients, 2 patients were admitted to surgery due to solitary neck lymph nodes involvement and 1 patients to ovarectomy due to 131I uptake (teratom was histologically proven). In 12 patients subsequent radioiodine therapy was scheduled with tailoring of the administered dosage according to skeletal, lung or nodes involvement. Conclusion: Results of the post-treatment SPECT/low dose CT scans were finally implemented into the management of all patients, 17 patients were spared further examination and findings in 2 patients helped to direct additional follow-up. SPECT/low dose CT examination was found to be a valuable tool in management patients with thyroid cancer.

V. Valotasiou, S. Gerali, C. Zerva; "Alexandra" University Hospital, Athens, GREECE.

Introduction: Diffuse liver uptake (DLU) seen on 131I WBS of patients with operated thyroid cancer, represents liver metabolism of iodoproteins and may indicate either functional thyroid remnants, recurrence of the tumor or functioning metastases. Aim: The aim of our study was to evaluate the frequency and clinical significance of DLU on 131I WBS in patients with thyroid cancer in the presence and absence of thyroid visualization (TV). Materials-methods: We studied 244 patients (45 men, 199 women) with operated thyroid cancer (164 papillary, 19 follicular, 56 mixed papillaryfollicular, 5 Hürthle), mean age 53.47 years (age range:22-86 years). Two hundred thirty-three out of 244 patients (Group A) underwent post therapy WBS 4-15 days (mean 10.3 days) after the administration of 30-200 mCi of 131I (mean 99.86 mCi), while 63/244 patients (Group B) had diagnostic WBS. DLU was graded by two nuclear medicine physicians from 0-3 (0=no uptake, 1=faint uptake, 2=moderate uptake and 3=intense uptake). Results: Group A: 203/233 patients had TV (Group A1) and 30/233 patients (Group A2) had no TV. In Group A1, 189/203 patients had DLU (11/189 had visible metastases on WBS) and 14/203 patients had no DLU (1/14 patient had visible metastases). In Group A2, 27/30 patients (Group A2a) had DLU and 3/30 patients (Group A2b) had no DLU. Group A2a: 9/27 patients had visible metastases on WBS (6/9 had DLU grade=3) and thyroxin-free thyroglobulin (TG) levels 2-455 ng/ml. The other 18/27 patients had thyroxin-free thyroglobulin (TG) levels 1.6-44 ng/ml, findings which raised the suspicion of hidden metastases in these patients. Group A2b: thyroxin-free TG was 0-1.4 ng/ml. Group B: 61/63 patients had TV (Group B1) and 2/63 (Group B2) had no TV. In Group B1, 8/61 patients had DLU (1/8 had visible metastases on WBS with DLU grade=3) and 53/61 had no DLU (1/53 had visible metastases on WBS). In Group B2, 1/2 patient had DLU and 1/2 had no DLU. Conclusion: DLU in the presence of TV may be due to functioning thyroid remnant although the possibility of recurrence or functioning metastases can not be excluded. Nevertheless, DLU in the absence of TV on delayed post therapy WBS, may indicate hidden metastases and therefore could offer additional information in the management of patients with thyroid cancer. Aim: To evaluate the role of the parathyroid hormone (PTH) assay in patients with primary hyperparathyroidism (PHPT). Material and methods: We studied 82 patients, mean age 57 years, clinical and biochemical diagnosis of PHPT, surgical complete exploration after the Sestamibi scanning and anatomopathological confirmation of the removed glands. The PTH values were obtained before surgery, by range of normality 15 and 65 pg/ml. Results: The patients presented a mean average of PTH 134 pg/ml. 1. PTH/Histology: PTH/Hyperplasia: N=16, mean=152, 4000, Tip deviation=50, 10762, Tip error=12, 52690 PTH/Adenoma: N=73, mean=132, 9775, Tip deviation=52, 23478, Tip error=6, 11362 2. PTH/99mTc-Sestamibi scintigraphy: PTH/Negative: N=81, mean=133, 8267, Tip deviation=53, 56779, Tip error=5, 95198 PTH/Positive: N=84, mean=135, 5757, Tip deviation=53, 31358, Tip error=5, 81699 3. PTH means: N=83, minimum=50, 96, maximum=308, 00, mean=134, 7171, Tip deviation=53, 28254 4. Glandular weight means: N=102, minimum=100, maximum=7250, mean=1309, 92, Tip deviation=1186, 400 Conclusion: We didn't observe significant relation between the scintigraphy and the PTH. There was obtained a statistically significant difference (p=0,038) between the averages of the weight of adenomas (1440, 28 mg) and hyperplasias (614, 5 mg). The comparison of the PTH values of both groups hadn't got statistical significance. The results of the Sestamibi scanning didn't show statistical relation with the PTH values. Aim: Several authors have reported false positive I-131 accumulations due to various clinical conditions in the absence of residual thyroid tissue or metastasis of differentiated thyroid carcinoma (DTC). In this report, we present a case with DTC having false positive I-131 accumulation due to a large hydatid cyst in the liver is presented. Case Report: A 37 years old woman underwent bilateral near total thyroidectomy for 1.5 cm papillary thyroid carcinoma located right lobe. Sonographic examination of the patient demonstrated an ovoid, complex cystic mass with dimensions of 15 x 10 cm in the right lobe of liver. The mass was well delineated, and contained septated cystic parts as well as solid appearing components. The appearance of the some solid parts was in favour of detached membranes. Color Doppler ultrasonographic evaluation yielded no vascular signal in the mass. These sonographic findings were found to be concordant with a type CE-3 hydatid cyst according to the World Health Organization classification. The immunoblot test was confirmed hydatid disease. Surgical extirpation of the cyst suggested by interdisciplinary consultations was planned to be performed after the radioiodine therapy. Two month later the thyroid surgery 100 mCi (3700 MBq) radioiodine therapy was performed for ablation of the thyroid remnant. The post-ablative whole body I-131 scan displayed minor uptake in the thyroid bed concordant with residual thyroid tissue and a focal, intense and homogeneous uptake of radioiodine in right lobe of the liver which was reported to be a hydatid-cyst lesion by USG. Conclusion: While some cystic lesions of kidney and liver have been previously reported as causes of false positive radioiodine accumulation, this is the first reported case of uptake I-131 by a hepatic hydatid-cyst up to our knowledge. We therefore suggest that hydatid cystic lesions should be considered as false positive I-131 accumulating pathologies while interpreting wholebody I-131 scans.

A. Mestre, M. Negre, G. Obiols, J. Mesa, F. Porta, J. Castell-Conesa; Hospital Universitari Vall Hebron, Barcelona, SPAIN.

Purpose: To assess the role of 123I scintigraphy in the initial staging of differentiated thyroid cancer in comparison with 131I post-treatment imaging. Methods: This prospective study included 20 patients, 5 male and 15 female, age range 26-80 years. All of them were diagnosed of differentiated thyroid cancer (17 papillary, 3 follicular) and treated with total thyroidectomy. We compared 123I scans (10 of them with SPET) with their corresponding post-treatment 131I whole-body images with a maximum interval of 2 months between them, evaluating the number of foci and localization in each exam. Patients received a dose of 4 mCi of 123I. Images were obtained 12 to 24 hours after administration. Therapeutic dose of 131I (100-150 mCi) after was used as the gold standard diagnostic scanning. 19 patients were studied with rhTSH administration and one with thyroid hormone withdrawal. Results: In 15 out of 20 patients 123I scan findings were completely concordant with those of corresponding post-treatment 131I images with a concordance rate of 75%. 17 patients showed the same number of foci in cervical region (concordance 85%) while three patient showed an increased number of lesions in 131I image. Three patients showed more intense uptake in131I images than in the 123I ones. Two out of 20 patients presented metastatic disease in 123I and 131I scans. Nevertheless, at least two additional foci were observed on post-treatment 131I images. Conclusion123I pretherapeutic scan is comparable to 131I post-therapeutic imaging in differentiated thyroid carcinoma patients with an acceptable concordance in cervical region and at distant site. Although some lesions were missed on 123I images, no changes in therapeutic management of patients were observed.

131I versus 99mTc-sestamibi to detect thyroid cancer recurrence in cervical lymph nodes in cases with increased serum thyroglobulin S. Gerali 1 , P. Valsamaki 1 , J. Koutsikos 1 , S. Tsiouris 2 , E. Pantazi 1 , E. Karga 1 , S. Luccetti 1 , C. Zerva 1 ; 1 "Alexandra" University Hospital, Athens, GREECE, 2 University General Hospital of Ioannina, Ioannina, GREECE.

Aim: The detection of cervical node metastases from differentiated thyroid cancer (DTC), in the setting of increased serum thyroglobulin (Tg), may be accomplished by the post-therapeutic 131I whole-body scan (131I-WBS). The method's effectiveness is directly dependent on the iodine-trapping ability of the cancer cells, under thyrotropin (TSH) stimulation (TSH>30 μIU/L). In this clinical setting, we used the non-specific tumor-seeking radiotracer 99mTc-sestamibi as an alternative diagnostic approach. Scintigraphic findings were correlated with neck ultrasonography (US) and evaluated against the results of lymph node biopsy. Materials & Methods: We retrospectively studied 20 DTC patients [5 men, 15 women, aged 25-60 years (mean ± SD = 44.4 ± 13.3 years). The histologic types were: 12 papillary cell, 5 follicular cell, and 3 Hürthle cell carcinomas. Patients had undergone total thyroidectomy and 131I ablation therapy and eventually presented with elevated serum Tg levels. We performed neck US and 99mTc-sestamibi WBS, 20 min after IV injection of 740 MBq tracer activity. Repeat ablative dose of 131 (3700-5550 MBq) was then administered and posttherapeutic 131I-WBS was performed 3-7 days later. The findings of the three imaging diagnostic modalities were correlated and compared with the lymph node biopsy histology that provided the definite diagnosis. Results: 99mTc-sestamibi identified 18/20 cases of cervical lymph node metastases (11 papillary, 4 follicular, and all 3 Hürthle carcinomas). Positive post-therapeutic 131 -WBS was observed in 5/20 cases. Detection of DTC recurrence in cervical lymph nodes by 99mTc-sestamibi scintigraphy and post-therapeutic131I-WBS was accomplished with a sensitivity of 90% versus 25%, respectively. Conclusion: The application of 99mTc-sestamibi in detecting DTC metastases in cervical lymph nodes seems rewarding, since it demonstrates higher sensitivity than 131I-WBS, probably due to additional recognition of dedifferentiated non-iodophilic lesions. Also, no discontinuation of the thyroxine replacement / suppression therapy is required and the method offers high-quality imaging, with results available on the same day. We present our experience in the follow-up of these patients with serum calcitonin assays and DMSA (V) scans. A retrospective review of the hospital's medical records was performed. Sixteen Patients (11 males, 5 females, Age; 32-60 yrs) with histologically proven medullary thyroid carcinoma, and who had basal serum calcitonin assays and DMSA (V) scans as part of their post-operative follow-up assessment, were included in the study. 56 DMSA (V) scans were performed on these between 1993-96. All patients had prior total thyroidectomy. Two patients had synchronous papillary carcinoma of the contralateral thyroid lobe and 1 patient had MEN 2A syndrome. 7 patients had serum calcitonin assays performed pre-operatively or within 2 weeks of surgery. All 7 patients had calcitonin levels greater than 100pg/ml. The lowest level was 272 pg/ml. Four out of 7 patients showed normalisation of the serum calcitonin levels within 6 months of surgery. Of the 3 patients with elevated serum calcitonin levels, 2 patients showed an initial decline in calcitonin levels up to 12 months post-surgery (but still above 50 pg/ml) and a subsequent increase. Both patients were found on subsequent DMSA (V) scans to have residual or recurrent foci of disease. The 3rd patient was lost to follow up. Tc-99m DMSA (V) scans and serum calcitonin levels performed within a month apart were analysed. Findings were concordant in 38 of 48 instances (79.2%) and discordant in 10 of 48 instances (20.8%). Sensitivity of DMSA (V) scans for detecting recurrence was 71.4%, using calcitonin levels as the reference. There were no false positive scans. Clinical follow-up periods ranged from 9-142 months. Two patients had only one follow-up scan performed within 6 months of surgery and were considered lost to follow-up. At the end of their follow-up periods, 6 of 14 patients (42.8%) were disease -free, 3 patients (21.4%) had residual or recurrent disease; the other 6 patients' (42.8%) status had biochemical recurrence without detectable disease. In conclusion, calcitonin levels are a sensitive and specific indicator of disease recurrence in postoperative follow-up of patients with medullary thyroid carcinoma. Calcitonin normalisation (<50 pg/ml) within 6 months of curative surgery may be a strong predictor of disease-free status whereas a less than complete normalisation of calcitonin may predict eventual disease recurrence. In cases of elevated calcitonin, Tc-99m DMSA (V) is an affordable, readily available and sensitive imaging agent. Objective: The objective of the study was to evaluate the usefulness and accuracy of intra-operative hand held gamma probes in minimally invasive radio-guided surgery (MIRS) of parathyroid adenomas. Material and Methods: 8 patients who were suspected as having parathyroid adenoma by virtue of a high serum PTH and were subsequently diagnosed as having a solitary parathyroid adenoma on the basis of localization study with Tc-99m-Sestamibi were included in the study. All these patients then further underwent minimally invasive parathyroid surgery by being injected with Tc-99m-Sestamibi 3 to 4 hours before their planned surgeries. A hand held gamma probe was used intra-operatively to precisely localize the adenoma followed by the surgery. Results: Tc-99m-sestamibi correctly identified and precisely localized the parathyroid adenoma in all 8 cases. Intra-operative gamma probe also was able to localize the parathyroid adenoma and hence facilitated in the MIRS. All patients have been disease and symptom free on a 6 month follow up. Conclusion: Gamma probe guided MIRS is a very attractive surgical approach to treat patients with primary hyperparathyroidism due to a solitary parathyroid adenoma. The procedure is technically easy, safe, with a low morbidity rate and has better cosmetic results and lower overall costs than convention bilateral neck exploration. Introduction: In primary hyperparathyroidism, the main diagnostic procedures for presurgical localization of parathyroid adenomas are ultrasound of the neck and radionuclide imaging. The sensitivity of the nuclear imaging has proven to be far superior to ultrasound as later is operator dependant. Difficulties in radionuclide imaging arise when primary hyperparathyroidism presents with a multinodular goiter with an incidence ranging from 20% to 75% in endemic regions. Case Report: Presented here is a case of a 42 year old female who presented with bony aches and pains. On examination she was found to have a MNG. Her labs showed the hormonal assays of the thyroid to be in normal range, however, she was found to have a high serum PTH. She was advised a parathyroid scan for the localization of adenoma which showed an area of increased tracer uptake at the lower pole of the left lobe of the thyroid. This area however corresponded with a palpable left sided thyroid nodule on clinical examination. To remove any controversy as to the true origin of this nodule she was advised a Tc-99m-pertechnetate scan. The pertechnetate scan showed an area of photon deficiency in the same area. The patient was then underwent an ultrasound which on Doppler studied confirmed a parathyroid adenoma at the lower pole of the left lobe of the thyroid. The patient was then planned for a minimally invasive parathyroid surgery by injecting MIBI 3 hrs before the planned surgery. A successful surgical outcome was reported and a parathyroid adenoma confirmed on histopatholgy. At 6 months follow up, her PTH and calcium levels became normal and she had also shown remarkable recovery symptomatically.

Unusual metastatic localizations of differentiated thyroid carcinoma N. Ben Rais; Ibn Sina Hospital, Rabat, MOROCCO.

Introduction: The majority of thyroid cancers have a slow evolution, a more often loco-regional extension, and a good forecast. Remote metastases, when they exist, generally touch the osseous skeleton and/or pulmonary tissu. However, unusual metastatic localizations much more exceptional are possible. The authors report through this work two cases of atypical metastasis of differentiated thyroid carcinoma followed in Nuclear Medicine department of Ibn Sina hospital in Rabat. Material and methods: Our two patients had initially underwent a total thyroidectomy for differentiated thyroid carcinoma histologically confirmed. They had profited 4 weeks after the surgical gesture from a reference isotopic exploration (131 Iodine whole body scan and thyroglobulin dosage). The paraclinic assessment was supplemented by a computed tomography (CT). Results: Revealing symptomatology in the first 69 years old patient was dominated by a blindness associated with an elective up-take of radioactive 131-Iodine on the level of hypophyseal gland extending to the sphenoid bone. The second 55 years old patient reported right basithoracic pains resisting to the usual antalgic treatment with a bulky mass driving back the kidney right to the bottom at CT with and important up-take 131-Iodine at whole body scan; a surrenalectomy was thus carried out with conservation of the kidney. In the 2 cases the rate of thyroglobulin was considerably high. An activity of 3,7 GBq 131-Iodine was managed with the 2 patients. The evolution was marked, in the short run, at the first patient by a recovery partial of the sight, the disappearance of pain in the second patient and a remarkable reduction of thyroglobulin rate at both. Discussion: Unusual metastasis of differentiated thyroid carcinoma constitute an exceptional entities in the evolution of the disease. Their treatment and following up does not seem to be significantly different from that of the traditional metastatic forms, insofar as the 131-Iodine therapy keeps all its value to improve or at least stabilize the evolution of this pathology. The diagnostic process and further therapeutic decisions in a case of the solitary pulmonary nodule (SPN) pose a challenge in everyday medical practice. Differentiation whether the SPN is benign or malignant based on traditional methods, may be inconclusive and does not ensure prompt diagnosis and optimal medical management. In this context, evaluation of the usefulness of the receptor scintigraphy with somatostatin analogue 99mTc-Depreotide in diagnosis of a SPN seems to be essential and determines the aim of this study. Material. Examined group consisted of 35 patients with the SPN diagnosed radigraphicaly. Computed tomography (CT), somatostatin receptor scintigraphy (SRS), and fine needle aspiration biopsy (FNA) or surgery with histopathological verification were performed in all the patients. In each case the surgery type was selected based on pathological result: in some cases an operation was more radical with excision of the local lymph nodes. Method. AP and PA projections of the planar images and SPECT examination were carried out between the 2nd and 4th h after IV injection of 99mTc-Depreotide. Radiopharmaceutical activity was 740 MBq. SRS was performed using a dual-head gamma camera Varicam (Elscint, Haifa, Israel) equipped with high-resolution collimators. Tomographic projections were acquired every 3° in 360° geometry, each of 25 s duration. A matrix of 128×128 pixels was applied (4.42 mm/pixel). Reconstruction of the images was performed by means of the iterative method. Semiquantitative analysis of 99mTc-Depreotide uptake in the pulmonary nodules and lymph nodes was based on the calculation of the tumor/ background ratio (tumor activity/ activity in a region located in the contralateral lung). Results. In 27 patients with radiotracer uptake visible in an area corresponding to the tumor location on CT, the diagnosis of pulmonary cancer was confirmed. False negative result was obtained in one case (no Depreotide accumulation in a nodule which turned out to be a cancer). In 3 cases uptake of somatostatin receptor analogue was seen in the non-cancerous lesions (carcinoid in 2 patients and tuberculoma in 1 person). There was no tracer accumulation in 7 benign lesions. Conclusion. Obtained results suggest that SRS performed with 99mTc-Depreotide is clinically useful and may be recommended as a part of the diagnostic algorithm for the management of the SPN.

Thallium-199-scintigraphy in differential diagnostics of inflammatory and neoplastic processes of lungs and mediastinum Purpose: to estimate the efficiency of 199Tl-scintigraphy in differentiating the inflammation and tumor of the lungs and mediastinum. Materials and methods: The 199Tl-scintigraphy has been applied in the investigation of 29 patients (13 male and 16 female of mean age of 42.0±26.0 years) with 30 affection localizations. The scintigraphy was carried out at early and at deferred phases (in 20 and 180 minutes after the intravenous introduction of 185MBq 199Tl, respectively). The accumulation focus has been estimated visually, and the coefficients ER, DR, and RI=DR/ER have been evaluated. The 199Tl-scintigraphy results have been compared with the data of clinical examinations and the results of treatment (n=29), radiography (n=29), and CT (n=22). The affection of the lungs and mediastinum have been confirmed in 23/30 cases (4/30 -inflammations, 19/30 -tumors), and rejected in 7/30 cases. Results: The affections have been visualized in 18/23 (78.3%) cases (14/19 -tumors, 4/4inflammations). The absence of an 199Tl-scintigraphy uptake has been found in 5/23 cases (5 false-negative results). The found absence can be referred to a tumor type and/or tumor smallness (d < 3 cm). The correlation between coefficients RI and ER at inflammations (r=-0.95, p<0.05) and tumors (r=-0.37, p<0.05) is due to the delivery and removing 199Tl from an accumulation focus by the blood-groove. We found that RI=-0,183 ER+1.060 at inflammations, and RI=-0,180 ER+1.335 at tumors. On this basis, we offer the formula RIcrit.=-0.182ER+1.197 to differentiate inflammations and tumors. Thus, the quantitative criterium of an inflammation is RI<-0.182ER+1.197, while at a tumor -RI>-0.047·ER+0.979. Conclusion: The differential diagnostics of inflammations and tumors in lungs and mediastinum has been found to be correct in 18/18 cases. The sensitivity, specificity, and accuracy of the tumor diagnostics by 199Tl-scintigraphy have been estimated as 73.7%, 100% and 83.3%, respectively, and as 100% for all three parameters (estimated on a sample of small amount) of the inflammation diagnostics.

S305 P25 -Monday, Oct. 15, 2007, 2:30 pm -4 :00 pm, Poster Area Diagnostic Oncology: Planar Scintigraphy and SPECT -Breast cancer scintigraphy

A. Spanu 1 , F. Chessa 1 , G. B. Meloni 2 , D. Sanna 1 , P. Cottu 3 , A. Manca 4 , S. Nuvoli 1 , G. Madeddu 1 ; 1 Dept. of Nuclear Medicine University of Sassari, Sassari, ITALY, 2 Dept. of Radiology University of Sassari, Sassari, ITALY, 3 Dept. of Surgery University of Sassari, Sassari, ITALY, 4 Dept. of Pathology University of Sassari, Sassari, ITALY.

Aim: Planar scintimammography (SM) acquired with a conventional gamma camera has proved a useful complementary tool to mammography (Mx) in the diagnosis of BC, but with unsatisfactory sensitivity in small size carcinomas. In this study we assessed the role of planar SM with a high resolution DBC in the diagnosis of BC, comparing the results with those of Mx. Methods: A consecutive series of 129 patients scheduled for biopsy for suspect BC at conventional procedures (clinical examination, Mx, US) was studied. 99mTc-tetrofosmin planar SM was acquired in all patients using a new developed small field of view high spatial resolution (1.6 mm) DBC (LumaGEM 3200S/12k) mounted on a modified mammography unit allowing the similar projections as Mx as well as breast compression during acquisition. Scintigraphic data were compared to Mx findings and correlated to histological findings. Results: 113 patients had BC (unifocal in 92 cases and multifocal in 21 cases) and 16 patients had benign disease; in total 132 carcinomas (40 10 mm and 92 > 10 mm) and 17 benign lesions were ascertained. DBC planar SM was true positive in 111/113 (98.2%) BC patients, detecting 129/132 carcinomas (overall sensitivity: 97.7%), and was true negative in 14/16 (87.5%) patients with benign disease, excluding malignancy in 15/17 lesions (overall specificity: 88.2%). SM sensitivity was 100% in carcinomas >10 mm and 92.5% in those 10 mm. Globally, SM was more accurate than Mx in 36/113 (31.8%) cases, detecting cancer in 8 patients with Mx indeterminate for dense breast (7/8 tumors were <10 mm), assessing additional tumor foci (all <10 mm) in 5 pts with multifocal disease and correctly classifying 23 patients as affected by cancer (7 cases) or by benign disease (16 cases), all of these with inconclusive mammographic findings. However, Mx was more sensitive than SM in 2 patients, in each of these detecting one BC < 10 mm, false negative at SM. Conclusion: DBC planar SM appears a highly sensitive diagnostic tool in the detection of primary BC, also when small in size at a very early stage and in the assessment of multifocal disease. A wider employment of this procedure is thus suggested, especially in indeterminate or inconclusive mammographic findings to improve sensitivity and specificity of Mx. Aim: Preliminary studies have demonstrated the usefulness of planar scintimammography (SM) with dedicated breast camera (DBC) in the detection of unifocal primary BCs. In this study we evaluated the usefulness of this radioisotopic procedure in the diagnosis of multifocal/multicentric BC, comparing the results with those of mammography (Mx). Methods: A series of 127 consecutive patients with suspected BC, imaged preoperatively from November 2005 to February 2007 with DBC planar SM in adjunct to standard procedures, including Mx, was reviewed. Following the i.v. injection of 99mTc-tetrofosmin, SM was acquired in all cases using a new developed small field of view high spatial resolution (1.6 mm) DBC (LumaGEM 3200S/12k) mounted on a modified mammographic unit allowing the similar projections as Mx as well as breast compression during acquisition. Scintigraphic data were related to final surgical histopathological findings and compared to those obtained with Mx. Results: At surgery, 20/127 (15.7%) patients had multifocal (12 cases)/multicentric (8 cases) BC, bilateral in one case, including 15 patients with palpable multiple ipsilateral invasive BC and 5 with non palpable multiple microscopic foci of carcinoma in situ. DBC planar SM was true positive for cancer in all cases, while Mx was true positive in 19/20 cases and false negative in one who had 2 distinct foci (10 and 5 mm in size) of invasive carcinoma. SM assessed multifocal/multicentric condition in 14/15 patients with multiple invasive BC, showing additional tumor foci than Mx in 4 cases, while in one patient missed a subcentimetric focus, also negative at Mx. Moreover, SM correctly defined tumor extension ascertained at surgery in all 5 patients with carcinomas in situ, including 4 with only microcalcifications without masses at Mx. In no case Mx was more accurate than SM. Conclusion: High resolution DBC planar SM proved a very useful diagnostic tool in multifocal/multicentric BC detection correctly assessing local disease extension and demonstrating a better performance than conventional Mx. A wider employment of this radiosotopic procedure is thus suggested as a complementary tool to conventional methods in planning the surgical treatment of multifocal/multicentric BC patients.

Correlation of mammographic density with the mode of scintimammographic 99mTc-(V)DMSA uptake in various breast pathologies V. Papantoniou 1 , E. Sotiropoulou 1 , S. Tsiouris 2 , N. Ptohis 1 , M. Sotiropoulou 1 , A. Tsigris 1 , A. Stipsanelli 1 , K. Sirgiannnis 1 , K. Dimitrakakis 1 , P. Valsamaki 1 , E. Kounadi 1 , N. Makris 1 , C. Zerva 1 , A. Antsaklis 1 ; 1 "Alexandra" University Hospital, Athens, GREECE, 2 University General Hospital of Ioannina, Ioannina, GREECE.

Aim: To investigate the mode of 99mmTc-(V)DMSA distribution in correlation with mammographic density, in women with dense breasts and various breast lesions. Materials & Methods: 55 women (aged 53.2±11.8 years) scheduled for breast surgery due to suspicious palpation and/or mammography, were submitted to doublephase (V)DMSA scintimammography (10 and 60 min after intravenous tracer administration), 2-7 days before surgery. Dense breast (%) area on mammography ([dense breast area / whole breast area] × 100%) and tracer uptake (%) area on scintimammography ([tracer uptake area / whole breast area] × 100%) were calculated by computer-assisted means and were correlated with the histological findings. Calculation of the lesion-to-background (L/B) ratios at 10 and 60 min was performed at the sites of maximal breast activity. Retention Ratio (RR = L/B60min minus L/B10min) and Retention Index (RI = [L/B60min minus L/B10min] / L/B10min] × 100%) were calculated and compared (Mann-Whitney U test) between the various breast pathologies. Continuous data are expressed as mean ± SD; significance level was set at p<0.05. Results: Histology revealed 20 benign non-proliferating lesions (BNPL), 10 benign proliferating lesions (BPL), 17 carcinomas in situ (CIS), and 14 infiltrating carcinomas (IC). BPL were associated with the highest breast density values, followed by CIS. Breast density was 31.48±14.68 in BNPL, 47.20±17.30 in BPL, 35.80±10.19 in CIS, and 24.04±13.30 in IC. Significant density differences were found between BNPL-BPL (p=0.031), BPL-IC (p=0.0039), and CIS-IC (p=0.014). Likewise, BPL were found to have significantly higher (%) tracer uptake compared to the other histologies. Scintimammographic (%) uptake was 22.45±8.09 in BNPL, 31.79±9.25 in BPL, 26.39±8.73 in CIS, and 15.3±9.2 in IC. (V)DMSA retention over time was profound in BPL and CIS. RR was 0.32±0.35 for BNPL, 1.50±0.88 for BPL, 0.50±0.32 for CIS, and 0.35±0.29 for IC, while the RI was 22.10±20.30, 49.80±25.80, 38.90±25.00, and 23.41±20.55, respectively. Significant differences in (V)DMSA RR were found between BNPL-BPL (p=0.001), BNPL-CIS (p=0.005), BPL-CIS (p=0.048) and BPL-IC (p=0.02), whereas significant RI differences were found between BNPL-BPL (p=0.006), BNPL-CIS (p=0.039), and BPL-IC (p=0.02). Conclusion: (V)DMSA's kinetic behaviour is possibly related to the early onset of cell proliferation in the process of carcinogenesis, in women with dense breasts. Furthermore, increased breast density is associated with benign proliferating lesions with potential of evolving into malignancy and also with CIS. The combination of mammography and scintimammography may be helpful in selecting those women at risk, who could benefit from prophylactic treatment.

A. Spanu 1 , A. Farris 2 , F. Chessa 1 , D. Sanna 1 , M. Pittalis 2 , S. Nuvoli 1 , G. Madeddu 1 ; 1 Dept. of Nuclear Medicine University of Sassari, Sassari, ITALY, 2 Dept. of Oncology University of Sassari, Sassari, ITALY.

Aim: Conventional imaging procedures proved of limited value in assessing tumor response to neoadjuvant chemotherapy in patients with LAPBC. In the present study we evaluated and compared the usefulness of 99mTc-tetrofosmin planar scintimammography (SM) and SPECT in monitoring the response to neoadjuvant hormone or chemotherapy in patients with LAPBC. Methods: 32 patients affected by LAPBC were studied before and after completing hormone (10 cases) or chemo (22 cases) neoadjuvant therapy prior to surgery. In all cases, following 740 MBq 99mTctetrofosmin i.v. injection, both conventional planar SM and SPECT were acquired using a dual-head gamma camera equipped with HR parallel hole collimators. In 15 cases planar SM with a new developed small field of view high spatial resolution (1.6 mm) DBC (LumaGEM 3200S/12k) mounted on a modified mammography unit allowing similar projections of mammography and breast compression during acquisition was also acquired. Planar and SPECT findings were evaluated visually, mutually compared and correlated with definitive histopathological findings in all cases. Results: Four patients had a complete pathologic positive response, while residual tumor was ascertained at histology in 28 patients. No uptake areas were detected at both conventional planar SM and SPECT, excluding residual tumor after therapy, in 4/4 (100%) cases, in accordance with histology. DBC planar SM was performed in 1 of these 4 cases resulting true negative. Conventional planar SM detected residual tumor in 23/28 (82%) cases, resulting false negative in 3 patients with a pT1c tumor, including one mucinous BC, and in 2 patients with multiple and scattered subcentimetric tumor foci. SPECT was true positive in 25/28 (89.2%) cases, but missed the mucinous BC and the 2 subcentimetric tumors which were also false negative at conventional planar SM. However, these latter 2 carcinomas were identified only at DBC planar SM which was true positive also in the other 12 patients with macroscopic residual tumor in whom the procedure was performed. Conclusion: Both conventional planar SM and SPECT proved useful diagnostic tools in monitoring the response to neoadjuvant hormone or chemotherapy in LAPBC. SPECT appears more sensitive than conventional planar SM in detecting residual tumor; however, our preliminary data seem to suggest that sensitivity can further increase by high resolution DBC planar SM, especially in subcentimetric tumor foci. These data need to be confirmed in larger series of patients.

The role of 99mTc-MIBI Gated SPECT for assessment of anthracycline cardiac effects in breast cancer patients A. Tzonevska, K. Timcheva, M. Dimitrova; National Oncology Hospital, Sofia, BULGARIA.

Aim: Evaluation of adverse cardiac effects from anthracycline breast cancer therapy may enable identification of patients of risk for cardiotoxicity. The aim of the study is to assess the possibilities of 99mTc-MIBI Gated SPECT for early evaluation of patients of risk after anthracycline therapy. Material and method: The study included S306 18 patients with breast cancer (mean age 53 years ) after anthracycline therapy ( total dose 600 mg Farmarubicine ), 6-12 months after treatment. All of the patients had clinically normal cardiac status and performed echocardiography (EchoCG). Gated SPECT myocardial scintigraphy was performed at rest after i.v. injection of 740 MBq of 99mTc-MIBI. A SPECT gamma camera Siemens DIACAM was used. Data were acquired for 45 s for each projection using 64 x 64 matrix over 180°. Images were gated at 8 frame per cardiac cycle with an R-wave trigger. Myocardial perfusion in each segment was estimated and regional systolic wall thickening and ejection fraction (EF) were measured and compared to EchoCG. Results: The results demonstrated normal myocardial perfusion, regional systolic wall thickening and EF in 11 patients. In 7 patients there was mean to moderate hypoperfusion affecting myocardial segments ( anterior segments in 4 patients, inferior segments in 3 patients ). Among these patients, 2 patients established normal EF ( 70%-72%) and 5 patients had slightly reduced EF ( 48%-52%) and regional systolic wall thickening in the hypoprfused regions as these results matched the EchoCG findings. It is concluded that 99mTc-MIBI can be of use for early detection of adverse effects of anthracycline cancer treatment, before positive EchCG results.

The role of 99mTc-MIBI scintimammography in recurrent breast cancer Z. Rajkovaca 1 , J. Mijatovic 1 , G. Vuleta 1 , A. Matavulj 2 , P. Kovacevic 2 , N. Ponorac 2 ; 1 Clinical Centre, Banja Luka, BOSNIA AND HERZEGOVINA, 2 Medical Faculty, Banja Luka, BOSNIA AND HERZEGOVINA.

Breast conservative surgery has now become commonplace as it is less mutilating than radical surgery. The probability of recurrent tumour in this form of surgery increases. Post-surgery and radiotherapy changes as fibrosis, inflammation have reduced the accuracy of convectional method of breast imaging as X-ray mammography. The aim of this study is to asses the accuracy of 99mTc-MIBI scintimammography in patients with suspected recurrent breast cancer in the breast or loco regional tissues. Methods: Nineteen (18) women (median age 46 years, range 23-64 years) with suspected recurrent breast cancer in the breast or loco regional tissues were investigated. After routine analyses (clinical examination, ultrasound, X-ray mammography and fine needle aspiration biopsy) they were examined by scintimammography (10 minutes after iv injection of 740 MBq of 99mTc-MIBI). All patients with suspected recurrent cancer in the breast or loco regional tissues (12) undergone surgery and the final diagnosis was determined by histopathological examination. Another 6 patients were followed 6-24 months. The scintigraphic studies were correlated with radiological findings and/or with histopathology. Results: There were 11 patients with recurrent cancer (8 with loco-regional recurrent and 3 in another breast). X-ray mammography identified seven of these cancers. 99mTc-MIBI scintimammography identified ten of eleven recurrent breast cancers. The one cancer not seen on scintimammography was positive on X-ray mammography. In the five out of seven patients without cancer, scintimammography were reported as having no changes consistent with cancer. X-ray mammography showed suspected cancer lesions in three out of seven patients without cancer. There were two false-positive scintimammograms and one false negative. Axillary lymph node recurrence occurred in two patients. Bought of them were positive on scintimammography. 99mTc-MIBI showed higher sensitivity, specificity and accuracy per patient than did X-ray mammography (90.9% vs. 63.6%, 71.4% vs. 57.1% and 83.3% vs. 61.1%, respectively). Conclusions: 99mTc-MIBI scintimammography has high sensitivity, specificity and accuracy in patients with suspected recurrence of cancer in the breast or loco-regional tissues. To identifying recurrent breast cancer disease is better to use scintimammorapfy than X-ray mammografphy. Aim: To evaluate breast scintigraphy in the diagnosis of breast cancer by quantitative analysis and image enhancement to emerge suspected lesions. Breast scintigraphy demonstrates better specificity of mammography in cases where mammography is proven to be non-diagnostic (dense breast, scar tissue).. Method: 12 patients with a suspicious breast lesion and an abnormal mammography completed a scintigraphic study of the breasts. 740-925MBq of Tc99m-Tetrofosmin is injected intravenously in the arm vein contralateral to the breast with the suspected abnormality. The patient was laid prone with a single breast dependent from the imaging table of a SPECT gcamera. The contra lateral breast was compressed against the table to prevent cross talk of activity. The images obtained, as an interfile , were transferred via procyon starlab program to a PC and processed by Image Pro Plus, software for data analysis, visualization and application development that combines the tools necessary for interactive analysis and display. Results: The visualization of the image improved significantly, by applying image-processing techniques. In the histograms of the image pixels, brightness/contrast deficiencies are illustrated. The image contrast is adjusted appropriately by applying spatial filters and gamma correction technique. Highactivity chest and abdominal organs such as the myocardium and liver are masked out, in regions of interests ROIs, by count subtraction. A logarithmic scale is chosen so that low-count areas are enhanced. Semi-quantitative parameters were determined to characterize and improve the sensitivity and specificity. The tumor to background ratio (T/B) was calculated by using regions of interest (ROI) of standardized shape and size over the site of the greatest activity and the surrounding normal tissue and creating the corresponding profiles. Focal, increased uptake relative to surrounding tissue is classified as a positive study through the profile index. In every case scintigraphic results are compared with histological findings. Conclusion: Breast scintigraphy seems to be a very promising alternative imaging technique, especially, where mammography proves to be non-diagnostic. Image processing techniques improve both the specificity and the sensitivity of the technique. One of our near future goals is to classify the grade of malignancy through the technique of image processing in breast scintigraphy.

Tc99m-depreotide scintigraphy: Priliminary study L. Iordanidou, A. Georgakopoulos, N. Bolanos, E. Trivizaki, S. Saranti, K. Rethimniotakis, N. Stefanakos, P. Koutsiouba; Metaxa Cancer Hospital, Piraeus, GREECE. Aim:. Accurate staging of disease recurrence is critical on treatment decisions. Findings from conventional imaging can often be inconclusive, especially in areas previously treated with surgery or radiation. The aim of this study was to determine the potential role of 99m Tc depreotide scintigraphy in the evaluation of breast cancer recurrence , particularly to intrathoracic tumor sites after primary treatment. Patients and Methods 99m Tc depreotide scintigraphy (whole body and thoracic SPECT) was performed in 15 female patients (mean age 56, age range 23-79 years) who had previously treated for invasive breast cancer. The impact of 99m Tc depreotide on defining the disease recurrence was determined by comparing Tc99m depreotide results at the time of the examination with findings from conventional imaging (CI) performed before(mean time interval of 15 days, range, 0-40 days) The final diagnosis of recurrent or metastatic breast cancer was confirmed by histopathological findings or clinical and radiological follow up . Results Overall of the 15 patients under study, 13 patients had confirmed recurrent or metastatic breast cancer, and 2 were free of disease recurrence. Eight of 15 female patients had equivocal findings on CI of the thorax, and 7 had findings indicative for metastatic disease. . 99m Tc depreotide SPECT correctly identified the nature of equivocal findings as detected by CI imaging in 7 out of 8 patients: 6 patients were truth positive ( malignant) , 1 patient was truth negative ( benigh) and 1 patient false positive (infection). 99m Tc depreotide scintigraphy detected in all 7 patients the metastatic lesions that had already been shown by CI imaging and in comparison with CI findings showed extent of disease increased in 5 (new metastatic lesions ) and no change in 2 patients. Conclusions These preliminary results suggests that 99m Tc depreotide scintigraphy is useful for detecting recurrent breast cancer and it seems to provide a better understanding of the extent of disease as compared with conventional imaging modalities. Objectives: It is important for clinical physician to stage, to evaluate effectiveness, to diagnose recurrent and survived tumor in routine clinical practice. The purpose of this study was to validate the clinical application value of 18F-fluorodeoxyglucose (18F-FDG) using single photon emission computed tomography with coincidence detecting imaging in staging of lymphoma and evaluating the therapeutic effective. Methods: Eighteen patients with NHL were performed with 18F-FDG metabolic imaging preand post-therapy using a Vertex Plus EPIC MCD/AC from ADAC Company. The imaging was performed 60 min postinjection of 18F-FDG 129.5-168.5 MBq using ADAC Vertex plus MCD/AC (SPECT with coincidence detection). Qualitative and semi-quantitative analyses were made during interpretation of 18F-FDG imaging. Qualitative analysis is that malignant neoplastic lesions were identified if there were 18F-FDG concentrated area beyond normal tissues (brain, heart, gastricintestinal tract, kidney and bladder et al). Semi-quantitative analysis, such as T/B (ratio of radioactive counts of tumor and normal tissue) was performed. When T/B > 2.0 the lesion are regarded as malignant lesions. 18F-FDG images were compared with synchronous routine images such as ultrasonography and CT. Results: Thirty studies were performed in 18 patients with NHL in this study. There were 21 true positives, 6 true negatives, 2 false positives and 1 false negative. The accuracy, sensitivity, specificity, positive predictive value(PPV) and negative predictive value(NPV) were 90%, 95.4%, 75%, 91.3%, 85.7%, respectively. 18F-FDG imaging led to a change of 16.7% in the clinical staging, and 46.7% in the management. The PPV and NPV of recurrence detected by 18F-FDG SPECT/PET were 100% and 80%, while CT's were 50% and 25% after therapy. Four of five patients with negative entered clinical complete remission (CR), whereas all the 11 patients with abnormal 18F-FDG uptake relapsed or reprogressed. Progression-free survival (PFS) with negative 18F-FDG was 16-47 months (median: 28.7 months) and PFS with positive was 3-46 months (median: 8.3 months). Conclusion: 18F-FDG metabolic imaging using SPECT with coincidence detection plays an important role on clinical application of the diagnosis and management of patients with NHL. Key words: 18F-FDG; SPECT; coincidence imaging; Lymphoma rituximab and 0.5 ml of an Medronate kit, reconstituted in 2 ml of 0.1M PB was irradiated for 20 min at 302 nm. Irradiated solution was aliquoted into nitrogen-filled vials and stored at -80oC. Each aliquot was labelled with 700 MBq of 99mTcpertechnetate. Radiolabelled antibody was sterilised by filtration under aseptic conditions using a 0.2 um filter. The effectiveness of the labelling method was evaluated by determination of the number of free thiol groups per photoreduced antibody using 5-iodoacetamidofluorscein reaction method, radiochemical purity determination of 99mTc-rituximab by TLC and size-exclusion HPLC and testing of in-vitro stability of the preparation. Immunoreactivity of 99mTc labelled Rituximab was further explored on Ramos cells using a direct binding assay. Until now six patients (age 42-70 y) with CD20+ lymphoblastic B-cell NHL and one with CD20-NHL as diagnosed by lymph node biopsy and planned for Mabthera® or 90Y-Zevalin treatment, were injected with 500 MBq of 99mTc-rituximab. Whole body and SPECT images were taken 1h, 3h, 6h and 24h post injection. Scintigrafic results were compared with CT findings. Results In all cases high radiochemical purity over 95% was observed with preserved affinity of 99mTc radiolabelled rituximab for CD20 antigen, IRF being above 93%. On average 4.11 fee thiol groups per photoreduced rituximab were determined. In all patients expected activity was seen in the blood pool, liver, spleen and kidneys. Accumulation of 99mTc-rituximab in involved sites was clearly seen on the whole body and SPECT images performed as early as 3 h p.i. in some patients and 6 and 24 h p.i images in all patients. Pathological, moderately to markedly increased 99mTc-rituximab activity was seen in all CT confirmed NHL involved sites 6 h and 24 h p.i.. Conclusion 99mTc-Rituximab is a promising imaging agent suitable for assessing expression of CD20 in patients with NHL prior to (radio) immunotherapy.

Bone involvement in lymphoma:comparison of 99mTcMIBI and 99mTcMDP scintigraphy D. Vassileva 1 , A. Tzonevska 2 , M. Dimitrova 2 ; 1 National Centre of Haematology and Transfusiology, Sofia, BULGARIA, 2 National Centre of Oncology, Sofia, BULGARIA.

Bone lymphoma is uncommon and presents diagnostic and therapeutic difficulties. Aim:The purpose of the study was to compare 99mTcMIBI and 99mTcMDP scintigraphy in bone lymphoma, with an attemt to define the relevance of each modality with respect to disease detection and possibly the interrelationships of scan pattens with disease activity. Material and methods: 40 patients with malignant lymphoma (Hodgkin's disease, non-Hodgkin's lymphoma and myeloma) and suspected bone involvement were investigated. The bone scans were obtained at 2 hours after intravenous injection of 740 MBq 99mTc MDP and 30 min and 3 hours after i.v. injection of 740 Mbq 99mTcMIBI. The scintigraphic results were compared with the data of conventional imiging methods and hystological results. Results: The results from the both scintigraphies were devided in 4 groups: I group-In 17 patients with osteolytic lesions both 99mTc MIBI and 99mTc MDP scintigraphy were true positive for the presence of active disease. The MDP scans depend on the osteoblastic activities around the lesions. The scans detected 38 lesions, especially in the femur, humerus, ribs,sternum, thoracic and lumbar spine, pelvis. II group-The 99m Tc MIBI scans were positive ( 7 lesions) and 99mTc MDP negative in 5 patients. 99mTcMIBI accumulation attributed to bone marrow metastases may occur at an early stage, before the bone remodeling process can be detected on conventional bone scans. III group-In 10 patients, positive 99m Tc MDP scans and negative 99mTc MIBI scintigraphy were found. Pathological fractures and persistent reactive bone formation after therapy (17 lesions) were detected in patients by positive bone scintigraphy only. The 99m Tc MIBI image may become positive before the 99m Tc MDP and may subsequently revert to normal in the presence of an abnormal 99mTc MDP scan. In one patient with positive 99mMDP scintigraphy demonstrated lesion in humerus, the bone biopsy showed osteomyelitis. IV group-No abnormal images on the both scintigraphy were found in 8 patients, defined as a desease remission. Conclusion: 99mTc MIBI scintigraphy is helpful in early diagnosis , in detecting the extraosseous lesions and in early remission after therapy in lymphoma. 99mTc MDP scintigraphy is of limited value for the initial diagnosis of sceletal involvement but is a sensitive method for the detection of pathological fractures and osteblastic activity after chemotherapy.The combination of 99mTcMIBI and 99mTcMDP scintigraphy gives an accurate diagnosis and helps to asses the extent of the disease in lymphoma with bone involvement. The purpose of this ongoing clinical study is to optimize the follow up as well as the primary diagnosis of patients with neuroendocrine tumors. Different methods, like F-DOPA-PET/CT and In-111 Octreotid SPECT/CT, conventional imaging modalities and biochemical markers are performed individually in a comprehensive concept. Methods: Up to now 42 patients with suspicion of recurrence of a neuroendocrine tumor or in a preoperative assessment have been examined in our department. In addition to conventional imaging studies (CT/MRI or ultrasonography) F-DOPA PET/CT, if demanded In 111-Octreotid SPECT/CT, a complete patient history, physical examination and biochemical markers (including CgA, a 24 h urine collection for determination of 5-HIAA and the predominant pancreatic peptide) were performed. Results: 10 patients demonstrated pathological findings in the F-DOPA PET/CT and/or in the In-111 Octreotid SPECT/CT. The results from the two imaging modalities were helpful in deciding the primary treatment options, meaning adequate resection with curative or palliative intent for primary and regional lesions. The somatostatinreceptorscintigraphy allows additional information about the treatment option with somatostatin analoga. In one patient with recurrence of a carcinoid tumor (clinical symptoms, 5HIES + CgA elevated) F-DOPA PET-CT demonstrated clearly the extent of the metastatic disease (multiple peritoneal and iliacal metastases). In-111 Octreotid SPECT/CT, however, demonstrated only tracer uptake in the iliacal lymphnodes, the multiple peritoneal metastases showed no Somatostatin receptor expression -showing the different tumor biology of the metastases in one single patient. Conclusion: Each of the performed modalities (MRI,CT, ultrasonography, F-DOPA PET/CT, In-111 Octreotid SPECT/CT, patient history, physical examination and biochemical markers) are of great value and can contribute in the whole concept of treatment options, follow up and therapy monitoring in patients with neuroendocrine tumors. 111In-octreotide scintigraphy is a very important procedure for the staging and followup of somatostatine receptors expressing cancers. However, a major drawback of the technique is the lack of anatomical landmarks. The best solution to this problem is the fusion with radiological images obtained using SPECT/CT devices. Since this kind of machines is not still widely available, we propose a simple way to improve the anatomic localisation of 111In-octreotide foci. Patients and methods: 111Inoctreotide images (after injection of 300 MBq activity) have been recorded at 4, 24 and, if necessary, 48 hours. According to the findings on the images acquired at 4 hours, planar and tomographic images at 24 hours have been obtained with a simultaneous double isotope acquisition, after administration of a bone tracer (99mTc-HMDP, 800 MBq) Three different energetic windows have been centered respectively on the two 111In peaks (245 and 171 keV) and on the 99mTc peak (140 keV) We validated this technique in 10 consecutive patients. Results: We show several images where the association between 111In-octreotide and bone scan provided useful information on the anatomical localization of the lesions visualized by the somatostaine scintigraphy. Conclusion: Double isotope tomography is a simple technique and it's easily feasible in every nuclear medicine department. This modality of image acquisition allows to improve the anatomical localization of 111In-octreotide scintigraphy. Aim: Pentetreotide is a DTPA conjugate of octreotide, a long-acting analog of the human hormone, somatostatin. 111In pentetreotide (OctreoScan) binds to somatostatin receptors on cell surfaces, and can be used for scintigraphic localization of neuroendocrine tumors bearing corresponding receptors. The aim of the study is detection of primary and metastatic neuroendocrine tumors. Patients and Methods: The total of 20 patients (8 males and 12 females, age 53±7 years) patients were investigated. Scintigraphy of the whole body, (and tomography 360o/6o if necessary) were performed 4h, 24h and 48 h after i.v. administration of 111MBq 111-In pentetreotide. If needed, the study was supplemented with liver/spleen radiocolloid and/or bone diphosphonate scintigraphy. The study was performed with Orbiter gamma camera and MicroDelta computer, using medium energy collimator and two photopeak activities (171.3keV±20% and 245.4keV±20%). Results: In the group with seven neuroendocrine carcinomas of unknown origin, there were six true positive (TP) findings (two with liver metastases, two with liver, lung, and bone metastases, one with liver and mediastinal lymph node metastases and one with liver and retroperitoneal lymph node metastases), while one was false negative (FN) (poorly differentiated carcinoma with retroperitoneal metastases). In four patients scintigraphy influenced further patient management. From the group of nine pancreatic neuroendocrine tumors, in five neuroendocrine pancreatic carcinomas there were three TP (two with liver metastases) and one FN (poorly differentiated). In two patients with pancreatic gastrinomas both findings were TP, while in one patient with insulinoma it was TP and in the other TN. In four patients scintigraphy influenced further patient management while in two contributed. From the group of four neuroendocrine lung tumors there were two TP (two patients with bronchial carcinoid, one with liver metastases and the other with liver, lung and bone metastases), in one patients with atypical lung carcinoid after surgery, finding was TN, while in one with neuroendocrine lung tumor (ACTH secreting) it was FN (small mediastinal tumor. In one patient scintigraphy influenced further patient management while in one contributed. Because of the the high uptake of radiopharmaceutical, and widespread metastases, six patients were indicated for radionuclide therapy with 90Y-DOTA TATE, and three of them received it. Conclusion: Preliminary results show that scintigraphy of neuroendocrine tumors is a useful method in diagnosis, staging and follow up of the patients suspected to have neuroendocrine tumors in the lungs. It is also helpful in the appropriate choice of therapy, including the radionuclide one.

centre, we noticed an increasing number of referrals for Octreotide studies in patients with mild symptoms or signs suspicious for a NET and raised GI peptides but no history of a NET and no suggestion of a NET on other imaging. Therefore, an audit was undertaken to assess the use of Octreotide studies in this patient group. Method A retrospective review was performed of all Octreotide studies performed in 2005 to firstly detect what percentage of referrals were performed for this group of patients. Secondly, within this group, the number of normal and abnormal studies was examined. Results 88 studies were performed in total in 2005 with 26 of these falling the category of interest. 23 of these were normal with the remaining 3 raising the possibility of an abnormality, but further imaging appeared normal. Discussion & Conclusions We concluded that Octreotide studies did not appear to be useful in investigating this subgroup of patients. Aim. The aim of this study based upon a large series of consecutive patients evaluated by SPECT 111In-pentetreotide for a neuroendocrine tumor, was to evaluate the variability of reconstructing parameters used during SPECT study, in relation to the patient body weight and body district, looking for the possibility to standardize such parameters. Materials and Methods. 124 patients underwent 111In-pentatreotide scintigraphy by 4-and 24-hr whole-body and planar scans, and 24-hr SPECT examination. All patients were injected with 140-150 MBq of 111In-pentetreotide at least 1 week after somatostatin analogs discontinuation. SPECT was sitematically acquired at the level of the head, chest, and abdomen. SPECT parameters were selected as follows: acquisition, gamma-camera dual-head, medium energy collimators, step and shoot method, no circular orbit, matrix 64x64, 30 sec. per view for a total of 64 views; reconstruction, two procedures were compared, Iteractive Method using 10 iterations vs. Filtered Back Projection using Butterworth filter with different cut-off and order values. Results. The results we obtained are summarized on Table (see below) , where reconstructing parameters of 111In-pentetreotide SPECT were correlated to patient's boby weight (b.w.) and body discrict.

Patients with b.w. Patients with b.w. part lower than 70 kg greater than 70 kg HEAD Cut-off Order 7-8 Cut-off Order 7-8 0,30-0,40 0,30-0,40 THORAX Cut-off Order 7-9 Cut-off Order 7-9 0,35-0,50 0,35-0,40 Order 7-9 ABDOMEN Cut-off Order 7-9 0,55-0,80 Order 7-10 0,50-0,70

Order 7-9 0,55-0,80 Order 7-10

Conclusions. In our experience, the optimal SPECT images were obained by applying the Butterworth filter. Moreover, it was possible to standardize the reconstructing parameters for the body districts of the head and chest, while in the abdomen the choice of these parameters was more variable; this is probably due to the fact that 111In-pentatreotide is physiologically trapped in various abdominal areas, and in different manner as a function of time, especially the liver, the spleen, the bowel, and the urinary tract. Aim: As SPECT/CT evolves, its applications, including CT parameters, need to be evaluated in order to improve diagnostic accuracy and to assure that radiation exposure is minimal. Here, we evaluate the added value of an additional "diagnostic" CT-scan (centred on a solitary focus) in cancer patients referred for bone staging and, for whom, a conventional low-dose SPECT/CT acquisition was planned. Material and Methods: Patients with a solitary focus observed on whole-body bone scintigraphy (WBS) and classified as indeterminate or suspicious, underwent a low dose SPECT/CT acquisition (120 kV, 30 mAs, 5 mm slice thickness); the CT-scanning area being similar to that obtained during the SPECT acquisition. In addition, a "diagnostic" CT-scan (120 kV, 100 mAs, 1.25 mm slice thickness) centred on the focus obtained from the CT-topogram, was performed. Nuclear physicians considered prospectively WBS, low-dose SPECT/CT and finally the centred SPECT/CT. Radiation dose exposure was evaluated by means of a computed tomography dose index (CTDI). Results: Thirty-one consecutive patients (mean age: 62 yrs +/-12) were included in the study. Whole-body bone scintigraphy depicted solitary indeterminate or suspicious foci in 20 and 11 patients, respectively. After low-dose SPECT/CT, these foci turned out to be malignant, or benign, in 8 and 17 patients, respectively, and remained indeterminate in 6 patients. Low-dose SPECT/CT altered the interpretation of the WBS results in 15 pts of the "indeterminate focus" group and 5 pts of the "suspicious focus" group. An additional diagnostic CT-scan was accurately centred in all but one patient and altered low-dose SPECT/CT results in only 1 patient, in whom a solitary indeterminate focus on WBS was classified as indeterminate on low-dose SPECT/CT and subsequently benign on diagnostic SPECT/CT. Additional foci (not found by WBS) located outside the scanning area of the centred diagnostic CT-scan were found in 9 patients. CTDI measurements were 3.30 +/-1.44 mGy and 10.18 +/-2.97 mGy in low-dose and "diagnostic" CT, respectively. Conclusion: These preliminary results show that, (1) a conventional low-dose SPECT/CT is adequate for patients presenting with a solitary focus on WBS, provides an acceptable radiation dose exposure and identifies 25/31 (80%) of foci; (2) a CT volume session should not be limited to the area of the solitary focus since additional foci overlooked by WBS and located outside the centred CT-scan occurred in 9 pts (29%) and thus required CT data acquired over the entire SPECT region of interest for thorough elucidation.

199Tl-scintigraphy in differential diagnostics of inflammatory and malignant tumoral processes of the musculoskeletal system Purpose: to estimate the efficiency of 199Tl-scintigraphy in differentiating the inflammation and tumor. Materials and methods: The 199Tl-scintigraphy has been applied in investigation of 53 patients suffering the inflammatory and neoplastic diseases of the musculoskeletal system. The scintigraphy was carried out at early and at deferred phases (in 20 and 180 minutes after the intravenous introduction of 185MBq 199-thallium, respectively). The intensity and contour's sharpness of the radiotracer accumulation focus have been estimated visually, and the coefficients ER, DR, and RI=DR/ER have been evaluated. The thallium-199-scintigraphy results have been verified morphologically (n=46) and compared with the data of ultrasonic (n=18), 3-phase scintigraphy (n=11), MRT (n=7), WBC-scintigraphy (n=4), radiography, (n=56), CT (n=20), clinical examinations, and results of treatment (n=67). Results: The affections have been visualized in 53/56 (94.6%) cases (33/36inflammations, 20/20 -tumors). The correlation between coefficients RI and ER at inflammations (r=-0.74, p<0.05) and tumors (r=-0.35, p<0.05) is due to the delivery and removing 199-thallium from an accumulation focus because of blood-groove. We have found that RI=-0.050·ER+0.892 at inflammations, and RI=-0.044·ER+1.066 at tumors. On this basis, we offer the formula RIcrit.=-0.047·ER+0.979 to differentiate inflammations and tumors. Thus, the quantitative and qualitative criteria of an inflammation are: (1) RI<-0.047·ER+0.979; (2) at an early phase, the contour's sharpness of the radiotracer accumulation focus is better than at a deferred phase; (3) a homogeneous accumulation of radiotracer at a deferred phase. At a tumor they are: (1) RI>-0.047·ER+0.979; 2) at an early phase, the contour's sharpness of the radiotracer accumulation focus is worse than at a deferred phase; 3) a heterogeneity accumulation of radiotracer at a deferred phase. Conclusion: The use of the above formulated criteria results in 52/56 (92.9%) success in the differential diagnostics of inflammations and tumors. The sensitivity, specificity, and accuracy of the 199Tlscintigraphy are estimated as 91.7 %, 90.3 % and 91.0 %, respectively in the diagnostics of inflammations, and as 95.0 %, 95.7 % and 95.5 % -in that of tumors.

patients with lung cancer. Furthermore,to quantify the octreotide uptake for the positive SR metastases in order to assess the potential benefit of somatostatin derivatives therapy. Patients and methods: Twelve patients (9 males and 3 females, aged from 33 to 77 years old) with histologically confirmed lung cancer were evaluated (8 with SCLC and 4 with NSCLC).Final diagnosis of bone metastases was based on the combination of clinical findings, the results of imaging methods including X-ray, computed tomography(CT) and bone scintigraphy(BS).The octreotide scanning included anterior and posterior views at 4 and 24 hours tomographic images when it was necessary and quantification of SR regional uptake for detected bone metastases graded with score 0 to 3(0,no uptake; 1,low uptake; 2,moderate uptake; 3,intense uptake;).The images of each patient were evaluated independently by at least two nuclear medicine physicians. Considering the small patient population no statistical analysis was performed. Results: SR scintigraphy visualized the primary tumour in all cases. SR scintigraphy showed skeletal involvement in 7 patients (6 with SCLC and 1 with NSCLC). The detected bone lesions were fewer than in the BS (sensitivity on a lesion basis 72,2 %), although two patients demonstrated more widespread bone metastases than the BS . In the remaining 5 patients SR scintigraphy showed no skeletal involvement (sensitivity on a patient basis 58,3% ). In our series,10% of skeletal metastases showed strong uptake, 30% showed moderate uptake ,while low uptake was demonstrated in 30%.Thirty percent of skeletal metastases showed no uptake. Conclusion:111Indium octreotide scintigraphy provides great potential for the visualization of receptor-positive metastases mainly in SCLC patients. The patients with high SR uptake (grade 2 and 3) could benefit from the treatment with radiolabeled somatostatin analogues. Aim: This study looked at the incidence of positive bone scans in patients with low prostate specific antigens levels and compared this with the published recommendations for bone scanning in prostate cancer. Material & Method: We looked at 100 bone scans in patients with known prostate cancer undertaken at our institution in 2006. These were all reported as clearly "negative" or "positive". Scans which were in any way ambiguous were excluded from the study. We then looked at the prostate specific antigen (PSA) levels in these patients and compared this to the published recommendations which state that bone scans can be confidently be excluded in cases where the PSA< 5, should be omitted where PSA<10 and can cautiously be omitted at PSA<20. Results: We had no positive bone scans at PSA< 5 in agreement with the published data, However, there were 2 positive scans at PSA <10; 3 positive scans at PSA<15 and 5 positive scans at PSA <20. This is an incidence of 5%, which is much higher than the published data would suggest. For those patients with high PSA values >50, 18/30 (60%) patients had a positive scan in agreement with published data. Conclusion: Patients with prostate cancer and PSA< 5 should not routinely have bone scan imaging but those with PSA 5-20 have a 5% incidence of a positive scan and should be considered for bone scintigraphy. Purpose: Breast cancer is the most common form of malignant disease among women associated with metastases in bones. CA 15.3 and CEA are two of the most widely used tests for monitoring breast cancer.99mTc MDP bone scintigraphy is the most widely using imaging test for early detection of bone metastases. Carbon anhydrite Antigen (CA) 15.3 is a high molecular weight glycoprotein defined by two monoclonal antibodies (DF3 and 115D8), of clinical relevance in the monitoring of treatment and detection of recurrence in breast cancer. This is a prospective study evaluating the efficacy of CA 15.3 and CEA in monitoring breast cancer and early detection of metastases in bones. Methods: |Sixty two females with high-risk breast cancer were included in the study. Response evaluation was based upon clinical examination, -rays or histology and elaborated marker criteria. Results : Elevated CA 15.3 were found in 8 patients with breast cancer associated with bone metastases (19.04%) and 2 patients without bone metastases(10%). The sensitivity of CA 15.3 tests was 19%, whereas specificity was 90%. Elevated CEA levels were found only in 2 patients with breast cancer associated with bone metastases (4.87%). CEA sensitivity was only 4.8% whereas specificity was 100%. The specificity of bone scintigraphy for early detection of bone metastases were 98% whereas specificity were 95%. The combination of CEA and CA 15.3 increased the overall sensitivity by only 1.4%. CA 15.3 was a significantly more powerful marker than CEA for early detection of bone metastases, but clearly less favorable than bone scintigraphy. Conclusions: CA 15.3 monitoring should be considered an expensive and inefficient method for early detection of bone metastases from breast cancer, and it provides no additional value when used in combination with CEA. Bone scintigraphy still continuous to be most efficient test for early detection of bone metastases. (210) other malign disease (bladder ca, renal cell ca, colon ca, multiple myeloma, uterine ca, leukemia, lymphoma, malignant mesothelioma, thyroid ca, thymic ca, pancreatic ca, larynx ca, etc.). The most metastatic cancers for bone are prostate ca (43%), breast ca (24%), lung ca (17%), gastric ca (14%), respectively. For the other malignancy types, bone metastasis ratio is 27%. Bone metastasis determined in 30% of the patients with malignancy. Suspicious lesions were not evaluated as metastasis. We frequently find the metastatic locations at extremities, pelvic bones and vertebrates for prostate ca; vertebrates, ribs and pelvic bones for breast ca; ribs, vertebrates and pelvic bones for lung ca; vertebrates and pelvic bones for gastric ca; extremities and ribs for others. Conclusion: Visualisation of metastatic bony lesions in 1/3 of cancer patients indicated the importance of whole body bone scintigraphy for these patients. If we assume some of the suspicious lesions as metastasis, the ratio of metastasis is increase (40-65%). The excess amount of the bone metastasis and the frequency of the metastatic extremity lesions are unexpected.

Comparison of bone scintigraphy and X-ray imaging in the patients after revisal endoprotesis operation of hip joint.

P. Korol, A. Kosiakov, N. Shincarenko, D. Levinskiy; Clinical City Hospital # 12 of Kyiv, Kyiv, UKRAINE.

Aim: The aim of the study to evaluate the level of disease after revisal endoprotesis operation of hip joint using of bone scintigraphy and X-ray imaging. Material and method. 62 patients after revisal endoprotesis operation of hip joint were imaged by a standard method of whole body bone scan. Intestinal uptake was observed visually 3 hours after the intravenous administration of 740 MBq 99m Tc MDP. A whole body bone scan; anterior, posterior, oblique spot views of the hip joint region were obtained. The data of bone scan were compared with X-ray imaging. Results. Total number of 62 patients with bone scans and X-ray imaging was statistically evaluated. 38/62 pts (61%) with bone scans had in the field of hip joint inflammatory process that is indicative of instability of the hip joint endoprotesis. However, on X-ray imaging, inflammation in hip joint was identified in 6/62 pts (9 %) events only. In total there were 62 matching scans and statistical data showed overall good correlation r=0,58.

Within the group of different matching regions correlation varied: r=0,51 for head of hip; r=0,47 for broach of hip; r=0,56 for cervical of hip. Conclusion. Bone scintigraphy is more sensitive and specific method of the determination to stabilities of the hip joint than X-ray imaging in the patients after revisal endoprotesis operation of hip joint. Complex regional pain syndrome I (CRPS) previously known as Reflex Sympathetic Dystrophy (RSD) is a disabling condition with annual incidence estimated at 26.2/100,000 general population. Symptoms include intense, prolonged pain and burning of the extremity, change in limb temperature, sweating and swelling. Proposed mechanism is an abnormal response to noxious stimuli resulting in dysfunctional interaction between sensory, motor, immune and autonomic nervous systems. CRPS could be related to prior fracture or sprain, significant physical stress (surgery, myocardial infarction) or thought to be idiopathic in up to 40% of cases. Important associations of CRPS with other clinical conditions include hepatitis C, cirrhosis, AIDS, Pancoast and pancreatic tumors. CRPS is believed to represent a paraneoplastic syndrome in these conditions. Our exhibit focuses on the radiographic/scintigraphic features of CRPS; reviews the current literature regarding association of CRPS with malignancy and presents an illustrative case of a patient who developed CRPS affecting the hand in association with metastatic bone lesion in proximal forearm. CRPS was the first presenting symptom of osseous metastasis in this patient. The main goal of this exhibit is to increase interpreters' awareness of CRPS, its potential association with malignancy, and the need for imaging investigations to establish the diagnosis and associated pathology. Imaging features: Plain radiography is normal in the early stages; patchy subchondral and peri-articular osteopenia can develop later, occasionally in combination with soft tissue swelling. Three phase 99m-Technetium-

To evaluate the relapse frequency of malignant melanoma (MM) in patients (p) diagnosed of MM, who underwent surgery and sentinel lymph node detection and biopsy (SLNB) Materials and Methods: 82 p (aged 20-90; mean 58,1) who underwent surgery and SLNB during 1998-2002 were included. Parameters studied were: absence/presence of disease, tumor relapse (local or spread to other organs) and number of deaths. These items were evaluated depending on: MM's localization ( Head-neck -HN, Chest -CH-, arms -A-or limbs -L-) and Breslow index (BI). The survival was estimated by Kaplan-Meier method Results: The SLNB was positive in 68 p and negative in 14p. 94% of p studied with SLNB negative were free of disease during our evaluation (4 years). Depending on MM's localization: In 39p it was located in CH (48%). Relapsed 7p of them (18%); (BI>4 mm in 5p and 0,75>BI4 mm 1p and 0,75>IB<4mm 1p). In 24p it was located in L (29%). Relapsed 5p of them (21%; IB>4mm; SLNB positive). Local relapse in 4/5p and metastasis in 1/5p. None of the patients with MM located in A (11p; 13%) showed local relapse or metastasis.

In the group of patient analysed the most frequent localization was CH, and the worst prognostic factors were: MM's localization (L and CH), IB>4mm and SLNB positive. These results lean upon de value of SLNB as a good method to foresay de long term tumor's relapse. Aim Multiple radioactive lymph nodes are often detected by lymphoscintigraphy to identify sentinel lymph node(s) (SLN) in breast cancer patients. It is not clear whether these additional lymph nodes are "true" sentinel nodes, or second-echelon lymph nodes that have received radiocolloid particles passing through the SLN. Various criteria based on the degree of radioactivity regarding the "hottest" node have been proposed to define which radioactive lymph nodes should be removed in order to minimize the false negative rate of the procedure. Aims of this study were: to determine the frequency with which the most radioactive node "fails" to be pN+ when the less radioactive lymph nodes contain metastatic disease; to establish which lymphoscintigraphic criteria best define the radioactive lymph nodes to be removed.

A total of 576 patients referred to Pisa University Hospital with operable breast cancer underwent radiocolloid lymphatic mapping and radioguided SLN biopsy. To determine how often a less radioactive sentinel node is positive for tumor when the most radioactive lymph node is not, we considered as SLNs both those with the highest counts and any additional radioactive lymph nodes counting 20% or more of the hottest node. We identified two groups of pN+ patients, the former in which the most radioactive node was positive for tumor and the latter in which the less radioactive lymph nodes contained metastatic disease when the "hottest" did not. Results: A total of 113 out of 576 patients (19.6 %) were found to have sentinel node metastases detected by histology or immunohistochemistry. We identified 70 positive axillary nodal basins from 70 patients in whom at least one positive sentinel node was found and more than one sentinel node was harvested. In 16 out of these 70 nodal basins, a less radioactive lymph node was positive for tumor when the most radioactive sentinel node was negative. If only the most radioactive sentinel node in each basin had been removed, 23% of the nodal basins with positive sentinel nodes would have been missed. The "parallel" lymphoscintigraphic pattern (multiple lymphatic channels originating in the region of the primary tumor and running to different lymph nodes) was associated with increased likelihood of finding the "hottest" lymph node negative for tumor while another, less radioactive, sentinel node contained metastatic disease (11 of out 16 patients; 69%). Conclusion: We suggest the intraoperative threshold of 20% for optimal detection of nodal metastases in breast cancer patients. Aim: Due to its ability to depict sentinel nodes (SN) in expected and unexpected sites of lymphatic drainage lymphoscintigraphy is an important part of the sentinel node procedure. However, in prostate cancer lymphoscintigraphy has limitations in indicating the anatomical localization of deep located sentinel nodes inside and outside the pelvis. For this purpose SPECT-CT was evaluated in addition to lymphoscintigraphy in patients scheduled for laparoscopic pelvic lymphadenectomy. Methods: In 16 patients (mean age 64.1y, range 53-74y) with prostate cancer of the intermediate prognostic group (inclusion criteria: T3 or PSA>10μg/l or Gleason score >6) 99mTc-nanocolloid was injected peri/intratumorally in 2 depots of 0.1ml per lobe guided by transrectal ultrasound. Images were performed at 15 min and 2-4h. Delayed planar images were followed by SPECT-CT (SPECT: matrix 128x128, 60x25-sec frames, CT: 130 kV, 17 mAs, B60s kernel) with 15-min acquisition using a hybrid camera. After correction for attenuation and scatter SPECT images were fused with CT and analysed using 2D orthogonal reslicing. SN were anatomically identified according to the lymph node groups inside/outside the pelvis and evaluated in relation to laparoscopic extended pelvic lymphadenectomy (EPL) which was performed in all patients in combination with laparoscopic gamma probe guided SN dissection. Results: Mean injected dose was 232 MBq (range 203-275MBq). SN were visualized in 15 patients (94%). In all these patients drainage was bilateral. Drainage to the lymphatic groups included in the EPL area was seen in all patients and SPECT-CT enabled anatomical SN localization in all of them. In 6 patients (38%) additional SN, appearing in early images of lymhoscintigraphy, were visualized outside the area of EPL (para-aortic, aortic-iliac junction, pre-vesical, inguinal). All SN outside the EPL area were found at laparoscopy. SN metastases were found in 4 patients (25%). In two of these patients metastases were found in SN located outside the EPL area.

Conclusion. In addition to the anatomical localization of pelvic SN in prostate cancer, SPECT-CT may lead to an accurate identification of SN outside the pelvis. The anatomical SPECT-CT information concerning the location of these SN may subsequently guide its resection using a laparoscopic gamma probe. Aim: Determine if the size of the metastases in the sentinel node (SN) of patients (p) affected of breast cancer smaller than 3 cm has any relationship with the finding of metastases in other axillary lymph nodes (AM1 Conclusion: the detection of the sentinel node with the combination of the gamma probe and the blue dye is also possible in T>3cm. In 50% of these patients axillary lymph node dissection can be avoided, and in 25% the SLN is the only one affected. Therefore we consider that these patients should be included as a general indication in breast cancer sentinel node detection.

The usefulness of sentinel lymph node mapping in colon cancer staging: preliminary experience. Aim The presence of regional nodal metastatic disease in colon cancer is an important prognostic factor. Improving identification of lymph node disease would significantly better select patients who may benefit from adjuvant chemotherapy. Our study aimed to determine the usefulness of sentinel lymph node (SLN) mapping in detecting regional lymph node metastatic disease in patients with potentially curable colon cancer. Materials and Methods We prospectively studied 24 patients (18 men, mean age: 68 +/-7) with left colon cancer with no evidence of metastatic disease or lymphnode involvement at abdominal CT. Patients underwent surgical resection with standard colectomy confined to the affected segment. 99mTc-Nanocoll® (1mCi/ml x 4) was injected submucosally at 4 sites around the tumour by colonoscopy 24 hours prior to surgery. Lymphoscintigraphy was performed 3 hours after injection to verify radio colloid migration to the SLN. SLNs were harvested ex-vivo from the mesentery of the resected specimen using a gamma probe. All nodes were examined by haematoxylin & eosin (HE) staining. In addition SLN were multisectioned and examined by immunohistochemical (IHC) staining with cytokeratin. Results At least one SLN was identified in 96% of patients (23/24), with a mean of 3 SLN/patient (Range=1-5). The mean number of lymph nodes from the standard lymphadenectomy was 21 (Range=14-51). SLN examination with HE adequately predicted the regional nodal status in 13 of 23 (57%) cases (8 negative and 5 positive). In 6 patients (25% of all patients studied), IHC of SLN was the only indicator of metastatic disease. SLN failed to predict nodal metastatic disease in 4 patients (false-negative rate 26%). Conclusions Lymph node mapping using radio colloid is feasible in colon cancer, yielding a high rate of SLN identification. Although the false-negative rate is high (26%), SLN technique improves staging in colon cancer patients, upstaging 25% of patients, who may benefit from adjuvant chemotherapy.

Follow-up in primary breast cancer after sentinel lymph node biopsy. During the follow-up (FU) period, we analysed the appearance of axillary and/or locoregional metastases in both groups by performing an echography of the axilla twice a year and annually a mammography. We also considered the presence of systemic metastases in both groups. Results: In Group A, 293 pts (81%) were followed-up for two to four years. One pt (0.3%) experienced axillary metastases after two years from surgery (pT1c, G3, IDC with a single negative SLN removed); four pts had locoregional recurrences; one pt developed bone metastases and four pts showed systemic involvement (total recurrences: 10 cases). In Group B, 52 pts had only one positive SLN (44%), two positive SLN were found in 37 pts (32%), three positive SLN were removed in 16 pts (14%) and more or equal to six SLN were carried away in 12 cases (10%). Among the 69 pts in this group who had a complete FU (19%), there were two cases of systemic metastases.Conclusion: The accuracy of SLN method was 100%. The risk of developing axillary metastases in pts with T1 breast cancer seems to be very low in our follow-up.

Objective: Indication of sentinel node biopsy (SNB) has not been fully established for patients with DCIS. Our aim was to relate the conversion rate to invasive carcinoma with SN positivity in high risk DCIS, and also to refine the clinical presentation analysis in order to achieve a better patient selection for SNB. 

Relation between conversion rate and invasive carcinoma with SN positivity in high risk DCIS did not reach statistical significance, thus a subset of selected high risk patients could not be redefined. However , the relevance of SNB positivity cannot be overlooked in high risk DCIS patients, and more studies are still needed to refine its final indication.

Radioisotopic identification of sentinel lymph node in early stages of cervical cancer with Tc-99m Nanocolloid (preliminary results) V. G. Moschogiannis; "Metaxa 's" Cancer Hospital, Piraeus, GREECE.

The aim of this study is to investigate the feasibility and the utility of the detection of sentinel lymph node in early stages of cervical cancer with radionuclide method. Method: 11 women (median age 48,6 years) with cervical carcinoma, stage IA2 (no 1), stage IB1 (no 5), stage IB2 (no 5), underwent SLN detection during primary operation. Exclution criteria was stage IIB or more advanced disease. One day before the surgery, patients were injected intracervical with a total dose of 74 MBq Tc-99m Nanocolloid, devided in four injections, and one hour after the injection a lymphoscintigraphy was performed. On the day of surgery, 2 ml of patent blue dye was injected in the cervix, at the same sites as the radioactive isotope injections. Using a laparoscopic gamma probe and visual detection of blue nodes, the SLN were identified and removed for pathological assesment. Results: lymphoscintigraphy identified one or more sentinel nodes in 10 out of 11 patients (90,9 %), while blue dye identified SLN in 7 pts (63,6 %). The combination of blue dye and radioactive tracer detected lymph nodes in 10 pts (90.9 %). In one woman, where the lymph nodes were not identified with Tc-99m Nanocolloid, the stage of the disease was IB2. In 4 pts, we had a bilateral visualisation of lymph nodes. The average number of SLN per patient was 1,8. Metastatic disease to the lymph nodes was found in 2 pts. In total, in 6 pts. the sentinel nodes were located in the distal parametrium, in 1 pt they were located paraaortic and in 3 pts, in the area of the external and internal iliac artery. Conclusion: Our findings confirm that sentinel lymph node detection with radiocolloid, in combination with blue dye, is feasible and improves detection rate in patients with cervical carcinoma and also allows the identification of lymph nodes in areas that are not frequently sampled. This technique must be evaluated in larger studies, that may lead to better treatment selection of patients with early cervical cancer. The sentinel lymph node (SLN) is the first node in a nodal basin that receives the direct lymphatic flow from malignant melanoma (MM). However, in some patients, their lymphoscintigraphic study reveals the presence of lymphatic nodes in the area between the primary MM and the regional basin. These nodes are called "in transit nodes" or "aberrant nodes" and, by definition, they are also SLNs. Aim: To determine the percentage and location of "in transit" SLNs in our group of MM patients and assess if it is really necessary to harvest them. Method: In this study a total of 900 patients were included. The day before surgery a lymphoscintigraphy was performed by injecting 74-111 MBq of 99mTc-nanocolloid in four doses around the primary MM or the biopsy scar. Blue dye was injected in the majority of patients a few minutes before surgical procedure. A hand-held gammaprobe was used to better localize the SLNs. Results: Lymphoscintigraphy showed "in transit" SLNs in 80/900 patients (8.8%). During surgical procedure 77 of them were harvested (96.5%). SLN identification and excision proved most difficult to achieve in the popliteal and epithroclear regions. Metastatic cells deposits were subsequently identified in 13 (16.8%) of these "in transit" SLNs. Conclusions: Lymphoscintigraphy has a pivotal role in the identification of "in transit" SLNs. The incidence of these nodes is relatively low in MM patients. However, these SLNs present metastatic deposits in a significant percentage of cases and it warrants a surgical search for them.

Role of SPECT-CT in Sentinel node identification and intraoperative lymphatic mapping. First results of a pilot study in patients with breast cancer in Thailand.

C. Chotipanich, Y. Kongdan, K. Sumboonnanonda, R. Suvikapakornkul, P. Lertsithichai, K. Cheuamsamakkee, s. Promma, K. Poonak, P. Chouplywech, C. Sritara; Ramathibodi Hospital,Faculty of Medicine, Mahidol University, Bangkok, THAILAND.

Purpose: To retrospectively evaluate the clinical usefulness of the role of SPEC-CT in sentinel lymph node identification in patients with breast cancer which has not yet been established in Thailand. Material and Methods: A retrospective study of 20 women ranging from in the age of 29 to 80 years(median age 51 year) who underwent SPECT-CT lymphoscintigraphy from January 2006 to December 2006 was analyzed. All of the patients underwent lymphoscintigraphy with subareolar injection of Tc-99m Dextran with planar and SPECT-CT fusion imaging. Planar and SPECT-CT fusion images were assessed separated by a nuclear medicine physician. Sentinel lymph node biopsy guided by intraoperative injection of vital dye (Blue patent) and hand held gamma probe was performed. Results: The sentinel node was detected using two methods in all cases (100%) and positively metastatic in 93.75%. There were concordance between lymphoscintigraphy findings and blue dye in 95%. Of the total 46 lymph nodes, planar imaging detected 31 nodes (67%), while SPECT-CT fusion detected 43 nodes (93%). SPECT-CT fusion detected 15 nodes, which were missed by planar imaging (7 were obscured by the scattered radiation from the injection site and 8 were misinterpreted as a single node on planar). One of the 20 patients (5%) had a non-nodal false positive on planar imaging, when further assessed in SPECT-CT data.

In additional, SPECT-CT fusion imaging gave information on localization of sentinel lymph nodes (14 at level I, 1 at level II, 2 at level III, 3 more than one level), which could not be evaluated by planar imaging. Conclusion: It can be concluded that SPECT-CT fusion is more feasible and useful for identification of sentinel lymph nodes in breast cancer and provides information on the anatomical localization. Background: it is considered that previous excisional biopsy might affect the performance of the sentinel node localization in breast cancer, and it is the aim of this study to present our experience in the therapeutic approach of the SLN biopsy in patients with previous excisional biopsy because of non-palpable breast cancer. Methods: retrospective study of 482 cases of breast cancer in the period 2001-2006 divided in group A (110 patients) with prior diagnostic excisional biopsy and group B (373 patients) with non-previous surgery. Lymphoscintigraphy was performed after peritumoral injection of 99mTc-colloidal rhenium sulphide (nanocis); the sentinel node was located with a gamma ray detection probe (europrobe) and periareolar isosulfan blue dye (lymphazurin). Axillary lymph node dissection (LND) was completed only when the SLN was positive for metastasis or not located. Results: Table 1 . Sentinel lymph node detection rates in previous excisional biopsy.

Number positive lympho-positive of patients scintigraphy gamma probe/blue dye A (previous 110 92 (84%) 105 (95%) excisional biopsy)

In 5 cases the SLN was not detected and Axillary lymph node dissection was performed (2 positive and 3 negative for metastasis). Because non-palpable lessions are smaller (most of them are microcalcifications) the rate of metastasis in the SLN is clearly smaller than in the conventional group of palpable breast cancer. Conclusion: lymphatic mapping and the combination of the gamma probe with the blue dye in the detection of the sentinel node is also feasible in patients with previous excisional biopsy. Aim Our work was aimed to a retrospective evaluation of our series of sentinel lymph node scintigraphy in order to evaluate the relationships between breast tumour dimensions and frequency of positive results. Patients and Methods In the last 7 years 310 patients, in TNM stage 1 or 2, all females, underwent sentinel lymph node scintigraphy for a breast cancer. The test was performed according to usual procedures (subcutaneous injection of 10 MBq of 99mTc-nanocolloid followed by repeated breast scans until the first lymph node was scintigraphically evident allowing the record of its position with a marker on the skin. At surgery, (a quadrantectomy was usually performed), the sentinel lymph node was histologically extemporaneously examined in order to detect the possible tumoral involvement. According to TNM system the patients were grouped as T1a (13 cases), T1b (64 cases), T1c (164 cases) and T2 (69) cases. Due to the small number of subjects in class T1a in our study these patients were grouped together with T1b patients. Statistical analysis of the differences of the positive case frequency between the groups was performed by chi square test.

As expected, bigger tumour dimensions were associated with higher frequencies of positive cases. In fact, the frequency of positive extemporaneous studies resulted of 3 cases in the T1a-T1b group (3/77 = 0.039); of 29 cases in the T1c group (29/164 = 0.176) and of 17 cases in the T2 group (17/69 = 0.246). The frequency differences between group (T1a+T1b) and group T1c (p<0.006) and between group (T1a+ T1b) and group T2 (p<0.001) resulted highly statistically significant. The frequency difference between group T1c and T2 group did not reach statistical significance (p<0. 3, ns) . Conclusions The relationships between breast cancer dimensions and lymph node metastatic involvement are well known, thus our data could not appear to offer a new and original contribution to address this issue. However, our study discloses some additional quantitative insights in order to evaluate the specific phenomenon of sentinel lymph node metastatic involvement and can, consequently, be of interest in breast cancer care. Larger series of patents (the work is in progress) will allow us to study the frequency of positive sentinel lymph node scintigraphy according also with the different histotypes of breast cancer.

Sentinel lymph node scintigraphy (SNC) in the preand perioperative diagnosis of breast cancer E. Schmidt, Z. Szabo, G. Szalai, E. Kalman, G. Tizedes, G. Pavlovics, K. Zambo; University of Pecs, Pecs, HUNGARY.

The importance of SNC in the perioperative diagnosis of breast cancer is well-known. Using the method with further completitions, results useful additional informations. The aim of our study was to establish, how these informations influence the treatment and management of the patients. Patients and methodes: 100 women were observed whose breast cancer was proved by fine needle biopsy (FNB). SNC was performed a day before the planned operation. The radiopharmaceutical (80 MBq 99mTc-Senti-Scint) was injected peritumoral, in 4-8 portions, using US guide. Anterior and lateral planar scans were performed 1 and 3 hours after the injections from the chest and axilla. The projections of the SN were marked on the skin. With help of this markers US guided FNB and cytology of SN was performed in 71 cases. The operation was carried out the next day with removing of SN and low axillary blockdissection, or -in cases of metastatic laesions -total axillary blockdissection. In both group, dynamic lymphoscintigraphic images were recorded for 30 minutes immediately after the injection. Then, static images were taken until the SLN was visualised. Two-four hours after the radiopharmaceutical injection, patients were taken to the operating room. Before the incision, blue dye solution was injected peritumorally to all cases. Aided by blue dye and gamma probe, SLN detection was carried out during the operation. Then, histopathological confirmation was performed. Results: There was not a significant statistical differance between Group I and Group II in terms of patients characteristics. In Group I, identification rate of SLN was 100% (17/17) in both lymphoscintigraphy and intraoperative gamma probe application. In 15/17 cases of this group, only one SLN was observed in the axillary region; however, in 2/17 patients, SLNs were found in both axillary and internal mammary regions. There was a positive correlation among lymphoscintigraphy, intraoperative gamma probe application, blue dye and histopathological examination in 100% of this group. In Group II, detection rate of SLN was 68.75% (11/16) in lymphoscintigraphy; however, this rate was 81.25% (13/16) in the intraoperative gamma probe application. All SLNs, which were detected with nuclear medicine techniques, were in the axillary region in this group. There was a positive correlation among lymphoscintigraphy, intraoperative gamma probe application, blue dye and histopathological assesment in 68.75% of Group II patients. However, this rate increased to 81.25% when the results of lymphoscintigraphy were excluded. Conclusion: Tc-99m HIG, which appears to be more effective and successful than Tc-99m nanocolloid, may be a preferable agent on SLN identification in both lymphoscintigraphy and intraoperative gamma probe application in patients with early-stage breast cancer.

Usefulness of lymphoscintigraphic imaging prior to surgical detection of SLN in breast cancer Aim: the sentinel lymph node (SLN) radioisotopic detection is a well established method in the surgical management of invasive breast cancer. However the interest of lymphoscintigraphy (LS) before surgery remains questionable. Methods: in a prospective study including 51 patients with breast cancer, 74 MBq of radiocolloid (Nanocoll* Health Amersham) were subcutaneously injected in the peri-areolar breast bearing a less than 2 cm tumor 1 day before surgery. All patients had a planar anterior LS with a large field of view camera (Helix Elscint General Electric*) of the thorax, axillary and basicervical region. The body contour was imaged with a transmission view of a 57Co planar source in the back of the patient. Women were operated by 4 validated surgeons and divided into 2 groups: in group I (n=30) the more radioactive node was marked on the skin and the LS and report were known by the surgeon; in group II (n=21), no marker was drawn and the surgeon does not know LS results. Intraoperative identification of the SNs was based both on blue dye mapping and probe detection (Gammed IIB Eurorad system) Scar length, surgical duration time and number of removed SLN were compared within both groups using Mann-Whitney test. Results: LS showed axillary SLN in 90%, mammary internal SLN in 9.8% and supra clavicular SLN in 2%. The median scar length was not significantly different in both groups (p = 0.63): 37.5 mm [30] [31] [32] [33] [34] [35] [36] [37] [38] [39] [40] in group I and 37.5 mm [35] [36] [37] [38] [39] [40] in group II. The median duration time for surgery was not significantly different (p = 0.15) in group I (15mn [11] [12] [13] [14] [15] [16] [17] [18] [19] [20] ) and in group II (9 mn [8] [9] [10] [11] [12] [13] [14] [15] ). The number of removed SLN was not significantly different (p = 0.22) in both groups (group I: 3 [1] [2] [3] , group II: 2 [2] [3] Objectives -To calculate the rate of detection of the SN in patients with BC subjected to N-C. -To establish the predictive value of the SN with respect to the axillary state. Material and Methods. We studied 43 patients with locally advanced BC subjected to N-C; age 27 -74 years (average 50 years). The initial size oscillated between 3 -9 cm (average 4' 9)

, showing good answer 44' 1%, partial 41' 9% and bad 14%. They were administered between 37-111 MBq of 99mTc-nanocoloides in peritumoral intraparenchymatous location (18) or combined (intradermal and intraparenchymatous) (12). In nonpalpable cases the injection was guided by ultrasound or stereotaxy (13 cases). Static images were taken between 30 minutes and 18 hours postinjection, being made external cutaneous mark of the SN. The SN was extirpated separately, being followed by a complete axillary ganglionary dissection. The histological study of the SN included staining with haematoxylin-eosin and inmunohistochemical in negative cases. Results In the linfoscintigraphy at least one SN was visualized in 39 out of 43 patients (90' 7%), with drainage to internal mammary in 5 cases (11' 6%). The rate of intraoperating detection was 90'7% (39/43). Two visible cases could not be localized in the operating room and 2 nonvisible cases could be extirpated. 3 out of 4 cases (75%) not located had axillary ganglionary affectation. The histological study of the SN with haematosylin-eosin was negative in 30 out of 39 cases (76' 9%) showing tumoral invasion of the rest of the chain in a single case (Rate FN 2' 5%). 3 out of the 30 negative cases were positive with inmunohistochemical (10%), being in the three cases the only positive node. This was the only positive case in 7 (63' 6%), of the 11 cases with affectation of the GC.

Without axillary affectation

A sensitivity for ganglionary affectation of 92' 3% with a NPV of 96' 3% was obtained. Conclusions. The technique of the SN is feasible in BC subjected to N-C with a rate of detection above 90%. The failure in the location of the SN seems to indicate bad prognosis due to the high incidence of ganglionary affectation. A negative GC or with micrometástasis can avoid the complete axillary node dissection due to the high NPV for the rest of the chain.

phytate lymphoscintigraphy (SPECT) and CT from December of 2006 to March of 2007. Lymphoscintigraphy was performed 6 hours after subcutaneous injection under the nipple of Tc-99m phytate using a gamma camera (Symbia; Siemens, Forchheim, Germany, and Hoffman Estates, Ill.). Contrast-enhanced CT was performed using Acuillion 64 (Toshiba medical systems, Tokyo, Japan). Image fusion between SPECT data and CT volume data was performed using fusion soft (Fused Vision 3D) on Siemens e.soft workstation. Twenty-six patients were divided into 3 groups. The first group patients (8 patients) were examined without markers. The second group patients(14 patients) were examined by SPECT and CT with markers on the upper and lower ends of sternum ( 2 markers). The third group patients (4 patients) were examined with markers on the upper and lower ends of sternum and outside of the nipple of opposote side (3 markers) . A small vessel containing Tc-99m was used as marker for SPECT and that containing beads of 2mm-diameter for CT. Results: In the first group patients examined without markers, preparation of the fusion images of SPECT and 3D-CT were difficult. In the second group patients examined with 2 markers (the upper and lower ends of sternum), preparation of the fusion images were sometime difficult. In the third group patients examined with 3 markers (the upper and lower ends of sternum and outside the nipple of opposote side), the fusion images were easily prepared and the anatomical identification of sentinel lymph node of breast carcinoma could be easily performed. Conclusion: The fusion images of SPECT and 3D-CT were easily prepared by placing markers at the upper lower ends of sternum and outside the nipple of opposote side. As a result, anatomical location of sentinel lymph nodes of breast carcinoma could be easily identified. Resection of non-palpable breast lesions without needle-guide needs an intraoperative pathological examination to confirm lesion inclusion and healthy margins. In those hospitals without an intraoperative pathological resource, a second surgery may be needed. ROLL technique to guide surgeon is more extensive. The use of tracer inside the tumour allows the lesion resection with free margins and decreases the number of second procedures. Moreover, an intraoperative image can be acquire intraoperatively with a portable gammacamera, which can predict if margins are involved. Aim: To value the usefulness of an intraoperative gammacamera to assess non-palpable breast lesions resection. Material and methods: Patients: 42 women with non-palpable breast lesions were included, mean age 59 ± 7.8 years. Injection: The day previous to surgery, an intratumoural injection of 99mTc-Nanocolloid was performed guided by ultrasonography. Lymphoscintigraphy: It was performed to know the lymphatic drainage and spread of radiotracer in the breast. Surgery: The lesion was removed guided by a gamma-probe. An image of the surgical piece was acquired by the intraoperative gammacamera (Sentinella S102, GEM Imaging, Valencia, Spain) and a second image was performed using a technetium pointer to draw the outline. An image over surgical bed was done to confirm the absence of activity after resection. AP: Lesion inclusion and healthy margins were evaluated intraoperatively. Results: All lesions were removed. Centred lesion was found by portable gammacamera in 23/42, out of place in 15/42 and in contact in 4 cases. A pathological exam detected free margins in 15/23 with centred lesion (65%), affected margins in 10 of 19 with lesion not centred. That means a concordance of 60% (25/42). Conclusion: Bearing in mind these issues, the use of an intraoperative gammacamera can avoid an extra surgery in those centres without pathological exam during sugery, without delay in the surgical act. Some aspects can raise the rate of concordance: to increase the number of projections or to improve the way of injection. Objectives: The purpose of this study is to evaluate the efficacy of SLN biopsy using imaging and gamma probe in oral cancers. Material and Methods: 26 patients (mean age = 54.5 yrs) with operable oral cancers with clinically negative lymph adenopathy were studied. Standard neck dissection was performed in all. Scintigraphy was performed a day before surgery by injecting Tc-99m labeled nannocolloid submucosally in the peri-tumoral area. First lymph node to appear on the scan was labeled sentinel lymph node and marked on the skin. This hot node was explored intraoperatively using gamma probe followed by block neck dissection. Results: The sentinel lymph node (sometimes associated with additional nodes) was identified in 23 patients (88.4% success rate). In 3 patient (11%) SLN was not visualized on the scan (failed study). The gamma probe guided localization was successful in 17 while in 6 cases it failed. In 14 out of 17 (82%) cases sentinel lymph node stood in agreement with the result of histopathology of remaining lymph nodes (11 benign and 3 malignant). The remaining 3 lymph nodes, however, showed a discordance with the final histopathological result. SLN was negative in all 3 cases with disease spread to other nodes (? skip lesion / varied drainage patterns). Conclusions: Early results of lymphoscintigraphy with gamma probe guided SLN biopsy have been encouraging; however, a variable lymphatic drainage pattern may result in skip metastasis. Therefore, we recommend that every hot lymph node should be biopsied to minimize the possibility of this discordance. Further, studies should be undertaken to establish the operator learning curve in this technique. Introduction: Sentinel node biopsy quickly became standard of care in breast cancer, before consensus on the technique was reached and without randomised studies having shown a similar or decreased axillary recurrence rate. A review of twenty-six learningphase studies on sentinel node biopsy followed by routine axillary node dissection demonstrated a median false-negative rate of 7% (range of 0-40%), which is more than the 5% that is generally considered acceptable.1 Axillary clearance is no longer done in patients with a tumour-free sentinel node. Long-term follow-up results of such patients have now been published and these prompted this literature review to determine the axillary recurrence rate of the sentinel node procedure in breast cancer patients. Methods: We searched the current literature for studies concerning patients with breast cancer, a clinically node-negative axilla, no subsequent axillary node dissection in case of a sentinel lymph node without disease, and a median follow up duration of at least three years. The axillary recurrence rate was calculated in the patients with a tumour-negative sentinel node biopsy. Results: Fourteen studies were published between 2004 and 2006 describing a total 3802 patients with a median follow-up time of 47 months. All papers describe the injection of a radiopharmaceutical and the use of lymphoscintigraphy. 99mTc-nanocolloid was the most common radiopharmaceutical, used in nine studies. Ten investigators additionally injected blue dye intraoperatively and all surgeons used a gamma ray detection probe. Twenty-four of the sentinel node-negative patients recurred in their axilla with a median time to recurrence of 19 months (range of 4-63 months). The median recurrence rate was 0.3% and calculated when corrected and weighed for the number of patients per study. Conclusion. The sentinel node procedure was introduced to limit morbidity without exceeding the 1-2.3% axillary recurrence rate seen in the past after routine axillary clearance. It is gratifying that this review of studies with a long-term follow-up finds the recurrence rate in sentinel node-negative patients well within the desired range. (82%); mean age 53y (23-69y). Lymphoscintigrapy was performed 2h post peritumoral radiocolloid injection. A subdermal reinjected dosis was performed in cases of no lymphoscintigraphy sentinel node detection post peritumoral injection. A handled gammaprobe was used to radioguide sentinel node surgery. Axillary lymph node dissection (ALND) was performed on 186p (14%), (22p from group A and 164p from group B). The following parameters were analysed in both groups: sentinel node lymphoscintigraphy detection rate (SNLD) and the subdermal reinjection requierements (SR), sentinel node surgical detection rate (SNSD), number of sentinel node metastases as well as the presence of metastases in other axillary lymph nodes. In the non sentinel node surgical detection group the rate of positive nodes was also analysed. Results: Data of pelvic SLN scintigraphy helped to determine the direction of lymph outflow from tumor-affected testis or the stump of spermatic cord and prostate to sentinel lymph nodes by normal or changed lymph collectors. Thus, SLN scintigraphy led to exact determination of local lymph node dissection or delineation of fields' size and configuration for local radiation therapy. Conclusions: Finding of the lymph outflow routs with 99 mTc-colloid increases the validity of early lymphatic cancer spread detection, including or excluding cases of lymph nodes enlargement. Determination of the lymph outflow routs gave an opportunity to configure the radiation fields within sites of 99 mTc-colloid accumulation.

The aim of this study was preoperative scintigraphic imaging and subsequent intraoperative detection with small hand-held gamma probe and blue dye in some malignant tumours to identify the sentinel node (SLN) of breast cancer Group I and colorectal cancer Group II. Method: Group I -102 female with histologically proven breast cancer in early stage T1-T2 by palpable and non-palpable lesions. Scans were performed in anterior, oblique and lateral view 2-3 hours after administration of 99mTc-colloid / 60 MBq in total volume 0.8 ml / peritumourally. By patients with non-palpable lesions (56 patients) injections were under sono-graphic guidance. The site of sentinel nodes was marked on the skin. The same method was used for 42 patients with colorectal cancer Group II, with more scans and without skin markers. Results: Group I -sentinel node was found in 91 /102 patients except nodes in the internal mammary chain and nodes located very close to tumour. The sensitivity in this group was 89%. All nodes were examined routinely and by immunohistochemical staining. Histologically 25/91 sentinel nodes were positive (micrometastases in eleven). Group II involved 42 patients with colorectal cancer. Lymph-nodes were found in 36 /42 cases. The sensitivity of the method in this group of patients was 86%. According to pathologist 14/36 had tumour positive lymph-node. The method of detection of the sentinel node in total mesorectal excision is not therapeutic but diagnostic method, and it has quite a high level of sensitivity. Conclusion: This study has demonstrated feasibility of the proposed procedure. Sentinel node biopsy requires a multidisciplinary approach (surgery, pathology and nuclear medicine) for reliable results. The association of blue dye (in breast cancer only) and intra-operative gamma probe has made the procedure more effective, less time-consuming and less invasive. Lymphoscintigraphy and radioguided surgery can be very useful as a prognostic sign, whether it detects sentinel lymph-node (some with micrometastases that would otherwise be missed). This method is easy and safe. The histological examination of SLN improves staging of the disease and can help in planning of the follow up treatment.

Initial experience of preoperative lymphocintigraphy and sentinel lymph node biopsy in thyroid cancer patient.

C. Chotipanich, Y. Kongdan, K. Cheuamsamakee, S. Amnuaywattakorn, C. Sritara; Ramathibodi Hospital,Faculty of Medicine, Mahidol University, Bangkok, THAILAND.

Purpose: To evaluate the clinical usefulness of the lymphoscintigraphy and of hand held gamma probe procedure for SLNB in well differentiated thyroid cancer which have not yet been established in Thailand. Material and Methods: Three female patients with thyroid nodule highly suspected for thyroid carcinoma by fine needle aspiration cytology ranges from the age of 23 to 41 years underwent preoperative lymphoscintigraphy. All of the patients underwent lymphoscintigraphy with intratumoral injection of Tc-99m Dextran 0.3 mCi under ultrasonography guidance. Sentinel lymph nodes were identified using gamma probe. Results: Three patients had papillary carcinoma.The sentinel lymph node was detected in all cases (100%). One patient showed a lymph node metastasis in the sentinel lymph node in the jugular compartment. There were no intra or operative complications. Conclusion: This is the first report of SLND in thyroid carcinoma in Thailand. Our preliminary findings indicate that the identification of sentinel lymph nodes in thyroid cancer is a practical and safe method. In order to improve this technique as a standard procedure for staging of thyroid cancer further studies with a larger number of patients in Thailand have to be done. Key Words: Sentinel Lymph Node, Thyroid cancer, Lymphoscintigraphy

Radioisotopic identification of sentinel lymph node in early stages of cervical cancer with Tc-99m Nanocolloid (preliminary results) E. Trivizaki 1 , V. Moschogiannis 1 , S. Saranti 1 , L. Iordanidou 1 , P. Zarganis 2 , K. Rethimniotakis 1 , A. Georgakopoulos 1 , P. Koutsiouba 1 ; 1 Department of Nuclear Medicine, "Metaxa' s" Cancer Hospital, Piraeus, GREECE, 2 Department of Gynecology, "Metaxa' s" Cancer Hospital, Piraeus, Greece, Piraeus, GREECE.

The aim of this study is to investigate the feasibility and the utility of the detection of sentinel lymph node in early stages of cervical cancer with radionuclide method. Method: 11 women (median age 48,6 years) with cervical carcinoma, stage IA2 (no 1), stage IB1 (no 5), stage IB2 (no 5), underwent SLN detection during primary operation. Exclution criteria was stage IIB or more advanced disease. One day before the surgery, patients were injected intracervical with a total dose of 74 MBq Tc-99m Nanocolloid, devided in four injections, and one hour after the injection a lymphoscintigraphy was performed. On the day of surgery, 2 ml of patent blue dye was injected in the cervix, at the same sites as the radioactive isotope injections. Using a laparoscopic gamma probe and visual detection of blue nodes, the SLN were identified and removed for pathological assesment. Results: lymphoscintigraphy identified one or more sentinel nodes in 10 out of 11 patients (90,9 %), while blue dye identified SLN in 7 pts (63,6 %). The combination of blue dye and radioactive tracer detected lymph nodes in 10 pts (90.9 %). In one woman, where the lymph nodes were not identified with Tc-99m Nanocolloid, the stage of the disease was IB2. In 4 pts, we had a bilateral visualisation of lymph nodes. The average number of SLN per patient was 1,8. Metastatic disease to the lymph nodes was found in 2 pts. In total, in 6 pts. the sentinel nodes were located in the distal parametrium, in 1 pt they were located paraaortic and in 3 pts, in the area of the external and internal iliac artery. Conclusion: Our findings confirm that sentinel lymph node detection with radiocolloid, in combination with blue dye, is feasible and improves detection rate in patients with cervical carcinoma and also allows the identification of lymph nodes in areas that are not frequently sampled. This technique must be evaluated in larger studies, that may lead to better treatment selection of patients with early cervical cancer.

Radionuclide study of sentinal lymph nodes in breast cancer patients N. Voit; Institute of Oncology of AMSU, Kyiv, UKRAINE.

Background. Dissemination of breast cancer (BC) to lymph nodes plays is essential not only for survival but also for choice of tactic of the treatment. In accordance with a concept of sentinel lymph nodes (SLN) a study of them is aimed to the identification of first draining nodes respectively to nodes of primary tumor. Specific feature of SLN is enlargement of first lymph node and visualization of afferent lymph vessel from tumor to it. Aim was to study status of sentinel lymph nodes during their intraoperation detection using manual gamma Europrobe. Materials and Methods. 20 BC patients were examined using lymphscintigraphy in combination with intraoperation detection of SLN. A technique was performed using 99mTc-nanocole infused peritumoraly and intracutaneously (10 MBk/kg body weight) and 0.2-0.3 ml of water. Next step of study was performed using OFECT "E CAM" (Siemens). Early (20 min) and late (2 h after administration of RPP) images were obtained. A day after intraoperation detection of SLN was performed by manual gamma-probe. Results. In accordance with the obtained data it was revealed that in 17 of 20 patients lymph nodes of axillar pool on side of the lesion were visualized. In 2 patients lymph nodes on contralateral side were detected. In 14 patients with visualized lymph nodes histological examination revealed SLN. In 11 patients they appeared to be affected by metastases, in the remains -no malignancies. Conclusion. Examination of SLN using manual gamma-probe can be used for estimation of pathways of metastatic spread and rate of malignant injury of lymph nodes in BC patients. Using of lymphoscintigraphy in combination with gamma-detection and following biopsy of SLN is a perspective direction in the development of organ-saving surgical interventions in breast cancer. Aim of study: While investigating different kinds of tumours, the conception of sentinel node has been used in our hospital for many years. In our work we are trying to find out the usage of mapping of lymph node and its biopsy on those patients who suffer with carcinoma of colorectum. Method: We examined a group of patients with carcinoma of colorectum. With the help of applied colloid 99mTc and patent blau we performed lymphatic mapping in a submucosly or subserosly circulatory way around tumor. The searched nodes were presrved and marked. Marked nodes were later investigated in a histological and imunohistological way. Conclusion: We are persuaded that in the foreseeable future with this method we will be able to specify staging and decide on an operation and actinotherapy extent, wich should be proved by an ongoing study with oncological and oncosurgical departments cooperation. in the future we can also see lymphatic mapping utilization on laparoscopic operationsin oncosurgery of colon and rectum. Lymphatic mapping also brings a possibility to detect aberant lymph vessel and lymph nodes in tumour surroundings. Aim: Multi-drug resistance (MDR) is a major challenge in treatment of multiple myeloma (MM). 99mTc-MIBI is washed out from malignant cells in the presence of P-Glycoprotein (PGP) MDR1. This phenomenon results in non-visualization of the lesions and low sensitivity of whole body scan (WBS) in detection of active MM. The objective of the present study was to assess the value of sestamibi WBS in prediction of response to treatment and MDR. Materials and Methods: Thirty four patients with MM (25 male, 9 female, 54.12±11.46 years) entered the study. Thirteen patients had no previous history of treatment and 21 had history of previous chemoradiotherapy. The diagnosis and staging of the disease were based upon the standard criteria. For each patient routine laboratory tests, PGP measurement and WBS with 99mTc-MIBI were performed in the beginning of the study and the response to treatment was assessed during one year follow up. The baseline WBS was considered positive for detection of active lesion when at least one area of non-physiologic increased activity was noted while the result of WBS was positive for MDR when the patient had active disease but no abnormal activity was seen. The value of the baseline PGP tests and WBS for prediction of patient's outcome and response to therapy were assessed. Results: The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of WBS for determining the active disease were 61.5%, 75%, 88.9%, 37.5% and 64.7%, respectively. In cases who were in active state, these values for diagnosis of MDR with WBS were 38.9%, 62.5%, 70%, 31.2% and 46.1%, respectively. Also the above values for detection of MDR with PGP were 50%, 50%, 69.2%, 30.8% and 50%, respectively. The percentage of patients who were resistant to multiple course treatment during one-year follow up was 68.8% in cases with active disease and positive baseline WBS (11/16) and 70% in those with active disease and negative baseline WBS (7/10), with no statistical difference. Conclusion: Neither the baseline scan nor PGP findings are of great value in detection of MDR. Furthermore, no difference was noted between the sensitivity of baseline WBS for detection of active lesion in the group of the patients who showed drug resistance later in the course of treatment and in the group with complete response to therapy. So, the low sensitivity of WBS for detection of active MM lesions is not definitely related to drug resistance. Purpose: The aim of this study was to evaluate 99mTc-DTPA-deoxyglucose (99mTc-DTPA-DG) for the assessment of chemotherapy effect and biodistrbution in breastbearing nude mice. MEHTODS: Each animal was xenografted subcutaneously in the right fore-leg with 1×107 cells per 0.2mL of the MCF-7 breast carcinoma cell line. On day 9 postinoculation, mammary tumor-bearing mice (18-23g, n=5 per each group) were administration a single i. v. injection of taxol (1.3mg/kg) and doxorubicin (0.6mg/kg) in group 1, taxol (2.6mg/kg) and doxorubicin (1.2mg/kg) in group 2 respectively. Mammary tumor-bearing mice were treated with cisplatin (0.6mg/kg) in group 3 and cisplatin (1.2mg/kg) in group 4. 0.1mL of saline was injected intravenously in control group. On day 0, 3, 7, 14, 21, 28 post-therapy, tumor-bearing mice were imaged with 99mTc-DTPA-DG (0.1mCi/mice, i.v. ) at 0.5-2 hours after administration. The radio of tumors to non-tumors (T/NT) was counted by ROI technology. Tumor volume and inhibition rate of each group were calculated. Radioactivity in each sample tissue was calculated as the percentage of the injected dose per gram of tissue wet weight (%ID/g). Results: Scintigraphy in tumor animal models demonstrated that tumor tissue could be clearly visualized with 99mTc-DTPA-DG. There was significance difference in the T/NT among group 1, group 2 and control group (F=10.18, P=0.001) on day 14 post-therapy. There was significance difference in tumor volume between group 4 and control group (P<0.01) On day 14, 21, 28 post-therapy. Biodistrbution of 99mTc-DTPA-DG demonstrated tumor uptake was observed, at the same time less brain and heart uptake was observed. Conclusions: 99mTc-DTPA-DG could assess the chemotherapeutic tumor response. The technique developed allows for mechanism-specific targeted assessment of cell nuclei activity using 99mTc-DTPA-DG. Aim Neuroendocrine gastroenteropancreatic tumors (NeGEP) are relatively rare tumors arising from neuroendocrine cells. They are characterized by slow growth and by specific symptoms and syndromes. The location (foregut, midgut or hindgut) of the primary tumor affects the functionality, the clinical course, and the treatment of the disease. For inoperable, well-differentiated tumors, biotherapy with somatostain analogs (SA) or interferon alfa represents the treatment of choice with two purposes: to control symptoms and tumor proliferation. Somatostatin Receptor Scintigraphy (OCTREOSCAN -O) has been proven to play an important role to plane the clinical management of patients (pts) with NeGEP. Aim of this work was to compare accuracy of O alone or in association with CT and Chromogranin A (CgA) serum level and to evaluate impact on quality of life of SA treatment. Material and methods: We submitted 11 pts with primary NeGEP tumors originated from foregut in 6/11 ( 36% stomach, 18% pancreas), from midgut in 4/11 ( 27% ileum, 9% coecum) and from hindgut in 1/11 ( 9% rectum) to O, CT and serum CgA levels assessment. Then, six of them received long acting SA treatment for a mean of 17 months and performance status was assessed by ECOG criteria before and after therapy. 5/6 pts submitted to SA, followed by CT and serum CgA, repeated O after at least 1 year. All pts were intravenously injected with 185 MBq of 111In-Pentetreotide. 4, 24 and 48 hours whole body and abdomen O SPECT scan were obtained. Results O diagnosed primary tumors or metastatic lesion in 7 and was truly negative in 3 pts. Both the results were in agreement with CT and CgA. O resulted false negative in 1 pts when compared with CT and CgA serum levels. Similarly CT and CgA were, in two other pts, false positive and false negative, respectively. Pts treated with SA, especially whose with no metastases, showed performance status improvement, except one, who suspended biotherapy after 1 month, because of side effects. Its worth of note that in pts who after biotherapy had normal O and CT scan, also CgA lowered within normal limits. Conclusions In our limited series we showed a significant improvement of accuracy to detect NeGEP by combining O, CT and serum CgA and their association allows to select people to administrate Somatostatin analogs, able to improve quality of life through a control of symptoms and tumor growth stabilization. Aim: The aim of this study was to compare the efficacy of low dose Tc-99m methoxyisobutylisonitrile (MIBI) administration to high dose Tc-99m MIBI administration on intraoperative localization of parathyroid adenomas with gamma probe in patients with primary hyperparathyroidism (PHPT). Material and methods: Twenty-seven patients with PHPT were included in this study. These patients were divided into 2 groups. Group I consisted of 13 cases ( 11 women, 2 men; mean age: 60.31 ± 16.17 years) to whom 37 MBq of Tc-99m MIBI was injected intravenously in the operating room 10 minutes before the start of the surgery. Group II was composed of 14 patients ( 9 women, 5 men; mean age: 58.79 ± 13.88 years) to whom 555 MBq of Tc-99m MIBI was administered 2 hours before the operation.The minimally invasive parathyroidectomy was performed in all cases. Intraoperative localization of the pathological gland was carried out by the use of gamma probe in all subjects. Surgical resection of the parathyroid adenomas was carried out. Then, the excised tissues were evaluated histopathologically. Parathyroid hormone (PTH) level was registrated prior to and after the surgery in all cases. Results: Significant statistical difference was not found between Group I and Group II in terms of patients characteristics. The parathyroid adenomas were identified (total 27 parathyroid adenomas) and excised in all Group I (100%) and Group II (100%) patients. When the results of gamma probe application to the results of histopathological examination were compared, a positive correlation was found between them. In Group I, the mean preoperative level of PTH was 362 ± 74 pg/ml (reference range:12-72 pg/ml); however, the mean value of PTH after the operation was 66 ± 35 pg/ml. In Group II, these values were 216 ± 26 pg/ml, 32 ± 9 pg/ml, respectively. The mean operation time was 71 ± 19 minutes in Group I and 66 ± 18 minutes in Group II. There was not a statistical difference in the operation time between two groups. Conclusion: Low dose Tc-99m MIBI application may be prefered in the intraoperative identification of parathyroid adenomas with gamma probe in patients with PHPT since this procedure appears to be as effective as high dose Tc-99m MIBI application. Moreover, unlike high dose administration, low dose Tc-99m MIBI application does not require a long waiting period after the radiopharmaceutical injection and in this method the radiation exposure of the patient and operation team is much lower. Aim: The aim of this study was to compare the effectiveness of low dose to high dose Tc-99m methoxyisobutylisonitrile (MIBI) applications on intraoperative identification of parathyroid glands in chronic renal failure patients with secondary hyperparathyroidism. Material and methods: Nineteen patients with secondary hyperparathyroidism were included in the study. Patients were divided into two groups. Group I included 9 patients ( 7men, 2 women; mean age: 25.11 ± 5.22 years) to whom 37 MBq of Tc-99m MIBI was injected intravenously in the operating room 10 minutes before the surgery. Group II consisted of 10 patients ( 6 men, 4 women; mean age: 37.44 ± 4.19 years) to whom 555 MBq of Tc-99m MIBI was administered intravenously 2 hours before the operation. Aided by gamma probe, parathyroid gland localization was carried out during the operation in both Group I and II. All patients underwent surgical resection of the parathyroid glands which were then evaluated histopathologically. Parathyroid hormone (PTH) level was registrated prior to and after the parathyroidectomy in all subjects. Results: Regarding the patients characteristics, significant statistical difference was not observed between Group I and Group II. The hyperplastic parathyroid glands were identified and excised (total 74 parathyroid glands) in all Group I (100%) and Group II (100%) patients. When the results of gamma probe application to the results of histopathological examination were compared, it was observed that they were correlated. In Group I, the mean preoperative level of PTH was 629 ± 209 pg/ml (reference range:12-72 pg/ml); however, the mean value of PTH after the operation was 32 ± 10 pg/ml. In Group II these values were 835 ± 359 pg/ml, 37 ± 14 pg/ml, respectively. The mean operation time was 166 ± 29 minutes in Group I and 186 ± 57 minutes in Group II. A statistical difference was not found between two groups in the operation time. Conclusion: The low dose Tc-99m MIBI application may be prefered in the intraoperative identification of parathyroid glands with gamma probe in patients with secondary hyperparathyroidism because it appears to be as effective as high dose Tc-99m MIBI application. Additionally, in contrast to high dose, low dose Tc-99m MIBI application does not require a long waiting period after the radiopharmaceutical injection and with this method radiation exposure of the patient and operation team is much lower.

Radioguided sentinel node biopsy after breast surgery P. Santoro 1 , C. Mazzone 1 , G. D'Eredità 2 , F. Lauriero 1 , A. Niccoli Asabella 1 , G. Rubini 1 ; 1 Nuclear Medicine, Bari, ITALY, 2 General Surgery, Bari, ITALY.

Aim. Previous breast surgery is often considered a controindication for subsequent lymphoscintigraphy and radioguided sentinel node biopsy (RSNB) because of surgery deep lymphatic drainage changes. This study wants to measure RSNB feasibility and accuracy after breast nodulectomy. Patients and Methods. Between March 2005 and February 2007, 10 women, who were previously submitted to breast nodulectomy were enrolled. In all these women sentinel node wasn't dissected because of false negative extemporary histopathological examination on breast surgery piece. All women were submitted to lymphoscintigraphy on the day before surgery with subdermic tracer injection. Nanocoll was injected in four points around scar in pts undergone higher-external quadrantectomy. In pts undergone a different quadrantectomy tracer was injected in 2 points around scar + in 2 points in higherexternal quadrant or in retroareolar site only. On the day after lymphoscintigraphy lymph node identified as sentinel lymph node (SLNs) was dissected during surgery. The radioactivity of lymph node was detected in vivo and ex vivo by intraoperative of gamma-probe (scintiprobe MR-100 Pol. Hi Tech.). All lymph nodes were examined histopathologically with hematoxilin and eosin staining. Lymph nodes metastasisnegative were immunostained with anticytokeratin antibodies. Results. In 9 women, preoperative lymphoscintigraphy showed a sentinel lymph node; in one patient there wasn't tracer drainage (she was 73 years hold and with voluminous breast). Preoperative identification rate: 90%. Lymphatic metastases were detected only in 2 sentinel nodes of 2 women; these patients were submitted to total axillary dissection. Both node metastases were located in sentinel nodes and axillary non sentinel nodes were all negative at histopathological and anticytokeratin antibodies stainings. At a median follow-up of 14 months, no axillary relapses were observed in patients who were not submitted to axillary lymphadenectomy (Positive predictive value=100%). CT and PET/ CT, performed at our Institution, were main imaging follow-up surveys. Conclusions. RSLNB after previous limited breast surgery appear feasible and reliable for its high positive predictive value. It is necessary to analize a larger number of women and to follow them for a longer period. Aims: Liver regeneration after loss of hepatic tissue is a fundamental parameter of liver response to injury. Recognized as a phenomenon from mythological times, it is now defined as an orchestrated response induced by specific external stimuli and involving sequential changes in gene expression, growth factors production, and morphologic structure. Much of the investigation on the mechanisms and kinetic of hepatic growth has been done only in partially hepatectomized animals and in hepatocytes primary cultures. The study of the hepatic extraction fraction (HEF) by radioisotopic methods gives information about physiological mechanism of uptake, transport and allows also the excretion quantification of the hepatobiliary system by using 99mTc-IDA derivates. This prospective study aimed to estimate the interest of HEF in the evaluation of human liver regeneration / function of patients with hepatic tumoral disease underwent partial hepatectomy. Methods: 22 patients with colorectal metastases (n=18), hepatocellular carcinoma (n=2) and others (n=2) were included. Liver function was assessed after intravenous bolus injection of 99mTc-N-(3-bromo-2,4,6-trimethylphenylcarbamoilmethyl 1-iminodiacetic acid (Mebrofenin) that was uptaked by the hepatocytes and eventually excreted via billiary pathway without any change to its chemical structure. The HEF is calculated using deconvolution analysis of first pass curve coming from scintigraphic data. We evaluated the pre-operative HEF and in the 5th day and one month after the hepatic resection. We considered the HEF values of 98.8 ± 0.4% (MED ± SD) as normal. For statistical analysis, T-Student test was used. Results: The pre-operative, 5th day or one month after the partial hepatectomy HEF (MED±SD) was 98.33±3.36%, 98.37±3.06% and 97.1±5.37%, respectively. There was not statistically difference between the three evaluations of HEF (ns). Conclusion: These results allow us to say that the human liver regeneration is early enough to normalize the HEF at day 5 after partial hepatectomy, being this evaluation of undoubtedly interest to know the function kinetics and indirectly knowledge about human liver regeneration. Additionally, this fast functional liver recovery has high clinical importance, once more aggressive adjuvant chemotherapy can start much early after surgical treatment. Objectives: Some studies have demonstrated that a newly developed body diffusionweighted (DW) MRI is useful for differentiating benign or malignant lesions in patients with bone and soft tissue tumors. Thallium-201 (Tl) SPECT has been widely used for clinically same purpose. We compared DW-MRI with Tl-SPECT to clarify the characteristics of these two methods. Methods: Both MRI and Tl-SPECT were performed on 42 bone and soft tissue tumors (12 malignant lesions and 30 benign lesions), whose final diagnosis was based on histology. DW-MRI was performed with an echo planar imaging sequence. The apparent diffusion coefficient (ADC) value (×10<sup>-3</sup> mm<sup>2</sup>/sec) was calculated on the lesions. The early and delayed Tl-SPECT were performed, and the uptake ratio of the lesion to the contralateral normal tissue was obtained on the early images (early ratio; ER) as well as on the delayed images (delayed ratio; DR). The diagnostic accuracy of malignant lesions was evaluated by visual interpretation. The ADC values as well as ER and DR in the lesions were evaluated and compared for quantitative evaluation of DW imaging and Tl-SPECT, respectively. Results: High sensitivity was observed in both DW-MRI and Tl-SPECT in visual interpretation. Low specificity was observed on DW-MRI (44.4 %), suitable specificity was observed on Tl-SPECT (80%). In quantitative assessment, the sensitivity, specificity were calculated when the cut-off value of ADC was less than 1.7 on DW-MRI, and the cut-off value of ER was over 3.9 on Tl-SPECT. Specificity on ADC was only 36.4%, although high sensitivity 100 % was observed. There were significant differences between the uptake ratio of the benign and that of the malignant lesions (ER: 6.23 ± 2.13 vs 26.72 ± 8.91, p < 0.01; DR: 1.32 ± 0.42 vs 4.35 ± 1.45, p < 0.01). However, there was no significant difference between the ADC values of the benign and that of the malignant lesions (4.29 ± 8.50 vs 1.76 ± 0.77), suggesting that the ADC values might not be conclusive in distinguishing between the benign and malignant lesions. Conclusions: The ADC values of bone and soft tissue tumors overlapped and could not be used to differentiate between benign and malignant tumors. Whereas the ER values and delayed visual assessment of Tl-SPECT has high diagnostic ability for bone and soft tissue tumors. Therefore, Tl-SPECT has a better diagnostic ability than DW-MRI for evaluation of bone and soft tissue tumors.

Clinical usefulness of Thallium-201 scintigraphy in diagnosis of desmoid-type fibromatoses: comparison of planar and SPECT images T. Shinya 1 , S. Akaki 2 , S. Sato 2 , S. Kanazawa 2 ; 1 Okayama kyokuto hospital, Okayama-city, JAPAN, 2 Okayama university medical school, Okayama-city, JAPAN.

Aim: It has been reported that delayed thallium-201 (Tl-201) scintigraphy is useful for differentiating malignant soft-tissue tumor from benign lesions. Physiological muscle accumulations increase on delayed images in most cases, which often make it difficult to evaluate Tl-201 accumulation on planar images in patients with soft-tissue tumors. Desmoid-type fibromatoses are relatively rare soft-tissue tumors of fibroblastic origin and are locally aggressive. They are classified within the intermediate spectrum of fibroblastic/myofibroblastic tumors in the WHO classification. There are several case reports that describe Tl-201 accumulation in desmoid-type fibromatoses. Currently, however, no detailed documentation exists which describes Tl-201 accumulation in desmoid-type fibromatoses. The purpose of this study was to evaluate the usefulness of Tl-201 accumulation on planar and SPECT images, and the pattern of change in patients with desmoid-type fibromatoses. Material and Methods: Sixteen patients with desmoid-type fibromatoses underwent whole-body Tl-201 scans preoperatively, and we studied 21 desmoid-type fibromatoses retrospectively (12 primary tumors, 9 recurrent tumors). In all 21 tumors, early and delayed images were acquired at 10-15 minutes and 2 hours after injection. Tl-201 images were visually interpreted for degree of Tl-201 accumulation and pattern of change. We employed a three-grade system to evaluate degree of Tl-201 accumulation: 0 = no appreciable accumulation, 1= accumulation higher than that of normal muscle but lower than cardiac accumulation, 2 = accumulation higher than cardiac accumulation. We employed a three-pattern system in evaluating pattern of change on planar and SPECT images: Pattern of decrease= more accumulation on early images, Constant pattern= equal accumulation on both early and delayed images, Pattern of increase= more accumulation on delayed images. Surgical resection with histopathological analysis confirmed the diagnosis. Purpose: Cardiac sympathetic dennervation is a common event in synucleinopathies and the basis for to use scintigraphy imaging using iodine-labelled metaiodobenzylguanidine (123I-MIBG) with diagnoses purposes in these diseases. Our purpose is to explore diagnostic accuracy of this technique in order to differentiate patients with Lewy Bodies Disease (LBD) from others with cognitive and movement disorders not associated to synucleinopathies. Material and Methods: Series of cases constituted by 8 patients with LBD (McKeith Revised Criteria) and 9 control patients [essential temblor (5), Parkinson's Disease and dementia without sinucleinopaties (4)]. All the patients underwent scintigraphy imaging using 123I-MIBG and early and late Cordis/ Mediastinum (C/M) rate was measured. C/M rates between groups were compared (Mann-Whitney U-test) and area under ROC curve (aROC), Sensitivity, Specificity and proportion of correct classifications were calculated. Results: There were not differences between groups in age and sex. Early and late C/M rate were significant smaller in the group with Synucleinopathies (U=15; p<0.05 in both cases). Late C/M rate had a greater discriminatory ability (aROC=0.8) than early rate (aROC=0.77). For the late C/M rate, value 1.8 shows a sensitivity 0.88 and a specificity 0.82, with correct classification of 82% of the patients. Conclusions: In this small series, scintigraphy imaging using 123I-MIBG shows a good discriminatory ability to correct identification of LBD patients. We used the established criteria for the diagnosis of every disorder and the DSM-IV criteria for the diagnosis of dementia. The majority of the patients had an MRI and the rest a brain CT scan. All the patients had a brain SPET with 99m-Tc HMPAO (adult dose 740 MBq, single-headed camera, UHR parallel-hole collimator,30 sec/image, 128 images on a 128x128 matrix. We applied the Neurogam Software on the reconstracted data for the evaluation of rCBF alterations in specific Brodmann(Br) areas in the left(L) and right(R) brain hemispheres. Results: From logistic regession analysis we found statistically sigificant correlation of a number of neuropsychiatric symptoms with alteration of rCBF in the following Brodmann areas: 1) Delusions related to hypoperfusion in 22L BrA 2)Agitation related to hypoperfusion in 46R BrA 3)Depression related to hypoperfusion in 7L and 45L BrA 4)Anxiety related to hyperperfusion in 5L BrA 5)Apathy related to hypoperfusion in 39L BrA 6)Irritability related to hypoperfusion in 5L BrA 7)Disinhibition is associated to dysfunction in several regions, related to hypoperfusion in 11R, 20L, 46R BrA. Conclusion: The data support the involvement of multiple cortical regions in both hemispheres in mediating social and emotional behaviour and the subsequent neuropsychiatric symptoms resulting from rCBF alterations in degenerative dementias.

The contribution of Dopamine Transporter imaging to the distinction between Dementia with Lewy Bodies and Alzheimer's disease (besides Tc-99m HMPAO findings) X. Geronikola-Trapali 1 , I. Armeniakos 1 , T. Doskas 2 , G. Stampoulis 2 , A. Prentakis 1 , A. Stefanoyannis 1 ; 1 UNIVERSITY GENERAL HOSPITAL "ATTIKON", Nuclear Medicine Department, Athens, GREECE, 2 UNIVERSITY GENERAL HOSPITAL "ATTIKON", Neurological Department, Athens, GREECE.

Aim: Distinguishing between Dementia with Lewy Bodies (DLB) and Alzheimer's disease (AD) is often very difficult because of the significant overlap between them. The pathological features of DLB include cerebral cortex loss, Lewy Body inclusions and loss of nigrostriatal dopaminergic neurons. On the other hand in AD there is no significant dopaminergic degeneration. The aim of this study was to evaluate the role of dopamine transporter imaging with I-123 Ioflupane (DaTSCAN) in order to distinguish these two types of dementia in case of inconclusive Tc-99m HMPAO brain perfusion findings. Materials & Methods:22 patients over the age of 65 who fulfilled the DSM-IV criteria were studied. Cognitive function was assessed using MMSE, Clock and Verbal Fluency test. Neuroimaging data were obtained from MRI scans and all diagnoses were made before and independent of the SPECT scans. Applying these criteria 13 patients with AD (possible) and 9 patients DLB (possible) participated. Ten controls, group matched for age and the same clinical assessments as dementia patients were recruited. Our study included two different steps: 1st: We performed cerebral perfusion SPECT imaging 90 min after i.v. injection of 740 MBq Tc-99m HMPAO (CERETEC -Amersham). Interpretation of the data followed. 2nd: One group of the above patients (i.e. without the predominant CBF pattern) were further evaluated with I-123 Ioflupane (DaTSCAN). SPECT imaging was performed 3-4 hours after i.v. injection of 148 MBq I-123 Ioflupane. Results:The interpretation of Tc-99m HMPAO images revealed significant perfusion deficits in temporoparietal regions in the 6/13 AD patients. Parietoocciptal deficits were identified in 5/9 DLB patients. We found evidence of DaTSCAN results: Seven patients with neuropathology consistent with AD had a normal striatal uptake. Three patients fulfilling the criteria of DLB showed a marked reduction of the tracer uptake in the putamen bilaterally. One patient with clinical diagnosis of DLB revealed a generalized bilateral decrease of uptake with preservation of the striatal shape. Conclusion:I-123 Ioflupane (DaTSCAN) improves significantly the distinction between DLB and AD patients (in life) and it could be a useful tool towards this direction. Objectives: Long-term chronic alcohol consumption is associated with regional structural brain damage and cognitive deficit including memory impairment. Neuroimaging research has commonly linked chronic alcohol abuse with generalized frontal hypoperfusion. The aim of our study was to evaluate rCBF in alcohol induced cognitive decline and effect of memantine on rCBF. Methods: Twenty-eight patients (M:28, mean age: 59.0±7.1, age range: 39~67) who fulfilled DSM-IV criteria for alcoholic dementia were enrolled in the study. On resting state, we were studied with technetium-99m ethyl cysteinate dimer single-photon emission computed tomography (Tc-99m ECD SPECT) before and after memantine treatment. These results were analyzed with SPM2 (statistical parametric mapping version 2). Results: Brain areas with increased rCBF after memantine treatment in alcohol dementia; uncus (BA38) of both limbic lobes, parahippocampal gyrus (BA28) of left limbic lobe, both superior frontal gyrus (BA10), right inferior parietal lobule (BA40), cuneus of left occipital lobe (BA30), and left superior temporal gyrus. Brain areas with decrease rCBF after memantin treatment in alcohol dementia; left medial frontal gyrus (BA6), cingulate gyrus (BA31) of left limbic lobe, left claustrum, right brainstem, left superior temporal gyrus (BA38), fusiform gyrus (BA20) of right temporal lobe, culmen of left cerebellum, and fusiform gyrus (BA37) of right occipital lobe. Conclusion: We demonstrated increased rCBF of cognitive-related areas (BA10, BA28) of brain after memantine treatment in alchoholic dementia. In conclusion, we suggest that use of memantine will be a new possible treatment of alcohol induced cognitive decline. patients (4 initially MCI and 4 normal at NT) clinical symptoms worsened; DemTect became suggestive for D in the 4 MCI cases and in 3/4 patients initially normal and for MCI in the remaining negative patient. MMSE became positive for D in the former 7 patients who were enrolled for therapy and persisted negative in the latter one, in all of whom SPECT worsened. The remaining 5/13 patients (4 initially MCI and 1 DemTect negative) did not show clinical/NT change, while SPECT further worsened in one MCI patient persisting negative in depression case.Conclusions: 99mTc HMPAO SPECT may be a useful complementary tool to NT, in particular DemTect, to identify and monitor MCI and to early ascertain its progression to D. Moreover, in our study, SPECT proved more sensitive than NT also preceding MCI diagnosis in some cases.

The purpose of the study is to demonstrate imaging features of PET brain in dementia and to determine whether the MRI anatomic changes correlate with Dementia. Method: From January 2005 to December 2006, 15 patients with suspicion for dementia clinically performed FDG PET/CT (7 women, 8 men, age range from 45-80 y). PET/CT results were compared and correlated with most recent MRI (1 day to 1 month). Results: Ten patients with Alzheimer's disease diagnosed clinically were consistent with hypometabolism of the temporo-parietal cortices on PET-CT frequently in an asymmetric pattern, with increasing degrees of frontal cortex hypometabolism in relation to advanced disease. There was sparing of the occipital and cerebellar cortices and motor sensory strips. On PET-CT imaging, 2 cases showed temporo-parietal defects similar to Alzheimer's disease, but there also was additional hypometabolism of the occipital cortices. These imaging findings were congruent with the clinical findings of visual hallucinations, leading to a diagnosis of diffuse Lewy body disease. In this study, both Alzheimer's disease and Lewy body dementia correlated with age-appropriate global atrophy in 4 of total 12 dementia patients; 4 of 12 medial temporal lobe atrophy on MRI. Two patients presented clinically with Alzheimer's type dementia. PET-CT with MR correlation showed vascular dementia in one patient, with wedge shaped hypometabolism in right fronto-temporal distribution and left cerebellar diaschisis. The other patient had bilateral mesial temporal hypermetabolism on PET-CT and increased signal intensity in the bilateral temporal lobes on T2WI of MRI, representing limbic encephalitis. One patient had both normal PET/CT and MRI. Conclusion: PET is useful modality of illustrating metabolic distribution of dementia. Medial temporal lobe atrophy and age-related brain atrophy are associated with dementia. MRI can detect structural alteration and differentiate underlying non-dementia disease such as mesial temporal encephalitis. Aim: Dementia is the progressive decline in cognitive function due to damage or disease in the brain beyond what might be expected from normal ageing. Particularly affected areas may be memory, attention, language, and problem solving. It`s a disease strongly associated with age; 1% of those aged 60-65, 6% of those aged 75-79, and 45% of those aged 95 or older suffer from the disease. The most common cause is Alzheimer's disease. Positron emission tomography (PET/CT 18F-FDG) is a valuable tool for understanding functional changes in brain's patients (pts) with several causes of dementia. As such, it can provide valuable physiological alterations for diagnosis, management and research of dementia disorders. PET helps to identify dementia causes and makes a differential diagnostic with other illnesses. The aim of the present study was to evaluate the value of the PET/CT 18F-FDG metabolic patterns for the differential diagnosis and the cause of dementias. Material and Methods: Between January 2005 and March 2007, 26 pts (14 women, 12 men; age: 47-77 years; mean: 60.7 years), with isolated cognitive deficit or dementia (using standard clinical criteria) underwent PET/CT 18F-FDG brain studies, after a reversible illness had been excluded. PET/CT was performed in fasting pts 60 minutes after a 185 MBq 18F-FDG intravenous administration. Some days before PET/CT, Single Photon Emission Computed Tomography (SPECT/CT) was done in 10 of the 26 patients. FDG-PET brain scans results were evaluated and compared to SPECT/CT. Results: 18F-FDG PET/CT scans confirmed the presence of a bilateral temporo-parietal hypometabolism pattern associated with Alzheimer`s disease in 17/26 pts (65%); 9/17 presented a frontal involvement and 4/17 a occipital involvement. In 5 (19%) pts we can see fronto-temporal hypometabolism pattern suggesting a frontal lobe dementia and in 3 (12%) pts a bilateral temporal hypometabolism is present that could imply a premature stage Alzheimer's disease. Only 1 patient had a 18F-FDG-PET/CT pattern compatible with vascular dementia (4%). PET/CT and SPECT/CT are congruent positive results in all studies. Conclusion: 18F-FDG PET/CT brain scan may provide clinician with additional information helpful to establish the cause of dementia after reversible illness has been ruled out. The Purpose: is to demonstrate the imaging features of dementias on brain FDG PET and to determine whether visible anatomic changes on MRI correlate with these findings. Methods and material: Fifteen patients (7 women and 8 men, age range 45-80 years) with clinically suspected dementia underwent FDG PET/CT from January 2005 to December 2006. The results of PET/CT were retrospectively correlated with the findings from the most recent available brain MRI (1 to 30 days from the date of the PET/CT). Results: Ten patients with clinically diagnosed Alzheimer's exhibited temporo-parietal cortical hypometabolism on PET, frequently in an asymmetric pattern, with increasing degrees of frontal cortical hypometabolism seen in relation to severity of disease. There was sparing of the occipital and cerebellar cortices and motor sensory strips. On PET imaging, 2 patients showed temporo-parietal defects similar to Alzheimer's disease, but with additional occipital cortical hypometabolism. This additional abnormality was congruent with clinical findings of visual hallucinations, leading to a diagnosis of diffuse Lewy body disease. Of 12 patients with Alzheimer's disease and Lewy body dementia, 4 showed age-appropriate global atrophy, and 4 showed medial temporal lobe atrophy on MRI. Two other patients presented with Alzheimer's type dementia, however PET-CT with MR correlation showed multi-infarct dementia in one, with wedge shaped hypometabolism in a right fronto-temporal distribution and left cerebellar diaschisis, while the other patient showed bilateral mesial temporal hypermetabolism on PET and increased signal intensity in the bilateral mesial temporal lobes on T2WI MRI, consistent with limbic encephalitis. One patient had normal PET/CT and MRI, despite clinical dementia. Conclusions: PET is a useful modality for aiding in confirmation and differential diagnosis in dementias. Medial temporal lobe atrophy and diffuse brain atrophy are seen with dementia but lack of specificity by MRI. MRI is a powerful tool for differentiating dementias from other underlying disease, such as mesial temporal encephalitis.

Cerebral SPECT with hypercapnia in the examination of cerebrovascular reserve capacity P. Sirucek 1 , O. Kraft 1 , T. Hrbac 2 ; 1 Clinic of Nuclear Medicine University Hospital, Ostrava-Poruba, CZECH REPUBLIC, 2 Clinic of Neurosurgery University Hospital, Ostrava-Poruba, CZECH REPUBLIC.

Aim Aim of this diagnostic examination is choice of suitable patients with neurological deficit the most often after cerebrovascular accident with demonstrated carotid artery or intracranial artery occlusion. These patients would have benefit from bypass surgery (anastomosis between arteria cerebri media and arteria temporalis superficialis). Methods From 2003 to 2005 we examined 37 patients (16 women, 21 men, average age 58.5 yrs. The oldest patient was 76 yrs old, the youngest 31 yrs old). Scintigraphy was done by means of double-headed camera E.CAM by Siemens with convergent collimators fan beam (matrix size 128x128, zoom 1.23, degrees of rotation 180, number of views 64, time per view 20 sec.). Processing was done by means of software e.soft. We have used filtered back projection reconstruction, filter Butterworth (cutoff 0.5, order 5). In all patients we have done brain SPECT in native conditions and then after stress -by inhalation of air enriched by CO2. After increase 2 kPa of partial pressure of CO2 in expired air we injected i.v. 700 MBq radiopharmaceutical 99mTc bicisate (Neurolite) and then we did brain SPECT. Native (rest) and stress examinations were compared. Visual evaluation divided findings in three-grade scale: cerebrovascular reserve capacity (CVRC) was normal in unchanged finding in stress and rest, CVRC was reduced or strongly lowered in worsening of finding in stress. Results 15 pts had normal CVRC, 11 pts had CVRC decreased and 11 pts strongly reduced. 14 pts were operated: in 12 pts EC-IC anastomosis, endarterectomy in 2pts. In EC-IC anastomosis a blood flow was controlled by means of ultrasonography. In 10 pts anastomosis was functional and in 2 pts non-functional. 6 pts indicated improvement of neurological finding. 8 pts had unchanged finding, but from these 8 pts 5 patients had normal finding in time of surgery. 3 pts had pathological finding without change, but after surgery they were without another stroke. In these 3 patients we expect risk decrease of another cerebrovascular ischemic accident. Conclusion Examination of CVRC by means of brain SPECT and hypercapnia is an easy method which is able to help with choice of patients with cerebrovascular occlusion for bypass neurosurgery and to determine patients in whom surgery will improve neurological finding. Introduction: Interictal F-18 FDG PET is frequently used in the identification of epileptogenic foci in patients with intractable partial seizure. We have observed increased metabolic activity in the posterior ocular bulb (POB) in some patients with intractable partial seizure undergoing PET scanning in our facility. The purpose of the current study was to further investigate this observation by evaluating and comparing increased FDG uptake in (POB) in patients with seizure and in normal volunteers. Methods: Brain FDG PET/CT images for fifteen normal volunteers and 24 patients with intractable partial seizure referred for interictal cerebral were retrospectively evaluated. All studies were acquired on a dedicated PET/CT scanner (Gemini, Phillips) with low-dose, non-contrast CT. Two nuclear medicine physicians, blinded to clinical data, indepedently analyzed the POB tracer activity. Chi-square test and interrater reliability with kappa were used. Brain MRI was available in 23 of the 24 seizure patients. A radiologist reviewed brain MRI studies for any possible POB pathology. Results: Of the 15 normal volunteers, 14 (93%) showed no significant FDG uptake in the POB. In the one volunteer with increased POB uptake, significant falx calcification of unknown significance was noted on the CT portion of the PET/CT exam. Of the 24 seizure patients, 23 (96%) had increased FDG uptake in the POB: unilaterally in 3 and bilaterally in 21 cases. On a patient bases, statistical significance was present between the two studied groups (p = 0.000). On an individual eye basis (15 x 2 for normal volunteers + 24 x 2 for seizure patients =78 POB areas), a high interrater agreement (kappa 0.87) was present for most cases (73/78) demonstrating feasible delineation of normal from abnormal POB uptake. Available brain MRI of 23 patients showed no abnormalities at the POB or orbits. Conclusion: When present, visually increased FDG uptake along the POB is abnormal and may be associated with seizure. However, further studies are needed to investigate underlying pathophysiologic mechanism(s) for this phenomenon. A prospective study including ophthalmological and neurological examination is pending in our institution. Aim: There is a continuous scale of preoperative FDG-PET findings (from normal to abnormal) in temporal lobe epilepsy (TLE) patients. The discrimination between normal variability and pathology seems to be a clinical challenge in some cases. The aim of this work was to define the cut-off point for different methods of FDG-PET evaluation and to define their accuracy. Materials & methods: Patients with refractory TLE were indicated to preoperative FDG-PET from three departments. All 58 consecutive patients, in whom histopathology proved hippocampal sclerosis (HS), were included into this study. The control group consisted of 27 oncologic patients without any clinical signs of brain involvement. ROC analysis was utilized for the assessment of accuracy of semi-quantitative parameters of manual evaluation by two operators as well as automated brain analysis using two software applications: Scenium (Siemens; alpha v.1.1) and Brass (HERMES Medical Solutions; v.3.4) . Results: The areas under the ROC curves were calculated for the extent of asymmetry in hippocampus 0,92 (Brass), 0,91 (Scenium); for side difference of Z-value in mesial temporal lobe 0,93 (Scenium); for manual assessment of asymmetry 0,95 (operator 1) and 0,91 (operator 2) and didn't differ significantly between respective methods. A similar analysis in all other regions of interest gave worse results. The correlation coefficient of subjective evaluation between both operators was r=0,971 (CI 95%: 0,956-0,981). The cut-off points for the best discrimination between HS and control groups were for asymmetry of hippocampus: 4,5% (Brass) and 3,9% (Scenium); for manual assessment of asymmetry: 6,9% (operator 1) and 6,7% (operator 2); for side difference of Z-value in mesial temporal lobe: -1,2 (Scenium). The extent of asymmetry assessed by all 3 methods was able to correctly predict the side of operation in 100% of patients with TLE (CI 95%: 0,938-1,000). Conclusion: FDG-PET is a reliable diagnostic tool for discrimination between patients with HS and control group. Sensitivity and specificity is at the level of 90% approximately, regardless of the method of evaluation used. Furthermore FDG-PET is capable to correctly predict the side of operation in 100% of patients with HS. Completely automated analysis is less laborious and operator independent. It gives the same results as careful manual assessment. Manual assessment requires meticulous compliance with standardized evaluation methods. Objectives: To evaluate the diagnostic performance of our new 3D ordered subsets expectation maximization (OSEM) algorithm vs. conventional FBP (Filtered Back Projection) reconstruction algorithm in the functional brain perfusion SPECT imaging with Tc-99m HMPAO and ECD in investigation of cerebrovascular decease, dementia, seizure disorders, tumors and arteriovenous malformation. Methods: The Tc-99m HMPAO or ECD brain SPECT data for 55 patients (n=55) acquired for clinical purpose as a standard-of-care for the deceases listed above were retrospectively reconstructed. The subjects with independently confirmed (e.g. by MRI studies) presence of perfusion abnormalities were selected for this study. The patients were administered 30 mCi of Tc-99m HMPAO or ECD 60 minutes prior to imaging. Prior to radiopharmaceutical administration, standard pre-injection protocol was applied including placing the patient in a dark, quiet room with minimal visual and auditory stimulation. The SPECT scans were acquired with a triple-head gamma camera (Triad 88, Trionix) equipped with low energy high-resolution fan-beam collimators (128x128, 360 degree, 3-degree stops for 25 s). The reconstructed images for the same patients were obtained using the standard-of-care clinical FBP algorithm with Hanning filter (0.6 Ny) and our new 3D OSEM algorithms. The same radiologists in blinded studies independently read them. Our 3D OSEM algorithm is a fully 3D reconstruction method with fan-volume system model and with total variation optimization. The clinical findings from images reconstructed by the two algorithms were compared with ground truth information provided by corresponding complementary studies including CT, MRI, PET, clinical examination and follow-up studies. Results: We established an increase in the specificity and sensitivity in locating the site and spatial extent of brain perfusion abnormalities while using our 3D OSEM, as compared to FBP algorithm. Conclusions: Our new 3D OSEM algorithm applied to HMPAO and ECD SPECT brain studies instead of conventional FBP algorithm resulted in improved diagnostic performance. To obtain a good quality ictal SPECT, the determining factor is the time delay from ictal EEG onset to tracer injection. Aim: The aim was to study which phase of the EEG is the determining factor for reporting the lateralization of the ictal SPECT using SISCOM. The 3 key phases in EEG chosen for study are brain activity lateralization (BAL) at the onset (BAL_O), BAL at the moment of tracer injection (BAL_TI) and then again 20 seconds postinjection (BAL_20) Methods: The study consisted of 53 patients (27 males and 26 females) of an average age of 34 years, with drug resistant complex partial seizures. There were 23 temporal and 30 extratemporal seizures. The SPECTs were ictal in 43 cases and postictal in the remaining 10, with an average tracer injection time of 47 seconds from seizure onset. Brain SPECTs were carried out after the injection oh HMPAO-Tc99m using an ECAM gammacamera (SIEMENS) and following SISCOM methodology for an accurate identification of the maximum brain activity during ictal SPECT. 2 analysis was used to establish which of these 3 EEG phases showed most agreement with the BAL seen in the SISCOM. Results: SISCOM identified BAL on one side in 51/53 patients while EEG in 38. All 15 cases without BAL using EEG, were lateralized using SISCOM. BAL_O occurred in 35 patients, BAL_TI in 31 and BAL_20 in only 15. In the agreement study between BAL_O and SISCOM, of the 33 cases with BAL, 28 were lateralized on the same side and 5 in the contralateral side (P = 0.001). In the case of BAL_TI, of the 29 patients that were lateralized, 28 of these patients were on the same side of the brain and only one in the contralateral side (P = 0.000). Finally, in the case of BAL_20, 15 patients were lateralized, 13 of these were on the same side and two on the contralateral brain hemisphere (P = 0.062). Conclusions: The highest degree of agreement was between SISCOM and BAL_TI. This suggests that the tracer injection time is the determinant in correct interpretation of ictal SPECT. Purpose: I-123 iomazenil(IMZ) is a one of the benzodiazepine partial-inverse agonist and has been widely used to evaluate a distribution of central benzodiazepine receptors. Some authors reported that 3D-SSP could be useful to detect subtle change of tracer distribution in brain. However, a result of 3D-SSP depends on the normal database. We hypothesized that a distribution of central benzodiazepine receptors may change with age. The purpose of this study was to evaluate an age-specific normal distribution of I-123 iomazenil(IMZ) SPECT imaging. Method and Materials: Twenty-nine subjects who were hospitalized in our hospital were studied. IMZ brain SPECT and brain MRI were performed within 2 weeks period. They were suspected of having epilepsy on the basis of clinical findings, but no significant abnormality was seen in their IMZ SPECT and no major abnormality in their MRI. These findings visually interpreted by 2 radiologists. These subjects were classified into 4 groups by their age; 1-5 years (5 males, 3 females), 6-12 years (3 males, 4 females), 13-30 years (5 males, 3 females), and 31 years and older (2 males, 5 females). Three hours after the intravenous injection of 167 MBq of IMZ, SPECT data acquisition was performed using a triple head digital gamma camera system. Unpaired Student t tests were performed to compare the IMZ accumulation in each group using 3D-SSP, and z score maps were obtained. Two radiologists visually and independently evaluated these z score maps, and compared the IMZ accumulation between each group. Results: The IMZ accumulation of the 1-5 years group in the cerebellar hemisphere was higher than the other 3 groups. It of the 1-5 and 6-12 years groups in the central sulcus were also higher than the other 2 groups. On the other hands, it of these younger 2 groups in the frontal lobe were lower than the other 2 groups. Furthermore, it in the posterior cingulate gyrus and the occipitotemporal lobe increased with age. COCLUSIONS: According to our result, the distribution of IMZ could be change with age, and to assemble an age-specific normal database might be important. Aim: to assess the role of brain perfusion SPECT in the management of patients with Spontaneous Intracerebral Hemorrhage (SICH). Method: 19 SICH pts were studied. All pts underwent same day CT and brain SPECT with 99mTcHMPAO, 24h-4d from onset of stroke. Results: 14/19pts (73.68%) showed a larger perfusion defect than expected after CT. In 4 pts hematoma diameter was comparable on CT and SPECT; 1pt had quasinormal aspect of SPECT study. In pts with larger defects, SPECT revealed a large cold spot with similar size compared with CT, and a surrounding hypoperfused area. 6/19 pts revealed cortical hyperperfusion, adjacent to hypoperfused area and corresponding to a normal-appearing brain tissue on CT. In 3 pts we found crossed cerebellar diaskisis. In 2pts we found cortical hypoperfused area in the contralateral cortex, with normal appearing brain tissue on CT. Discution: Many mechanisms and scenarios were proposed in order to identify the pathologic factors involved in the pathology of SICH: edema, ischemia, inflammation, microglial activation, hemotoxicity, apoptosis... All of these factors are affecting brain tissue surrounding hematoma and are responsible of the progressive neurological deterioration; most of these damages are not revealed by anatomical imaging techniques. Despite the latest advances in medical treatment and neurocritical care, patients suffering SICH still have a very poor prognosis, with a greater mortality and larger neurological deficits at the survivors than for ischemic stroke. In a significant number of our patients (73.68%!) brain perfusion SPECT revealed different types of perfusion changes in the brain tissue surrounding hematoma, corresponding to normal appearing brain tissue on the CT scans. Further studies are definitely required to demonstrate prognostic significance of these changes, but we can assume that all these areas contain viable tissue that can be a target for neuroprotective strategies. Conclusions: Brain perfusion SPECT can play an important role in SICH, by early demonstrating functional changes responsible of clinical deterioration, thus allowing prompt dedicated therapeutic intervention. Aim: to evaluate influence of hypotensive treatment on cerebral perfusion and cognitive function in patients (pts) with arterial hypertension (AH). Material and methods: The study involved 31 patients (19 males and 12 females, mean age 53±5) with moderate essential hypertension. Perfusion brain SPECT with 99mTc-HMPAO and comprehensive neuropsychological testing were performed before and after 3months of antaginist Ca treatment. Brain SPECT slices were divided into 14 symmetrical (right and left) regions of interest per patients: inferior and superior frontal lobes, temporal, anterior and posterior parietal, occipital lobes and cerebellar hemispheres. Regional cerebral blood flow (rCBF)(ml/100g/min) in these regions was calculated. Results: Hypoperfused regions were revealed in 27 pts. All pts had no focal neurological symptoms. Antihypertensive therapy within 3 month led to the brain perfusion improvement and positive effect on cognitive function in pts with AH. Medical treatment followed by the increase in rCBF relative to baseline in right and

left anterior parietal regions (47.6±0.7 vs 44.9±0.5, p=0.01; 47.3±0.6 vs 44.7±0.5, p=0.002, correspondingly), in left temporal cortex (50.8±0.8 vs 48.2±0.6, p=0.003), in left inferior frontal region (50.4±0.8 vs 47.1±0.5, p=0.003). Also growth in cerebral perfusion in right and left superior frontal regions, in right inferior frontal cortex and right and left occipital regions was observed. Measures of immediate verbal memory, delayed verbal memory and learning showed a significant increase theirs after treatment an average on 10% (p=0.0001), 15% (p=0.024) and 9% (p=0.004), correspondingly, as well as improvement in immediate and delayed visual memory, attention on 28% (p=0.00006), 26% (p=0.003), and 35,8% (p=0.01), correspondingly. Relationship between the changes of cerebral perfusion and dynamics of cognitive status was found. Improvement of immediate verbal memory correlated well with increase in rCBF in left temporal region (R2=0.339; p=0.018). Betterment of delayed verbal memory related to growth in cerebral perfusion in left anterior parietal region (R2=0.26; p=0.042) and left inferior frontal region (R2=0.25; p=0.047). Positive correlation was shown between dynamics of attention and changes rCBF in right and left anterior parietal regions (R2=0.55; p=0.001, R2=0.531; p=0.028, correspondingly). Conclusion: Our results suggest that brain SPECT is useful technique for evaluation of medical treatment dynamic and understanding of cognitive disorders mechanisms in patients with arterial hypertension. Improvement of cognitive functions after treatment in patients with AH was connected with the increase in brain perfusion.

Efficacy assessment of encephalo-duro-arteriosynangiosis for childhood moyamoya disease using 3dimensional stereotactic ROI template analysis of brain perfusion SPECT S. Hyun, K. Lee, S. Lee, Y. Cho, E. Lee, J. Choi, Y. Choi, Y. Choe, B. Kim; Samsung Medical Center, Seoul, REPUBLIC OF KOREA.

Objectives: We evaluated the efficacy of encephalo-duro-arterio-synangiosis (EDAS) for childhood moyamoya disease using 3-dimensional stereotactic ROI template (3DSRT) analysis of brain perfusion SPECT. Methods: Eighteen patients (F: M = 14: 4, mean 7.9 ± 2.6 yr) with childhood moyamoya disease who underwent bilateral simple EDAS were included. Resting and acetazolamide (Acz) challenged cerebral perfusions were measured with 99mTc-ECD SPECT 8.9 ± 8.6 days before the one side operation and 15.8 ± 7.5 months after the other side operation. The SPECT images were anatomically standardized using SPM99 followed by normalization of counts using proportional scaling with the mean value of cerebellum at 50. We calculated the cerebral vascular reserve index (CVRI) image as follows: CVRI (%) = [(Acz image -resting image) / resting image] x 100. Fully automated ROI analysis with 3DSRT was performed on resting, Acz, and CVRI images. 3DSRT calculated the area-weighted mean value of 12 segments by quantification of 318 constant ROIs in each hemisphere. We compared the mean value of each segment between pre-and postoperative groups. Wilcoxon matched-pairs signed-ranks test was used for statistical analysis. Results: Comparison between pre-and postoperative brain SPECT revealed no significant improvement in resting perfusion. After EDAS, there was significant Acz challenged perfusion improvement in the central (pre 43.6 ± 7.3 vs. post 45.7 ± 4.8, p=0.003) and parietal region (pre 45.3 ± 9.4 vs. post 46.1 ± 8.1, p=0.008). CVRI improved in the central region with a mean difference of 2.1 (pre -6.3 ± 7.0 vs. post -4.1 ± 4.7, p=0.016) and the parietal region with a mean difference of 2.0 (pre -7.0 ± 7.8 vs. post -4.9 ± 4.5, p=0.093). CVRI in the lenticular nucleus region was significantly reduced (pre -0.6 ± 5.6 vs. post -3.9 ± 4.8, p=0.002). Conclusions: Pre-and postoperative cerebral perfusion and vascular reserve in childhood moyamoya disease can be effectively assessed by 3DSRT. Our results provide objective evidence that simple EDAS improves cerebral perfusion in the middle cerebral artery territory without direct benefit in the anterior and posterior cerebral artery territories. 12 segments: callosomarginal, precentral, central, parietal, angular, temporal, posterior cerebral, pericallosal, lenticular nucleus, thalamus, hippocampus, and cerebellum Aim of the Study: To evaluate metabolic activity using 18F-FDG CT-PET in order to establish both carotid vulnerability to rupture and asymptomatic progression linked to plaque inflammatory cells. Methods: 15 patients with symptomatic or asymptomatic unilateral carotid arteries were studied. All of them were scheduled for carotid endarterectomy (CE). 18F-FDG head and neck CT-PET was performed using a Discovery ST scanner (GE Healthcare) prior to CE and 100 days following surgery. Two speciality-trained persons blinded to the vascular examinations results reviewed and quantified the scans. Two-centimeter circular regions of interest were drawn on CT images around the area including carotids in each slice, and then transferred onto the corresponding coregistered PET image to enable 18F-FDG uptake values based on maximum standardized uptake value. The analysis included vascular region 56 mm over and below the level of the carotid bifurcation, and slice-activity curves were calculated in order to visualize plaque and basal metabolism. Results: Carotid plaques with inflammatory infiltrates had a major 18F-FDG uptake (p<0.05). No significant correlation was found between degree of 18F-FDG uptake and time from symptoms to CT-PET imaging, symptomatic or asymptomatic patients, degree if carotid stenosis and vascular risk factors. We found significant correlation between the degree of 18F-FDG accumulation in carotids scheduled for CE and contralateral carotids (p<0.005). The 18F-FDG ratios in the contralateral arteries remained increased on the follow-up imaging at 100 days. Statines treatment was correlated with more pronounced decreased in 18F-FDG-uptake at 100 days (p<0.05). Conclusions: This is the first in vivo study using 18F-FDG CT-PET imaging demonstrating that carotid atherosclerosis is a bilateral disease. Identification of inflammatory regions in the contralateral carotids has the potential to offer early aggressive pharmacotherapy in these patients. Aim. We report our clinical experience with 99m Tc-HMPAO SPECT imaging in patients with giant intracranial aneurysm in order to identify patients without a sufficient collateral perfusion during internal carotid artery (ICA) temporary occlusion test (TOT). Material and methods. 20 consecutive patients (1 man, 19 women; mean age 43 years; range 19-67 years) affected by a giant intracranial aneurysm, who could potentially benefit from permanent ICA occlusion, underwent a TOT to evaluate the efficiency of cerebral collateral perfusion. One patient with sudden onset of intese headache during TOT (absolute contraindication for permanent ICA occlusion) was excluded from this series whereas 19 patients were injected with twenty mCi of 99m Tc HMPAO after a endovascular balloon had been blown up for ten minutes. Images were obtained by a dual headed gamma camera using a circular orbit and a 3° step and shoot technique. Data were processed after a backprojection and an attenuation correction, by using a low pass filter. Both a qualitative and a semiquantitative analysis of images were performed. Results. In 15 patients, no perfusion impairments were found and a permanent ICA occlusion was made. The procedure resulted in aneurysm thrombosis and no signs of ischemic injures occurred in the follow-up period. Four patients showed a reduced perfusion during TOT. One of these patients underwent surgical revascularization by EC/IC bypass. A new TOT, after surgical revascularization, revealed no perfusion alterations and the patient underwent permanent ICA occlusion without any subsequent ischemic injury. Conclusion. 99m Tc HMPAO is an effective tool in identifying patients who cannot undergo permanent ICA occlusion. Intracranial arteriovenous malformation (AVM) is an abnormal collection of immature blood vessels within the brain. Treatment of the brain AVMs includes three modalities: endovascular embolization, which reduces the size and vascularity of the lesion, standard microsurgery or radiosurgery. Very little relevant literature concerning the role of SPECT in the evaluation of AVM treatment through endovascular embolization encouraged us to study this problem. Material. Examined group included 13 patients ( 8 women and 5 men) at the age of 12-59 years. All the patients had been previously diagnosed with intracranial AVM and subsequently qualified for the endovascular embolization procedure. The patients were in good clinical condition and had no symptoms of recent intracranial haemorrhage. Methods. Brain scintigraphy was performed on the same day, prior to embolization and 1-22 days after treatment. Administrated activity of 99mTc-ECD (POLATOM, Poland) was 491 to 925 MBq. SPECT examination was carried through 20 minutes after IV radiotracer injection with two-head gamma-camera VARICAM. Acquisition was performed using high-resolution collimators, with one projection for each 3° in a 360° orbit. A matrix of 128×128 pixels was applied. Filtered back projection with Metz filter was used for reconstruction. Regional cerebral blood flow (rCBF) was evaluated visually and semiquantitatively using voxel-based analysis with Brain SPECT Quantification software (Compart, Warsaw, Poland). Embolization procedure was performed under general anaesthesia. Angiography was carried out using Siemens equipment (Multistar). Partial or complete obliteration of AVM was followed by postembolization angiography. Results. No serious side effects were observed after embolization. In each patient, SPECT showed the nidus of AVM as a region of decreased radiotracer accumulation. After embolization significant changes of perfusion (cut off cluster size-10,0 ml, cut-off percentage-10% in semiquantitative analysis) in an area adjacent to the AVM nidus were found in 10 pts: deterioration of perfusion in 9 pts (10,8ml-68,7ml mean 35,4±23,9 ml, 14%-26% mean 17,7±2,9%) and improvement in 1 patient (13,7 ml, 16,5%). Significant perfusion changes in the areas remote to the nidus were seen in 12 pts: 21 areas of perfusion deterioration and 14 regions of rCBF improvement after embolization. These areas were located in cerebral and cerebellar hemispheres both ipsilateral and contralateral to AVM. Conclusions. Perfusion changes in patients with AVM treated through endovascular embolization can be detected by means of 99m Tc-ECD SPECT with voxel-based analysis. Deterioration of perfusion after embolization seems to prevail over improvement.

Mean cerebral blood flow,response to PaCO 2 and rCBF distribution in the patients with diabetic mellitus A. Komatani; Yamagata Univ., Yamagata, JAPAN.

Aim: The diabetes mellitus (DM) is widely known as a risk factor of many diseases e.g. retinopathy, nephropathy, neuropathy and angiopathy, etc. To confirm the possibility of DM as a risk factor for the cerebral infarction and/or vascular dementia, we inspected mean cerebral blood flow (CBF), its distribution, and flow reserve in patients with DM. Materials: Fifty-one males aged 62.1±11 and forty seven female aged 66.5±11 with DM. Ten males aged 56.7±20 and twelve females aged 58.2±17.4 for healthy control. Methods: Mean CBF was measured using 133 Xe-SPECT with Kanno-Lassen's method, and the flow reserve was estimated as a response to PaCO 2 by sodium bicarbonate (HCO 3 -) injection. The distribution of regional cerebral blood flow (rCBF) was estimated using statistical parametric mapping (SPM) with 99m Tc-ECD. Results: The mean CBF was 47.0±6.3 ml/100g/min in the group of DM patients, and 52.9±3.5 ml/100g/min in the group of healthy control. No significant difference was seen between the both groups (p=0.13). Regional flow reduction in the white matter especially at the sub cortical region was observed in most of the DM patients. No significant difference in the mean CBF was seen between with and without complications of hypertension and/or hyperlipemia. The correlation between the mean CBF and the dilation of the disease tend to have negative correlation (p=0.025). The percent increase with the sodium bicarbonate injection was 19.1±8.4% in DM patients and 45.8±8.7% in healthy controls. The flow reserve in DM patients was significantly poor compared with control group (p<0.001). Conclusion: The most obvious findings of DM patients were flow reserve reduction, and the reduced regional flow in the white matter especially at the sub cortical area. The reduction in mean cerebral blood flow was not so major characteristic of DM patients. DM should be a certain risk factor for the cerebral infarction and/or vascular dementia due to micro angiopathy with DM.

Brain metabolism in patients with unilateral carotid stenosis.

Regional changes evaluation after endarterectomy using CT-PET with 18F-FDG A. Fernandez Leon 1 , J. Krupinsky 1 , M. Font 1 , R. de Juan 1 , P. Pifarre 1 , A. Carvajal 1 , F. Rubio 1 , A. Domenech 1 , C. Gamez 1 , J. Gispert 2 ; 1 IDIBELL. Hospital de Bellvitge. Unitat PET., Barcelona, SPAIN, 2 IDIBELL. Hospital de Bellvitge, Barcelona, SUDAN.

Aim of the work: Atheroesclerosis is a chronic inflammatory disorder but it is still unclear whether patients with unilateral carotid disease are at higher risk of contralateral carotid artery progression. Both carotid vulnerability to rupture and metabolic brain changes related to vascular disease may be linked to plaque inflammatory cells. Imaging with 18F-FDG PET has been shown to be unique in detection of plaque inflammatory activity and secondary brain changes. Methods: We studied 15 patients with symptomatic or asymptomatic unilateral carotid arteries. All of them were scheduled for carotid endarterectomy (CE). All patients received an integrated FDG-PET/CT using a Discovery ST scanner (General Electric Healthcare) prior to CE and 100 days following surgery. PET was performed with 3,71 mm slice thickness with no overlapping slices in 3D mode including brain and neck structures. A stiff cervical collar was worn to minimize patient movement. Approximately 370 MBq of FDG was administered intravenously as a bolus and static emission images were obtained 30 min later. Attenuation correction 4-slice CT helical scans (CTAC) were obtained at 3,71 mm slice thickness, 120 KV tube voltage and 60 mA tube current. All images were pre-processed using the algorithms provided with the SPM2 software package. Images were normalized to the PET template and smoothed with a gaussian kernel of 8 mm FWHM. Then, images were masked so that all remaining voxels had an activity higher than 80% of the brain global value in all cases. Relative intra-subject changes in brain metabolism were determined in a voxel-by-voxel manner by subtracting the POST and PRE images and expressing this difference in percentage units relative to the first image [100x(POST-PRE/PRE)]. Finally, these images were thresholded and the number of voxels showing changes over/under 10% were recorded, as well as the average relative metabolic change in them. Results: In 5/15 patients significant increased metabolism in unilateral or bilateral carotidean territories were observed after endarterectomy. In half cases there was concordance between brain changes and affected carotid. In 1/15 we observed decreased bilateral metabolism after CA. No changes were observed in 9/15 patients, all of them with left arterial disease. No significant correlation was found between brain changes and time from symptoms to PET imaging, symptomatic or asymptomatic patients, degree of carotid stenosis and vascular risk factors. Conclusions: 18F-FDG CT-PET imaging can demonstrate bilateral changes in brain metabolism after endarterectomy, mainly in carotidean territories. Objective To evaluate the efficacy and the diagnostic value of cerebral perfusion quantification in patients (p) with carotide artery stenosis (CAS) who underwent surgical endarterectomy. Materials and methods 11 p were studied. 5 showed right and 6 left carotide stenosis. Most of them had bilateral CAS and underwent surgery of the main affected artery. Eco-Doppler, basal and 3 months after endarterectomy 99mTc-SPECT with 25 mCi of 99mTc-ECD scan (VG GEMS gamma camera, fan beam collimator) were performed in all p. The perfusion was analysed by SPM2 comparing each patient's study (pre and post surgery) with a healthy control group. The changes in both the extension and intensity of the cerebral hypoperfusion before and after surgery were also evaluated. Results A significant carotide artery flow improvement was found in all p by Eco-Doppler. In 3p the basal cerebral perfusion analysis by SPM2 was normal. In 3 p an increase of the intensity (mean 42,6%) and extension (mean 272%) of the hypoperfused areas seen in the basal study was detected. In 5 p a decrease of the intensity (mean 42,6%) and extension (mean 62,8%) was seen. Conclusion SPM2 is a useful method to analyse the post surgery cerebral perfusion changes in p with carotide stenosis, detecting a significative hypoperfusion decrease (intensity and area) in 5 of 8 p. A post surgery worsening was found in 3p. These results are uncertain and further long term studies would be needed to clarify these findings. Aim: Study of brain perfusion in patients with arterial hypertension (AH) and type II diabetes mellitus (DM). Material and methods: Fifty seven patients with moderate essential hypertension (mean age 51,6+5,7 years) were investigated by brain SPECT scanning with 99m Tc-hexamethylpropylene amine oxime ( 99m Tc-HMPAO). Thirty three patients were found to have AH without carbohydrate metabolism disturbance (Gr.I) and 24 patients -AH with type II DM (Gr.II) in stage of compensation and subcompensation. All patients had no focal neurological symptoms. SPECT was performed at baseline and during adenosine test. Results: Hypoperfused regions were revealed in all patients. The dercrease in radiopharmaceutical accumulation was found in 181 of 1188 brain regions in patients of Gr.I. The most significant cerebral blood decrease was marked in parietal brain region (20%). Hypoperfused regions were observed less frequently in temporal (16%), occipital (16%) and frontal (12%) brain lobes. Cerebral perfusion disorders in patients with AH and DM were more pronounced in comparison with patients of Gr.I (p=0,021). Thus, 162 of 864 brain regions (19%) were hypoperfused in pts of Gr.II. Microcirculation disorders of greater degree were found in occipital brain lobes, where hypoperfusion was revealed in 38 of 144 (26%) brain regions. The less pronounced decrease in accumulation of 99m Tc-HMPAO was observed in parietal (22%), temporal (18%) and frontal (14%) brain lobes. Use of adenosine test in both patients groups did not affect cerebral perfusion in hemispheres (p=0,342 and p=0,768, respectively). However, in some cases brain perfusion decrease in individual regions was observed. At the same time in frontal lobe almost double increase in hypoperfused regions quantity as compared with baseline was found. This fact may testify to cerebrovascular reserve decrease in frontal region in these patients. Conclusion: Our results suggest that the signs of brain hypoperfusion and the decrease in cerebrovascular reserve take place in patients with essential hypertension and diabetes mellitus as well as in AH patients without it even if they have no focal neurological symptoms. The most pronounced cerebral perfusion disorders are revealed in patients with AH and diabetes mellitus in comparison with AH patients without carbohydrate metabolism disturbance. [123I]FP-CIT is suitable for the quantification of dopamine (DA) transporters localized on the membrane of presynaptic dopaminergic neurons. The practical use of [123I]FP-CIT SPECT has become a routine diagnostic tool to investigate the integrity of the nigrostriatal pathway in vivo and also to directly assess the progression of parkinsonism. Previous studies applying ROI methods for data analysis have evaluated the effect of medications on the striatal DA transporter imaging, that is however still debated. Aim of the study was to evaluate the effect of treatment with dopamine agonist drugs on DA transporters in patients with Parkinson's Disease (PD) by means of a voxel-based analysis of [123I]FP-CIT SPECT data. SPECT [123I]FP-CIT binding to the DA transporters was evaluated in 21 patients both without any medication and during treatment with dopamine agonist drugs (ergot-derivatives and non-ergotderivatives) after reaching the maximal optimazed dose (mean 35 days). A 2-head gamma camera equipped with LEHR collimators was used for data acquisition (128 x 128 matrix, pixel size 3 mm, 128 projections, 360° circular orbit) after the i.v. injection of 185 MBq of [123I]FP-CIT. Filtered back projection with a Butterworth prefilter (0.4 cycles/cm, order 8) was used for reconstruction, applying uniform attenuation correction (0.12 cm-1). Reconstructed data were realigned, spatially normalized to a [123I]FP-CIT SPECT template and smoothed. Individual voxels values were expressed as % of occipital mean counts. SPM2 was then used for data analysis. Both caudate and putamen [123I]FP-CIT binding values were bilaterally not significantly different on baseline and during treatment (p<0.001). No statistically differences were also observed when comparing patients treated with ergot-derivatives versus non-ergot-derivatives. In conclusion, the results of the voxel-based analysis, a less operator-dependent approach than ROI methods, confirm that dopamine agonist medications do not affect the SPECT imaging with [123I]FP-CIT and support the needless of withdrawing both ergot-derivative and non-ergot-derivative drugs to measure DA transporter levels. The absence of effect of this treatment on SPECT measurements is particularly important when the neuroprotective effect of dopamine agonist drugs is going to be assessed by [123I]FP-CIT imaging. The diagnosis of Alzheimer's disease (AD) versus Lewy-body dementia (LBD) and Parkinson's disease (PD) with dementia is often problematic, especially in patients with both dementia and parkinsonism. Aim of the study was to assess the usefulness of SPECT with [123I]FP-CIT, a dopaminergic presynaptic ligand evaluating integrity of nigrostriatal pathways, combined with rCBF SPECT for differentiating in-vivo LBD, PD with dementia and AD, by means of a voxel-based approach. Most previous SPECT studies have applied ROI methods for analysis, which are subjective and operator-dependent. Fifteen patients with probable LBD, 15 with probable AD (NINCDS/ADRDA criteria) and 10 patients with dementing PD underwent rCBF SPECT with 99mTc-ECD and a brain SPECT with [123I]FP-CIT. Patients were matched for age, sex and severity of cognitive impairment (MMSE). SPECT was performed with a dual-head gamma-camera 3-4 hr after the i.v. injection of [123I]FP-CIT (185 MBq) and about 1 hr after 99mTc-ECD (900 MBq). Comparison of the[123I]FP-CIT striatal binding ratios and rCBF SPECT patterns among AD, LBD and PD was performed by means of the voxel-based SPM analysis (SPM2, unpaired ttest for statistical analysis). The SPM analysis showed a significant (p<0.001) bilaterally reduced binding in caudate and putamen in LBD and PD patients compared to AD. Striatal uptake was indistinguishable between patients with LBD and PD. AD patients had significantly (p<0.001) reduced rCBF in the temporo-parietal and frontal areas versus both the LBD and PD groups. LBD and PD patients showed significantly reduced (p<0.001) rCBF in the occipital regions versus the AD patients. Whereas, no statistical differences in the rCBF patterns were found between LBD and PD patients. In conclusion, the SPM voxel-based approach is a viable alternative to the method of ROI analysis, and could be included in the routine clinical analysis. Nigrostriatal impairment as evaluated by means of [123I]FP-CIT SPECT allows to differentiate LBD or dementing PD from AD patients. The rCBF study adds further informations about the existence of a common or different neurobiological substrate underlying the clinical spectrum of parkinsonism-dementia. On the other hand, it appears that [123I]FP-CIT and rCBF imaging cannot differentiate LBD from PD with dementia. Background A differential diagnosis between Idiopathic Parkinson's Disease (IPD) and Multiple System Atrophy (MSA) is clinically difficult. We analyzed the difference in glucose metabolism between IPD and MSA using SPM (statistical parametric mapping). Methods This study included 7 IPD patients (age range: 47-77 yr), 3 MSA patients (age range: 57-65 yr) and 11 healthy controls (age range: 33-68 yr) who underwent F-18 FDG PET. Using SPM2 (Statistical parametric Mapping 2, Wellcome Department of Cognitive Neurology, London, UK) software, all the images were spatially normalized into the standard template, smoothed with 6 mm FWHM isotropic Gaussian kernel. The count of each voxel was normalized versus the total count for the brain (proportional scaling in SPM) to remove global cerebral blood flow differences between the individuals. Images of IPD were compared with those of healthy controls and MSA patients in a voxel wise manner using SPM2 (uncorrected p < 0.01).

The IPD patients were found to have a significant glucose hypermetabolism in comparison with the healthy controls in both basal ganglia, thalami, cerebellar areas and decreased metabolism in motor cortical areas. The MSA patients demonstrated diffusely decreased cerebral glucose metabolism in both both cerebellar areas compared to the IPD patients. Conclusion Although the number of patients studied is small, SPM analysis may be useful in differential diagnosis of patients with Idiopathic Parkinson's Disease and Multi-System Atrophy. Further studies including more patients may be warranted . Normal or aspecific findings at CT/MR. Brain SPECT was performed 3-4 hrs after 148 MBq 123I FP-CIT (DaTSCAN, Amersham Health) i.v. injection by a dual head gamma camera with fan beam collimators. SPECT images were analyzed qualitatively and quantitatively calculating conventional putamen/occipital (p/o) and caudate/occipital (c/o) ratios normalized with phantom and compared to age matched normal controls (C) provided by the data processing software (normal values: p/o=8.25±3.79; c/o=7.76±3.54). When the two analysis data were controversial the binding potentials were determined by another software (NEUROTRANS 3D, Mirage) that corrects the partial volume effect applying the Talairach atlas as anatomical 3D reference. Results: 123I-FP-CIT SPECT was normal at qualitative analysis in 56/134 (41.8%) patients without difference in both p/o and c/o ratio in respect of C, thus classifying these cases as affected by ET. SPECT was pathological in 78/134 (58.2%) cases; in 48 of these, monolateral putamen uptake defects were ascertained in concordance with clinically evidenced site and p/o ratios (3.83±0.98) in all involved putamen were significantly lower than in controlateral ones (7.93±1.17; p<0.001) and C (p<0.00001). Bilateral defects were detected in the remaining 38/78 pathological cases, clinically classified as monolateral; however, p/o ratio was bilaterally low only in 28/38 cases with mean values significantly lower (p<0.0001) than C in both putamen (left: 3.48±0.89; right: 3.84±1.07) while, it was low monolaterally in the remaining 10/38. However, in these latter, at 3D analysis, binding potentials were low bilaterally. All 78 patients classified as PD underwent L-Dopa therapy. Conclusions:123I-FP-CIT Brain SPECT may be useful in patients with clinically suspected resting tremor of recent appearance to clarify uncertain differential diagnosis between PD and ET, thus permitting the most appropriate treatment. Moreover, SPECT also gave more information on disease extension in respect of clinical data utilizing both qualitative and semiquantitative analyses, with 3D binding potentials evaluation obtaining higher performance in our cases. 2) The placement of ROIs in basal ganglia not uniquely defined. These issues are most prominent in patients with low tracer uptake in the basal ganglia (advanced PD, candidates for surgery etc.), but also of importance in longitudinal studies. We propose an automated method relying on histogram analysis that does not involve operator interaction. Materials and Methods The algorithm exploits the pharmacokinetic feature of high target-to-background ratios of the ligands. Simple histogram analysis of the image slices containing the basal ganglia and occipital cortex can reveal estimates for specific and unspecific uptake. The histogram analysis consists of 3 parts: 1) thresholding for extraction of brain pixels, 2) calculation of the median pixel value in the brain as an estimate of unspecific uptake, 3) calculation of the median of the pixels with the highest tracer uptake corresponding to the size of the basal ganglia. The algorithm was tested on FP-CIT images from 23 patients and compared to the manual "Crescent ROI" analysis. The parameter of interest was the ratio of uptake in the basal ganglia compared to the background. Results In 15/22 datasets the agreement of the ratios was within 0.3, in 19/22 datasets within 0.5. Datasets with "patchy" tracer uptake with areas of low uptake in the background region exhibited the largest differences. In one dataset, the algorithm failed to identify the slice with the basal ganglia. This dataset was excluded. Conclusion Despite its simplicity, the algorithm reproduces clinically reported results in most cases with good correspondence. Deviations are prominent in cases with patchy unspecific uptake. In longitudinal studies the algorithm may provide valuable information as both inter-and intra-operator variance are removed.

White matter normalization -a novel analysis method with improved sensitivity in PET perfusion studies of neurodegenerative diseases. P. Borghammer 1 , K. Y. Jonsdottir 2 , A. Gjedde 1 ; 1 PET center, Aarhus University Hospital, Aarhus, DENMARK, 2 Center for Integrative Functional Neuroscience, Aarhus University, Aarhus, DENMARK.

Aim: In PET studies of cerebral blood flow (CBF) and glucose consumption, the data analysis is complicated by the very large inter-subject variability. To overcome this problem, data normalization is often carried out by dividing each voxel in a subject scan with the global mean (GM). It is an often overlooked fact, that even subtle differences in global mean between the groups introduce bias into the analysis. We suggest, that normalization to white matter mean (WM) might improve analysis sensitivity and diminish the risk of creating artifacts. Materials & Methods: 9 earlystage Parkinson’s Disease (PD) patients and 15 healthy age-matched controls underwent CBF PET scans while resting. We employed both region-of-interest (ROI) and voxel-based statistics. The analysis was carried out on non-normalized data and after normalization to GM and WM mean, respectively. The findings of these three analyses were compared. Results: ROI: No significant differences were found in absolute values of CBF in whole brain or any of the 4 major lobes. After normalization to GM, PD patients had decreased CBF in parieto-occipital lobes, and in whole grey matter (all p<0.05). After WM normalization, we found significant differences in the same areas and additionally in the frontal lobe (all p<0.05). Voxel-based: GM normalization yielded a single small voxel-cluster of significant decrease in the medial occipital lobe and a cluster of significant increase in left primary motor area (mostly white matter). WM normalized data disclosed 3 much larger significant clusters of decreases CBF in occipital lobe and lateral parietal lobe bilaterally (p<0.05 for all clusters), but no increases. Conclusion: Following WM normalization, significantly larger areas of cortical CBF decreases were detected than after GM normalization. Conversely, only in GM normalized data, we detected increased CBF in PD. WM hyperactivity has been reported numerous times before in studies of PD patients. There is no basis or prior evidence for WM hyperactivity in animal models of PD. We propose, that the WM hyperactivity, reported in numerous PET studies of human PD, is an artifact created by wrongful normalization to GM, since GM is most likely decreased in PD, although this is rarely detected in the absolute data due to insufficient subject sample sizes. The WM normalization method seems to be more sensitive to detect expected (true) decreases and less prone to create artifacts such as WM hyperactivity. Aim. 123 I-FP-CIT is a neuroreceptor tracer successfully used in diagnosing dopaminergic deficit in Parkinsons' disease (PD) at an early stage due to the loss of dopamine transporter (DAT). This study evaluates the possibility of making a more extensive and larger early diagnosis of the dopaminergic damage using semiquantitative analysis of 123I-FP-CIT SPECT in patients with suspected Parkinson's disease compared to only qualitative tests. Methods. the study was carried out on 154 patients with suspected PD. Another 18 people were involved as a control group, they were similar age-wise to the PD group and at follow-up 24 months later essential tremor was evidenced and not PD. SPECT was carried out 4 hours after the DAT tracer had been administered. Both qualitative and semi-quantitative analyses were performed in the region of the striatum in the 154 patients studied. The semiquantitative analysis was made out and the patients with results superior to the 1 standard deviation of the established range were selected. Result. In 134 patients out of 154 (87%) a reduction of DAT activity in at least one region of striatum was evident. Visual analysis of the images diagnosed dopaminergic damage to the putamen controlaterally to the side where the symptoms were present in 60.4%; to adjacent caudate nucleus in 31.3% and damage to the base nuclei isolaterally to the symptoms in 8.2%. While the semi-quantitative analysis gave the following results: 32.8%, 50.7% and 16.4% respectively.Conclusions. The results indicate that 123 I-FP-CIT SPECT allows a more accurate characterisation of the dopaminergic damage in patients with suspected Parkinson's disease. G. P. Sechi 1 , S. Nuvoli 2 , V. Agnetti 1 , K. Paulus 1 , F. Chessa 2 , G. Cocco 1 , A. Spanu 2 , G. Madeddu 2 ; 1 Neurology DPT, University of Sassari, Sassari, ITALY, 2 Nuclear Medicine DPT, University of Sassari, Sassari, ITALY.

Aim: In Parkinson's disease (PD) patients we used 123 I-FP-CIT SPECT to investigate whether the tripeptide GSH may have an effect on DAT, GSH ability to cross the blood-brain barrier (BBB) being still debated. Material and methods: Twenty consecutive PD patients (H-Y stage 1-35) were studied, 9 never been treated (Group 1) and 11 on chronic carbidopa/levodopa and/or dopamine agonist therapy (Group 2). In all PD patients and in 8 healthy subjects were performed: UPDRS motor battery and Webster step-second Test, and SPECT 3-4 hrs after 148 MBq 123 I-FP-CIT (DaTscan, Amersham GE) i.v. injection. SPECT images were evaluated both qualitatively and semiquantitatively calculating putamen/occipital (p/o) and caudate/occipital (c/o) ratios, normalized with phantom and compared to age matched normal controls (C) provided by processing software data. Both Group 1 and Group 2 patients were treated for 6 weeks with i.m. GSH therapy, 600 μg twice daily, Group 2 maintaining basal treatment. After GSH, PD patients repeated SPECT and neurological tests comparing data to basal values. Results: At the first observation, in 15 involved putamen of Group 1 patients and in 20 of Group 2, p/o was low (<4.55), with mean values, in the 35 putamen, significantly (<0.0000001) lower (3.41±0.72) than the 5 not involved putamen (5.59±0.68), and those of healthy subjects (6.14±0.64) and C (8.25±3.70) ; no difference was ascertained between the latter 3 groups. In all cases c/o was normal. After GSH therapy, there was p/o increase in 25/35 involved putamen with an increment percentage >30 in 36% of cases, mean values (5.30±1.01) being significantly (p<0.004) higher than basal values (3.94±0.51); in 8/35 putamen p/o had no change and in the remaining 2/35 further decreased, but not significantly. In particular, an increment percentage >30% there was in 40% of Group 1 putamen and in 15% of Group 2. The 5 not involved putamen had no significant change. UPDRS slightly improved in 9 patients. Conclusions: 123 I-FP-CIT SPECT proved useful to evidence that GSH therapy may increase putamen DAT binding, particularly in never treated PD patients in our series, thus indicating BBB penetration of this tripeptide. A potential therapeutic role of parenteral GSH might be suggested in PD patients. Objectives: Many studies show changes of serotonin transporter (SERT) in various neuropsychiatric diseases. SERT is also the primary target for selective serotonin reuptake inhibitors (SSRIs), widely prescribed for the treatment of major depressive disorder and other mood and anxiety disorders. So, in vivo measurement of SERT function is useful tool for studying pathophysiology of neuropsychiatric diseases. Recently, as most valuable candidate for measurement of SERT function, 11 C-3amino-4-(2-dimethylaminomethylphenylsulfanyl)benzonitrile ( 11 C-DASB) was developed and showed its potential for evaluation of SERT. Use of 11 C-DASB thought to be able to investigate various neuropsychiatric diseases, but age-related change of SERT density is reported in normal cases. In this study, we tried to measure the density of SERT with 11 C-DASB in healthy volunteers, and evaluate the age-related change of SERT density. Methods: We studied SERT activity in 10 male subjects (34-61 y old) using 11 C-DASB and PET brain imaging. PET examination was performed 90 min after intravenous injection of 11 C-DASB. Regions of interest (ROIs) were drawn on MR images and pasted to corresponding PET slices. All subjects had also SPECT perfusion studies with 99m Tc-ECD. Three analytical methods without arterial blood sampling (the transient equilibrium, the linear graphical analysis, and the ratio of target to reference region) were used to estimate binding potentials (BPs). Cerebellum was used as the reference region in each method. Results: BPs obtained from each method had almost same values. Test-retest reproducibility showed the verification of this study. A significant negative correlation was observed between 11 C-DASB SERT binding and age (thalamus: r = -0.89; P = 0.001, striatum: r = -0.91; P = 0.001). Decrease of 11 C-DASB binding was approximately 5% per decade in thalamus. Conclusion: In this study, we showed the age-related decline of SERT in thalamus and striatum with 11 C-DASB in normal subjects. These results indicate that 11 C-DASB can apply for clinical studies on treatment of neuropsychiatric diseases using age-matched controls. Background: The prevalence of depression in Parkinson's disease (PD) is about 40% and the rate of depression is twice that seen in other disabling diseases. However, the pathophysiology of depression in PD remains obscure. Regional brain changes have been demonstrated in non-PD patients with depression with the core perfusion deficit in bilateral parietal regions. Objective: To determine whether PD patients with major depression exhibit differential brain perfusion compared to non-depressed PD patients. Methods: We studied 9 right-handed PD patients who fulfilled DSM-IV criteria for depression (dPD: 3 females, mean age 59±8 years, mean disease duration 11±2 years) and 15 right-handed non-depressed PD patients (ndPD: 2 females, mean age 59±8 years, mean disease duration 10±4 years). Diagnosis of PD was made according to the UK Parkinson's Disease Brain Bank criteria. All dPD and ndPD patients were in Hoehn and Yahr stage 2 or 3 and matched for age, disease duration and severity (UPDRS-III). We excluded patients with dementia, cognitive and/or executive function deficits assessed by the Mini Mental State Examination, the Frontal Assessment Battery and the Wisconsin Card Sorting Test. The Beck Depression Inventory (BDI) was used to quantify the severity of depressive symptoms. All subjects underwent resting state 99m Tc-ethylcysteine dimer brain perfusion SPECT. Statistical Parametric Mapping (SPM2) was used for data analysis (p<0.001 uncorrected). Results: We observed hypoperfused regions in the left and right inferior frontal gyrus and in the left middle frontal gyrus; furthermore we found two areas of hyperfusion: the first one in the right thalamus and right hyppocampus and the other in the posterior cingulum, cerebellar tonsil and posterior lobe of left cerebellum. BDI mean score was 21±3 for dPD and 3±2 for ndPD (p<0.01, Mann-Whitney test); UPDRS-III mean score did not differ between PD subgroups (dPD: 34±10, ndPD: 33±12). Conclusion: Our analysis outlined that major depression in PD is associated with hypoperfusion of inferior and middle frontal gyri. The findings suggest that loss of dopaminergic innervation in PD might cause impairment of fronto-striatal circuits and which plays a key role in the manifestation of depression in PD.

Introduction Obsessive-Compulsive Disorder (OCD) has been suggested to be a neurobiological disorder arising from abnormalities in the serotonergic system. Despite the therapeutic efficacy of serotonin uptake inhibitors, evidence from neurobiological studies does not provide consistent evidence for serotonergic abnormality. Converging lines of evidence suggest a role for dopamine in OCD. Objectives To investigate the binding potential change of [ 11 C]-SCH23390 to dopamine D1 receptors in patients with OCD. Methods Seven patients fulfilling the DSMIV criteria for OCD and seven age and gender matched (39 +/-14 years) volunteers underwent a single 60 minute dynamic Positron Emission Tomography (PET) scan with [ 11 C]SCH23390 (630 +/-100 MBq) with a Specific Activity of 820 +/-400 Ci/mM. PET scans were co-registered to individual MRI and regions of interest compared. From the individuals MRI, a cerebellar grey-tissue was defined as the reference region. Logan graphical analyses was performed and Distribution Volume Ratios (DVR's) defined for Caudate, Putamen, Anterior Cingulate, Orbito-Frontal-Cortex and Thalamus. Results Significant reductions (p = 0.026) in D1 binding potential were found in the caudate nuclei of patients in comparison to controls. Conclusion This study is the first demonstration of a dopamine D1 abnormality in OCD. The findings implicate dopamine in the neurobiology of OCD and may help explain neuropsychological and neuroimaging findings associated with the disorder. Background: Cerebral activity patterns are distinctly modified by clozapine and typical neuroleptics. However, no study has directly compared to date the brain activity patterns while treatment with clozapine and other atypical antipsychotics. This comparison could contribute to a better comprehension of its respective mechanisms of action. The Aims of this study were to compare the regional cerebral blood flow (rCBF) patterns of a group of schizophrenic patients who were switched from risperidone to clozapine due to lack of efficiency and to assess the corrrelation between the improvement in symptoms and the perfusion changes. Material and Methods: We have studied 9 patients (5 males; 7 paranoid and 2 undifferentiated patients, according to DSM-IV criteria) with 99m Tc-HMPAO-SPECT imaging at baseline (after a chronic treatment with risperidone) and after a month of treatment with clozapine. Patients were performing a Stroop test paradigm 10 minutes before and 10 minutes after a bolus intravenous inyection of 740 MBq of 99m Tc-HMPAO. SPECT images were analyzed with the SPM99 (from the Welcome Dept. of Cognitive Neurology, London, UK) software package comparing baseline and after clozapine conditions. One-tailed significant threshold was set to P=0.001 with a minimum extent of 20 voxels. The correlation between the clinical improvement and the changes in rCBF was assessed with a SPM general linear model using rank-transformed symptom scores and checking separately for direct and inverse associations. Results: In comparison to the risperidone condition, brain perfusion with clozapina was significantly lower on the posterior orbital gyrus in the right side and on the ipsilateral parahippocampal gyrus. In addition, patients showed a higher perfusion as compared to risperidone on the inferior prefrontal cortex as well as on parieto-occipital region. Positive symptom improved was directly correlated with the increase of activity in two frontal areas, left prefrontal and left premotor and the improvement in negative symptoms was directly related to the increase of perfusion on cerebellum and on visual association areas. However, no association was found between decreases in perfusion and clinical changes. Conclusion: These data suggest that the effects of clozapine and risperidone on rCBF patterns during the perfomance of a cognitive test were quite distinct. The clinical changes correlated with the higher perfusion areas produced by clozapine. This may be consistent with the effectiveness of clozapine in patients that failed to respond to risperidone.

HUNGARY, 3 Department of Nuclear Medicine University of Szeged, Szeged, HUNGARY.

Several data suggest the role of the dopaminergic system in depression, but the results with functional imaging are contradictory. The selective serotonin reuptake inhibitor (SSRI) antidepressants are believed to mainly act by selectively binding to the serotonin, but some of the SSRIs also exhibit other neuropharmacologic effects. The aim of this study was to evaluate the DAT activity of untreated patients with unipolar depression and compared to healthy volunteers. We also studied the effect of sertraline on dopamin transporter activity in depression. Materials and methods: We performed overall 30 123I-FP-beta-CIT-SPECT examinations in 8 healthy controls (MINI) and in 11 depressed patients (DSM-IV), the inclusion criteria was a score of at least 19 on the Hamilton Depression Scale (HAM-D, 21 items). In age-matched healthy subjects and in patients baseline 123I-FP-beta-CIT-SPECT investigations were done, in the depressed patient group the DAT SPECT was repeated after 3 weeks sertraline treatment. On the transversal reconstructed SPECT slices at the level of the basal ganglia, regions of interest were fixed by self-developed semiautomatic technique. The binding potential was estimated by the ratio of the specific to non-specific activity ({mean striatal activity-mean occipital activity}/mean occipital activity.) Results: In the patients group, the median baseline binding potential was 3.16 (range: 2.67-3.6), in the control group, this value was 3.09 (range: 2.78-3.6). A Mann-Whitney U-test revealed that this difference was not statistically significant (Z=-0.32, p=0.96). In the patient group, the median binding potential after sertraline administration was 2.79 (range: 2.64-3.33), which indicates a decrease of 9 % of FP-CIT binding. HAM-D scores showed 48% decrease after sertraline treatment. Spearman's correlation indicated no significant relationship among binding potentials, HAM-D scores, age, and education (p>0.5). Conclusion: We didn't find any significant difference in the baseline values of DAT activity between control and untreated depressed subjects. The HAM-D score showed decrease after treatment, which prove effectiveness of therapy. Sertraline treatment decreased the DAT occupancy (9 %) but further investigations are needed to support this finding. Aim: Dopamine D2 receptor (D2R) availability appears to be important in addictive behavior. For example, low striatal D2R binding predicts high rates of intravenous cocaine self-administration in animals. The study of striatal D2R availability in mouse models of cocaine addiction may therefore be important to unravel the role of the D2R in addiction. Additionally, endogenous dopamine release, induced by psychostimulants, may differ in drug-addiction. We recently developed a highresolution single-pinhole SPECT system to perform studies in small laboratory animals. In this study, we evaluated the feasibility to image D2R and to assess dopamine release in mice using the D2R antagonist [ 123 I]IBZM and our pinhole SPECT system. Materials and Methods: Male c57BL/6J mice were scanned on our single-pinhole SPECT system [Habraken et al. JNM 2001] . In this system, the mouse is tightly fitted in a cylinder which is positioned directly and horizontally above the pinhole aperture, and rotates during data acquisition. The pinhole collimator is connected to an ADAC ARC3000 © scintillation camera. A 2-mm pinhole aperture was used. All experiments were acquired, step and shoot, with a 20% energy window around 159 keV in a 64 x 64 matrix, ROR of 25 mm, field of view 28.8 mm. Reconstruction was performed using the Feldkamp algoritm. Images were analyzed with fixed ROIs for the striatum and cerebellum. In a first study, mice were injected intravenously with 20 up to 70 MBq [ 123 I]IBZM and scanned continuously up to 2 h p.i. (10 frames of 12 min.) to study the pharmacokinetics of the radiotracer (7 studies in 4 mice). In a second experiment, the feasibility to assess dopamine release was evaluated. Nine mice were injected 5 min. before IBZM injection (40 MBq) with saline i.p., and acquisition was started 90 min. (1 timeframe of 30 min.) after bolus injection of IBZM. Approximately 1 week later, the same group of mice was rescanned, but now the mice received 2.5 mg per kg body weight amphetamine i.p. 5 min. prior to the injection of IBZM. Results: Injection of [ 123 I]IBZM resulted in clear specific binding in the striatum, with highest specific to non-specific binding ratios 90 min. after injection. In the second experiment, amphetamine induced a significant decrease in striatal IBZM binding ratios. Conclusion: This study shows the unique possibility to image striatal D2R and to assess endogenous dopamine release in the mouse brain. Aim: Quantitative assessment of functional PET data is attractive since it can lower variability across institutions and may enhance the consistency of image interpretation independent of reader experience. Various quantitative indices have been suggested for functional brain imaging of the dopaminergic system including advanced kinetic models and simplified semi-quantitative measures such as the Specific Binding Index (SBI) computed as the ratio of uptake in a region with specific receptor binding to a reference region. A common problem with these indices is their dependence on the reference region of interest (ROI) and the spatial resolution of the imaging system. Therefore, partial volume effect results in underestimates of this index compared to the true value. Materials and Method: A new index named the Specific Uptake Size Index (SUSI), which considers total uptake in the object not just activity concentration, was recently proposed and claimed to be independent of ROI size and system resolution. The validity of this index is assessed in this work using PET images acquired from an anthropomorphic striatal phantom study and 9 18 F-DOPA studies of patients potentially suffering from Parkinson's disease. For the latter, the external brain contour was drawn manually using the patient's coregistered MRI to exclude the bony skull and cerebral border thus avoiding partial volume effect. The influence of ROI size was assessed by drawing non-overlapping ROIs of different size around the striatum not necessarily covering the whole striatum. Results: Phantom studies showed that SBI measures based on maximum counts were 2.94 and 3.12 for right and left striatum, respectively, and proved to deviate considerably from the true value (8.0). The SUSI estimate is nearly constant in the striatum for ROIs greater than 57 cm 3 . Below this volume, the SUSI estimates are not reliable. The clinical studies seem to report that the SBI derived from SUSI is always greater than the SBI derived from maximum counts in the ROIs. The SBI derived from SUSI that uses total uptake instead of maximum uptake is likely to be more accurate for small objects. Conclusion: We have demonstrated using phantom and clinical data that the SUSI is approximately independent of the ROI size allowing to guarantee good reproducibility of quantitative parameters estimates. Significant increases and decreases of regional uptake were obtained using t-statistics at every voxel from patients and normal control groups. Clusters consisting of a minimum of 50 contiguous voxels with an uncorrected P<0.01 were considered to be significantly different. Results: The GMFCS scales of the spastic diplegia type CP patients were Level 1 in 2 patients, Level 2 in two and Level 4 in one patient.The pyramidal tracts in the patients were grossly normal in terms of connectivity and white matter volume. [ 18 F]-FFMZ binding was increased in the motor and premotor areas and bilateral visual cortices. Conclusion; Altered GABA A receptor binding in the motor cortices might play a important role in the pathogenesis of motor dysfunction in spastic type CP as The GABAergic signaling in the motor and visual cortices plays an important role in the development of peri-lesional or use-dependent plasticity after brain damage. MSA is a neurodegenerative disease that manifests itself with clinical symptoms of parkinsonism combined with cerebellar ataxia, autonomic failure and pyramidal signs. The form with predominant parkinsonism (MSA-P) accounts for 80% cases and its differentiation from Parkinson's disease (PD) is often difficult. The aim was to examine potential role of scintigraphy in differerential diagnosis of MSA-P and PD using binding potential of the striatum for 123I-FP-CIT (DaTSCAN) and 123I-IBZM to reveal complex dysregulations in dopaminergic transporter/receptor system. Methods: The study has been performed in patients suspected for diagnosis of MSA-P based on clinical criteria including MRI and poor response to dopaminergic therapy (n = 13), patients with verified PD (n = 25), and age-matched healthy controls in order to obtain normal values of diagnostic indices with FP-CIT (n = 20) and IBZM (n = 9). Inclusion of individuals and their informed consent has been approved by ethical committee of the hospital. In patients, both FP-CIT and IBZM examinations have been performed with the same administered activity (185 MBq). Control subjects underwent only one study, either FP-CIT or IBZM. SPECT data have been recorded by triple-head gamma camera Picker Prism 3000 and dual-head gamma camera GE Infinia-Hawkeye. Striatal binding capacity has been assessed visually and semiquantitatively as binding ratios striatal/occipital (SOR) for FP-CIT and striatal/frontal (SFR) for IBZM. Results: In comparison with healthy controls, significantly reduced SOR has been found in both MSA-P and PD patients (p=0.01) in nucleus caudatus and in putamen. However, no difference has been found between the two groups of patients. In patients with MSA-P, there was no difference in density of presynaptic Dtransporters between nucleus caudatus and putamen. In contrast, SFR has been significantly reduced in nucleus caudatus and in putamen in patients with MSA-P with respect to healthy controls (p=0.01) while no such difference was found in patients with PD. In 5 of 13 patients suspected for MSA-P, diagnosis has been changed to PD due to normal density of D2 receptors in the striatum. In patients with MSA-P, binding capacity for postsynaptic D2 receptors was reduced more in putamen than in nucleus caudatus (p=0.05). Conclusion: Assessment of dopaminergic transporter density in striatum using only FP-CIT is not sufficient to differentiate MSA-P from PD. Instead, complex information is required on the dysfunction of dopaminergic transporter/receptor system in the striatum that can be obtained by comparison of FP-CIT and IBZM scans. Aim: To evaluate the usefulness of calculating an Specific Uptake Index (SUI) and the 123I-Ioflupane SPECT (DATSP) cut-off points as a supporting tool to diagnosis. Material and Methods: We included 327 patients (135 men and 192 women with an average age of 66) who had a diagnosis of suspected Essential Tremor (ET) vs Parkinsonian Syndrome (PS). All patients received DATSP four hours after a dose of 185 MBq loflupane -I123. Using a visual appraisal method, we clasified the patients into normal (0), minor(1), moderate (2) and severe (3) . The quantification was made on two consecutive central transaxial views, drawing irregular and/or geometric regions of interest (ROIs) in Striatum (Str), Caudate Nuclei (C), Anterior Putamen (AP), Posterior Putamen (PP) and Occipital. We calculated the SUI using the following formula: counts in ROI-counts in Occipital/counts in Occipital. We drew COR curves to determine discrimination cut-off points of pathological trouble. All data was captured and recorded in Microsoft Excel format, with analysis carried out using the statistical package, SPSS. Results: The results from the visual appraisal method were 84 normal, 67 minor, 52 moderate and 124 severe patients. We calculated two discrimination cut-off points for the SUI Str of pathologic (1+2+3) and severe (3) with values < 5,5 (S 80%, E 60%) and <4,4 (S 80%, E 75%) respectively. We also calculated two discrimination cut-off points for the SUI PP of moderatesevere (2+3) and severe (3) with values of <6 (S 80%, E 75%) and <6 (S 80%, E 75%) respectively. We related the SUI in Str, C, AP and PP and the differents pathological groups. We obtained statistically significant difference between the SUIof the 3 group and the rest. Conclusion: Quantification of the SUI is statistically significant to differenciate the severe group from the rest. The calculation of the SUI PP is more useful given its highest Sensitivity and Especificity. Regarding to gender and age , there were no significant statistical differences found. The visual appraisal method continues to be, in our case, the best tool for diagnosis to differenciate between these type of patients than obtaining quantitative values. Aim It has been demonstrated that [ 123 I]FP-CIT single photon emission computed tomography (SPECT) might be useful to characterize dopamine transporters (DAT) loss in basal ganglia in Parkinson's disease (PD), Progressive Sopranuclear Palsy (PSP) and Lewy Body disease (LBD) patients, but it is not capable to distinguish between these diseases. The aim of our study was to quantify serotonin transporters (SERT) availability in the mesencephalic region of PD, PSP and LBD patients by [ 123 I]FP-CIT SPECT. Materials and methods 60 patients (18 age-matched PD, 10 age-matched PSP, 16 age-matched LBD and 16 age-matched healthy controls) were enrolled in this study. SPECT was performed in all cases after i.v. injection of 111 MBq of [ 123 I]FP-CIT, using a double head gamma camera (INFINIA-GE). Software coregistration of functional and morphological (MR) imaging data were then used to define regions of interest (ROI) including mesencephal and the occipital lobe. The ratio of specific (mesencephal -occipital lobe) to non specific (occipital lobe) binding was calculated. Results By semiquantitative analysis, the ratio of mesencephaloccipital lobe (specific) to occipital lobe (non specific) were different between PD (mean=0.78, range=0.4-0.9), PSP (mean=0.14, range=0.10-0.22), LBD (mean=0.08, range=0.06-0.09). When compared to controls (mean=0.8, range 0.7-0.9), were not different for PD. As compared with control values, the PSP and LBD patients had a significant reduction of specific [ 123 I]FP-CIT binding in the mesencephalic region. Conclusions Our results suggest that SERT in mesencephalic region can be used in diagnostic differentiation between PD, PSP and LBD. Our findings need to be confirmed in larger number of patients. Objective: It is necessary to obtain an arterial blood sample to calibrate and individualize the standard arterial input function for regional cerebral blood flow mapping with iodine-123-IMP (IMP) autoradiographic (ARG) method (J Nucl Med 1994; 35: 2019) . The objective of this study was to propose an alternative method without blood sampling to estimate individual calibration coefficients for ARG method. Methods: If the individual difference in the brain distribution volume (Vd) of IMP is small enough, the calibration coefficients for the standard input function (Cf: (kBq/ml) / (CPS/g blood)) can be estimated from a product of Cf and Vd that can be obtained by 2-compartment model analysis of brain time-activity data using the uncalibrated standard arterial input function. To validate this method, 109 consecutive patients with various cerebral diseases (67 ± 13 years old, M/F=60/49) were studied with IMP dynamic SPECT. IMP (167 MBq) was infused intravenously over 1min. Immediately after starting the infusion, dynamic SPECT data acquisition (14 rotations/35 min) was performed. Seven to ten minutes after starting the infusion, onepoint arterial blood sampling was performed to measure Cf. By threshold percentages (5, 10, 20, 30%) to the maximum, the mean+2.5SD and the mean+2SD of voxel count in the brain, twelve whole brain time-activity curves (TACs) normalized by the volume of interest given in kBq/ml were generated. Each TAC was fitted to 2compartment model using the uncalibrated standard arterial input function to obtain a product of influx rate constant (K1: ml/min) and Cf (CfK1), and efflux rate constant (k2: 1/min). Dividing CfK1 by k2, the quotient (CfK1/k2) gave a product of Cf and Vd (CfVd). The correlation between estimated CfVd from 2-compartment model analysis and measured Cf from arterial blood sampling was investigated in a set of brain TACs. Results: Measured Cf ranged from 0.20 to 1.07 (0.49 ± 0.14). In every 2compartment model fitting, CfK1, k2, and CfVd could be determined with small error of estimate. Among the eight conditions for determining the brain border, the best correlation between estimated CfVd and measured Cf was noted in the set of TACs determined by the threshold of 10% to the mean+2.5SD of voxel count (Cf=0.045 CfVd +0.216, R 2 =0.694, n=109, RMSE=0.0776, P < 0.0001). Conclusion: In ARG method, the calibration coefficients for the standard arterial input function could be estimated without arterial blood sampling, using proposed linear regression equation. Brain death is present when all functions of brain stem have irreversibly ceased. Before discontinuation of artificial ventilation and organ harvesting the instrumental confirmation is necessary in addition to neurological findings. Authors present own experiences with brain perfusion scintigraphy in the diagnosis of brain death. Patients and method: 71 brain scintigraphies for confirmation of clinical diagnosis of brain death in 70 patients (45 male, 25 female, in age 18-78 years) were performed in the years [2003] [2004] [2005] [2006] . 63 patients were examined as potential donors of organs, seven from other reasons. About 700 MBq of 99mTc-HMPAO was injected as bolus to central vein. Dual-head SPECT gamma cameras with LEHR collimators for acquisition of the date were used. Flow images (2 s per frame) were acquired from the time of tracer injection to one minute. Planar images in four projections or SPECT of the head were obtained subsequently. In brain death flow images show completely absent of the blood flow superior to the circle of Willis circulation and planar images or SPECT demonstrate no radiopharmaceutical uptake in the whole brain. Results: In 68 patients the brain death was unambiguously confirmed. In two patients (a female after cerebellar hemorrhage and a male after suicide of hanging with repeated scintigraphy after 24 h) had brain perfusion partly preserved and brain death was not confirmed. We did not find mismatch between dynamic and static images. No side effects were observed. Conclusions: Cerebral perfusion scintigraphy is simple, reliable, safe and cost-effectives method for confirmation of irreversibility of clinical signs of brain death. The great advantage against X-ray angiography is exactness of findings also in cases of head injury and after craniotomy. Other advantage of perfusion scintigraphy is non-invasivity and there is no fear of damage of organs for transplantation due to injected X-ray contrast substances. Aim: To determine whether age-matched normal database (NDB) is necessary for the detection of Alzheimer's disease (AD) using brian FDG PET and automatic image analysis. Material and Methods: We generated 6 age-specific NDB sets ranging in age from 20 yr to 70 yr; each consisted of 10 males and 10 females. In order to assess the diagnostic performance using these NDBs to distinguish AD patients from normals, 34 patients (11 males, 23 females; mean age, 66.2 ± 8.2 yr) with probable AD and 20 normal subjects (10 males,10 females; mean age, 67.4 ± 8.0 yr) were recruited. The image analysis was performed using NEUROSTAT. The changes of relative FDG activity with age were measured for the posterior cingulate gyri and precunei (PCGP). A receiver-operating characteristic (ROC) analysis was performed for comparison of the diagnostic accuracy using these NDBs. Results: There was no significant difference in area under the ROC curves (Az) for the discrimination of AD patients from normals (Table) . Furthermore, there was no significant correlation between the relative FDG activity in PCGP and age. Conclusions: Our results indicate that age-specific normal database for FDG PET may not be necessary for the detection of AD. This could be explained by the lack of significant correlation between relative FDG activity in PCGP and age. Aims: Anatomical imaging methods, especially computerized tomography (CT) and magnetic resonance imaging (MRI) are helpful in diagnosis of acute traumatic brain injuries (ATBI) however, they are not as efficient as single photon emission computed tomography (SPECT) for the diagnosis of traumatic brain injury with chronic symptoms (TBICS). Our aim was to compare brain perfusion SPECT and CT or MRI findings in patients with a history of THICS being followed for more than one year. Material and Methods: Ninety two patients fulfilled the criteria to enter our study. Sixty-two of these patients had a history of a mild brain disease (Group A) while the remaining 30 cases had a history of moderate to severe brain disease (Group B) .The age of our patients ranged between 19-66 y, with mean age 40.55 ± 11.96 y. The mean post-traumatic period was 1.22 ± 0.43 y. These patients presented with various neurological signs and symptoms especially due to hypofrontality and hypotemporalism. Brain perfusion SPECT with 99m Tc-ECD and CT or MRI were obtained in all patients with a maximum interval of one month between each procedure. In our study, the brain was divided into ten areas five regions in each hemisphere. The SPECT, CT and MRI images were interpreted separately by two nuclear medicine physicians and two radiologists who were blinded to all study results. Results: Out of a total of 920 brain regions, brain perfusion SPECT revealed 460 lesions (50%) while, anatomic modalities CT or MRI detected significantly less lesions (42.3%) (P<0.05). Conclusion: Brain perfusion SPECT may be more useful than anatomic imaging procedures in identifying TBICS, especially in patients presenting with symptoms of hypofrontality or hypotemporalism. Brain perfusion SPECT can be effectively used to identify the chronic complications of remote traumatic brain injuries.

Effect of aerobic training on Tc99m-sestamibi uptake by rat brain: evidence for exercise augmentation of the blood-brain barrier (BBB) function ? Introduction-Aim: BBB effectively contributes to brain homeostasis maintenance. Tc99m-sestamibi does not enter normal brain and its uptake is very low. Cerebral capillary endothelium, a major BBB component, is characterized by a five-fold mitochondrial content compared to capillaries of systematic circulation. High mitochondrial density is potentially related to increased pumping energy demands of the BBB. Mitochondria are also a known subcellular target of Tc99m-sestamibi. Moreover, P-glycoprotein, a membrane efflux pump, using Tc99m-sestamibi as substrate is abundant on BBB. This study investigates the impact of the aerobic trainning on brain uptake of Tc99m-sestamibi and a possible explanation is discussed Animals and methods: Twenty-four adult male Wistar rats were allocated to a trained (n=13) and an untrained (n=11) group. Endurance exercise on a motor-driven treadmill had the following characteristics: speed 25 m/min for 60 min, 5 days/wk for 14 weeks. On completion of the training program, Tc99-sestamibi (5.6 MBq/kg body weight) was administered i.v. to all animals. Two hours after injection, heart, brain, blood and various skeletal muscles of the hindlimbs were removed. Tc99m-sestamibi uptake was calculated, after activity measurement in a well-type counter, as % of injected dose (ID) per tissue gram. Differences between trained and untrained rats were assessed for significance at p<0.05 level by the independent Student's t test. Results: Tc99sestamibi uptake in both myocardium and skeletal muscles of trained animals was significantly higher than that of untrained, thus evidencing the effectiveness of the exercise scheme.Tc99-sestamibi uptake was very low in brain, comparable to blood levels. However, uptake in trained rats was about double than in untrained: 0.0094 vs 0.0056 %ID/g, p<0.001. Conclusion: Despite being low, Tc99-sestamibi uptake in rat brain is increased after a period of aerobic training. Both accelerated fuel transportation and increased prohibitive activity against various exercise-related metabolic products by the BBB during repeated exercise bursts, may induce mitochondriogenesis in BBB endothelium, thus explaining increased Tc99-sestamibi uptake in trained animals.

The purpose of this study was to investigate the neurological variables associated with chronic traumatic brain injury in amateur boxers. Material and Methods: Cerebral perfusion changes were evaluated using Technetium-99m hexamethylpropyleneaamineoxime single photon emission computed tomography (Tc-99m HMPAO SPECT). SPECT were performed in 14 boxers and 16 healthy volunteers. Images were acquired using a dual-headed gamma camera equipped with high resolution parallel-hole collimators. Quantitative analyses were done using brain SPECT assessment tool in General Electric Xeleris work station (Neurogam). Results: Analysis of Tc-99m HMPAO SPECT images showed that the boxers had more cerebral perfusion changes than healthy volunteers. All cortical areas showed decreased blood flow especially in frontal and temporal areas in boxers. Conclusion:

In conclusion, the results showed that Tc-99m HMPAO SPECT could be helpful to investigate cerebral blood flow abnormalities in amateur boxers and differences from healthy volunteers. Cerebral perfusion changes should be taken into consideration in evaluating boxers having any neurological symptoms.

The difference of brain FDG uptake pattern between health adults and cancer patients M. Si, J. Liu, G. Huang, X. Sun; Renji Hospital, Shanghai Jiaotong University, Shanghai, CHINA.

Aim: To determine the difference of brain FDG uptake pattern between health adults and cancer patients. Material and Method: The brain FDG uptake patterns of 585 patients who performed PET/CT scan in our center from Aug. 2004 to Dec. 2005.were retrospectively studied. The inclusion criteria is: (1) absence of clear focal brain lesions (epilepsy, cerebrovascular diseases etc). (2) absence of metabolic diseases, such as hyperthyroidism, hypothyroidism and diabetes. (3) absence of psychiatric disorders and abuse of drugs and alcohol. (4)cancer patients were diagnosed definitely of variable cancers except brain cancer or brain metastasis. The normal group consists of 295 subjects for tumor screen and got negative results. The age is ranging from 21 to 88 yr. The cancer group consists of 290 various cancer patients. The age is ranging from 21 to 85 yr. Both groups were sub grouped into six starting from 21 years old with the interval of 10 years old, and the gender, educational background and serum glucose were matched. All 12 subgroups were compared to the subgroup of normal 31-40 years old called control subgroup (84 subjects). The t-statistic analysis was applied to all brain images using the SPM2 software. Results: With the increasing of age, similar hypometabolic brain areas are detected in both normal group and cancer group ,they are mainly in the cortical structures such as bilateral prefrontal cortex, superior temporal gyrus(BA22),parietal cortex (inferior parietal lobule and precuneus(BA40),insula(BA13)),parahippocampal gyrus and amygdala(p<0.01)and are especially apparent in the prefrontal cortex(BA9)and sensory-motor cortex(BA5,7)(p<0.001). But characteristic hypometabolism in cingulate gyrus and bilateral cerebellum are only seen in cancer group.Compared to the same age interval of normal subgroup, each cancer subgroup shows significant hypo-metabolism in cingulate gyrus (p<0.001),as well as bilateral cerebellum and basal ganglia(lentiform nucleus and thalamus)(p<0.01). Conclusions: Relative hypometabolism in limbic system such as cingulate gyrus and basal. Fahr's Disaese is a rare of unknown aetiology disorder characterised by massive symmetrical calcifications of the basal ganglia, dentate nuclei and subcortical white matter. Although the clinical pattern of Fahr's Disease is variable; neurobehavioural, cognitive, extrapyramidal-cerebellar symptoms, dementia, seizures and speech disorders are most common clinical features. Clinical and CT scan examination is enough for diagnosis. In the literature there is no study performed to evaluate the value of HMPAO brain perfusion SPECT in Fahr's Disease to the best of our knowledge. The clinical, CT scan and HMPAO brain SPECT findings of a 42 years-old woman with Fahr's Disease is reported. The patient presented to a neurologist with difficulty to use the upper limbs bilaterally (more prominent of the left side) and reduced movement ability six years ago. On neuropsychiatric examination; a mild deterioration of frontal functions was mentioned and computed tomography showed no abnormality. When symptoms progressed she was reevaluated and a non-enhanced CT scan revealed extensive, symmetrical intracranial calcifications involving the dentate nuclei and white matter of cerebellum, globus pallidus, putamen, caudate nucleus, internal capsule, thalami and centrum semiovale. Serum levels of ionised calcium, phosphorus and parathyroid hormones were within normal range. She had no family history and was diagnosed as idiopathic sporadic Fahr's Diasease. SPECT images did not demonstrate perfusion abnormalities in all calcification foci visualised bilaterally on CT scan. HMPAO brain perfusion SPECT images showed hypoperfusion in the left visual centre compared to that of right side and perfusion defect in the right basal ganglion. SPECT images did not demostrate perfusion abnormalities in all calcification foci visualised bilaterally on CT images. SPECT findings were not only congruent with the coresponding CT scan abnormalities but also correlated more specifically with the clinical findings. This case suggests that HMPAO brain perfusion SPECT is useful in the clinical approach of Fahr's Disease providing more specific and clinically relevant information as compared to anatomical imaging. Chronic fatigue syndrome (CFS) is an heterogeneous disease: disabling fatigue lasting at least 6 months and accompanied by numerous rheumatological, infectious and neuropsychiatric symptoms. Nowadays there is not a test with enough sensitivity or specificity to constitute a reliable diagnostic tool. Aim: To describe the usefulness of brain perfusion SPECT in the evaluation of patients with chronic fatigue syndrome (CFS), comparing the basal brain perfusion pattern with the cortical changes after physical exercise and a mental test. Material and methods: Thirty-five patients (29 female, mean age 46 years) with clinical criteria of CFS (Holmes and Fukuda) were included. All of them underwent a 99m Tc-ECD brain perfusion SPECT (925 MBq, double-headed gammacamera) in basal condition and after a stress test. The study consisted in physical exercise in the morning and injecting the tracer at the middle of a neurocognitive test (WAIS modified) in the afternoon. All the brain SPECT were blindly evaluated by 2 experts, using a semiquantitative score: normal uptake (score 0), slight hypoperfusion (score 1), mild hypoperfusion (score 2) or severe hypoperfusion (score 3). Cortical areas: frontal, temporal, parietal and occipital.

Results: 4 patients showed a normal brain SPECT in basal and stress condition and 5 patients (14.2%) showed decreased perfusion in both studies, without changes in the intensity and localization of perfusion deficits. In 26 patients (74.3%) changes in perfusion were appraised: eighteen (51.4%) showed decreased perfusion after psychological test with regard to basal condition (p= 0.0001). Frontal and temporal lobes were predominantly involved. Eight patients (22.8%) showed improvement in brain perfusion after the neurocognitive test (p= 0.001). Conclusion: Our results showed a high percentage of blood flow impairment in CFS patients, which worsened after a combination of physical and stress-mental test. Brain perfusion SPECT might be a useful tool to improve diagnostic approach to an elusive illness such as CFS. The use of an objective neuroimaging method may help in the characterization and monitoring of brain perfusion abnormalities in CFS. The intoxication has adverse effects on health: digestive, endocrinologic and neurologic symptoms. These symptoms are unspecific (dizziness, asthenia, itchy sensation..) and often difficult to distinguish from a functional disorder. The aim of this work was to evaluate the brain perfusion changes in patients exposed to organophosphorate compounds. Material and methods: Nine patients (p) (9 women; aged 20-50 years; mean age: 42) with chronic exposure to organophosphorates were included. Brain perfusion SPECT (25 mCi 99m Tc-ECD) was performed in all p using GEMS VG, Hawkeye gamma camera and fan beam collimator. Brain perfusion was analysed in all patients using SPM2 program and comparing each patient with a healthy control group. In all cases neuropsychological test, electroencephalogram, CT scan were also obtained. Results: In 2p the brain perfusion was normal. The 7 remaining showed hypoperfusion in different brain areas: 4p (parietal lobe -2 right; 2 left-); 1p (posterior frontal); 1p (right mesial temporal); 1p (posterior temporal, anterior and temporo-parietal). Conclusions: In 7 of the 9 patients exposed to organophosphorates SPM2 detected significant brain hypoperfusion. The cerebral lobe involved was variable. Further studies are necessary to confirm these results. Recently, the Physikalisch-Technische Bundesanstalt (PTB) and the company AEA Technology (now: QSA Global) organized a joint national comparison of 99m Tc solutions in order to obtain information on the quality of routine activity measurements in nuclear medicine in Germany. The participants were asked to measure the activity in P6-type glass ampoules and in syringes. The results and supplementary information on the instrument characteristics, uncertainties, radionuclidic impurities and steps for quality control had to be stated in a questionnaire prepared by the organizers. In this contribution, the 99m Tc comparison results for two different geometries are presented and compared with results of previous comparisons. In particular the distribution of the deviations (A i -A i, ref )/A i, ref with the activity A i stated by the participants and the PTB reference activity A i, ref were analyzed. About 92% of the results fulfil the limitations prescribed by the European Pharmacopoeia [1] , i.e. the deviation to the reference value is less than ±10%. The data clearly indicate a considerable reduction of the deviations compared to results obtained in previous comparisons [2, 3] . In spite of this improvement there is still a considerable number of results which do not comply with the ±10% criteria. These data were carefully analysed to detect potential causes for discrepancies and to find steps for further improvements of the quality in nuclear medicine. After a period in which the results of all participants were collected, all of them obtained a calibration certificate stating the reference activity value from the PTB. This document can be used as an important tool for quality control in the respective institute. [ (T) Time from the elution to the labeling. Test ANOVA (p = 0.044 <0.05) indicates significant differences and test of Bonferroni specifies that these occur between group 1 with respect to 2 and 3, and do not occur between groups 2 and 3. Conclusions The increase of the RCP in groups 2 and 3 indicates that can be used eluents with a time over to 2 hours, unlike at the specified in the technical leaflet of the Ceretec®. This radiochemical can be used in the leukocytes labeling without decrease in its efficiency. Aim The development of 99m Tc-labeled infection imaging agents will contribute in the differential diagnosis of infection versus aseptic inflammation. Currently, there are several formulations for the labeling of fluoroquinolones with Tc-99m that show contradictory data. Our aim was the development of Tc-99m analogs of fluoroquinolones (norfloxacin and ciprofloxacin) of well-defined structure as well as their biological evaluation in vitro and in vivo. Materials and Methods Fluoroquinolones, FQ (norfloxacin and ciprofloxacin) have been functionalized at the N atom of the piperazine ring, by conjugation on suitable bifuctional chelators, N, N-(2-picolyl)amino-diacetic acid (PADA) and L-cysteine to form o-C 5 H 4 N-CH 2 N(CH 2 COOH)CH 2 CO-FQ (FQ-PADA) and HOOCCH(NH 2 )CH 2 SCH 2 CH 2 CH 2 -FQ (FQ-cys) respectively. FQ-PADA and FQ-cys reacted with [ 99m Tc(CO) 3 (H 2 O) 3 ] + (0.5 mL, 1-10 mCi) and produced two types of neutral 99m Tc complexes, fac-[ 99m Tc(CO) 3 (FQ-PADA)] and fac-[ 99m Tc(CO) 3 (FQ-cys)]. In vitro studies were performed, by incubating these 99m Tc complexes with 1x10 7 CFUs of S. Aureus and E. Coli. In vivo studies were performed by injecting 10 μCi of the 99m Tc complexes via the tail vain in mice. Results and Conclusions The 99m Tc complexes synthesized were analyzed by HPLC and showed, in all cases, the formation of one radioactive species. In vitro studies of the 99m Tc complexes resulted in 20-27% binding in S. Aureus, while the binding to E. Coli was found to be lower for all the compounds tested (10-15%). In vivo biodistribution studies in mice (5 and 120 min p.i.) showed that all the compounds present fast blood and soft tissue clearance. Preliminary studies showed that only small percentage of activity accumulates in muscles with induced aseptic inflammation (turpentine oil, negative control) resulting in an inflammation to normal tissue ratio 1.5. Further in vitro and in vivo evaluation is in progress, in order to prove the potential radiopharmaceutical use of these novel technetium-99m compounds as specific infection imaging agents. Aim: The application of the heart-lung machine in human medicine implies the sideeffect of activated granulocytes which may cause inflammatory processes in the human organs. For this reason Tc-99m HMPAO labeled granulocytes were used to localize the inflammatory process in pigs. Imaging was performed to determine the distribution of Tc-99m HMPAO labeled granulocytes in the organs and thereby the state of inflammation. Material and Methods: Domestic pigs aged about 3 month weighing 34 -58 Kg were examined. After gradient centrifugation of 80 ml venous blood from the animal to isolate the granulocytes for labelling with 93 -250 MBq Tc-HMPAO, the labeled granulocytes were then reinjected into the pig following thoracotomy. Imaging was performed after at least 2 hours of incubation time with a DST-XLi gamma camera (GE). In each case a whole body scan (AP; scan speed 6cm/min) was carried out and in some cases SPECT imaging (128 projections; acquisition time 30s/step). For quantification the geometric mean of the corresponding ROI's over the liver, spleen, lung and brain of the anterior and posterior view of the whole body scan were obtained. The count rate was correlated to the administered activity and the weight of the animal. As reference organ the liver was selected. E.Coli LPS induced inflammations were generated as a positive control. Results: The main part of the activity is located in the liver (30%). The activity in the spleen is decreased by a factor 1,8 and the activity in the brain is reduced by a factor 14 in comparison to the liver. Partly found unexpected high count rates in the lung were related to pneumonia of the animals. Artificially generated inflammations were well displayed. Conclusion: This method is basically suitable for inflammatory process imaging in pigs. The presented model is herewith suitable to answer questions concerning inflammatory process imaging in human medicine. The animals should be pre-treated with antibiotics in individual cases to preclude unspecific activity enhancement if applicable.

Introduction: The recommended method (Meth1) to determine the radiochemical purity (RCP) of Tc-99m tetrofosmin (TFOS) involves developing an ITLC-SG strip in dichloromethane:acetone (65:35). In this system, colloids and hydrophilic impurities remain at near origin, free pertechnetate (TcO 4 ) runs near the front, and TFOS migrates with an Rf of ~0.6. The disadvantages of this method include the need to prepare a fresh mixture of volatile solvents daily, sensitivity to spot size, and slight variations in the Rf of TFOS which result in falsely low RCP values using the cut and count technique. An alternative method (Meth2) developed for RCP testing of Tc-99m sestamibi (Proulx et al, Appl Radiat Isot 1989;40:95-7) has now been validated for TFOS. Methods: Meth2 uses two strips of ITLC-SG developed in 2-butanone and saline, respectively. In 2-butanone, insoluble impurities and Tc-99m gluconate intermediate (GLUC) remain at the origin while TFOS and TcO 4 migrate near the front, whereas in saline the impurities TcO 4 and GLUC migrate with the front and the remainder stays at the origin. RCP is calculated as 100% minus the two impurity measurements (note that GLUC is double counted, however it is a very minor component). Meth2 was compared with Meth1 on samples of TFOS and impure mixtures with free TcO 4 , colloid, and/or GLUC added. A preparation at high radioactivity concentration without oxygen venting was used to produce an additional impurity. Results: With clinical preparations of TFOS there was no significant difference in RCP measurements: Meth1 96.9±0.7%, Meth2 97.3±0.8% bound, n=12; paired t-test p=NS. With impure mixtures (0.1-97.7%) the regression line had the equation: RCP(Meth2) = 0.944 RCP(Meth1) + 3.9, n=14, R 2 =0.990. Most importantly, in the critical region around the 90% cutoff, the Meth2 produced results ~1% lower than Meth1. In the period during which Meth2 has been in routine use, it has detected one product failure and the result was confirmed by Meth1. During this period the mean RCP was 96.8±1.5% (n=218). Conclusions: This report presents validation of a new method for RCP testing of TFOS which is rapid, uses standard solvents and media, does not require daily preparation of a mixture of volatile solvents, provides clear and reproducible separation between impurities, and can also be used with sestamibi. Aim: quality controls on renal scintigraphic agent 99m Tc-MAG3 prepared following procedures recommended by manufacturer, in our experimental conditions, gave poorly reproducible radiochemical purity results and often below the minimum acceptable. For this reason we investigated if modification of physical and chemical variables involved in preparation and storage could enhance 99m Tc-MAG3 radiochemical purity. Material and Methods: parameters involved in this study were the following: time elapsed between elution and labelling, age of the technetium generator column, opposite sequence of dilution and heating steps, activity/volume ratio for labelling, duration of heating and storage temperature of labelled drug.

Moreover, we aimed to study 99m Tc-MAG3 stability beyond four hours from labelling. Quality controls were performed immediately after labelling, at 30 minutes, at 1, 2, 3, 4, 6 hours and in some experiments till to 48 hours. As analytical technique a double paper chromatography (Whatman n.1) was choosen, eluted with acetone to separate free pertechnetate and with acetonitrile: water (60:40) mixture to separate reduced hydrolyzed technetium. Results: Dilution after labelling is not recommended. Storage at 4°C did not prolong stability, so it is also not recommended. The following parameters did not influence labelling yield and stability of 99m Tc-MAG3: time elapsed between elution and labelling, age of technetium generator column, prolonged heating. Labelling with innovative activity/volume ratio (1.5 GBq in 2.5 ml) constantly gave higher radiochemical purity results compared to recommended ratio (11 GBq in 4 ml). Beyond, it was demonstrated for both labelling procedures a prolonged stability of 99m Tc-MAG3 till to 8 hours after labelling. Conclusion: 99m Tc-MAG3 chelation complex demonstrated an high physical chemical stability significatively influenced only by activity and volume used in labelling procedure. Labelling with 1.5 GBq in 2.5 ml allows preparation of an higher number of doses from the same kit and the execution of diagnostic procedures requiring higher activities than conventional. Finally, if evidences emerged from this study about 99m Tc-MAG3 prolonged stability will be confirmed by other experiments, it would be possible to administrate it till to 8 hours after labelling, a double time compared to 4 hours time interval recommended by manufacturer. Aim: Sodium Iodide-123 is well known as a radioisotope that is used for studies of the thyroid and its metastases. 123 I labelled compounds are used for kidney, heart and brain studies.Since demand for I-13 is increasing a serious effort for production of I-123 has performed. Material and Methods: For production of 123 I, a home made target was designed. The main part of the target contained; conical target vessel that was mounted in an aluminium cylinder of length 30 cm and diameter 8.5 cm for water cooling during bombardment. Front and rear target windows made by titanium foil and cooling system. In addition, some other part such as a cold finger, decay vessel, vacuum pump and four fingers also designed and installed on the system. 123 I was produced from the reaction of 28 Mev protons with 99.9 % enriched 124 Xe with Cyclon-30. Bombarded xenon was transferred to the vessel and stored there up to about 6 hours to allow 123 Cs decay to 123 I with the maximum efficiency. The remaining xenon gas was then transferred into the reservoir capsule using a cryogenic technique. The produced, 123 I which is deposited on the wall of the decay vessel, was rinsed out by dissolution in 0.05 μs water at 80ºC. Nitrogen gas pressure was used for the transfer the 123 I solution to the chemical hot lab. The pH, and adjusted with sodium hydroxide. Results and Discussion: A sample of production was send to quality control. Quality control results were in good accordance with the United States Pharmacopoeia Conclusion: Using this system with the above specification, the production yield could be increased by increasing the current. The results shows no chmical or radionuclide impurity, and enable to produce I-123 withouht any more purification step. Aims: In order to overcome the limitations of the reported methods, a short and simple method for the preparation of radioiodinated N-succinimidyl-4-iodobenzoate that is widely used for radioiodination of antibodies is described. Material and Methods: The method involves the reaction of in situe generated trimethylsilyl radioiodide from trimethylsilyl chloride with N-succinimidyl-4-[3,3(1,4-butanediyl)-triazene]benzoate available from the condensation of N-hydroxysuccinimide and 1-(4-carboxyphenyl)-3,3-(1,4-butanediyl)triazene in the presence of dicyclohehyl carbodiimide. The recent triazene was prepared by precipitating the diazonium ion of 4-aminobenzoic acid with pyrrolidine. A microwave-mediated rate acceleration was observed during the radioiodination step. Results: Activation of radioiodination reaction by exposure to microwave irradiation (in a domestic oven at 2450 MHz for 8 minutes) afforded the radioiodinated product in 81% radiochemical yield. Conclusion: When compared with alternative methods, the present approach, which reduced the reaction sequence until 3 steps was faster and the method required less expensive reagents and purification was easier. Aim: Transarterial chemoembolisation (TACE) is a promising approach in the therapy of malignant, hypervascularized liver tumors. Developing and optimizing radioiodination reactions and adding the labelled product to an original drug-deliveryembolisation-system was the main goal of this present investigation. This may help to determine an individual, pharmakokinetical parameter and possibly will increase therapeutical effects in prospective animal and human studies. Material and Methods: In a first step Iodogen ® as radioiodination agent was used for labelling anthracycline analogs (doxo-, epi-. dauno-, iododoxorubicin). The labelled products were characterized and separated by HPLC (radio-and diodenarray-detektor) and TLC. In a next step another direct electrophilic radiolabelling [Iodine monochloride (ICl) methode] with c.a. I-123-NaI and I-131-NaI (20°, 30 min) has been performed. The subsequent HPLC-isolating was changed by SPE (SEP-PAK C18-cartrigde). After removing the solvent the product was solubilised in 0.9 % saline solution. Results: The radiochemical yield (RCY) with Iodogen-method was 9±3%. In comparison to that the iodine monochloride method achieved higher RCY's for doxo-(18±5%), epi-(12±8%), dauno-(20±7%) and iododoxorubicin (38±8%). In vitro stability of all products was controlled after 6h. Specific activity lay around 100 MBq/μmol. Conclusions: The direct iodination method with ICl was proved to be a viable labelling possibility of anthracycline analogs. Specific activities are very low, but these results are sufficiently working in case of use in combination with unlabelled therapeuticals in a chemoembolisation system. Higher RCY's of iododoxorubicin can be explained by isotopic exchange. After validation of radiolabelling conditions and results the chemoemolisation system with radiolabelled anthracycline and the sterilisation of the used materials needs further investigation. This could lead to a proved method for nuclear medical imaging of a radio-chemoembolisat for locoregional application. The development of new PET radiopharmaceuticals demands strategies for the identification of dedicated targets. Following the identification of a target, the "in silico" search for substrates is a promising approach to achieve specific drugs. Methods: The search for targets for new radiopharmaceuticals demands the use of large scale gene expression data, usually obtained by gene array techniques. We used gene array data, obtained from 42 tissue specimen (25 human tumors, 17 reference tissue samples) to search for differencially enhanced genes, in order to identify possible targets for new radiopharmaceuticals. Furthermore, ten samples from a human colorectal cell culture line were evaluated. Gene expression data were obtained using the U133A and U133 Plus 2.0 gene chip (Affymetrix Inc., Santa Clara, CA, USA). Gene expression values were converted to relative expression values (REV): REV = 1000 * (gene expression value -minimum expression value) / (reference gene expression -minimum expression value). The GenePET module of the PMOD software (PMOD Technologies Ltd., Adliswil, Switzerland) was used for data evaluation. The Fast Rigid Exhaustive Docking (FRED) software (OpenEye Scientific Software, Santa Fe, NM, USA) was used to assess receptor/ligand properties. Results: The gene expression data comprised 22283 (U133A) or 54675 (U133 Plus 2.0) probe values for each tissue sample. Following normalization, matrices were calculated for the ratios tumor/reference tissue as well as for the Mann-Whitney test variable of each gene. Search strings were applied to select those genes related to receptors and cell membrane proteins. Furthermore, discriminant analysis based on the support vector machines method (SVM) was used to select those genes from the subgroup which provide the best discrimination between tumor and normal tissue. The final SVM analysis provided 35 genes related to cell receptors, mainly belonging to the group of G protein-coupled receptors. Following the identification of targets, the FRED software was used to assess possible substrates for these receptors. Conclusions: Molecular biological data, obtained by gene array analysis, provide a promising approach for the development of new PET radiopharmaceuticals. The combination with computational drug software helps to select a subgroup of substrates for receptors and membrane structures, which are then further evaluated using conventional lab procedures. Aim Several radiolabelled amino acids have proven to be useful as a radiopharmaceutical substance for PET imaging of tumors. O-(2-[ 18 F]fluoroethyl)-Ltyrosine (FET) seems to be one of these promising compounds. This 18 F-labelled amino acid can be synthesized with high radiochemical yield. Large production and distribution is allowed by using 18 F. FET provides excellent quality for PET imaging of solid gliomas in brain. From these points of view FET is the right choice for our interest. The synthesis of FET is known, however, modification of the method for our facilities was necessary. The aim of this study was to adapt synthesis method in order to start production of FET as a commercial PET imaging tracer. Materials and Methods The synthesis was performed with TracerLab MX system (Coincidence), which is originally designated for production of [ 18 F]FDG. Therefore, some modifications in method had to be done. Synthesis is based on phase transfer mediated nucleophilic 18 F-fluorination of O-(2-tosyloxyethyl)-N-trityl-L-tyrosine tert.butylester with subsequent hydrolysis by mixture trifluoroacetic acid / 1,2-dichloroethane. Subsequently, purification of reaction mixture was completed by reversed phased HPLC. Quality control was done with HPLC for radiochemical and enantiomeric purity. Results Because the production automat did not resist the mixture trifluoroacetic acid / 1,2-dichloroethane, we changed the deprotection step and applied 5M HCl. The fluorination yield ranged from 80 to 85% and overall yield was 40-45% (uncorrected for decay). Radiochemical purity was over 95% and enantiomeric purity was 100%. Conclusion We successfully developed and tested the synthesis of [ 18 F]FET in our production conditions. Nowadays we are providing biodistribution and preclinical studies with animals. Finally, we are intended to distribute FET to medical facilities. Acknowledgement This work is supported by the project No Aim: Evaluation of a 68 Ge/ 68 Ga generator to produce carrier free 68 Ga radionuclide and optimization of a synthesis method to obtain 68 Ga-DOTATOC for clinical purpose. Materials and Methods: Imaging of SSTR expressing tumours, such as neuroendocrine, lymphomas, meningiomas and breast cancers, has been greatly improved by utilization of 68 Ga-DOTATOC radiopharmaceutical and positron emission tomography. In this study 68 Ga-DOTATOC was synthesized from a 30 mCi 68 Ge/ 68 Ga generator (CyclotronCo., Obninsk, Russia) carrying out the following steps: i) 68 Ga in cationic form 68 Ga 3+ was eluted from the generator by a 0.1 M HCl solution and trapped in a cation exchange cartridge. ii) Metallic and radionuclidic impurities, such as Fe (III) and Zn (II) were washed to waste by rinsing the cartridge with a 80% acetone / 0.15 M HCl solution. iii) 68 Ga 3+ was eluted to the reactor with a 98% acetone / 0.05 M HCl solution and reacted with 14 nmol of DOTATOC in a no buffered water solution. 68 Ge (IV) breakthrough and Ti (IV) impurities remained in the cartridge and were subsequently eluted to waste by 4 M HCl and water iv) After labelling, in order to eliminate not reacted 68 Ga 3+ , the crude solution was passed in a apolar C18 cartridge where 68 Ga-DOTATOC was trapped. v) Final product was eluted by ethanol and diluted with an appropriate amount of saline solution for the final formulation. During the validation of the method a complete set of quality controls including radiochemical purity by radio-TLC and radionuclidic purity by -spectrometry was performed; sterility of the preparations was also assessed. Results: About 30 syntheses were carried out during six months of activity and an amount ranging between 555 to 296 MBq (depending on the 68 Ge/ 68 Ga generator life) of 68 Ga-DOTATOC was obtained. Mean synthesis yield was computed to be 59±2 % (not corrected for decay) in a synthesis time of about 23 minutes. Radiochemical purity was about 98 % and highest radiochemical impurity resulted in free 68 Ga 3+ not reacted ( 68 Ga-DOTATOC: R f = 0.0 free 68 Ga 3+ Rf = 0.9). Radionuclidic purity was observed to be greater than 99.9999 % and final solution resulted sterile. Conclusion: After elution in cationic form and the purification steps described, 68 Ge/ 68 Ga generator can be considered a safe source of pure 68 Ga for high yielding labelling of peptide or other molecules. 68 Ga-DOTATOC produced with this method can be efficiently utilized in Nuclear Medicine department for clinical evaluations.

Synthesis and biological evaluation of 11 C-labeled acyclic-and furo[2,3-d]pyrimidine derivative of bicyclic nucleoside analogs (BCNAs) for structure-brain uptake relationship study of BCNA tracers S. K. Chitneni, J. Balzarini, A. Verbruggen, G. Bormans; Katholieke Universiteit, Leuven, BELGIUM.

We recently synthesized and evaluated several BCNAs labeled with C-11, F-18 or I-123 as potential PET or SPECT tracers for non-invasive imaging of varicella-zoster virus thymidine kinase (VZV-tk) gene. These studies resulted in a new reporter gene/probe system but none of these tracers were taken up in the brain in biodistribution studies despite fulfilling the theoretical requirements for passive diffusion of such molecules through BBB. We have now synthesized and evaluated a 11 C-labeled BCNA ([ 11 C]-(3)) with a hydroxyethoxymethyl side chain instead of a 2deoxy ribose sugar for BCNAs, and a BCNA without sugar moiety ([ 11 C]-(4)). Methods: The precursor compounds (1) and (2) were synthesized by Sonogashira coupling of 5-iodo-3-[(2-hydroxyethoxy)methyl]uracil and 5-iodouracil, respectively, with 3-hydroxyphenyl acetylene, followed by cyclization in situ. They were converted to non-radioactive (3) and (4) by methylation of the phenol for (3) and at the N-3 of the pyrimidine ring for (4) using CH 3 I in the presence of K 2 CO 3 in DMF. The radiolabeling was achieved using [ 11 C]methyl triflate. The methylation products were purified using C-18 semi-prep HPLC. The affinity (IC 50 ) of the non-radioactive compounds for VZV-TK was determined in vitro in competition with [[ 3 H]-CH 3 ]dThd. The logP of [ 11 C]-(3) and [ 11 C]-(4) was determined and their biodistribution was evaluated in normal mice at 2 and 60 min pi. Results: Synthesis yields were 25% for (1), 44% for (2), 56% for (3) and 32% for (4). The RCY for [ 11 C]-(3) and [ 11 C]-(4) was 28% and 50%, respectively, and the RCP was >99 % for both tracers. The identity of the tracers was confirmed by co-injection with the authentic (3) or (4). LogP 7.4 value of both tracers was 1.2. IC 50 values of (1), (2), (3) and (4) for VZV-tk were 37, 64, 430 and 79 μM, respectively. Similar to the previously synthesized BCNA tracers, negligible brain uptake was seen at 2 min and 60 min pi for both [ 11 C]-(3) and [ 11 C]-(4), which were cleared mainly by the hepatobiliary system and to a lesser extent to the urine at 60 min pi. Blood clearance was rapid for both tracers (<1.0% ID in blood at 60 min pi). Conclusions: Lack of uptake in brain for [ 11 C]-(3) and [ 11 C]-(4) confirms that BCNA tracers do not cross BBB despite their lipophilic character. In general, this observation can be extended to other uridine-or uracil-based nucleoside analogues also. This study was funded by the EC- Aim: Fluoromisonidazole [ 18 F]FMISO, has been used with PET in humans for the identification of hypoxic tissue in stroke. However, [ 18 F]FMISO suffers from low cellular uptake into hypoxic tissue and slow clearance from normal cells, requiring long periods between iv-injection and imaging. In 2006 we have reported the radiolabelling of another class of compounds (sulfoxide containing nitrogen mustards) that have great affinity for hypoxic tissue. In this study, we have performed in vivo analysis to evaluate these compounds ([ 18 F]SO101 and [ 18 F]SO201) as potential imaging agents. Method and Materials: To determine the uptake of the tracers in the ischemic penumbra, MCAO stroke-induced rats were injected with the desired tracer immediately after stroke. Uptake times of 0.5, 1 and 2h post injection were assessed and autoradiography performed. A delayed injection study (injection 6 hrs post stroke, sacrificed 2 hrs post injection) was also performed to determine if the tracer is binding to the infarct tissue. Autoradiography and histology was used to correlate infarct regions with uptake of the tracer. A PET/CT scan of SO201 was also investigated. All data was compared to the current gold standard [ 18 F]FMISO. Results: At 2h post injection, the density ratios and the hemispheric area of uptake of the three tracers ([ 18 (1, 2) carried out by distillation of the intermediate 18 F-Fluorobromomethane (FBrMe) and subsequent alkylation of dimethylaminoethanol (DMAE) or by gas phase conversation of FBrMe to 18 F-Fluoromethyltriflate followed by DMAE alkylation. The aim of this study was the investigation of a one pot synthesis without distillation on an automatic synthesis module for production of high radioactivity amounts of FMC. Materials and Methods: Trapping the target water on an anion exchanger, elution with Kryptofix® 2.2.2/potassium carbonate and azeotropic drying was performed according to a standard procedure. The nucleophilic substitution with Dibromomethane as precursor was optimized with respect to time and temperature. The second reaction step was carried out by addition of DMAE in acetone to the intermediate FBrMe and also optimized with respect to time and temperature. Subsequently the solvents were evaporated and a sodium hydroxide solution was added to the residue and heated for additional 10 min. By transferring the product solution over a cation exchange the FMC was trapped on the cartridge. After washing with ethanol and water, FMC was eluted with saline. The QC was performed by HPLC and TLC. Results: The strategy for the synthesis of FMC (according to (3) ) was transferred to an automatic, remote controlled synthesis unit. The optimization of the nucleophilic substitution results in a radiochemical yield of 50-60% in 10 min at 90°C. The alkylation reaction in the same reaction vessel proceeded with radiochemical yields of 70-80% in 12 min at 100°C. This result in an overall radiochemical yield of 35±5%, which only slightly differs from the non automatic synthesis (35-50% (3)). Destroying the byproduct Bromomethylcholine by basic hydrolysis was nearly quantitatively. Total synthesis time was approximately 50 min. The radiochemical purity was >95%. Conclusions: The two step one pot synthesis of FMC was successfully adapted to an automatic, remote controlled synthesis unit. This process allows the efficient and reliable production of FMC with high radioactivity amounts in less than one hour. References: (1) Introduction: There is an increasing need for PET radiotracers to be produced at high specific radioactivity (SA) to delineate low population binding sites in man or for imaging studies on small animals. These studies often require radioligands with very high binding affinities, which also imposes the need for producing the radioligand at high SA. An example of these tracers is the high affinity dopamine D2/3 radioligand [ 18 F]fallypride which we are using for human and microPET studies. To perform these studies successfully and in particular to enable us to perform two PET studies consecutively from one radiochemical preparation we have investigated means to improve the SA of the final product. Method and Results: Based on analysis of the various components of the radioligand synthesis, including the precursor's chemical purity, the key determinate of the SA of [ 18 F]fallypride was identified to be the cyclotron-generated [ 18 F]fluoride, prepared by the 18 O(p,n) 18 F method. Using our standard [ 18 F]fluoride production protocol based on 45μA for 60min which produced 69-89 GBq, we obtained 7-14GBq of [ 18 F]fallypride at end-of-synthesis (EOS). The SA was determined, using a calibrated radio-HPLC-UV system, to average 170GBq/μmol (range 75-260 GBq/μmol, n=27). We then modified our [ 18 F]-fluoride production method to perform an irradiation consisting of 45μA for 5min in which the target product was then emptied unused. This was followed by a second [ 18 F]fluoride production (45μA for 60min) to be used for the radiosynthesis process. The amount of [ 18 F]fluoride (70-86 GBq) and the radiochemical product of [ 18 F]fallypride (7-21 GBq) did no change significantly. However the SA of [ 18 F]fallypride at EOS was found to increase significantly to average 300 GBq/μmol (115-571 GBq/μmol, n = 19). With these SA we are able to perform two consecutive human studies within 4 hrs from EOS while keeping to our imaging protocol criteria of 110 MBq dose and a maximum limit of 2 nmol of co-injected mass of fallypride. Conclusion: Using a two stage irradiation protocol we have been able to double the SA of our [ 18 F]fallypride product. As well as being at the required level for performing microPET studies these SA allows us to perform multiply PET studies from one preparation enabling more efficient use of our regular productions of this tracer. Using this protocol has also enabled us to reduce the required activity of [ 18 F]fallypride to be produced while still obtaining the required SA's for our studies, therefore reducing radiation dose to the production staff.

U. Choudhry 1 , R. Paul 2 , P. Blower 2 , S. Biagini 1 ; 1 University of Kent, Canterbury, UNITED KINGDOM, 2 King's College London, London, UNITED KINGDOM.

Background: Current methods for 18 F labelling of peptides for PET imaging are timeconsuming and complex. More efficient (preferably single step) methods, analogous to 99m Tc kits, are required because of the short half-life (110 min). We have previously shown that the reaction of fluoride with alkoxytrialkylsilanes is fast and that the product is stable to hydrolysis up to pH 7.5 when bulky alkyl groups are used. We therefore selected the tert-butyldiphenylalkoxysilane group for evaluation with nocarrier-added 18 F. Aims: To demonstrate radiolabelling of a tertbutyldiphenylalkoxysilane with 18 F and establish appropriate conditions. Material & Methods: 18 F in K.2.2.2/CH 3 CN/K 2 CO 3 was prepared by a conventional procedure: 2ml of aqueous F-18 (120 MBq) was passed through the QMA cartridge (conditioned with 10 ml of 1M sodium bicarbonate and 20 ml water) and eluted in 2 ml K.2.2.2/CH 3 CN/K 2 CO 3 solution. No azeotropic drying was performed. To this solution was added 0.5 ml tert-butyldiphenylmethoxysilane (1mg/ml in CH 3 CN) and 10μl trifluoroacetic acid (TFA). RP-HPLC (water/acetonitrile/0.1% TFA) and TLC (silica/hexane) were performed after 5 min incubation at room temperature. Results: Both HPLC and TLC showed the presence of a single radioactive, hydrophobic species corresponding to a bona fide cold sample of the tert-butyldiphenylfluorosilane (RT 11 min, Rf 0.5) and no significant residual free 18 F (Rf 0). Conclusion: The alkoxytrialkylsilane prosthetic group reacts very efficiently at room temperature with 18 F in the presence of kryptofix without the need for drying by azeoptropic distillation, offering the basis of a very convenient route to radiolabelling biomolecules for 18 F PET. Objectives: Intra-arterial administration of particles containing beta-emitting radionuclides appears to be a useful alternative of liver tumour therapy. Particles of a well-defined size are trapped in the vascular bed of the tumour and remain there while delivering a high dose of radiation in order to destroy both primary and metastatic liver tumours. Methods: Ho-PLA-MS were prepared using the solvent evaporation technique. Ho-Acetylacetone complex and Polylactic acid (PLA) was dissolved in chloroform and consequently added to 2% polyvinyl alcohol. This mixture was stirred S332 for at least 12 hours until chloroform was evaporated. The precipitated microspheres were centrifuged, washed with distilled water and 0.1M HCl and finally collected on a cellulose nitrate filter. Microspheres were placed in the screwed titanium ampoules and irradiated in the channel providing lower neutron flux in order to avoid radiation degradation of prepared microspheres. Results: Generally, 200mg of microspheres were irradiated at the neutron flux 10 12 cm -2 s -1 and the radioactivity reached after 30 minutes neutron irradiation ranged from 1100-1500MBq. The particle size distribution highly depended on the speed of the stirrer and on PLA molecular weight. Microspheres of the ideal size 20-50mm and the mean diameter of 27mm were obtained after stirring at 1200rpm and microsieving using 20mm and 50mm pore size sieves. Holmium as a paramagnetic lanthanide was visualized using MRI. Study was performed using the polyacrilic glass phantom. Non-radioactive microspheres containing holmium in 5% Agar was used. The amount of microspheres used for visualisation ranged from 5 to 100 mg and and this amount corresponds with the amount intended for the future aplication. Discussion: Microspheres of the size of 20-50mm is considered to be an ideal size for immobilisation inside the tumour tissue. Granulometric analysis proved minimally 86 % prepared particles conform to this dimension. MRI study on Holmium loaded microspheres provided image of sufficient signal strength within the all studied concentration range and seems to be promissing for possible imaging of microspheres after decreasing radioactivity owing to decay. .

Interest of Ytracis ® radiochromatographic control prior to Zevalin ® radiolabelling. Aim: The Zevalin ® (ibritumomab tiuxétan) radiolabelling with Ytracis ® ( 90 Yttrium) fails in about 2 per cent of cases despite following a rigorous and well tried procedure. The origin of the failures remains unclear in most cases. After experiencing a labelling failure in our department we performed a chromatic control of the Ytracis ® marker solution. Materials & methods: One patient who presented a recurrence from a refractory follicular lymphoma was referred to our department for a 90 Y-Zevalin therapy. The radiochromatographic purity (RCP) of the labelled Zevalin ® was controlled by Thin Layer Chromatography (TLC) using 3 strips of ITLC-SG paper and 0.9% NaCl solvent. In the present case the strip scanning performed with a radiochromatograph showed a RCP value of 77.5 ± 0.5% (m ± 1 SD) (Normal > 95%), and an impurity peak with a migration front (Rf) of 0.79 ± 0.02. For this reason, the treatment was cancelled. The analysis of the critical procedure steps (registration, storage, labelling, RCP control) and the manufacturer inquiry did not permit to identify the non conformity source. Therefore the present Ytracis ® lot has been controlled by TLC as well as 3 successfully used lots with the same procedure as performed for the Zevalin ® RCP test. Results: The TLC strip readings of the 3 control Ytracis ® lots gave a single migration peak (Rf: 0.67 ± 0.01). The TLC strip readings of the tested Ytracis ® lot showed a first migration peak (Rf: 0.67) corresponding to 64.6 ± 2.2% of the deposited activity. A second migration peak with a Rf: 0.85 ± 0.04 not present on the control lots was detected corresponding to 33.3 ± 2.7% of the deposited activity. The impurity nature could not be identified due to the lack of product. Conclusion: Considering the possible failures of Zevalin ® radiolabelling with Ytracis ® we suggest to include a simplified and systematic RCP control of the Ytracis ® solution during the source registration procedure. The RCP control is a main step before the Zevalin ® labelling and the patient convocation. At present, no useful data is available concerning the efficiency and the safety of 153 Sm-EDTMP (Quadramet®) therapy in patients with renal function impairment, especially in chronic renal failure treated with dialysis. We report the case of a 71years-old woman who suffered from painful bone metastases. Her medical history consisted of untreated asthma, hypertension, left breast adenocarcinoma and chronic renal failure for which she benefited from haemodialysis 3 times a week. The patient was referred by the geriatric department to perform bone scintigraphy for the initial evaluation of skeletal metastases because of her hypercalcemia and bone symptoms. The bone scan revealed multiple secondary lesions. Pain evaluation by visual analogic scale (VAS) was expressed as 7 and the recorded motor score was 5/20. These findings were diagnosed as extensive metastases of her breast cancer. This patient was given the opportunity to benefit from internal radiotherapy with Quadramet®. Considering her renal failure and urinary excretion of 153 Sm-EDTMP after intravenous administration, nuclear physician decided that careful and cost-effective treatment could only be achieved by performing 80 % of the conventional activity, i.e. 29.6 MBq/Kg (0.8 mCi/Kg) instead of 37 MBq/Kg (1 mCi/Kg), 16 hours before haemodialysis. Her haematological status recorded 48 hours before, made feasible the radionuclide therapy. The administration was performed in the nuclear medicine department without any problem. The clinical follow up included adequate monitoring of bone pain response, haematological status and supportive medication. Treatment efficacy was assessed according to VAS, motor score, analgesics consumption and performance status. Painful osteoblastic lesions were significantly alleviated after internal irradiation (VAS, 0 ; motor score, 19/20). Onset of pain improvement took place 2 weeks after internal radiotherapy. There was an obvious decrease in opioid analgesics use in the active phase of the treatment.. No relevant haematological toxicity occurred. However, a temporally recoverable mild anaemia was observed. This finding was likely related to arterio-venous fistula inflammation. Conclusion: In this case, management of painful bone metastases with Sm-153 EDTMP in a dialysis patient was successfully performed. Our observation demonstrates that such therapy is feasible in patients under chronic haemodialysis.

Radionuclide production for biomedical applications has been studied in recent years at INFN-LASA Laboratory, in co-operation with the Cyclotron Laboratory of the Joint Research Centre (JRC Ispra, Italy), taking advantage of extensive experience in the experimental nuclear physics and nuclear chemistry fields. Several research aspects concerning radiation detection and the relevant instruments, the measurements of excitation functions of the involved nuclear reactions and the required radiochemistry methods have been investigated. The latest studies on high specific activity, accelerator-produced radionuclides in no-carrier-added (NCA) form, for use in therapeutic applications and in related SPET/PET diagnoses investigated, are: 1. NCA 64 Cu, produced by nat Zn(d, xn), nat Zn(d,2pxn) and 64 Zn(d,2p) reactions for simultaneous + /metabolic radiotherapy, with intrinsic PET imaging, including the short-lived radionuclide 61 Cu; 2. 186g Re, produced by 186 W(p,n) and 186 W(d,2n) reactions, for bone metastases pain palliation by beta (1.1 MeV) metabolic radiotherapy, including SPECT imaging; 3. NCA 211 At/ 211g Po, produced by the 209 Bi( ,2n) reaction, with internal spike of the emitter 210 At from the 209 Bi( ,3n) reaction (leading to very small amount of 210 Po as radiotoxic long-lived impurity), for high-LET metabolic radio-and immuno-radiotherapy; Targets are irradiated at the Scanditronix MC-40 Cyclotron (K=40) of the JRC with proton or alpha beams up to 39 MeV, 3 He 2+ particle beam up to 53 MeV or deuteron beams up to 19.5 MeV. Activity measurements are performed either at JRC Ispra or at LASA Laboratory: , X spectra are measured with HPGe detectors, spectra with PIPS detectors with a resolution of 17 keV (FWHM), and spectra with a conventional liquid scintillation counting LSC and spectrometry system with Horrocks number capability for quenching correction, and a higher-resolution liquid scintillation portable spectrometer with / pulse shape analysis (PSA) discriminator. In order to produce NCA radionuclides suitable radiochemical separation processes for the radionuclides of interest, together with quality control checks must be developed. The radiochemical separations adopted are presented for each radionuclide produced. In order to evaluate production feasibility or to confirm the cross sections experimentally obtained, calculations for the involved nuclear reactions are carried out with the EMPIRE-II code, taking into accounting the major nuclear reaction channels. Objectives: Due to the more favourable physical characteristics of 188 Re, 188 Re-Lipiodol is an interesting alternative for 131 I-Lipiodol in the treatment of hepatocellular carcinoma (HCC). A water-in-oil emulsion (W/O) was prepared as carrier system using lipiodol as oil phase, containing 99m TcO 4 -/ 188 ReO 4 in the inner aqueous phase. The aim of present study was to optimize the formulation of the W/O emulsion based on a Plackett-Burman 12-run statistical design. Methods: 12 types of emulsions were prepared according to the orthogonal Plackett-Burman design. To optimize the formulation, the influence of causal factors such as rpm, rotation time, aqueous phase, oily phase, volume ratio, type and concentration of emulsifier was evaluated. For each run the cumulative percentage of administered activity released from each formulation (CPA), was calculated in vitro. The latter quantity will be an important indicator for the whole body irradiation of the patient. In vitro release rate characteristics were measured using a dialysis system. Results: Plackett-Burman analysis showed a significant influence (p<0,05) on CPA for volume ratio (p = 0,0000), rotation time (p = 0,0000), emulsifier concentration (p = 0,0000) and oil phase (p = 0,000) with volume ratio as most important factor. No significant influence was found for the aqueous phase (p = 0,4241), type of emulsifier (p = 0,6817) and rotation rate(p = 0,8384). Conclusion: Stable lipiodolized W/O emulsions could be prepared according to the Plackett-Burman experimental design. Based on our statistical screening design, volume ratio, rotation time, emulsifier concentration and oil phase could be identified as factors affecting the release characteristics of the formulation significantly (p<0,05). In further optimization steps, these factors should be taken into account.

Such conjugates were achieved when the ratios of rhIL2:HYNIC reactions were set from 1:6 to 1:12 (ca. 50% efficiency of the substitution), and the purification step was performed on PD-10 column. The next most essential parameter of radiolabelling reaction was the pH of the reaction medium, which should be kept in the range of 6 -6.5. GF-HPLC analysis indicated that two radioactive species of 99m Tc-HYNIC-IL2 (monomer and dimmer) are formed during radiolabelling, although dimmer could be selectively removed by purification on tC2 column. The optimized conditions of the wet-radiolabelling (30μg of rhIL2:HYNIC, 1-30 mg of tricine, 15-25 μg of SnCl 2 , pH 6-6.5, 60 min in RT) enabled to achieve 99m Tc-HYNIC-IL2 monomer (radiochemical purity >99%, specific activity ca. 9 MBq/μg IL-2) with overall yield of ca. 60%. The two vial freeze-dried kit was prepared: first vial with 50 μg HYNIC-IL2, second vial with 50 mg tricine and 40 μg SnCl 2 . Unfortunately, radiochemical purities of the 99m Tc-HYNIC-IL2 preparations obtained using the dry kit were unsatisfied and did not allow giving the purification step up. Conclusions: Our study showed that rhIL-2 can be efficiently radiolabelled with Tc-99m via bifunctional chelator -HYNIC, and tricine as coligand. However, investigation are still ongoing to receive one-step preparation of ready to use 99m Tc-HYNIC-IL2 radiopharmaceutical. Aim: The purpose of this study was to compare biodistribution profiles and elimination pathways of DOTA-Tyr(3)-octreotate (DOTA-TATE) and DOTA-l-Nal(3)-octreotide (DOTA-NOC) labelled with In-111 in rats. Whereas clinically used radiolabelled DOTA-TATE shows high affinity to somatostatin receptor subtype sstr2 and low or absent affinity towards the other somatostatin receptor subtypes, DOTA-NOC exhibits high affinity to somatostatin receptor subtypes sstr2, 3 and 5. Materials and Methods: For the cell experiments, rat pancreatic carcinoma AR42J cells expressing sstr2 receptors were employed. For biological experiments, male Wistar rats (190-260 g) were used. The peptides were administered to rats intravenously in the dose of 0.2 μg per animal. The kinetics of the peptide uptake in the kidney was also studied on the proximal tubule-derived opossum kidney (OK) cell line. Results: 111In-DOTA-TATE and 111In-DOTA-NOC showed high and comparable rates of internalization into AR42J rat pancreatic carcinoma cells in agreement with their similar affinity to somatostatin receptor subtype sstr2. Both peptides under study exhibited similar distribution profiles in rats. Radioactivity was rapidly eliminated from the blood and most organs and tissues. High radioactivity uptake in somatostatin receptor-rich organs and in the main elimination organ (the kidney) was determined. Due to higher lipophilicity of 111In-DOTA-NOC its plasma protein binding was higher, the blood radioactivity decrease was slightly slower and liver accumulation was significantly higher in comparison with 111In-DOTA-TATE. The physiological internalization of radioactivity into somatostatin receptor-rich organs (the pancreas and adrenals) was for 111In-DOTA-NOC about twice of that for 111In-DOTA-TATE. No significant differences in the renal radioactivity uptake were found. These results were confirmed also in the study of the peptide uptake by the OK cells. Elimination pathways were comparable for both peptides under study. Conclusion: Radiolabelled DOTA-NOC represents promising somatostatin receptor-specific peptide for diagnosis and radiotherapy of some neuroendocrine tumours due to its very high uptake in tissues with high density of somatostatin receptors. The study was supported by the Grant Agency of the Czech Republic -grant No. 305/07/0535. Whereas the peptides labelled with radiometals were eliminated into urine mostly in the parent form and only traces of metabolites were detected, a significant portion of metabolites of iodinated compounds (especially in the longer time intervals after dosing) in rat urine were found. In time intervals up to 1 hour after dosing, the distribution profiles of all peptides under study were similar. High radioactivity uptake in organs with high density of somatostatin receptors (the pancreas and adrenals) and also in the kidney was determined. Whereas high radioactivity accumulation in the above-mentioned organs continued for a long time for the peptides labelled with radiometals, this uptake significantly decreased with time for iodinated derivatives. The physiological internalization of radioactivity in somatostatin receptor-rich organs is mediated by their somatostatin receptors. Renal uptake and retention of the peptides involves glomerular filtration and subsequent partial reabsorption in the proximal tubular cells by endocytosis. The peptides could be consequently transferred to lysosomes and digested by proteolytic enzymes. Resulting breakdown products remained in the lysosomes for a long post-injection period for the agents labelled with radiometals. On the other hand radioiodinated break-down products could cross biological membranes from the sites of metabolism to the central distribution compartment and finally be eliminated by urine. Conclusion: The reason of different metabolites proportion of the peptides under study in rat urine was in different rates of externalization of brake-down products from the sites of biotransformation. 

K. Durkan, F. Yurt Lambrecht, P. Ünak; Institute of Nuclear Science, Izmir, TURKEY.

Aim: Bombesin-like peptides are neurotransmitters and cancer growth factors. Bombesin-like peptides express several human cancer, including small cell lung, prostate, breast, colon and pancreatic cancer receptors. Litorin is a peptide derivative as amphibian bombesin. In this study, a new 99m Tc labeled BN-like peptide (Litorin) was prepared and biodistribution studies in normal rats were investigated. Materials & Methods: Litorin was labeled with Tc-99m by using 25 μg stannous chloride at pH 3.0. After the labeling procedure, the radiochemical analysis of radiolabeled peptide was determined by radio thin layer chromatography (RTLC) and radio high performance chromatography (RHPLC). In vivo biodistribution studies were performed in normal male Albino wistar rats with blocked and non-blocked receptors. The stability was investigated in human serum. Results: Labeling yield was 95.04±1.4%. Serum stability results showed that in vitro stability of the radiolabeled peptide was quite high. The radiolabeling efficiency was 87.4±1.1 at 4h during incubation. Significant uptake in bombesin/gastrin releasing peptide (BN/GRP) receptor rich tissues such as the pancreas (23.56±0.01 %ID/g, 30 min post injection) was observed. The uptake in the pancreas could be blocked by cold Litorin (0.28±0.02 %ID/g at 30 min). 99m Tc-Litorin exhibited very hydrophilic and eliminated via renal filtration and urinary excretion. Conclusion: 99m Tc-Litorin showed high uptake in the gastrin-releasing peptide receptor-rich pancreas and might be useful radiopharmaceutical in the detection of bombesine receptor-expressing cancers in vivo. Introduction: In the process of 153 Sm production, the 154 Eu (t 1/2 8,8 years, 123 KeV, 569 KeV, 247 KeV) is generated like main radionucleidic impurity. However, the low proportion of this radionucleid in the final product, inferior to 0.0093%, assures its harmless. Objective: To quantify the amount of 154 Eu present in the waste generated by 153 Sm-EDTMP use and to evaluate its incidence in the waste management. Material and methods: The remaining liquids of 10 Quadramet ® vials of different lots and patients' urine collected during 6 h p.i were analysed. The emission espectrum's analysis of each sample and the estimation of the Eu specific activity were performed with a NaI(Tl) detector. Results: The average 154 Eu ratio in vials versus the 153 Sm nominal activity was 0.0032%, which agreed with manufacturer indication. The mean 154 Eu ratio in vials and in urine were of 4·10 7 Bq/L y 9·10 4 Bq/L respectively. In both cases exceeded the valid limit for drinking water (833 Bq/L). 154 Eu / 153 Sm-EDTMP ratio in urine, was approximately of 0.3%. Conclusions: The waste management program of 153 Sm must consider current 154 Eu ratio, establishing the suitable dilutions, in agreement with the characteristics of each center, as the final concentration must not exceed the valid limit for drinking water. Biodistribution of the chemical species containing 154 Eu and 153 Sm seems to be differents.

The potential of the 10-30 kDa fraction of the water-soluble polymer polyethyleneimine, functionalised with methylene phosphonate groups (PEI-MP) and labelled with 99mTc (6 hr half-life and 140 keV gamma), 117mSn (13.6 d half-life, conversion electrons) and 186Re (3.7 d half-life, 1.1MeV beta-) has been described elsewhere. Distinct differences in the biodistribution in animal models were found for the different radionuclides. 99mTc-PEI-MP had high bladder and kidney uptake. 117mSn-PEI-MP had moderate reticuloendothelial uptake, reasonable bone-uptake and considerable uptake in the bladder wall. 186Re-PEI-MP showed rapid clearance of all organs as well as considerable and early excretion in the urine and little bone uptake. It is postulated that the size of the polymer complex changes with the different metal ions which is the reason for this difference in biodistribution. Methods: Nonradioactive Sn(II)-PEI-MP and Re-PEI-MP were prepared according to the labelling procedures. Parallel radiolabelled equivalents were used to prove the labelling was successful. As 99mTc is no-carrier-included, the mass of this metal ion is negligible and will not influence the result. Therefore the kit formulation (a mixture of PEI-MP, Sn(II), Sn(IV) and buffer) was used to simulate 99mTc-PEI-MP. All solutions were kept under Ar and were analysed for size by conventional GPC using an Agilent 1100 isocratic pump. Results: The average GPC size results showed that the size of the polymer fraction is 25.4 kDa, and 20.9 kDa for the Tc-99m kit formulation (99mTc-PEI-MP), 27.3 kDa for Sn(II)-PEI-MP and 32.2 kDa for Re-PEI-MP. Conclusions: It seems that the polymer contracts upon complexation with Sn(IV) due to ML2 complexes but expands with Sn(II) which prefers M2L complexes. As low specific activity Re was used in earlier experiments, it was expected that the size of Re-PEI-MP would be considerably higher. 90 Y is a widely used radionuclide in therapeutical nuclear medicine applications. To be safely administered to patients, 90 Y solution must fulfill specific quality requirements; it must be at correct pH, endotoxin free, metal free, and it should have only minute amounts of long-lived parent nuclide 90 Sr. The aim of this work is to develop a fast, efficient and reliable method to determine 90 Sr content in 90 Y solution. The separation of 90 Y and 90 Sr is performed by using highly selective extractive chromatographic Sr Resin. 90 Y sample is loaded to the column in diluted nitric acid. Yttrium under this condition does not retain on the column so it is first washed out and collected. Yttrium fraction is measured with a dose calibrator. Strontium is eluted from the column with water. The strontium fraction is evaporated to near dryness and dissolved in scintillation cocktail. Finally the sample is measured with liquid scintillation counting (LSC). The problem in using LSC in 90 Sr determination lies with the ingrowth of 90 Y in the sample. High energetic 90 Y spectrum (max. 2250 keV) overlaps 90 Sr spectrum (max. 550 keV), hence obtaining a 'pure' 90 Sr spectrum is impossible. An indirect mathematical model that utilizes counts of the beta spectra originating from each nuclide is a convenient method for subtracting 90 Y from the 90 Sr 90 Y spectrum. A pure 90 Y spectrum is measured and a window in the high energy area of the spectrum is selected. The window area is normalized with the yttrium-90 counts in the 90 Sr 90 Y spectrum. The two spectra are subtracted from each other resulting in a pure 90 Sr spectrum. The developed method allows a rapid 90 Sr content determination with 90 Sr/ 90 Y ratio as low as 10 -8 . The time needed for the entire quality control procedure is in the range of one hour. Same mathematical method can be used to determine tungsten-188 content in rhenium-188 solution from 188 W/ 188 Re -generator. (111). Only the patients with normal globular volume (VG) and VP (VG exp<25% VG theoretical; VP exp<25% VP theoretical) have been studied. Calculation formulas were: VG(HtS/(1-HtS)) for VP calc, 1,06 * age + 822 x body surface (BS) for female VG th, 1485 * BS -825 for male VG th, 1395 * BS for female VP th, 1578 * BS for male VP th. Data were analyzed for means. A Student test and regression analysis were performed using the excel program of MicroSoft, Inc. Results: The student test has shown that it existed a significant difference between VP exp and VP calc for males (p<0.05) and females (p<0.05). However, the regression analysis has shown a correlation of VP exp versus VP calc for males (r= 0.919 for 20 minutes blood sample) and females (r= 0.964 for 20 minutes blood sample). When the equations of correlation lines have been used to find VP exp from VP calc on a 2006 patient's sample, a significant difference was remained between the two VP. Discussion and conclusion: According to these results, the use of 125 I-HAS seems to be indispensable to obtain a good estimation of VP. As it has been shown by Morin, et al. in 1972 (Ouest-Médical, 25è année n°10, 10 mai 1972), the use of HtS to calculate the VP calc. explains this result. HtS is obtained from the formula: venous Ht * X where X estimation is 0.91. In reality, X depends on the person. So to limit the viral risk linking to the use of 125 I-HAS, only red cell mass measurement by 51 Cr will be done in research of myeloproliferative syndrome (Vaquez disease, ) and 51 Cr and 125 I-HAS will be used in other cases. To optimize the choice of the technique (single or double isotopes), we are developing a prescription medium in order to obtain all necessary informations to choose the best technique. Aim Activity measurement of 123 I radiopharmaceuticals, may be affected by several factors such as recipient shape and its nature (kind of glass, plastic, etc); as well as, the own attenuation produced by liquid volume in which radiopharmaceutical is dissolved. The aim of this study is the assessment of variation between measured activity and reference activity, using two different dose calibrators. As well as, the calculation of corresponding correction factors necessary to obtain the most exactly dose with each dose calibrator. Material and methods We have used two dose calibrator for activity measurement: Capintec CRC ® -15R (DC1) and Capintec CRC ® -12 (DC2). Activity measurement of 123 I was performed using the corresponding channel of each dose calibrator. 35 measurements of 123 I activity were performed to the radiopharmaceuticals into manufacturer vial, and others 35 after withdraw the whole radiopharmaceutical activity into a 5 mL syringe. Those measurements were performed in both dose calibrators. The measured activity in each case was compared with reference activity. Also, we have calculated the medium variation percentage (MVP) of measurements performed versus reference activity, as well as, the medium correction factor (MCF) for each measurement. Results The MVP of measurements performed versus reference activity in case of DC1 was 12.63 ± 5.70 in syringe and in manufacturer vial -29.29 ± 1.82. In case of DC2 MVP in syringe was 29.67 ± 6.36 and in manufacturer vial -22.57 ± 0.08. MCF were calculated in each case. For DC1: syringe, 0.89 ± 0.05; manufacturer vial, 1.42 ± 0.04; and for DC2: syringe, 0.77 ± 0.04 and manufacturer vial, -22.57 ± 8.08. Conclusions Our results showed than measured activity for 123 I using manufacturer vial was significantly lower than reference activity, in both dose calibrators; while, on the contrary, when the radiopharmaceuticals was measured in syringe, the activity resulted higher than reference activity, and moreover, higher in case of DC2. In consequence, to get the most exact activity measurement of 123 I radiopharmaceuticals, it is necessary the calculation and use of the correction factor corresponding to the dose calibrate used to the measurement, both for manufacturer vial activity and syringe activity. Introduction: Dextrans are glucose polymers, whose versatility has led to their application in numerous fields. 99m Tc-labelled dextrans have been proposed as possible substitutes for human albumin and labelled red blood cells in angiography and cardiac pool studies. Objective: To assess the pharmacokinetics of a 99m Tc-labelled dextran-70 preparation in rats. Material and Methods: Eight Wistar male rats with an average weight of 250g were administered with 18 MBq of 99m Tc-dextran-70 in a volume of 300 μl via cannula in jugular vein. Blood samples of 1 ml were taken at 10, 30, 60, 180, 360 and 480 min post-injection and kept in a flask with anti-coagulant; 0.5 ml of each sample was centrifuged to obtain plasma. Aliquots of 0.2 ml of total blood and plasma were measured in a well counter for 5 minutes. The activity of each sample was determined as a function of time and the following pharmacokinetic parameters were determined: plasma concentration, apparent distribution volume and plasma clearance of the radiopharmaceutical. Results: Tc-labelled dextran-70 shows the characteristic kinetics of a vascular tracer. In every case LE was tested: In vivo/in vitro method: 0.05-0.10mL 99m Tc-RBC aliquots were added to 2mL of NaCl 0.9% solution into sterile vacuum blood collection tubes. The tubes were centrifugated at 1300xg for 3 minutes and supernatant (cell-free plasma) was transferred into plastic test tubes. LE was calculated by measurement, both cell-free plasma and RBCs packed, activities using a dose calibrator (Capintec CRC ® -15R). In vivo method: 4mL whole-blood was withdrawn from a peripheral vein using a 5 mL heparinnized syringe. It was centrifuged at 1300xg for 5 min and supernatant was transferred into plastic test tubes. LE was calculated by measurement, both cell-free plasma and RBCs packed, activities using a well counter. LE was expressed as percentage and the mean value and the standard deviation were calculated for each method. The gammacamera used was a double headed variable tangential Philips Axis. Results Average LE of 39 99m Tc-RCBs by in vivo/in vitro method was 98.45±2.19% (low LE 91.57% and high LE=100%), on the other hand, the 42 99m Tc-RCBs by in vivo method yielded an average LE of 93.26±2.24%, in a range of 89.36 to 99.38 percent. In each case, gammagraphics images were tested by two different independent testers, neither of them detected any undesirable uptake because of low quality of 99m Tc-RCBs, or by any in vivo unlabelling. Conclusions According to our results, the LE using in vivo methods was slightly lower than LE by in vivo/in vitro method. Perhaps, both of them were into an acceptable range to be used for LVEF studies. Moreover, LVEF studies performed have not shown any significant difference, so both methods are useful to get 99m Tc-RBCs In fact, we think that the use of 99m Tc-RBCs by in vivo method is preferable, because it is a simple system, easy to perform, safe and efficient to assess LVEF getting good results and image quality. Introduction: Insulin-like growth factor 1 (IGF-1) and its binding proteins, mainly IGFBP3, have a very important role in the regulation of fetal growth. The synthesis of IGF-1 and IGFBP3 is regulated to diverse hormonal factors, such thyroid hormones. The purpose of this study is to determine the possible association between the hypothyroidism status of pregnant women and the levels of IGF-1 and IGFBP3 respectively. Objective: Assessment the relationship between thyroid hormone levels and IGF-1 and IGFBP3 serum levels in pregnant women. Aim: The polyazaligands such as DTPA or DOTA are suitable for transitionmetal and lanthanide ions, and their complexes have found important use in the radioimmunotherapy and radioimmunodiagnosis. A key parameter for these applications is a fast and efficient complexation of a convenient radioisotope. Acyclic DTPA forms complexes immediately; complexation with macrocyclic DOTA is much slower. However, the macrocycles are better from all other aspects (e.g. kinetic and thermodynamic stability). In general, the most suitable central ions for DOTA-like ligands are trivalent lanthanides and indium. The 111 In isotope was chosen for this study, because it has convenient radio-properties. We present here an investigation of two new bifunctional monophosphinic acid H 4 dota derivatives having distant paminobenzyl (DO3A-P ABn ) or carboxylic groups (H 5 do3ap PrA ) suitable for a further conjugation. Material and Methods: DO3A-P ABn and H 5 do3ap PrA were prepared according to the published procedures. 111 InCl 3 was purchased from Amersham Plc.. The reactions were followed with radio-TLC on silikagel plates or RP-HPLC on Lichrocart C18 column (Merck). Biodistribution and elimination studies were carried out using male Wistar rats. Results: The studied ligands exhibit a fast complex formation at optimized conditions (ligand:metal ratio 2:1, pH 6.5, 40°C, 5 min). As expected, higher pH and temperature accelerate the complex formation reactions. However, pH where precipitation of colloid metal hydroxides can occur (>~7) is not suitable. Biodistribution studies showed a rapid clearance from most organs including blood and muscle. The main elimination pathway was urine excretion mostly by the mechanism of glomerular filtration. Conclusion: The resultes indicate that DO3A-P ABn and H 5 do3ap PrA are promising for radiolabelling of target-specific biomolecules.

INITIAL

The relationship between proinflammatory cytokines, IL-6 and TNF-, and hyperthyroisdim is not well known. Serum levels of cytokines may indicate activity levels of immune functions. On the other hand some hyperthyroisdim variant have a immune component. Objective: To measure and compare serum concentrations of proinflammatory cytokines, interleukin-6 and TNF-, in patients with different hyperthyroid diseases. Material and Methods: Analyses were conducted in sera samples drawn from 14 patients with Graves-Basedow disease, 22 patients with multinodular goitre, 13 patients with thyroiditis and 20 euthyroid controls. Serum TSH, FT4, FT3, IL-6 and TNF-concentrations were measured by IRMA or RIA assays. Statistical analysis: A one-factor ANOVA and subsequent Bonferroni test were performed. Results: In-DOTA-tate in 100 μL is required. Under these conditions the radiolabelled peptide is vulnerable to radiolysis and oxidation, which results in loss of biological activity. Labelling conditions were investigated to obtain a chemically stable product with intact high and specific receptor-binding. Moreover, high SA can only be achieved when the ingrowth of non-radioactive competing 111 Cd is low. 111 Cd is the decay product of 111 In. 111 InCl 3 is produced and delivered every week, thus the radiolabelled peptide should preferably be stable for 1 week. 111 In-DOTA-tate was therefore tested chemically and biologically. Materials and methods: Labelling conditions like time of labelling, temperature during the labelling, specific activity and the addition of several quenchers (ethanol, ascorbic acid and gentisic acid) in different combinations and concentrations were tested. Radiochemical Purity (RCP) was determined by using a HPLC C 18 column at t=0 up to 1 week after labelling biological stability of 111 In-DOTA-tate was tested (at 10 -10 M) by performing uptake and internalisation experiments using the somatostatin receptor expressing rat pancreatic cell line CA20948. Parallel in vitro autoradiography was performed on rat brain sections, both with 5 *10 -10 M and 10 -10 M of 111 In-DOTA-tate. Results: 200 MBq/nmol 111 In-DOTA-tate was prepared. Use of quenchers was inevitable to maintain RCP and prevent loss of receptor affinity. Conditions were optimal in the presence of ethanol, ascorbic acid and gentisic acid. At t=0 RCP was 97±0%, whereas after 1 week the RCP was 95±0%. Uptake of 111 In-DOTA-tate (10 -10 M) to CA20948 cells was 40% [dose/mg protein] of which 90% was internalised. Similar results were found in experiments throughout the week. Receptor-binding of 111 In-DOTA-tate was confirmed on brain sections, and could be blocked in the presence of an excess (10 -6 M) of octreotide analogue. Corrected for decay and exposure time the specific receptor-binding of 111 In-DOTA-tate to brain also remained constant. Conclusion: Optimised labelling conditions of 111 In-DOTA-tate and the presence of a combination of quenchers enables the production of this radiopharmaceutical with a high and intact RCP for a week. Since the chemical status, and the intact high and specific receptor affinity are maintained, centralised production and shipment of "hot liquids" are now possible. Aim In order to satisfy the Good Preparation Norms in Nuclear Medicine all radiopharmaceuticals employed for diagnostic and therapy have to be tested by quality control (QC) by determining radiochemical purity (RP) The purpose of this study was to validate a simplified QC method for gamma and beta radiopharmaceuticals using storage phosphor screen technology and adapting the complexity of the OptiQuant software of Cyclone Perkin Elmer to common usage. Material and methods: Gamma and beta radiopharmaceuticals habitually used in our Laboratory (diluted 1:300 in normal saline) were tested by instant thin-layer chromatography (ITLC). All the chromatographic strips were tested exposing phosphor screen (Multi-sensitive Medium MS) at progressively increasing times (from 10 to 100 seconds) to establish the better time of exposure (for the average of our strips: 20 seconds). Then we have performed 10 ITLC for each radiopharmaceutical to calculate the average of distribution areas of radiopharmaceutical and its impurities in order to find the background area. Since Cyclone can simultaneously measure different chromatographic strips, we have estimated a minimal distance (1.5 cm) between the various strips avoiding images superimpositions. We have compared 30 ITLC results measured by Cyclone and by gamma-counter and the agreement was excellent (correlation coefficient 0.99). Then by the OptiQuant software we have saved in a scheme of lanes -templates-the exact dimensions of the chromatographic strips well as the distribution areas from the origin (O) to the solvent front line (F) and the background area of each radiopharmaceutical. Results This simplified method is easy for user at all levels of computer expertise, moreover consent to scan a screen, display and analyze the image, report the data of various chromatographic strips at the same time with high sensibility and resolution, clearly visualizing the distribution of the radiopharmaceutical and its impurities. The scheme of lanes (templates) saved in the software OptiQuant allows a rapid, automatic and exact measure of RP (less than 2 minutes for 9 different strips at the same time) providing a profile for a graphical representation of data. Conclusion This simplified method for the measurement of radiochemical purity is easy, rapid, optimized and standardized no matter who the users are. Introduction: Hidroxyethyl starch is the most used agent in the sedimentation of the erythrocytes during the radiolabelling procedure for leukocytes. Colloid dextran-200, a plasma expander, have been proposed as possible alternative to hidroxyethyl starch in this process. Objective: To assess the usefulness of the plasma volume expander colloid dextran-200 as an alternative to hydroxyethyl starch in the sedimentation of the erythrocytes in leukocytes radiolabelling by 99m Tc-HMPAO. Material and Methods: Two identical samples of 44 ml of blood in 6 ml of ACD were obtained from 27 patients referred to our department for labelled leukocytes scintigraphy. Leukocyte concentrations were obtained by using a HES solution, following the established protocol. Simultaneously, another leukocyte concentration was obtained using a 6% dextran-200 solution in saline solution of 0.9%. Concentrations of leukocytes, platelets and red blood cells were determined in the plasma obtained. The efficiency of the labelling was estimated, the cell viability was calculated by means of the Trypan blue method, and the in vitro leukocyte recovery and erythrocyte:leukocyte ratio in final suspension of labelled cells were determined. Results are expressed as arithmetic means ± standard deviation. The Student's t test for related samples was used to compare means, considering p < 0.05 as significant. Results: Aim: To assess the effect of scatter coincidences, partial volume, positron range and non-colinearity on the ratio of the specific striatal uptake to non specific uptake (SUR) in FDOPA PET studies. Materials and methods: The SimSET Monte Carlo code was employed to simulate acquisitions of the PET/CT Siemens Biograph scanner. The study was performed by using a numerical model obtained from a CT-image of a striatal phantom. Theoretical SUR values of 0.5, 1, 1.5, 2, 2.5 and 3 were simulated. Neither axial nor angular compression were considered. As a consequence, 1024 sinograms with 288 transaxial bins (bin size of 2.2 mm) and 288 angular positions were obtained. Simulations were carried out with/without positron range and noncolinearity effects. True and scatter coincidences were stored separately so that an ideal scatter correction (ISC) could be performed. A 3D iterative algorithm kept in the STIR library (http://stir.sourceforge.net) was used to reconstruct the 3D PET data. The reconstruction parameters were: 32 iterations, 4 subsets and a reconstruction grid of 128x128x63 (x-y pixel size of 1.7 mm and z pixel size of 2.5 mm). Different reconstruction strategies were employed in order to evaluate the effect of degradations: a) OSEM3D, reconstruction of the sinograms with total coincidences, b) OSEM3D+ISC, reconstruction of the sinograms with only true coincidences, equivalent to an ideal scatter correction, c) OSEM3D+ISC+PVC, reconstruction of the sinograms using the ISC and including a partial volume effect correction and d) OSEM3D+ISC+PVC+PRC+NCC, reconstruction of the sinograms using ISC, including a PVC and without positron range and non-collinearity effects. A linear regression analysis was carried out between calculated and theoretical SURs. The slope of the linear fit was considered to be the recovered SUR (rSUR). In all cases, the correlation coefficients were also calculated. Results: For all reconstruction strategies, the correlation coefficients were higher than 0.999. The slope of the linear fit was: a) OSEM3D: 0.551, b) OSEM3D+ISC: 0.653, c) OSEM3D+ISC+PVC: 1.012 and d Aim Recent developments in PET 3D scanners have enabled the spatial resolution to achieve 2-3 mm FWHM range. With such an optimization, even small patient movements during data acquisition can lead to severe image quality degradation. Frequently, patients who undergo PET brain scans suffer from movement disorders. If a head cushion is used, the probability of involuntary movements is still high. Monte Carlo simulator codes may assume a relevant role in understanding the image implication of these occurrences. The aim of this work is to show the potentiality of the Geant4 Application for Tomographic Emission (GATE) to simulate the results of head movements during a realistic static PET study in image quality. Materials and Methods We used GATE platform to model the ECAT EXACT HR+ scanner. An attractive feature of GATE is its capacity to simulate the behaviour of the scanner's detectors and the signal processing chain. To achieve this, we have defined a resolution of 25% and energy blurring between 20%-30% at 511 keV, a global sensitivity for each crystal of 88%, and an energy window of 350-650 keV. We have applied a paralyzable dead-time model. A 2 coincidence time window and a delayed window were simulated. The Hoffman brain phantom was used as an emission map to map 18F-FDG activity in ventricles, white and grey matter. A 150 MBq 18F-FDG administered activity 3D PET 15 minutes static Hoffman simulation was performed. Fiducial markers were simulated to allow the identification of movement occurrence directly in the brain sinograms. Results We obtained 1024 2D sinograms with 288 radial bins and 288 azimuthal bins for 30 seconds time frames. A total of 1.03043e+10 18F decays were acquired for each static aquisition. A C language programme was conceived in order to obtain a sinogram representing the whole of simulated data.

Through an exploratory analysis we verify that a 1:706 relation between fiducial markers' activity and 18F-FDG brain activity allows clear visual identification of these markers on the sinogram containing the whole data. Conclusions The preliminary results suggest that is possible to obtain realistic brain PET sinograms under realistic simulation conditions. We are currently simulating translation movements with different ranges of magnitude and to couple this information with marker activity v.s. marker dimension. Rotation movements of different magnitudes will also be simulated. Simulated sinograms will be used to develop a correction method suitable for correcting intra-frame movements.

Wall motion and thickening estimation in myocardial gated SPECT: a comparison between two commercially available programs L. S. Maffioli, A. Vignati, F. Cammelli, C. Songini; Ospedale Civile di Legnano, Legnano, ITALY.

Routinary interpretation of gated SPECT is based on a visual evaluation of the rest/stress perfusion images of the left ventricle, an analysis of global function expressed as ejection fraction (EF) and left ventricular volumes and an assessment of the regional wall motion and thickening in the gated SPECT images. In order to calculate left ventricular ejection fraction (LVEF), end-diastolic volume (EDV), wall motion (WM) and thickening (WT), various types of programs are commercially available. Aim of the study: We evaluated the reproducibility of EF, EDV, WM and WT results obtained from two commercially available software packages in a clinical model. Methodology: Fifty consecutive male patients with suspected or known CAD were evaluated with rest myocardial gated-SPECT. Each study was reconstructed using a standard filtered back-projection on the same processing workstation (Odyssey Philips). In order to avoid influences, pixel size and reconstruction parameters were maintained constant in all patients. Two programs were compared to evaluate functional parameters: Cedars-Sinai Quantitative GSPECT (QGS) and 4D-MSPECT (Michigan University). So, on the same reconstructed slices, LVEF, EDV, WM (in mm) and WT (%) were computed in a 5 segment model (apex, anterior, septal, inferior and lateral wall), representing the whole left ventricle. Statistical analysis was performed. Results: A good correlation between the programs was found only for the estimation of LVEF and EDV (R 2 =0.74 and 0.96 respectively), while a poor correlation was found for WT and WM. The R 2 values for WT and WM are summarized in Table 1 . QGS provided bad bull's eye images in 6 patients, and 4D-MSPECT, in 4 patients. Conclusions: Cedars-Sinai Quantitative GSPECT (QGS) and the 4D-MSPECT programs provide reproducible results for the estimation of LVEF and EDV. In spite of these favourable results, we noted that the estimation of WT and WM only moderately correlate between QGS and 4D-MSPECT. For these parameters, the poor correlation suggests caution for the clinical use of polar maps and values of WT and WM. Aim Various computer algorithms are available to segment the myocardium in gated myocardial perfusion scintigraphy, to calculate functional parameters such as left ventricular ejection fraction (LVEF). The ability of these algorithms to reproducibly detect the myocardium will depend on how well defined the wall is in the images of the heart, and hence on the size of any myocardial defects and the count in the heart. This study was carried out to measure the inter-operator variability of LVEF calculated with the Cedars-Sinai and Stanford methods, and to determine how this varied with count and defect size. Materials and Methods 84 consecutive gated myocardial perfusion studies carried out at the Bristol Royal Infirmary were included. A circular region of interest was drawn over the LAO image of the heart and the count in the region was recorded; patients were grouped into upper quartile, lower quartile, and intermediate counts. The defect size was determined using the perfusion quantification package MyoQuant, and patients were grouped into no defect (40/84), defect size 1-4% (18/84) and defect size > 5% (26/84). Data was processed to determine LVEF using MultiDim (Stanford) and QGS (Cedars-Sinai). Results LVEF was on average 3.7% (SD 5.6%) lower with MultiDim than QGS. Inter-operator variability for LVEF was 3.7% for MultiDim and 3.8% for QGS. LVEF decreased with increasing defect size for both MultiDim and QGS. The difference in LVEF between QGS and MultiDim decreased significantly, from 4.3% to 1.5%, as defect size increased from zero to > 5% of myocardium. Inter-operator variability of LVEF increased with perfusion defect size for MultiDim, but not for QGS. LVEF, and the difference between QGS and MultiDim, did not change with count. The inter-operator variability was greater for LVEF with lower count, for both MultiDim and QGS, but this was only significant for MultiDim. Conclusion The inter-operator variability of LVEF measurements in gated MPS may be affected by algorithm, count and defect size. Overall, QGS and MultiDim had very similar average inter-operator variability for LVEF, but MultiDim was more affected by count -worse with low count -and defect size -worse with large defects -than was QGS.

Aim: Imaging from the source that striking the whole crystal area with a uniform flux of photon, is the main method for calculation of non-uniformity in gamma camera systems. In such condition a perfect system produces images of uniform count density. However noise is a major problem in evaluation of non-uniformity in low count test images. Noise causes random fluctuation in count density that is hard to distinguish from real non-uniformity in the image. In this study we used statistical methods in Fourier domain for calculation of non-uniformity in simulation nuclear medicine images. Methods and materials: Using the Monte carol method, uniform and nonuniform flood images of different matrix sizes and counts density were generated. The uniformity of the images was calculated using the conventional method (integral and differential uniformity) and proposed (Fourier transformation) method. Results: The value of integral and differential uniformity shows that these parameters are suitable for calculation non-uniformity only in small matrix size image (high count density). However Fourier transformation could perfectly reflect the non-uniformity even at very low counts almost in all matrix size. Discussion: In daily uniformity test (low count density image) it is not possible to quantify the non-uniformity of test image accurately. However if data is transformed into the frequency domain, non-uniformity may be better be distinguished from random noise in data.

Aim:Simulation is the first step for improving the imaging tests and developing the imaging systems. SimSET is a routine powerful simulation software for simulating nuclear medicine systems specially PET and SPECT. It is necessary that the parameters of these simulation software be accuracy and according to standards in real systems. In this study we considered the SIMSET software with intrinsic quality control tests.Material and methods: we perform four routine intrinsic quality control tests(uniformity , spatial resolution , spatial linearity , energy resolution) in a virtual SPECT system that was simulated by SimSET. We also used the NCAT softwares to produce the phantoms of quality control. These tests were performed according to the NEMA methods. The calculations were done in mathlab and for more accuracy all the procedures were repeated 5 times.Result: We acquired integral and differential uniformity less than 1% for 1000 counts per pixel , spatial resolution less than 3 cm , spatial linearity less than 0.05% and energy resolution was exactly the same as the default value that be set. Conclusion:All the parameters that we calculated were according NEMA standards. But the calculated values were ideally less than the parameters in real SPECT systems. It shows that it needs more study to extend the result of simulating to real condition. Background: The discovery that the use of Herceptin® (trastuzumab) in breast cancer may cause cardiotoxicity in some patients has led to calls for rigorous cardiac monitoring of patients, both to ensure that they are eligible for the drug and at regular intervals once therapy has begun. One of the techniques indicated for this cardiac monitoring is the Gated Blood Pool Study (MUGA scan). Patients can only be accepted for therapy if their ejection fraction (EF) is within the normal range of the centre performing the study. It is therefore important that centres have a robust and reproducible method for measuring EF. The aim of this study was to assess the reliability of MUGA processing carried out at our centre. Method: Gated blood pool studies are performed following the administration of 800MBq Tc99m in vivo labelled red blood cells. The studies were performed on a Siemens ECAM gamma camera with a high resolution collimator. The data was processed using NUD Hermes FUGA software. We selected the 50 most recently reported MUGA studies which had been routinely processed by different operators. These 50 scans were retrospectively reprocessed by two experienced operators independently. The EF results initially reported were compared with those obtained by these investigators. Results: For the 50 studies assessed, the mean (± sd) reported EF was 59.5 ± 7.9 %. The mean EF obtained by investigator 1 was 55.3 ± 8.9 % and the mean EF obtained by investigator 2 was 55.4 ± 9.9 %. Using the paired t-test, there was found to be a significant difference between the reported EFs and those obtained by both investigators (p<0.001). However, there was no significant difference found between the EFs obtained by the two investigators (p>0.5). Review of the original data processing, showed that the selection of the background region was not consistent, with regions of high activity (e.g. gut) included in a number cases. Conclusion: In this preliminary review of our working practices, significant differences were found in the EF results reported when compared with subsequent re-processing by single operators carefully selecting the background region. Further work is intended to ascertain other possible reasons for these differences and assess whether further training and regular review of practice is needed to ensure reliable results are reported. Objectives: To enhance signal-to-noise ratio in a selected volume-of-interest (VOI) centered on the heart and to improve diagnostic performance of nuclear SPECT studies. Methods: The new method of simultaneous SPECT acquisition and reconstruction using a cone-beam and a parallel beam collimator has been introduced and evaluated. We simulated nuclear SPECT scans with Tc-99m sestamibi using Monte Carlo method (SimSet). We also acquired SPECT data using physical phantoms on a two-head gamma camera (E.Cam, Siemens). The normal hearts, as well as hearts with various size defects were imaged. For tomographic reconstruction we used our new fully 3D ordered subsets expectation maximization (OSEM) algorithm with cone-volume system model combined with parallel-volume system model. Total variation optimization regularization was also implemented in this approach. We evaluated signal-to-noise ratio improvement in the selected VOI and accuracy of determination of the extent and location of the defects in the heart using our combined cone-beam/parallel-beam acquisition and reconstruction method, as compared to conventional parallel-beam only approach. Results: We established an increase in the accuracy in locating the site and the spatial extent of heart abnormalities while using our combined cone-beam/parallel-beam acquisition and reconstruction method, as compared to parallel-beam only approach. Conclusions: Application of our new combined cone/parallel-beam method might results in improved accuracy in nuclear cardiology SPECT studies. I-123 MIBG is a radiopharmaceutical used for evaluation of cardiac symphahetic function based on the heart to mediastinum count ratio (H/M ratio) in myocardial scintigraphy. Images are acquired by detecting the photons within ±10 % energy window centered on the 159 keV photopeak. The radioactivity contains a considerable scatter fraction due to high energy gamma-rays with 529 keV (1.047 %) and others emitted from I-123. Scattering and penetration of these high energy photons thrausk the lead the collimator are the prime cause of deteriorating image quality. The aim of this study is to evaluate validity of a Monte Carlo code for estimating the fraction of scattered photons for various types of collimators on I-123 MIBG myocardial study. Materials and Methods: Calculations were carried out using a Monte Carlo simulator which consists of the HEXAGON code modelled the collimator and the NAI code modelled the NaI detector system including the back-compartment. The code provides the energy spectrum for every pixel identifying the unscattered, the scattered and the penetrated photons. The simulated image was formed using these energy spectra. The phantom used in the measurement was made from the breast-shaped sheets of paper soaked with the I-123 solution. The organs such as chest wall, left-and right-lungs and heart, were simulated by the overlapped sheets having the different activity densities, respectively. The Mix-DP plastic was used as the scattering medium. Experimental data were acquired using the PRISM IRIX (Philips) gamma-camera attached with various collimators such as the LEGAP, the LEHR and the MEGAP. Comparisons of the energy spectrum, the count profile and the planar image between the measurement and the simulation were made under the conditions with and without the scattering medium. Results: The simulated count profiles along a line agreed well with the measurements. The simulated and the experimental planar images were compared with each other using the method of power spectrum analysis. The characteristics of the images obtained on the frequency domain and the subtracted images agreed between the simulation and the measurement. Conclusion: Monte Carlo simulation of the scintillation camera system using I-123 enabled to reproduce the experimental images with a high accuracy. The present study is useful for the improvement of the quantitative evaluation on I-123 myocardial imaging.

Effect of administered dose level on image quality of brain perfusion imaging with 99m Tc-HMPAO: a quantitative analysis A. P. Stefanoyiannis, X. Geronikola-Trapali, I. Armeniakos, S. N. Chatziioannou, A. Prentakis, E. Efstathopoulos, A. Gouliamos; Second Department of Radiology, Nuclear Medicine Division, School of Medicine, University of Athens, Athens, GREECE.

Aim: Brain perfusion imaging by means of 99m Tc-labeled hexamethyl propylene amine oxime (HMPAO) is a well-established diagnostic procedure. The administered dose range recommended by the supplying company and reported in bibliography is rather wide (approximately 9.5-27 mCi). In this study, a quantitative evaluation of the radiopharmaceutical performance for different values of administered dose (10, 15, 20 mCi) was carried out, based on computer-generated indicators of image quality. Subsequently, a generic image quality index was correlated with the administered dose, to produce an overall performance indicator. By means of this analysis, the necessity of higher dose administration was examined, taking into consideration patient absorbed dose. Materials & methods: A sample of 78 patients (56 administered with 10 mCi, 10 with 15 mCi and 12 with 20 mCi) was utilised. Some patients were classified as normal, while others presented various forms of pathology. Evaluation of image quality was based on contrast, noise and contrast-to-noise ratio indicators, denoted CI, NI and CNR respectively. Calculation of all indicators was based on wavelet transform. An overall performance indicator (denoted PI), produced by the ratio of CNR by administered dose, was also calculated. Results: The results of quantitative evaluation are presented in table 1, where the % differences of estimated indicators for 15 mCi and 20 mCi subsamples versus the control subsample of 10 mCi are reported. Calculation of skewness parameter revealed the normality of CI, NI and non-normality of CNR, PI populations. Application of appropriate statistical tests (analysis of variance for normal and Kruskal-Wallis test for non-normal populations) showed that there is a statistically significant difference in CI (p<0.01), NI (p<0.001) and CNR (p<0.05), but not for PI (p>0.05) values. Application of Tukey test for normal populations CI, NI led to the conclusion that CI(10 mCi) = CI(20 mCi)<CI(15(mCi) and NI(10 mCi)>NI(20 mCi), while NI(15 mCi) can not be characterised. Finally, application of non-parametric multiple comparisons showed that CNR(20 mCi)>CNR(10 mCi), while CNR(15 mCi) can not be characterised. The Discovery STe is a dedicated brain and whole body PET scanner, with design features that enable high image spatial resolution combined with high sensitivity. The scanner combines eight multislice helical CT scanner with a PET tomography which consists of 13440 BGO crystals arranged in 24 rings. The crystal sizes are 4.7×6.3×30 mm 3 in the axial, transaxial, and radial dimensions, respectively. The PET detector ring diameter is 88.6 cm with axial and transaxial fields of view (FOVs) of 15.7 and 70 cm, respectively. The CT scanner is a 8-slice lightspeed. This study evaluated the NEMA2001 performance of the scanner. Performance measurements of spatial resolution, sensitivity, image quality, scatter fraction and counting rate performance for 2D and 3D were made using the NEMA2001 procedures. The low energy thresholds of 2-dimensional and 3-dimensional are set to 375 and 425 keV, respectively, and the both high energy is 650 keV. The coincidence time window of 2D and 3D are set to 11.05 ns and 9.75 ns, respectively. In addition, images from the 3D Hoffman brain phantom acquired in 3D modes is shown to demonstrate the image quality obtained from the scanner. The average transaxial (axial) FWHM resolution measured 4.9 (5.0) at R =1 cm and 5.6 (5.7) at R=10. The system sensitivity in the center for 2D and 3D was measured as 1.9 kcps/MBq and 9.9 kcps/MBq, respectively. The scatter fraction was 18.0% and 34.2% in 2D and 3D. The peak noise equivalent count rate (NECR) was 92.97 kcps at 64 kBq/ml in 2D and 86.56 kcps at 18 kBq/ml in 3D for a noise-free estimation of randoms. The contrast of the 22, 17, 13 and 10 mm hot spheres in the image quality phantom in 2D (3D) were 62.2% (77.4%), 50.6%(64.8%), 39.4% (55.2%) and 18.2% (42.1%), respectively. The results show good system resolution and sensitivity in both 2D and 3D, making this scanner highly suitable for brain and whole body studies. The choice of two-dimensional (2D) compared with three-dimensional (3D) imaging and the effect of reducing the scan time duration in BGO based Positron Emission Tomography Computed Tomography (PET CT) scanners remains a matter of discussion. In our study of 21 patients with known or suspected head and neck cancer (24 lesions total) we used a 2D and 3D acquisition protocol utilising 4min, 3min and 2min scan time durations on an axial single-field-of-view (SFOV). The scan sequence was 2D 4min, 3D 4min, 3D 3min, 2D 3min, 2D 2min and 3D 2min to minimise redistribution and decay bias in results. Semi-quantitative analysis was achieved by drawing regions-of-interest (ROI) around each tumour maximum FDG uptake (SUVmax) and associated uniform background mean uptake (B) in all scans to calculate SUVmax, lesion signal / background ratio (i.e. SUVmax/B) and image noise as the % coefficient of variation in the background (i.e. %CV in B). For SUVmax in all paired scans 2D > 3D at 4min, 3min and 2min; differences were highly statistically significant (P<0.0001) with mean % differences of approximately 21, 23, and 23 respectively favouring 2D. Lesion signal / background ratio differences between paired 2D and 3D scans were highly statistically significant at 4min, 3min and 2min (P<0.0001) with mean % differences of approximately 18, 19, and 16 respectively favouring 2D. Noise differences between paired 2D and 3D scans were statistically significant at 4min, 3min and 2min (P<0.004; P<0.01, P<0.007 respectively) with mean % differences of approximately 18, 16 and 18 respectively favouring 3D. All lesions were seen irrespective of acquisition mode or scan time duration. We conclude that scan time durations of 3min may be implemented in 2D without significant loss of semi-quantitative information when applying our acquisition protocols and reconstruction algorithms in head and neck cancer patients on a BGO based PET CT scanner. Aims: Modern PETCT systems have detector configurations and reconstruction algorithms optimised for maximising patient throughput for whole-body FDG oncology studies. The aim of this observer study is to determine the optimum scanning time for such studies and to assess how BMI can affect this time. To understand more about perceived image quality, the relationship between image quality and image noise is also assessed. Material and Methods: Twenty-five randomly selected patient studies were acquired in 2D mode on a GE DST PETCT scanner using list mode acquisitions, to allow the reframing of studies into imaging times of two, three, and four minutes per bed position. Data was then randomised and presented to three observers in three sessions. In each session three datasets of variable quality were presented as a training set before the observer was asked to rate image quality of the 25 study patients using a five-point scale. Image noise was also characterised at several locations throughout each dataset. Results: Reduced imaging time led to lower image quality scores, with paired comparisons showing the largest difference in scores (Mean:0.64 95%CI:0.47 -0.81) between 3 and 2 minutes per bed position. Using our imaging protocol, 4 minutes per bed position is necessary for an adequate (score > 3) scan in the majority of studies (18/25). The relationship between score and BMI for each scanning time is shown in Table 1 . For BMI's less than 25, 3 minutes per bed position were adequate in (11/13) studies. For (4/5) studies with BMI > 30 a scan time greater than 4 minutes was required. Image noise also decreased with imaging time in similar manner to image quality, and there was also a significant association between image noise and image quality (p < 0.05). However, no significant difference in noise was seen between adequate and inadequate scans, and no significant association was found between noise and BMI. Conclusions: Using our modern PETCT system and protocol, 4 minutes per bed position is adequate for most patients, although scanning time should be extended for obese patients, and could be reduced for those not overweight. Furthermore our data shows a strong relationship between image quality and image noise. and 37 mm) and by a torso background (fillable compartments), whose volume is equal to 9700 ml, was used. The tank and the spheres were filled with a set of known 18 F-FDG concentrations in multiple experiments. In every setup, the six spheres were filled with equal concentrations of 18 F-FDG in a fixed standard background concentration of 0.138 μCi/ml, simulating clinical situation. Background activity concentration was calculated from the analysis of 100 FDG-PET studies. The experiments was repeated 15 times; in each measurement the contrast of the spheres was 20% inferior in comparison to the previous one; we obtained contrast value ranging from about 2000% to 40%. The emission scans were performed in 2D mode, acquiring a single bed centred upon the spheres. The transmission scans were performed in spiral mode, 120 kV, 80 mA, slice thickness 3.75 mm, pitch 1.5. A 2D iterative algorithm (OSEM, 30 subsets, 2 iterations) was used for image reconstructions. A GE Xeleris workstation and an Advantage Windows workstation were employed for image analysis. For each measurement, contrast was estimated as a function of the diameter of the spheres. A contrast-detail curve was obtained, and contrast-detail threshold was estimated. To estimate volume of small lesions, we used a threshold at 40% of the maximum voxel intensity value of the lesion. Results Lesion nominal contrast is well correlated with lesion measured contrast (R 2 = 0.999). The TCDD (Threshold Contrast Detail Detectability) for the 10 mm diameter sphere is about 350%, for 13 mm diameter sphere is about 250%, for the 17 mm diameter sphere is about 100%, for the 22 mm diameter sphere is about 70%, for the 28 mm diameter sphere is about 40%. ConclusionsWe investigated the performances of our PET/CT scanner used in 2D modality for lesion detectability. Next step will be the investigation of the effect of acquisition and reconstruction on lesion detectability. PET has a reputation in the quantification of brain perfusion and metabolism. Recent advance of PET/CT brought a new era in oncology PET. Most of newly shipped PET instruments are PET/CT scanners, all of which are designed to use mainly in 3D mode and CT based attenuation correction. Although 3D acquisition and CT attenuation correction have many advantages, there are remaining problems in terms of quantitative accuracy. In this paper, we focus on the effect of direct photons from radioactivity outside the FOV, and the accuracy of CT based attenuation correction. The lack of interplane septa of 3D scanner results in an increase of random events of direct photons from outside the FOV. It may badly affect the accuracy of image. In particular, oxygen-15 gas inhalation study for brain, high radioactivity outside the FOV exists throughout the scan. We performed an O-15 CO2 gas inhalation PET scan in a healthy subject using 3D-LSO PET/CT, under the steady state condition. Thanks to the LSO detector, better quality images were obtained than expected prior to the scan. However, random events were 50 % of true events. A high fraction of random must be derived from activity outside FOV, especially from lung. In an experiment with external activities placing 15 cm apart from a phantom, image deterioration was observed with increase of the external radioactivity. To estimate the accuracy of CT based attenuation correction, we performed an experiment with high attenuation objects. A phantom with multiple rod inserts was used. Six inserts were filled with same amount of radioactivity, and 5 of the 6 were also filled with contrast material of different density. With the increase of density, measured events tend to increase, even the same activities exists. It might affect the quantitative accuracy in the region with high attenuation. Our goal is to establish a method to obtain highly quantitative brain PET images, using 3D PET/CT designed mainly for whole body scan. Aim: Contrast-to noise ratio (CNR), was studied as a function of emission scan duration (ESD) and activity at the start of acquisition (A acq ) for different target sizes and target-to-background (T/B) ratios using a multivariate approach in a wide range of conditions approaching the ones that can be encountered in the clinical practice, using a 3D-LSO based PET/CT scanner. Material and Methods: An annular ring of water bags of 3 cm thickness was fitted over an IEC phantom in order to obtain counting rates similar to those found in average patients. A supplemental set of micro-hollow spheres was positioned inside the phantom. The phantom was filled with a solution of water and 18 F (12 kBq/mL) and the spheres with various T/B ratios of 22.5, 10.3 and 3.6. Sequential imaging was performed to acquire PET images with varying background concentrations of about 12, 9, 6.4, 5.3 and 3.1 kBq/mL. The ESD was set to 1, 2, 3, and 4 min/bed. Lesion detectability was visually and quantitatively assessed. Results: With T/B ratios of 3.6, 10.3 and 22.5 the 13.0, 8.1 and 6.5 mm spheres were detectable for the whole ranges of background activity concentration and ESD, respectively. The regression equation that best summarizes the results obtained in a multiple regression model with CNR as predicted variable and T/B ratio, activity at the start of acquisition (A acq ), sphere area and ESD as predictor variables may be written as: CNR=-20.1+ 17.5x(1-1/T/B)+0.25 x(Aacq) 1/2 +0.0082 x sphere A +0.56 x (ESD) 1/2 The multiple R 2 of model fitting equals 0.71. All of the variables were statistically significant predictors of CNR, whose variance can be accounted for, in order of increasing weight, by ESD ( 4 = 0.60), T/B ratio ( 1 = 0.59), sphere A ( 3 = 0.37) and A acq ( 1 = 0.27). Conclusion: CNR depends only slightly on A acq : the weight of A acq in explaining CNR is more than halved with respect to the contribution of ESD. CNR values exhibited an essentially flat response for A acq in the wide range explored . (from 92.3 to 370.5 MBq). As CNR is closely related to lesion detection, this finding suggests that also lesion detectability might not strongly depend on the injected activity, in this range. If confirmed by further studies on lesion detectability on anthropomorphic phantoms, these findings would suggest using lower 18 FDG activities, which could be a gain both from a radiation protection and economical point of view. Aim: the respiratory gating system Varian RPM (real-time position management) was implemented on a GE Discovery STE PET-CT scanner to reduce artifacts and drawbacks due to breathing. Analyses of a moving phantom and patient acquisitions were performed to estimate the potential benefit of such a system in clinical practice. Material and Methods: a phantom containing 5 spheres of different size (volume ranging from 0.5 to 8 ml, filled with 18 F, lesion-to-background ratio of about 4:1) was acquired with a GE Discovery STE PET-CT coupled to a Varian RPM system. Breathing motion was simulated with the Standard Imaging gating respiratory platform (period 4 s, amplitude 20 mm). Two series of PET-CT acquisitions were performed: i) without taking into account the motion tracking (non-gated mode) ii) by dividing the breathing period in 6 bins and reconstructing PET-CT images for each bin (gated mode). Then 6 patients showing uptaking lesions in lungs or liver were acquired. The maximum of the weight body standard uptake value (SUV BW MAX ) was compared for gated and non-gated acquisitions for 13 lesions. The motion amplitude of each lesion was evaluated. Results: in the phantom trial the images acquired in gated mode showed better recovery coefficients: for the 4 smallest spheres the enhancement ranges from 93% to 160%. For the largest one the relative increase is 37%. In patient acquistions in gated mode 6 lesions showed an increase less than 10% in SUV BW MAX or a small decrease, 7 an increase from 11% to 99%. 6 lesions had motion amplitude less than 4 mm, showing an average enhancement of SUV BW MAX in gated mode of 10%. 7 lesions with motion amplitude higher than 4 mm (up to 16 mm) showed an average increase in SUV BW MAX of 27%. Conclusions: when a periodic movement due to breathing is present in PET-CT exams, the Varian RPM system provides a general improvement in the image quality, reduced motion artifacts in CT, higher SUV in PET, more precise match of CT and PET, more accurate volume delineation for radiotherapeutic purposes. A high variability in the advantages of a gated acquisition was observed, depending on lesion features such as the motion amplitude. Aim: F-18-DOPA PET is a well-established method to image dopamine transporter system in human brain. In PET/CT scanners, AC is performed with a CT-based method (CT-AC) as compared to Ge-68/Ga-68 source transmission scan (S-AC) of PET only scanners. The influence of CT-AC on the determination of the influx constant (Ki) to measure dopamine transporter expression is unknown. Methods: Ten volunteers and Parkinson disease patients (55±15y) underwent a 38-frame 120-min or 25-frame 96-min acquisition after the injection of 120MBq of F-18-FDOPA, performed after AC acquisitions (CT-AC: 140keV, 80mA; S-AC: 10-min transmission scan; Discovery LS, GE). Striatal and occipital ROIs were drawn and time-activity curves (TAC) were generated summing the 5 central slices encompassing the striatum. Ki was computed using the occipital cortex TAC as input function. Differences in striatal and occipital TAC were characterized, and differences in Ki derived using voxel-based kinetic analysis (PMOD software). Comparisons were performed with Pearson's correlation and Bland-Altman plots. Results: Absolute differences in striatal and occipital TAC between CT-AC and S-AC were <0.3kBq/mL (7%) in all studies (mean -0.01±0.16kBq/mL [-1±4%]). Absolute difference in Ki was <0.7E-3/min (7.7%) in any striatal voxel (mean -0.03E-3±0.3E-3/min [0.2±3.6%]). Correlation of Ki between both AC methods was excellent (y=0.9990 x+0.0, r=0.9947, p<0.0001) without systematic error (p>0.8). All measurement pairs were within Bland-Altman's reference range (-1E-3 to +1E-3/min). The largest variations were observed around the skull's outline and at the interface between air and bone, in relation to differences in AC maps resolution or minor patient motion (n=1). Conclusion: CT-based AC introduces a difference <7% in TAC and <8% in voxel-based striatal Ki estimates as compared to source AC. Average differences of 1±4%, an excellent correlation between AC methods and absence of systematic differences allows using both AC method or norms interchangeably when comparing patient groups. However, in follow-up studies aiming at assessing individual disease progression or response to treatment, the same AC method should be used to avoid introducing additional variability.

V. Schulz 1 , J. Zeintl 1 , A. Szikszai 1 , J. Hornegger 2 , T. Kuwert 1 ; 1 Clinic of Nuclear Medicine, University of Erlangen/Nürnberg, Erlangen, GERMANY, 2 Chair of Pattern Recognition, University of Erlangen/Nürnberg, Erlangen, GERMANY.

Aim: This study investigates the influence of CT-based attenuation correction on the quantification of uptake of I-131. Methods: Data sets acquired using a hybrid SPECT/ spiral-CT system (Symbia T2, Siemens, Hoffman Estates, IL) in 48 patients with thyroid cancer were retrospectively analyzed. The whole group of patients was divided into a subgroup exhibiting I-131 uptake in the thyroid bed (n = 25; TG) and another one with foci located elsewhere (n = 23; NTG). Using regions of interest (ROIs), ratios were determined between the counts in the focus and those determined in the whole transversal slice. ROI measurements were performed in uncorrected tomograms (NAC) as well as in images corrected for attenuation using the registered CT images (AC). The minimal distance of the focus to the surface of the body (DIST) was correlated to the ratio between the values determined for AC and NAC (AC/NAC ratio). Furthermore, the ROI measurements were also performed in AC scans in which SPECT and CT images had been misaligned by 1 cm in one dimension beforehand (ACX, ACY, ACZ). Results: The mean differences of I-131 uptake ratios between AC and NAC were 9.04 % in TG and 21.43 % in NTG. Both differences were, however, not significant due to their large standard deviations (p > 0.05). No significant correlation could be found between DIST and the AC/NAC ratio. AC using misaligned pairs of patient data sets led to a significant change of whole-slice uptake ratios for ACX and ACY in TG and for ACZ in NTG, the differences ranging between 2.90 to 21.39 % (p < 0.05). Conclusions: AC did not affect I-131 uptake ratios significantly in our study, probably due to the fairly high energy of I-131 or also heterogeneities of the investigated group of patients with regard to the location of the foci of I-131 uptake. In I-131-SPECT scans, CT-based attenuation correction should be performed with particular attention to artefacts caused by misalignment between SPECT and CT. Objective: In nuclear oncology, Ga-67 SPECT studies can still play a useful clinical role. Recently, hybrid SPECT/CT system provided nonuniform attenuation correction with the spatial distribution of attenuation coefficients using a CT data. The purpose of this study was to verify the effects of nonuniform attenuation correction on the hot spot lesion detectability in thoracic SPECT images with Ga-67. Methods: We evaluated 20 hot spot lesions from 14 patients with Ga-67 thoracic SPECT. Using our combined SPECT/CT system (Millennium VG, GE), all patients underwent Ga-67 SPECT and CT examinations. SPECT images were reconstructed with and without nonuniform attenuation correction. To assess the impact of attenuation correction, we compared the values of legion to normal tissue contrast. Furthermore, we performed simulation study with numeric digital phantom consisted of lung and soft tissue attenuation coefficients. The phantom imitated a human thorax, in which several lung hot lesions were located in the lung field with homogeneous activity. After generating projection data from the phantom with taking attenuation into account, reconstruction was performed with and without attenuation correction. As with patients study, we compared the values of legion to normal tissue contrast. This simulation study was calculated using the software "Prominence Processor" developed by Maeda. Results: In the patients study, the average values of contrast increased from 3.41 to 6.43 with nonuniform attenuation correction. The contrast of hot spot lesions was also improved by nonuniform attenuation correction in the simulation study. On the other hand, without attenuation correction, legion to lung contrast was decreased significantly depending on the background activity in the lung. Conclusion: Nonuniform attenuation correction using SPECT/CT improves the lesion contrast in Ga-67 thoracic SPECT imaging. (3), control study in MEN II (1) and primary pheochromocytoma (16). The scintigraphic result was correlated with those obtained in morphologic imaging techniques and follow up during a mean time of 17 months. Results: In 17 patients the scintigraphy was negative: in 9 of them the planar study was doubtful and SPECT-CT was negative and in 8 cases both of them were negative, showing the absence of uptake in the radiological lesions visualized in 6 of them (size of lesion < 20 mm). The scintigraphy was positive in 6 cases: 3 were positive in the planar imaging (in one of them, SPECT-CT localized higher number of metastases) and 3 were doubtful, contributing the SPECT-CT to the confirmation of pathological functionality and its location. The positivity of the 123I-MIBG scintigraphy confirmed the clinical diagnosis of pheochromocytoma and the consequent indication of surgical treatment in all cases (6), except in one with diseminated disease. The diagnosis in the negative cases was essential hypertension or non-hipersecretory lesions. The performance of the SPECT-CT represented an increase of the specificity (100% vs 48% for planar imaging). Conclusion: In 52 % (12/23) of cases the SPECT-CT helped to establish the final scintigraphic diagnosis contributing to a better diagnostic and therapeutic management accuracy. Aim Audit new low dose CT protocols used for localisation imaging on the Philips Precedence SPECT/CT system. Method 3 low dose protocols for localisation CT (L-CT) have been created. All are helical with identical pitch and use the Doseright-DOM auto mA feature: • L-CT Abdo: A body protocol for viewing conventional axial CT images (50mAs, 120kV, collimation 16x1.5, slice width 3mm, rotation time 0.5s, CTDI v 3.5mGy). • L-CT Abdo MPR: A modified version of L-CT Abdo with thinner reconstructed slices (collimation 16x0.75, slice 1.5mm) making it more suitable for multi planar reconstruction (MPR). The mAs was doubled (100mAs, CTDI v 7.8mGy) to maintain the same noise level. • L-CT Neck: A protocol for scanning the neck using the head filter (100mAs, 120kV, collimation 16x0.75, slice width 2mm, rotation time 0.5s, CTDI v 15.2mGy). Over 4 months, a range of SPECT/CT scans were performed of the body, neck or feet. An audit questionnaire was designed and completed by the reporting Consultant Radiologist to find out how L-CTs were viewed, the amount of detail required in the image, an acceptable level of noise and if the overall image quality was acceptable. Results 81 SPECT/CT scans were included in the audit, 4 using L-CT Abdo (mean DLP 228mGy.cm), 72 using L-CT Abdo MPR (mean DLP 227mGy.cm) and 5 using L-CT Neck (mean DLP 508mGy.cm). 63 scans were viewed in MPR mode, including 2 of the L-CT Abdo scans. Image detail of <1mm, 1-2mm and 2-5mm were required in 1 (1%), 65 (80%) and 15 scans (19%) respectively. 11 (14%) L-CTs were considered to have poor image quality, of which 6 were due to patient related artefacts. The other 5 unacceptable scans were of feet. 18 feet L-CTs were audited, 13 were considered acceptable but comments were made on 4 of these indicating that a higher resolution CT would have been preferred. Conclusion Despite the subjective nature of these results, we now have an insight into some of the imaging requirements of L-CT. The majority of viewing and reporting was done in MPR mode requiring the thinner slices of the L-CT Abdo MPR protocol. The low dose L-CT protocols are acceptable for most of our scans, except feet, where high resolution is critical (and more important than low noise). A new anthropomorphic phantom will be used to further develop these protocols and create new ones tailored to specific exam types. The audit will then be repeated.

Morphological Image Processing For Automatic Arm Removal In SPECT-CT Images.

Objectives: Image fusion of longitudinal SPECT-CT and CT to CT studies is frequently required to detect significant changes with time. But accurate image registration is hampered by the presence of the patients arms in the field of view which may take radically different positions or even not be present in some imaging sessions. The objective of this study is to investigate the feasibility of automatic arm detection and removal even in the difficult case when the arms are touching the body. Methods: The process of arm detection and removal consists of A: an automatic thresholding step is applied to each CT section to segment the data into foreground with value 1 representing the thorax , abdomen and arms if distinct from the body and background with value zero. B:Holes frequently occur within the thorax and abdomen from air , gas etc, to remove these areas the morphological image operation of opening using structured elements is applied to smooth out the resulting sections. C:Connected components are identified within each section and from the number and respective sizes of the detected regions the arms may be automatically detected and removed when distinct from the abdomen. D: Should the number of regions detected not reflect the presence of the arms then the morphological operation of watershed segmentation is applied . This operation automatically separates or cuts apart objects that touch. It starts with our segmented binary image and calculates a distance map to find the fattest parts of the object, the peaks or local maxima of the distance map. Purpose: The aim of this study was to control the inflammatory process and evaluate the volume of the inflamed synovium of the knee during the radiation synovectomy (RS) treatment of chronic synovitis. Gadolinium-DTPA contrast-enhanced T 1weighted images are useful in identification of pannus tissue, which can be seen as areas of increased signal intensity adjacent to low signal intensity of joint fluid. The fusion of 166 Ho-FHMA (Holmium Ferric Hydroxide Macroaggregates) SPET images and MRI images is often inaccurate. To avoid this problem, we aimed this volume procedure to facilitate fusion of MRI and SPET images. Methods and material: The patients with rheumatoid arthritis were treated with 166 Ho-FHMA. The SPET images were taken after 24 hours of RS. The MRI images were taken three times. The first MRI imaged before RS and study was used as a reference to the later imaged MRI studies. The second MRI was taken after one week and third MRI after three months after RS. All MRI control images are taken in the same manner. The images are processed with region growing method to separate inflamed synovium of the knee. The region of interests (ROIs) masked in every slices of the study. All ROIs were checked by two independent radiologists. The volume calculation was confirmed by the 20 ml filled syringe in the same manner like patient studies. Volume evaluation was possible and accurate with this procedure. Result: This volume evaluation procedure shows clearly the effect of the therapy. Comparing these volumes of the same patient we can see how inflamed synovium volume decreases. Also the changes of the joint fluid volume can be evaluated. Decreasing of the relative synovium volume after one week of RS and after three months of RS was average 24,6 % / 37,9%. Conclusion: MRI is an accurate procedure to estimate the volume of acute synovitis. The volume quantification of the inflamed pannus and synovial fluid was made possible by this procedure and the effect of the therapy is accurately determined. The volume evaluation of the treated knee with ROIs make possible to increase accuracy of SPET and MRI image fusion. Objectives: Reconstruction of PET images from projections is a problem which from a clinical perspective seems like a chapter completed in the mid eighties; in particularly replacing already established algorithms like FBP and OSEM are not easily accepted. This is well justified by lack of stability of the new algorithms, the often edgy looks of the resulting images, and in general by too complex ways of obtaining the results. Methods: For obtaining quantitatively correct results for use in S342 multi-subject region-of-interest(ROI) studies, it is also well known how crucial correct delineation of the ROI's for the individual subjects are, making it possible to compare binding potentials for specific ROI's between subjects. When delineating the ROI's, it is essential not to include tissue outside the respective region while at the same time, it is beneficial to include as much tissue as possible to lower the noise in data. This leads to the well known trade-off between bias and variance, where the size of the region is the parameter that can be optimized. Results: For a number of simulated tracer distributions, we demonstrate the effect that resizing the regions have on the mean activity within a region. Segmented MR images are used for simulating the tracer a possible tracer distribution in the brain and the mean activity in the insula and putamen are set to known values. Knowing the true mean activity, we visualize how a scaling of the regions minimizes the error on the mean activity. It is further shown how this scaling depends on the algorithm used for reconstruction and any filtering applied to the reconstructed images. Among the reconstruction algorithms, we show how an edge-preserving algorithm allows us to defining larger regions in the sense that the size that minimizes bias+variance is closer to the size of the anatomical region. Conclusion: For our simulations, we conclude that for obtaining quantitatively correct measures for the mean activities in the regions, we should define our regions smaller than the regions derived from the anatomical information and for a typical case, we can reduce our bias by half by choosing either penalized least squares or an edgepreserving algorithm instead of FBP. The PET-FDG dynamic acquisitions are usually used with compartmental methods which suppose a modeling stage. These techniques are not widely used in clinical routines because of their complexity. We propose a simple and direct non invasive approach without modeling stage. The aim of this work is the definition of the cerebral physiological kinetic curves activity of FDG since its injection. Material and Methods: 14 control subjects without cerebral diseases are evaluated for this study. All acquisitions are made on a Biograph TM 6 PET/CT (Siemens Medical Solutions) with 45 minutes total acquisition duration; an intravenous bolus of 18 F-FDG is done during acquisition. To determine the beginning of the volume reconstructions, the arrival time of the tracer in the brain is evaluated using List-Mode files. The number and duration of the 34 reconstructed volumes (AW-OSEM) are respectively: 7x5 seconds; 7x10 seconds; 7x30 seconds; 7x60 seconds; 5x300 seconds; 1x465 seconds. In-house IDL software (ITT Industries Inc.) was developed to construct and analyze the FDG time activity curves of grey and white matter, arteries and veins. Regions of interest (ROIs) for cerebral regions (8 ROIs for each matter and 6 ROIs for each vascular region) are drawn on the CT volume and then reported on PET volumes. Normalization of the 4 curves of each subject is done either by using the accumulated true events during each interval of reconstruction or by using the accumulated activity of FDG in the venous region. The standard deviations (STD) are calculated at each temporal sample of the "characteristic cerebral curves" (CCC) that we define as the mean subjects' curves. Results: Vascular FDG curves are constructed with good temporal sampling of the few seconds after the injection showing the FDG bolus arrival at early stage. The dispersion of the CCC is evaluated for normalized and unnormalized subjects' curves at late stage (between 105 seconds and 45 minutes). The maximum STD to mean ratio of the grey matter is 0.39 for unnormalized curves, 0.22 for the true events based normalization and 0.17 for venous based normalization; for white matter the values are respectively 0.35, 0.23 and 0.22. Conclusion: We have defined a direct approach describing the physiological normalized curves of FDG kinetics in the cerebral regions with good temporal sampling and low dispersion. This allows the definition of key parameters of the curves. The comparison of CCC with pathological cerebral curves could be done in diseases as Alzheimer.

The use of normal brain SPECT databases that are not age-matched to the subject(s) under investigation: a feasibility study L. Barnden; The Queen Elizabeth Hospital, Adelaide, AUSTRALIA.

Voxel-based statistical analysis of brain SPECT with the SPM package offers adjustment for nuisance effects that may produce false positive results or introduce regional nuisance variance that degrades the sensitivity for detecting effects of interest. For each voxel, the software essentially performs a linear regression of the nuisance parameter versus counts and removes (adjusts out) any effect before reporting results for the effect of interest. This 'analysis of covariance' can be used to adjust for age effects provided the ages of each subject are input to SPM and, in principle, should permit use of non age-matched normal databases. This approach was assessed by dividing a 90 subject normal database into four age groups 18-29 (20 subjects), 30-44 (27) , 45-59 (28) and 60-81 (15) and running SPM to detect significant regional differences between the 60-81 age group and each of the three other age groups with and without adjustment for age. Without adjustment for age, significant regional differences were detected for all three age groups with spatial distributions that resembled the ageing effects for the whole database. After adjustment for age, there was no significant difference between the elderly and any of the other three subgroups except for one location for the 60-81 to 18-29 comparison. The Coefficient of Variation in gray matter suggested that using the youngest group of normals may confer a slight statistical advantage. This work demonstrates that, provided extreme age differences are avoided, it is acceptable to use a normal database that is not agematched to the patient(s) under investigation. Introduction During the last years, SISCOM (Substracted Ictal Spect COregistred to MRI) analysis of multimodality images realised in the assessment of medically refractory partial epilepsy has been widely used. However, other methods can be explored like fractal analysis. Indeed, this mathematical tool is known for its ability to characterize heterogeneities into a structure. The aim of this work was to present the preliminary results of an application based of this tool for the characterization of observable anomalies in ictal and inter ictal SPECT. Methods We have developed an algorithm to evaluate the 3D fractal dimension (FD) of 3D images of SPECT. The FD is estimated by a differential box-counting approach which consists in iteratively subdividing the image on boxes with increasing size and to evaluate the DF as the slope of the regression line binding sizes of the boxes and the mean of maximum deviations of gray levels in each box. As a first assessment of the algorithm, we used simulated data with a well defined FD. Then we tested the algorithm on a database containing 21 patients with ictal and interictal exams and a control group of 60 volunteers distributed by age: 30 between 20 and 39 years, 17 between 40 to 59 and 13 more than 60. Finally, as application we used the method on an imagebase of 10 patients with partial epilepsy. Tc-99m HMPAO brain perfusion ictal and interictal images were acquired on a brain dedidated system: the Tomomatic 564 (Medimatic). The procedure was to subdivide the images into subimages and to compare the FD of the paired subimages of ictal and interictal. Results For the comparison of healthy groups and pathologic group, we found a significant difference (Mann-Whitney test, p<0.05) whereas no difference was observed between the different healthy groups. As for the final application, we found a significant difference between the subimage where hyper-fixation focus were detected. Conclusion In consideration with these promising preliminary results, we are working on a method to perform a multidimensional fractal analysis (multifractal) of the images. This method will lead us to fine characterization of local heterogeneities and thus a better localisation of epileptic focus. Nevertheless, routine application of ML techniques to large scale biomedical data set is still a relatively new occurrence. Otherwise, complex configuration and datapreprocess is an obstacle for physicians. This study proposes an innovative and userfriendly machine learning software for large-scale molecular and clinical data.

We choose the Excel file with customized header as the data standard. We use support vector machine (SVM) as our machine learning algorithm in the platform. SVMs are a set of related supervised learning methods used for classification and regression. For handling large-scaled molecular data, some feature selections methods like Recursive Feature Elimination are introduced in the system. The platform is a module of the PMod software (PMOD Technologies Ltd., Adlisvil, Switzerland). Results: On the machine learning platform, we developed some applications and did some researches related to molecular and clinical data. Some examples are illustrated as follows: (1) We developed a machine learning based tool for parameter imaging and kinetic modeling of dynamic PET study. We collected 227 studies of kinetic modeling as training samples and built different regression models for different PET parameters. Using the models, we can predict the quantitative PET parameters of VOIs or pixels according to the TAC. (2) Classification study for gene expression data. The study addresses the problem to find a small subset of genes which provides the best discrimination for a specified classification, for instance to discriminate between normal and tumor tissues. This subset can then potentially be used for genetic diagnosis, or for drug discovery. (3) We did a prediction study of short-term survival in patients with advanced non-small cell lung cancer following chemotherapy based on FDG-PET. The study demonstrates that a full kinetic analysis of the 18F-FDG kinetics is helpful for the classification into short or long survival and may helpful to identify those patients who may benefit from this palliative chemotherapeutic protocol. Conclusion: The new machine learning platform provided a very unique tool for the classification and regression analysis of molecular and clinical data. The studies on the platform show that it can be widely used in the medical and biological fields. Coronary artery disease (CAD) is one of the world's most premier causes of early mortality, so any improvement of diagnostic process is highly appreciated. In the clinical setting, CAD diagnostic is performed in a sequential manner. The four diagnostic levels consist of evaluation of (1) signs and symptoms and ECG at rest, (2) ECG testing during the controlled exercise, (3) stress myocardial perfusion scintigraphy, and (4) coronary angiography, which is considered as the reference method. In our study we focus on improving diagnostic performance of stress myocardial perfusion scintigraphy. This method bases on series of medical images. In clinical practice, these images are manually described (parameterized) and subsequently evaluated by expert physicians. We present an innovative alternative to manual image evaluation -an automatic image parametrization of multiple resolutions, based on texture description with specialized association rules, and image evaluation with machine learning methods. Our results show that multi-resolution image parameterizations equals the physicians in terms of quality of image parameters. However, by using both manual and automatic image description parameters at the same time, diagnostic performance can be significantly improved with respect to the results of clinical practice. Our experiments with ArTex image parameterization algorithm in conjunction with Bayesian machine learning (naive Bayesian classifier) produced highly significant results, improving diagnostic accuracy, specificity and sensitvity by more 8.7-13.3%. While these values contribute to more accurate clinical diagnostics, the improvement of sepecificity by almost 9% also suggests that 9% of negative patients (no CAD present) may be reliably diagnosed without resorting to coronary angiography. Background: Recently, it has been recommended that NHS clinical biochemistry laboratories routinely provide a measure of renal function, eGFR (estimated Glomerular Filtration Rate), based on the Modification of Diet in Renal Disease (MDRD) formula 1 which uses serum creatinine concentration, age, ethnic origin and gender. In our centre, a further modification is applied to the formula to account for the method of serum creatinine analysis. The aim of this study was to evaluate the accuracy of eGFR in our centre by comparing with the "gold standard" 51 Cr-EDTA GFR method. Method: We measure 51 Cr-EDTA GFR using a 2 sample technique following the recommendations in the British Nuclear Medicine Society guidelines. 112 patients were included in this retrospective study of which 44 were male and 68 were female, with mean age 60 years (range 24-87 years). Only patients who had 51 Cr-EDTA GFR measurements within two weeks of a reported eGFR were included. Where eGFR exceeds 90 ml/min/1.73m², it is reported as ">90" rather than an exact figure due to the decrease in accuracy with increasing GFR. Results: For the 112 patients, mean (± sd) measured GFR was 67.5 ± 25.6 ml/min/1.73m² and mean eGFR was 83.8 ± 32.2 ml/min/1.73m². The mean difference between measured GFR and eGFR was found to be 16.3 ml/min/1.73m². The correlation coefficient was 0.74 and a paired t-test showed there was a significant difference between the two methods (p<0.001). Limiting the analysis to patient's with eGFR<90 ml/min/1.73m² led to a similar correlation (0.7) and again significant differences were found using the paired t-test (p<0.001). For these 61 patients, mean measured GFR was 51.2 ± 18.3 ml/min/1.73m² and mean eGFR was 59.8 ± 18.7 ml/min/1.73m². The mean difference between measured GFR and eGFR was found to be 8.6 ml/min/1.73m². Conclusion:

In this preliminary study, absolute values of GFR and eGFR were found to be significantly different. In general, eGFR was found to overestimate compared with measured GFR. Our findings agree with previous work suggesting that eGFR becomes less accurate as GFR increases. However, eGFR may be a useful indicator of the intrapatient changes in GFR As QGS and ECTb behave differently and produce variable results from one another, they should not be used interchangeably. Introduction Estimation of reliable cardiac ejection fraction for oncology patients is of great importance in the therapy follow-up procedure. Aim The development of automatic processing algorithm for the determination of left ventricle and background regions. Methods Multiparametric method was applied for the LV ROI determination in every sequential image of the representative cycle. From amplitude, phase and temporary DC images of Fourier time analysis segmentation of both ventricle and atrium structures was performed in the phase histogram, the LV spatial structure was separated from the other heart components by the size condition and the local minimum counts in the DC component between LV and RV and LA. Backround region was computed from the definite number of pixels with minimum counts in the LV close vicinity. For quality control of segmentation the visual inspection during the analysis is provided for every frame and the manual LV delineation with manual or automatic background selection is used as an alternative method. Results Completely automatic computational algorithm is fast enough (less than 1 minute for 32 frames' study and 64x64 matrix) and gives highly comparable ejection fraction value to the standard 2 ROI method (r > 0.98; N=30) for well separated LV from RV and LV from LA studies. Visual inspection of the computation procedure is provided for the LV edge delineation by the cine display mode and the time sequence of parametric images for ejection and filling rates. Conclusions The new multiparametric pattern recognition method with the controlling visual tools was developed for the completely automatic processing of MUGA studies. For patient studies with careful positioning it can safely replaces the standard "manual" methods. Aim: To investigate the effect of crystal thickness on the spatial resolution of PET detectors which use artificial neural network (ANN) based positioning algorithms. Finding this relationship is important in determining the best trade-off between spatial resolution and sensitivity for the optimal design of a PET detector. Studies have been made to investigate this trade-off for the Anger based positioning algorithms but not for the ANN based algorithms. Materials and Methods: We took the approach of conducting Monte Carlo simulation studies due to the complex nature of this relationship. We chose parameter values for a continuous LSO based positron emission mammography (PEM) system. We used the BUILDER, GRIT and DETECT2000 software programs for the simulations. The detector consisted of a continuous LSO scintillation crystal with an area of 49x49 mm 2 and varying thickness levels of 3-30 mm. The Hamamatsu H8500 multi-anode (8x8) flat-panel PSPMT is assumed to be mounted on the crystal. Monoenergetic 511 keV photons have been sent perpendicular to the crystal surface. Training sets were constructed from simulated data on a 24x24 uniform grid with 1 mm for each interval with 100 photon incidences at each point for the first quadrant of the crystal. An energy threshold of 300 keV was set in order to reduce the influence of weak events, namely Compton scatters. Tests were performed on sets of simulated data on a 5x5 uniform grid with 6 mm for each interval taking 1000 photons at each point with the same energy discrimination. The inputs of the neural network, namely 64 PSPMT-anode outputs were reduced to four as x+, x-, y+ and y-, one from each corner of the resistor network. Results and Discussion: Initial results show that nonlinearity is considerably reduced and spatial resolution improved by the ANN method at different thickness values, thus rising also the question of whether the more expensive and less light efficient but more sensitive LSO should be prefered to NaI.

A Look-Up- Aim: The continuous crystal concept for PET offers a number of advantages such as low cost but suffers from edge effects, distortions and low spatial resolution when used with Anger logic. In particular, resolution degrades rapidly with increasing crystal thickness. In this study, we aimed to develop and evaluate a new positioning and depth of interaction algorithm to be used with a continuous crystal small organ PET system in order to overcome these deficiencies. Materials and Methods: The algorithm we present uses a lookup table, which is constructed by using the PMT outputs of scintillation events, simulated at each sample point of a three dimensional grid covering the entire crystal volume using the DETECT2000 Monte Carlo Simulation Package. Scintillation point estimation is done by matching the PMT outputs of an event with the data inside the lookup table. The Nearest Neighbor algorithm is used during matching. During the process, we apply a first threshold for each PMT output to eliminate low energy events and then a second threshold to the NN algorithm in order to remove probable Compton scatterings inside the crystal which reduce resolution. The performance of Anger logic and the new algorithms are compared over a limited region for a detector configuration consisting of 60x60x10 mm 3 continuous NaI crystal coupled to 16 square PMTs with dimensions 15x15 mm 2 each. The grid consists of 0.5 mm spaced points over the entire crystal volume. 511 keV rays are sent along a line perpendicular to the crystal face midway between the center and the edge of the crystal. Results: The anger logic results in resolution loss due to uncertain depth of interaction along any line perpendicular to the crystal face. We obtained an average resolution of 2.4 mm with the new algorithm as opposed to nearly 3 mm with the Anger logic. This reflects the reduction of the positional uncertainty caused by crystal thickness as well as the elimination of most Compton scattered rays. Furthermore, edge effects and nonlinearities are totally eliminated.

Simulation results show that the new algorithm implemented for a small organ PET can provide with acceptable performance in terms of resolution and distortion while offering a low cost alternative. This algorithm can also be used in the DOI determination.

Availability of a shielding system for brain studies in 3D thorax scan Aim To examine the potential availability of a shielding system for brain studies in 3D thorax scan using FDG. Material and Methods A PET scanner (GE Advance NXi), a shielding system for brain studies (IPL NeuroShield), a cylinder phantom ( 16cm × 15cm), IEC body and NEMA scatter phantoms were used in this study. The cylinder phantom was filled with 111MBq of 18F to simulate the brain. The background region of the body phantom was filled with an activity of 5.3kBq/mL. The four hot spheres were filled with an activity concentration of 4 times that of the background. The largest two spheres were filled with water only. The lung insert filled with foam pellets and water was placed in the center of the phantom. The line source of the scatter phantom was filled with 116MBq. Emission and transmission scans were performed in three conditions. In condition 1, the body and scatter phantoms were used according to the NEMA NU 2-2001 image quality measurement protocol. In condition 2, the cylinder phantom was used in addition to two phantoms used in condition 1 and placed on opposite side of the scatter phantom. In condition 3, the shielding system was used in addition to all phantoms and located between the cylinder and body phantoms. In every condition, emission data was acquired in 3D mode and for 20min, which was performed three times. Transmission scan time was 20min. After compensated by randoms correction, model-based scatter correction and segmented attenuation correction, the acquired data were reconstructed using FORE-2D iterative reconstruction with 1~10 iterations and 32 subsets. According to the NEMA protocol, the pixel values on each image were examined. Results With the % contrast and the accuracy of attenuation and scatter correction, there was not much difference among the results in three conditions. However, the % background variability for 10, 13, 17, 22, 28 and 37mm spheres in condition 2 were about 1.19, 1.20, 1.21, 1.22, 1.22 and 1.23 times those of condition 1, respectively. Those of condition 3 were about 0.96, 0.95, 0.93, 0.90, 0.88 and 0.87 times those of condition 2, respectively. These results show that the random events from the cylinder phantom were reduced by the shielding system. Conclusion In 3D thorax study with FDG, our preliminary results show that the shielding system is potentially useful to reduce the random events from Brain. Aim. To describe and quantitatively assess the influence of a malfunctioning block detector on reconstructed PET images for a full ring block designed scanner.

Methods. By using raw data acquired with fully calibrated and perfectly functioning ECAT HR+ PET scanner (CTI-Siemens) in 2D (span 15) and in 3D (span9) mode, one block detector with 100% loss of efficiency was simulated. The effect of defective block was studied with: -the 20 cm diameter 68 Ge uniform phantom scanned at high counting statistics and reconstructed with FBP ramp filter and AWOSEM 4i/16s (4 iterations, 16 subsets); -the anthropomorphic Alderson phantom filled with 18 F and acquired at clinical counting statistics and reconstructed with AWOSEM 2i/8s, as routinely used in WB-PET FDG studies, and 4i/16s. Defective block was simulated also on 2D transmission and blank scan data to separately study the effect on μ-maps.

Taking as reference the original images, defective images were evaluated qualitatively and quantitatively by assessing % difference of SUV ( SUV % .). Results. Defective block severely affects measured μ-map: overestimated coefficients can be generated along the correspondent fan angle. A considerable reduction of such artefacts can be obtained by segmenting transmissive data. Visually and quantitatively, defective block slightly influences reconstructed images of 2D or 3D emission data when segmented attenuation coefficients are used. As shown by reconstructed high counting statistics uniform images defective block generates different artefact shapes on 2D and 3D data: -in 2D mode with ramp FBP or 4i/16s AWOSEM they appear as cold stripes along the Fan angle covered by the defective detector; -in 3Dmode a very slight distortion on the edge tangential to the fan is visible only with AWOSEM. On the uniform and Alderson phantom images, in regions where artefacts were visible SUV% was less than 7%. Conclusions.This study showed that for HR+ scanner, even a 100% loss of efficiency of a block, in spite of the evident defect on sinograms, does not substantially affect qualitatively and quantitatively 2D/3D mode reconstructed images ( SUV% variations less than 7%) when segmented or non altered attenuation coefficients are used. Simulations on patient studies are under evaluation to confirm results obtained with phantoms. It is worth noting that the clinical use of a scanner with a defective block is to help temporary patient management and not to change maintenance scheduler or lower the quality standards.

Contrast and sensitivity performances of Elscint, General Electric, Siemens and SMV multi-heads cameras. MBq Tc-99m. A 20 cm-diameter cylindrical phantom with home made hot (4-20 mm) and cold (6-25 mm) rods inserts was filled with about 740 MBq Tc-99m. A tomography of 120 or 128 steps over 360° was recorded in H-mode with a circular trajectory. Using a 128*128 matrix and a hardware zoom, projection pixel size was adjusted to 3.7 mm for the VG, to 2.5 mm for the DST and to 2.7-2.9 mm for the other cameras. Reconstructed slices were obtained by ramp filtered backprojection and Chang attenuation correction using a GE Vision 6.0 Powerstation. Hot and cold contrasts were determined using in-house developed software. From the known shape of the phantom and the pixel size, this software automatically proposed a template of regions of interest (ROI) of predefined sizes. For each rod, two circular ROIs were used: one having the rod diameter and a smaller one. For each ROI, the software computed the contrast using the ROI mean pixel value and the ROI minimum (cold) or maximum (hot) pixel value. The user was allowed to shift and rotate the template in order to coregister the ROIs with the rods and the background areas. Results. The cold contrasts were very similar although the Multispect-3, the DST and, to a lesser extend, the Magicam delivered somewhat lower contrasts. The SMV cameras, the Multispect-3 and the Magicam, but again to a lower extend, generated lower hot contrasts than the other cameras. Among the cameras that presented the highest contrasts, the sensitivity of the E-Cam was 10 to 30 % higher. Conclusions. Recent multi-heads cameras from GE and Siemens perform equally well from the point of view of contrast in tomography but with differences in sensitivity amounting to 10-30 %.

Monte Carlo simulation for In-111 imaging using a scintillation camera with a low-energy general purpose collimator Indium-111 (In-111) emits gamma rays with two different energies, 171 keV (90%) and 245 keV (94%). For In-111 imaging, the use of a medium-energy (ME) collimator is preferable to a low energy (LE) collimator. The ME collimator, however, has poorer spatial resolution than the LE collimator. We reported the improvement in spatial resolution of In-111 imaging with the combination of the low-energy general purpose (LEGP) collimator and the collimator-penetration correction (CPC) by a blurring filter in EANM'06 Athens. The aim of this study is to validate a Monte Carle simulator developed for investigating the CPC method on In-111 imaging using the LEGP collimator. Material and Methods: In order to simulate a commercially available scintillation camera, we modified the in-house Monte Carlo program (MCEP code) that our coauthor has previously developed for the transport of photons and electrons in matter. In this modified MCEP code, interactions of photons in the scattering medium, the camera collimator, the NaI crystal, and the back-compartment (including the light guide, photomultipliers, and electronics located behind the NaI crystal) were accounted for. Furtermore, special attention was paid to collimator penetration. Simulations were carried out for some In-111 sources in air and in water, and energy spectra in the energy range 50 -300 keV and images with two 20% energy windows set at the 171 keV and 245 keV photopeaks were calculated. Images were separately obtained for unscattered, scattered and penetrated photons. In order to validate the modified MCEP program, data acquisitions were performed using the gamma camera (GCA7200A/DI, Toshiba, Japan) equipped with the LEGP or MEGP collimators under the same condition as the calculations. Results: The energy spectra calculated for both the LEGP and MEGP collimators were in good agreement with the measured ones. The simulated planar images for the In-111 source also agreed well with the experimental measurements in spatial resolution and the count profiles. The images simulated for the LEGP collimator's septal penetration of the 245 keV gamma rays were very similar to the acquired images. Conclusion: The modified MCEP program for the In-111 source was validated through comparison with experimental data measured on the real scintillation camera. Since this program allows for an accurate septal penetration of the 245 keV gamma rays on the LEGP collimator, it is very useful for studying and optimizing the CPC method. As Nuclear Medicine Imaging has been widely used in diagnostic and treatment, improving the image quality is so important which is not performed by conventional collimators. Slit-Slat collimator has been proposed for this purpose although the optimization of such collimators has not been performed yet. In order to compare the system with slit-slat and hexagonal collimator this work is performed, in which the gamma camera system with both slit-slat collimator and hexagonal collimator was simulated by Monte Carlo method. The simulation of Hexagonal system was compared with practical results and a good correlation was found between them so in this way the validity of our simulation code was confirmed. The NaI(Tl) crystal thickness for simulated Gamma camera systems with both slit slat and Hexagonal collimator for detection of 140 KeV photons was set to be 3/8 in .Since in our case we compare slit slat and hexagonal system ,collimator parameters were chosen the same as LEGP collimator. The simulated SS collimators consisted of 50 lead plates and the imaging was performed by rotating the SS collimator from 0 to 180 in 73 steps of 2.5 each. Spatial Resolution, Detection Efficiency, Geometric Efficiency and Modulation Transfer Function (MTF) of this system for both hexagonal and SS systems were evaluated and compared. Moreover the MTF of SS system was confirmed by the Fourier Transform of Point Spread Function. Based on the MTF value, our result showed that the spatial resolution of mentioned systems are the same whereas the relative detection efficiency of the SS system was about 51.1 times more than efficiency of hexagonal system as well as the Geometric Efficiency of slit slat system, which is 1.34 times more than hexagonal. The results of this study show that the SS collimators have great advantages over than hexagonal collimators by providing much higher detection efficiency, besides higher Geometric efficiency while maintaining a comparable spatial resolution. As a result using this collimator makes it possible to have a better image quality in nuclear medicine imaging systems.

A. Kamali Asl 1 , S. Sarkar 2 , S. Star artifact is one of the conventional artifacts in nuclear medicine imaging which is produced by gamma penetration in collimator septa. This effect is more profound for high energy photons. Thick collimator septa reduce septal penetration but lead to formation of hole pattern in detection area and consequently degrading the quality of images, (dark area under collimator surface). One of the most important issues in collimator design is to how to reduce contribution of photon penetration and hole pattern artifact in acquired images. A gamma camera system with both hexagonal parallel hole (HEX) and Slit-Slat (SS) collimators was simulated by Monte-Carlo method. The validity of simulation was done with practical data for 140 keV photons and a good correlation was found between them. Point Spread Function (PSF), Modulation Transfer Function (MTF), spatial resolution, efficiency, star artifact, hole pattern artifact and optimum geometry for SS collimator were evaluated for high energy photons ( up to 511 keV ) and were compared with those of a conventional HEX collimator. The efficiency of the system with SS collimator after background subtraction was measured to be 30 times higher than hexagonal collimator and spatial resolution was 14.5mm and 15.8mm with 8% statistical error for SS and HEX collimators respectively. Based on our SS collimator optimum geometry, septal penetration was reduced while star artifact was remained unchanged.. By increasing the number of step rotation of SS collimator, a free star artifact imaging is achievable. The contribution of septal penetration of an optimum SS collimator was reduced more than 50% in comparison with HEX collimator. Consequently our simulation data showed that with ideal collimator material, contrast has been improved about 30-40% . Our results showed that using SS collimator has a profound effect on increasing efficiency while the spatial resolution was comparable with the system using the conventional HEX collimator. In addition to increasing efficiency, star artifact was removed and contrast was improved using high attenuation material such as depleted uranium or high density material. Modelling of system response with depth-dependent resolution as part of iterative reconstruction has been proposed as a resolution recovery technique in SPECT. Recently, such schemes have become commercially available by manufacturers within routine reconstruction software implemented at clinically practical processing times. As well as improving on reconstructed spatial resolution such schemes may offer improvements in terms of signal-to-noise by supporting a more accurate detection model. We have assessed the performance of one such scheme, the Philips Astonish, available as part of OSEM reconstruction for clinical SPECT data. On the basis of point spread function measurements in a thorax and neck phantom the algorithm demonstrated substantial improvements in FWHM and FWTM for the parameters tested both with 99m Tc and 131 I SPECT data without affecting conservation of counts. An additional feature of precise modelling of the acquisition process appears to be an improvement in the statistical properties of the images with lower dependency on acquisition times. As convergence of statistical schemes is generally dependent on activity distribution the performance of the algorithm was assessed with more complex objects and with patient data. Patient data were acquired with 'concurrent imaging' allowing multiples of 5 seconds i.e. 5, 10, 15 and 20 sec per projection recorded from the same scan in order to assess the effect of counting statistics. On the basis of test objects, depth-dependent resolution modelling shows encouraging results for recovering resolution in data acquired with wider collimation and higher sensitivity. Preliminary results with 99m Tc-MDP and post-therapy 131 I SPECT studies demonstrate improvements in signal-to-noise levels and reconstructed resolution. Introduction: The Cyclone Storage Phosphor Imager is a digital film-less autoradiography system for qualitative and quantitative imaging of radioactivity. Reusable storage phosphor screens capture and store the activity and are then scanned to create a high resolution digitized image. The phosphor-imager is a versatile tool in nuclear medicine for a broad range of applications. Aim: To demonstrate the versatility of the phosphor-imager in common nuclear medicine techniques including in-vivo imaging, histology, quality control of protein radio-labeling and radionuclide uptake in cultured cells. Methods: Tissue from mice treated with 125I PR1A3 was exposed to storage phosphor screens. Histological tissue sections of rat with 111In and 99Tc labeled Octreotide were exposed to storage phosphor screens. Thin Layer Chromatography (TLC) plates spotted with 177Lu Octreotate and developed with solvent were exposed to storage phosphor screens. 111In cultured cells in multi-well plates and collimators were exposed to storage phosphor screens. Conclusion: The storage phosphor-imager is a versatile tool in nuclear medicine. It offers high resolution and quantitative analyses with a linear dynamic range of 5 orders of magnitude. It detects activity with a better efficiency than film and can significantly reduce exposure times compared to film. The storage phosphor-imager is a useful and relatively inexpensive autoradiography device for gels, chromatograms, tissues and multi-well plates. Determination of internal contamination is one of the important task in radiation accident management program. 137 Cs is one of the important radioisotopes in radiological and nuclear accident. Possibility for using routine gamma camera system for this situation could be of great value. An Adult Bottle Mannequin Absorption (BOMAB) phantom has been used for calculations. A gamma camera with Low Energy General Purpose (LEGP) and High Energy General Purpose (HEGP) collimators has been simulated with Monte-Carlo method and evaluated with practical data. The simulated BOMAB phantom has standard dimensions. Minimum Detectable Activity (MDA) and counting efficiencies for 137 Cs and 131 I were simulated individually. Also the members of BOMAB phantom with different contamination of 137 Cs and 131 I have been studied. The result of benchmarking showed a good correlation between simulation results and practical data. For the first time our new data regarding mixed 137 Cs-131 I source reveals strategies will exist for evaluation. The MDA for 137 Cs with gamma camera is several times higher than MDA's whole body counter but availability and logistically using the gamma camera in large accidents will be appreciated for primary triage and response. In other way our results showed that using a thicker or higher density of crystal can to improve the quality of results. Also background contribution has important rule in accuracy of MDA.

Determination of the weights of downscatter windows in I-123 SPECT studies R. de Nijs, C. Svarer; Copenhagen University Hospital, Copenhagen, DENMARK.

Aim Iodine-123 emits photons of 159 keV which are detected in an imaging window. Downscatter of high energy photons contributes significantly to this window, primarily by penetration of the collimator and backscattering into the crystal. For determining the weights in the Triple Energy Window (TEW) approach it is assumed that the count energy density varies linearly inside the imaging window. Since the peak value of the backscattering is positioned at 172 keV close to the energy of the imaging photons this is not the case, and the correct weight might be significantly different. For low count (e.g. dynamic) studies broader energy windows are preferred and a method of determining the weights is needed, since the ratio of the downscattered photons in the imaging window and the downscatter correction window is not known. Methods If it is assumed that there are no primary and scattered photons detected in the background of the projection data, the weight for a downscatter correction window can be determined by minimizing the background outside the object. As an illustration the Dual Energy Window (DEW) scatter correction was extended with a broad downscatter correction window D (184-216 keV). In the DEW approach a scatter window S (98-143 keV) is subtracted from the imaging window I (143-175 keV). Both the scatter and the imaging window were corrected for downscatter by subtracting the weighted downscatter window. Final images were reconstructed from I-k1*D-k2*C=I-(k1-k2*k3)*D-k2*S, where C denotes Compton scattering, k1 and k3 are downscatter weights for I and S, and the weight k2 is the empirical DEW scatter multiplier which was assumed to be 0.5. Measurements were performed on a 3-headed IRIX camera (Philips Medical) with LEGP collimators. Reconstruction was performed with and without (down)scatter corrections in 128x128 matrices (2.33 mm pixel size) using FBP, a low pass 4th order Butterworth filter at 0.3 Nyquist and uniform attenuation correction. Results Human studies of both the serotonin (I-123-ADAM) and dopamine (PE2I-123) transport system were analyzed. The downscatter weights k1 and k3 were measured to be 1.10-1.16 and 1.30-1.38 for both studies. For a flat energy spectrum these values would be 1.00 (same window width) and 1.41 (=45/32), respectively. Conclusions The weight of a downscatter window can be determined by minimizing the background in the projection data. This makes an extension of the DEW approach with a broad downscatter window possible. Objectives: We devised a new correction method that combined attenuation correction using a difference of intrinsic dual-energy between lower energy emissions (93keV) and higher energy emissions (185 or 300keV) without transmission scan and Compton scatter correction using triple-energy window (TEW) method for 93keV because of enhancing a difference of intrinsic dual-energy in 67 Ga citrate ( 67 Ga), and applied to JIS phantom and tumor phantom SPECT studies. Methods: Attenuation coefficients ratio and counts ratio for 93keV/185keV or 93keV/300keV were calculated from SPECT data acquired by energy window of 71keV,185keV and 300keV, respectively. The JIS phantom for concentration linearity and resolution measurements was used. In phantom study, size of tumor simulated 5 sphere types with 0.5, 1.0, 1.6, 2.0 and 3.0cm in diameter, and 3 tumor types were created with tumor to non-tumor (T/NT) activity ratios of 2.4:1, 4.4:1 and 6.6:1. The images reconstructed by non-attenuation-scatter (A(-)S(-)) as a conventional method, only scatter (A(-)S(+)) and attenuation-scatter (A(+)S(+)) correction were compared by visual and quantitative analysis, respectively. Results: The adequate attenuation coefficients ratio and counts ratio for 93keV/185keV were 1.243 and 20, respectively. For JIS phantom, concentration linearity was kept, and then FWHM was shown improvement. In the tumor phantom, the T/NT ratio was improved by attenuationscatter (A(+)S(+)) correction, and approached the real value. The quality of image for attenuation-scatter (A(+)S(+)) was higher than that for non-attenuation-scatter (A(-)S(-)). Conclusions: It is suggested that a new correction method that combined attenuation correction using a difference of intrinsic dual-energy and Compton scatter correction using triple-energy window (TEW) method for 93keV is useful in 67 Ga tumor SPECT studies. Background and Aim: In vivo neuroimaging techniques in correlation with MRI imaging, offers a potential which can reliably assess early clinical and pre-clinical diagnosis in Parkinson's disease. The aim of this study was to compare striatal's volume from MRI volumetric measurements with the Specific Binding Index (SBI) from regional DaTSCANS results Method: In thirty five patients both dopaminergic imaging using I 123 -FP-CIT SPECT and MRI scanning were performed. Specific Binding Index (SBI) has been calculated from regional DaTSCAN both for left and right striatum respectively, by applying the formulas: SBI left=( Cv left/ Cb-Vv)/Vs and SBI right=( Cv right/ Cb-Vv)/Vs where: Cv left: total counts in left striatum ROI, Cv right: total counts in right striatum ROI Cb: total counts in background region divided by volume of the background region. Vv: Volume of ROI, Vs: Volume of standard striatum (set to 11.2 ml) MRI imaging has been evaluated by employing high spatial resolution T 2 -weighted sequence such as T 2 -weighted/ Gradient-SpinEcho followed by a contiguous echo planar imaging sequence at the mid-brain striatal level in sagital projection. Multi-planar reconstruction images have been analysed and volumetric measuerements created in order to compare volume in relation to the SBI results. Statistical significance of these results was assessed using the Mann-Whitney test. Results: The overall results show a significant relation between the two imaging modalities for discriminating normal, Parkinsonian Syndromes ( PS) and Essential Tremor (ET) patients . Aim: Patients with carcinoma of the breast undergoing sentinel lymph node (SLN) imaging in nuclear medicine may also undergo ultrasound guided wire localisation when the primary tumour is non-palpable. The wire localisation is performed by radiologists shortly after sentinel node imaging using 99m Tc colloid. Due to operational restrictions the wire localisations can only be undertaken after sentinel lymph node imaging. Therefore, it was felt necessary to carry out a study to assess radiation dose to staff performing the wire localisation procedure. Method: In our centre there are two regimes for patients undergoing sentinel lymph node localisation; Patients injected with 20MBq of 99m Tc colloid are sent for surgery on the same day whilst patients injected with 40MBq undergo surgery the following day. A number of dose measurements were performed including extremity, whole body and instantaneous dose rate readings during the procedures. Chest and ring monitor badges were worn by the two radiologists whilst performing the wire localisations. In this study 10 patients were included of which 4 were injected with 20MBq and 6 injected with 40MBq. Results: For the 10 patients the mean delay between injection and the wire localisation procedure was 1.25 hours (20MBq) and 2.75 hours (40MBq). The mean duration of all 10 procedures was 10 minutes.. All doses measured using the body and ring monitor badges were below the minimum detectable limits of 10μSv (whole body badge) and 300 μSv (ring). A mean instantaneous dose rate of 12 μSv hr -1 was measured at the minimum observed source-radiologist separation (20cm) for patients injected with 40MBq. Based on this, body and finger dose estimates per procedure were calculated as 1.2μSv and 4.6μSv for the 20MBq patients and 1.9μSv and 7.7μSv for the 40MBq patients. Conclusions: The measured dose estimates from our study show that doses received by radiologists performing ultrasound guided wire localisation procedures following patients injected with 99m Tc colloid are insignificant. For comparison, in order to receive the annual public dose limit of 1mSv any one radiologist would need to perform approximately 500 procedures per year. Aim: Radioguided surgery and sentinel lymph-node biopsy has become standard of care in patients with breast cancer. These procedures are usually done in operating room working in close proximity to an electrosurgical unit (ESU) that is known to produce high levels of electromagnetic (EM) fields. This study analyses the risks deriving from the interference of ESU with the operation of a Gamma-probe (GP) and suggests some practical recommendations intended to minimize them. Methods: We investigated the function of 2 hand-held GPs of different manufacturers (CsI(Tl) scintillator) evaluating their change in operations and malfunctions in the presence of strong EM fields. While the tests were under way both ESU and gamma probe have been set as for routine clinical use simulating a typical operating-room environment (ESU's output power ranging from 80 to 250 W -full, ±50% and ±20% photopeak energy window). Results: All devices tested were affected by electromagnetic interferences (EMI) especially when the hand held GP was used in close proximity (<20cm) of the electrosurgical return-plate and the surgeon was coagulating tissues. The interferences recorded range from a simple buzzing noise to an erroneous data displayed. In the worst case the device emitted a continuous audio signal also there were no radioactive isotopes nearby. Conclusions: Our study demonstrates that gamma probes are particularly sensitive to electromagnetic disturbances that can be radiated during electrosurgery activities. Based on the previous results the overall suggestions and recommendations intended to avoid these unwanted effects can be summarized as follows: • Do not allow electrosurgery cables to lay over or contact the cables of GP; • Do not place the ESU's return-plate near the lymph-node excision region; • Whenever possible, use the narrower energy windows setting for the intended purpose; • All sources of RF energy should be kept at a sufficient distance from GP. Considering that Electromagnetic radiation it's governed by the inverse square law we suggest to place the ESU and all other accessories at least 0.5 meter away from GP. Aim: We aimed to analyze the different steps involved in the maintenance procedures required to run a medical cyclotron. We are operating an IBA Cyclone 18/9, which is dedicated to clinical PET radionuclides production. Cyclone 18/9 is a fixed energy cyclotron that accelerates Hions until 18 Mev and Dions until 9 MeV; our machine has eight exit ports equipped with five targets: one Titanium liquid target "large volume" for 18 F production, one Niobium liquid target "large volume" for 18 F production, one Silver liquid target "small volume" for 18 F production, one Aluminum gas target for 11 C production and one Aluminum liquid target for 13 N production. Materials and Methods: Eight scheduled maintenance interventions are required every year, 4 operated by IBA field engineers and 4 by the hospital staff; the

complexity of the maintenance interventions changes depending on which cyclotron part has to be checked. Target maintenance: no need to open the cyclotron (no vacuum shut-down); targets must be disconnected from the cooling lines; mean execution time: 30 min/target Source maintenance: cyclotron must be opened (vacuum shut-down); ion source must be disconnected from the cooling lines; mean execution time: 1 hour Stripper-foils maintenance: cyclotron must be opened (vacuum shut-down); mean execution time: 10 min After every interventions a short beam is made on each target to verify the cyclotron yield. Results: Since the cyclotron started to produce radionuclides, in May 2003, we made twenty-eight maintenance interventions, operated in part by IBA field engineers and in part by the hospital staff; intervention time varied from few hours to a maximum of two days. From the radiation protection point of view, the operator total body absorbed dose is mainly dependent on the time between the last radionuclide production and the intervention. For this reason maintenance intervention are scheduled on Monday, after 2 days of cyclotron stop. Up to now, from the collected data we measured a mean total body absorbed dose of 14 μSv (range 1-70 μSv) for hospital workers, with a mean time of stay inside the bunker of 34 min (range 5-85 min). Conclusion: After three years of experience we can state maintenance interventions (i.e. routine target, ion source and stripper foils maintenance) can be performed by hospital staff without particular problems. On the other hand, for more technical demanding problems, field engineers has to be called on-site to perform the required procedures. Background: Phantoms using printed radioactive paper sheets from an ink-jet printer may be used to provide test objects with a close approximation to the 3D activity distribution in organs. However, these phantoms do not necessarily accurately represent the attenuation properties of soft tissue since they are made of a composite of paper and Perspex. We propose that a stack phantom constructed of paper and sheets of spacing material can be produced with a close approximation to the attenuation properties of soft tissue, provided the correct ratio of paper to spacing material is used. Aims: To measure the effective linear attenuation coefficient of paper, and to use this information to calculate the composition of a paper and spacing material stack phantom to have soft tissue (water) attenuation characteristics.

The effective linear attenuation coefficients of paper and water were measured for 99m Tc using a gamma camera (Siemens e.Cam) with an LEAP collimator in broad beam geometry. The paper was a standard office printer paper, 80 g/m 2 . The measured values were used to select a spacing material from published attenuation values. Perspex was selected since it has a higher attenuation coefficient than water, to balance the lower attenuation coefficient of paper in the composite phantom, and because of its availability, low cost and ease of machining. The effective linear attenuation coefficient of Perspex was measured, and the correct proportions of paper and Perspex for use in the phantom were calculated. A stack phantom with these proportions was constructed and the linear attenuation coefficient of the paper-Perspex composite was measured. Results: The measured effective linear attenuation coefficients were 0.126 cm -1 for water, 0.094 cm -1 for paper and 0.144 cm -1 for Perspex. This gives a required paper to Perspex ratio of 0.554:1 for water equivalence. The linear attenuation coefficient of this composition was found to be 0.124 cm -1 (difference to water: 0.002 cm -1 ). In a 10cm thick phantom this difference in attenuation represents a small (1.8 %) increase in gamma ray penetration between soft tissue and the phantom. Conclusions: Paper-Perspex composite stack phantoms can be constructed to have attenuation properties very similar to soft tissue, enabling pseudo-anatomical soft tissue equivalent phantoms to be produced.

Production of radioactive quality assurance phantoms using a standard inkjet printer. J. A. van Staden, H. du Raan, M. G. Lötter, A. van Aswegen, C. P. Herbst; Univ. of the Free State, Bloemfontein, SOUTH AFRICA.

Aim: The use of a standard inkjet printer is proposed to produce radioactive phantoms that can be used for the routine quality control of gamma cameras. The purpose of this study was to evaluate the printed radioactive phantoms and demonstrate their use by the determination of the camera resolution. Material and Methods: The ink used to print the phantoms was obtained by adding a well mixed solution of black ink and 99m Tc pertechnetate to the cartridge of a Hewlett-Packard inkjet printer. MS Powerpoint software was used to create an image that is representative of the radioactive distribution required. The distribution was then printed on paper using the radioactive ink. Imaging was performed with a GE 400AT Starcam camera fitted with a low energy all purpose collimator and Alfanuclear acquisition software. The amount of activity to be deposited on paper per unit area was predicted and compared to the measured activity. The uniformity of the printouts was compared to the uniformity obtained with a standard 57 Co flood source. Joining two A4 size printed phantoms to create larger sources was evaluated. The spatial resolution obtained with printed sources was compared to that obtained using standard line source techniques. A resolution image was also obtained from a 99m Tc printed bar quadrant phantom and compared to an image obtained with the lead bar pattern using a 57 Co flood source. Results: The results indicated that the uniformity of the printed phantoms compared well with those obtained with the 57 Co flood source [integral uniformity 2.29% (printed source) and 2.10% ( 57 Co flood source)], and the accuracy of the activity predicted to be deposited was better than 10%. There was no difference in the resolution measurements obtained with the printed sources and those obtained with the standard methods. Conclusion: This study demonstrates that affordable phantoms can easily be created to evaluate system uniformity and resolution in any department where a standard PC and inkjet printer are available. Aim: A lot of sophisticated models are available for the quantitative interpretation of dynamic PET data. Parameters in these models are used to define quantities, such as metabolic rate, blood volume and flow, etc., characterizing the functional physiological and/or biochemical status of tissue in vivo. Normally, these models are so sophisticated that the physicians cannot easily handle them without much experience. This study proposes an innovative machine learning method for parameter imaging and kinetic modeling of PET data, which can automatically predict the values of quantitative PET parameters using learned regression models from accumulated training studies of kinetic modeling. Materials and Methods: The support vector machine (SVM) approach was used as machine learning algorithm in the tool. SVMs are a set of related supervised learning methods used for classification and regression. We used the cross-validation and grid-search for automatically choosing the kernels parameters. We choose the spreadsheet file with customized header as the data standard. Based on the Java implementation, the software is currently offered for different operating systems. By now, we collected 227 studies of quantitative PET parameters as training samples from 2-tissue compartments modeling. Each training sample comprises the value of PET parameter as Y value and input data as well as model data as X values. Then different regression models are built for different PET parameters. Using the models, we can predict the values of quantitative PET parameters of VOIs or pixels according to the TAC of them. The tool is integrated to the PMod software (PMOD Technologies Ltd., Adlisvil, Switzerland). Results: Squared correlation coefficient was calculated from cross-validation. The highest correlation coefficient was obtained for K1 for 0.859. Two correlation coefficients were also very high: vB = 0.734, INF= 0.796. Other three correlation coefficients were below 0.5: k2=0.338, k3=0.475, k4= 0.239. Parametric images were also calculated for these parameters using the trained models. Conclusion: The initial results show that machine learning based calculation of quantitative PET parameters is helpful for parameter imaging and kinetic modeling of PET data. It can be applied to any kinetic model based on the training studies of specific model from modeling expert. Specially, the machine learning based method can be integrated with other kinetic models and be used as initialization technique for the models to decrease the number of iteration of the iterative-based kinetic methods. Densitometry by dual-energy X-ray absorptiometry (DXA)is the gold standard for osteoporosis diagnosis and pharmacological treatment monitoring. The Hologic QDR-DiscoveryA densitometer offers a positioning scan mode and three different measurement scan modes: "fast-array", "array" and "high-definition", which differ in image definition, scan time and patient radiation dose. Aim of this study was to assess a possible significant differences, between in-vivo Bone Mineral Density (BMD) result measured by different scan mode and if this differences are clinically significant. Patients enrolment started just after annually routine maintenance and calibration procedures by Hologic Inc. All acquisitions were performed by the same skilled operator. Repeated acquisitions were performed for each skeletal site through the three different scan modes without repositioning of the patient between scans. Analysis on whole patients and on a obese subgroup (Body Mass Index > 30) was carry out. BMD was expressed as g/cm 2 and as T-score (SDs from normal reference population database) for instrumental diagnosis (T-score > -1 SD for normal; T-score ranging between -1 and -2.5 SD for osteopenia and T-score < -2.5 SD for osteoporosis). 96 patients (12 man) for lumbar spine and 25 (2 men) for femoral neck were enrolled. We found a significant differences between BMD measurement in fast array/array mode and High Definition mode (0,005 g/cm 2 p<0,001 ANOVA, Bonferroni's Multiple Comparison Test). Moreover, BMD differences were correlated with Bone Mineral Content (BMC) values for fast array vs high definition (R=0,666; p<0,001) and for array vs high definition (R=0,485; p=0,014). The difference between different scan modes were statistically significant, but seem too small to be relevant in order to achieve a correct clinical diagnosis; 6.3% of lumbar spine instrumental diagnosis based on array mode measure was different from those calculated on high definition and 3.2% of total hip on fast array from high definition. Our data suggest that for correct clinical diagnosis a physician evaluation of DXA results is needed. Aim: Renal volume measurement is an essential part of split renal function assessment in MR urography. The aim of this study was to assess the accuracy and repeatability of a three-dimensional segmentation algorithm based on the belief functions theory in calculating renal volumes from MR images. Materials and Methods: The true volume of 20 various sized animal kidneys was obtained by fluid displacement. Each kidney was examined using two different MR units. 3D proton-density weightedacquisitions with incremental slice thickness were obtained. The MR volume was then measured with a segmentation algorithm based on the belief functions theory. Two independent observers performed all segmentations twice. Accuracy, intra-and interobserver variability were evaluated by the Bland-Altman method. The number and type of manual corrections were recorded, as well as the whole processing time.

The mean renal volume estimated by fluid displacement was 114 mL (range, 38-224 mL). The maximal standard deviations of the difference were: 2.2 mL (accuracy), 1.2 mL and 1.8 mL (respectively intra-and inter-observer variability). Segmentation of axial slices provided better accuracy and reproducibility as compared with coronal ones. Overlapped coronal slices yielded poor results due to the partial volume effect. The mean processing time, including optional manual modifications, was shorter than 75 seconds. Conclusion: The belief functions theory is an accurate and reproducible mathematic method to assess renal volume from MR adjacent images. In the 1980s the discovery of expression of somatostatin receptors on NET cells made the use of somatostatin analogues in diagnosis and therapy possible. The aim of the study was to assess response of targeted radio-nuclide therapy with radio-labeled somatostatin analogue 90 Y [DOTA 0 , D-Phe 1 , Tyr 3 ] octreotate (DOTATATE) and mixed 90 Y/ 177 Lu-DOTATATE in treatment of disseminated NETs. Materials and methods: 20 patients with diffuse NETs were enrolled, divided into two randomization group by 10 pts. One Group was treated by 90 Y DOTATATE: 5men, 5 women, aged 56,7+/-11,2. Second Group was treated by 90 Y/ 177 Lu DOTATATE: 4 men, 6 women, aged 59,8+/-12,8. Before therapy blood tests for hematology, kidney and liver function, CgA were done. All patients underwent CT and scintigraphy with 99m Tc-HYNIC-TATE. Treatments of 90 Y -or mixed 90 Y/ 177 DOTATATE were repeated 4-8 weeks apart up to total calculated doses -200 mCi /m 2 ; per one course we usually used 100 mCi. Mixed amino acids infusion was used for kidney protection. Results: 90 Y DOTATATE: 1. Regression of disease (PR -decrease of size and number of metastases, decrease of CgA level, good clinical response) was observed in 5 pts 2. Stable disease (SD-stable size and number of metastases, decrease of CgA) was observed in 3 pts 3. 2 patients died No nephrotoxity was observed. WBC and PLT levels were stable during therapy in 3 pts. In 6 pts leucopenia was observed (WBC level < 4 x10 3 / mm 3 ); serious neutropenia < 2 x 10 3 / mm 3 , was observed in 2 pts. PLT level decreased in 5 pts, but thrombopenia was observed only in 1 patient . 90 Y/ 177 Lu DOTATATE 1. PR was observed in 4pts, 2. SD in 3pts. 3. 3 patients had progression of disease during the therapy, 1 of them died. In 2 pts increase of ceratinine level was observed (abnormal creatinine level from the beginning of therapy). Liver tests were stable.WBC level was decreasing during therapy in all patients; we observed no serious neutropenia. PLT decreased in 7/10 pts. Conclusions: 1. It seems that 90 Y DOTATATE or mixed 90 Y/ 177 Lu DOTATATE come to the same results in treatment of patients with diffuse neuroendocrine tumors in 6 month observation. 2. Higher decrease of PLT was observed in group treated by 90 Y DOTATATE than 90 Y/ 177 Lu DOTATATE. 3. Lower decrease of WBC was observed in group treated by 90 Y DOTATATE than 90 Y/ 177 Lu DOTATATE, however in that group serious neutropenia < 2 x 10 3 / mm 3 was observed P425 Results 90Y-DOTA TATE therapy in patients with neuroendocrine tumors -own experience of 2 years therapy J. Kunikowska 1 , L. Krolicki 1 , A. Hubalewska-Dydejczyk 2 , A. Sowa-Staszczak 2 , R. Mikolajczak 3 , D. Pawlak 3 , M. Kobylecka 1 , J. Maczewska 1 ; 1 Med.Univ. of Warsaw, NM Dept., Warsaw, POLAND, 2 Collegium Medicum Cracow, Cracow, POLAND, 3 OBRI POLATOM, Swierk, POLAND.

The aim of the study was to assess response of targeted radio-nuclide therapy with radio-labelled somatostatin analogue 90 Y-[DOTA 0 , D-Phe 1 , Tyr 3 ]-octreotate (DOTATATE) in the treatment of disseminated NETs. Material and methods: 12 patients (aged 56, 7+/-11,2): carcinoid-5pts, insulinoma-1pt, gastrinoma-2pts, pancreatic NET-2pts, neuroendocrine cancer without primary tumor-1, stomach NET-1pt were enrolled in the study. Before the therapy, blood tests for hematology, kidney and liver function and CgA were performed. All patients underwent CT scans and 99m Tc-HYNIC/EDDA-octreotate SRS. . Scintigraphy examinations were made with two-head Elscint gammacamera, using 99m Tc labelled somatostatine analogueoctreotate, with 700-800 MBq activity; using planar and single photon emission computed tomography (SPECT) techniques. 4 and 24 hours after injection the data was acquired in 120x30s mode, matrix 128x128. CT scans were performed on GE Light Speed 16. Images were acquired before iv injection of contrast media 5 mm slices thickness and in the arterial -1,25 mm, and portal venous phase-2 ,5mm.PMOD software was used for fusion imaging. Treatment with 90 Y-DOTATATE was repeated every 4-6 weeks up to the total of 200mCi/m 2 . Mixed amino acids infusion was used for kidney protection. Results: One year observation: regression of disease (PRdecrease of size and number of metastases, decrease of CgA level, good clinical response) was observed in 6pts, stable disease (SD-stable size and number of metastases, decrease of CgA) in 3pts. 3 patients died. No nephrotoxicity was observed. WBC and PLT levels were stable during therapy in 3pts (without chemotherapy). In 1 pt with previous chemotherapy (last course a month before radiotherapy), PLT level decreased (220x10 3 /mm 3 to 47x10 3 /mm 3 after the first course); the patient died two months after the beginning of the therapy. In 8 pts leucopoenia was observed (< 4x10 3 /mm 3 ) but serious neutropenia (< 2x10 3 /mm 3 ) was found in 3 pts with previous chemotherapy. Thrombocytopenia (PLT < 100x10 3 /mm 3 ) was observed in 2 patients with previous chemotherapy. Two years observation: prolonged PR -4pts; SD-3pts, progression of disease in 2pts: with gastrinoma and stomach NET without hormonal activity (4 and 9 months after radiotherapy). Blood tests stable. Conclusion: PR and SD were observed in 9/12 patients with disseminated NET. Severe haematologic toxicity was mainly observed in patients after prior chemotherapy -the question of optimizing the time between chemotherapy and radiotherapy is still open. This study was supported in part by a Research Grant for Scientific Research (3666/P.05-6/05) from the Ministry of Health and Ministry of Education.

O. Solodyannikova, G. Sukach, V. Tratsevsky; Institute of Oncology of AMSU, Kyiv, UKRAINE.

Background. Limitations of possibilities of radio-and chemotherapeutical methods for medullary thyroid cancer (MTC) resulted in use of radionuclide pharmaceuticals (RP) for its treatment. The most frequently used is 131 I-meta-iodinebenzilguanidin ( 131 I-MBG). Problematic is monitoring of MTC patients and estimation of treatment efficacy. Aim was the analysis of treatment results of MTC patients using 131 I-MBG and 99m Tc-carbomec for the follow-up and estimation of the treatment effectiveness. Materials and Methods. 18 patients received intravenous 131 I-MBG (3700 MBk). There were no complications or side effects during 5 day stay at a clinic. Three patients received repeated therapy with an interval of one year. The follow-up included scintigraphy (SG) of thyroid gland with 99m Tc-carbomec, estimation of blood calcitonin level, ultrasonic examination and in some cases computed tomography. The repeatedly treated patients were under the follow-up during two years. During this period the whole-body scanning on residual dose of 131 I-MBG and three times with 99m Tc-carbomec was performed. In seven patients, who received single 131 I-MBG treatment, diagnostic scanning was performed three times (follow-up -1.5 years). In eight patients, treated with 131 I-MGB, term of the follow-up -a year, diagnostic examinations with 131 I-MGB and 99m Tc-carbomec were performed twice. In 25 patients diagnostic scanning with 99m Tc-carbomec was performed after surgery, in 12 of them -once, in 13 -twice (follow-up -0.5-1.0 years). Results. During observation various reactions for 131 I-MGB treatment have been detected. In 12 of 18 patients ultrasonography, SG and calcitonin level 6, 9, 12 months after the treatment didn't detect prolongation of the pathologic process. after first course of therapy in one patient increase of calcitonin level 6 months after resulted in appearance of hyperfixed lymph nodes on SG with 99m Tc-carbomec. In one patient with metastatic foci in liver 131 I-MGB therapy and control with 99m Tc-carbomec 6 months after didn't detect negative dynamics. In two patients with MEN syndrome and MTC SG with 131 I-MGB, performed on residual therapeutic dose, revealed RP decrease but SG with 99m Tccarbomec performed 6 months after treatment and calcitonin level didn't reveal signs of disease progression. In 4 patients, who didn't receive 131 I-MGB, basing on diagnostic scanning with 99m Tc-carbomec dissection of neck lymph nodes was carried out and SG with 99m Tc-carbomec half a year after didn't detect prolongation of the process. Conclusion. Use of radionuclide therapy and diagnostics significantly increase outcomes of MTC patients' complex treatment and monitoring. P54 -Monday, Oct. 15, 2007, 2:30 pm -4 :00 pm, Poster Area Radionuclide Therapy/Dosimetry -Clinical Thyroid, bone pain palliation and miscellaneous 1

A. K. Sinha, Male; National University Hospital, singapore, SINGAPORE.

paper describing therapeutic uses of radium was published; in 1936, {sup 24} Na was administered as a therapy to a leukemia patient. Three years later, uptake of {sup 89} Sr was noted in bone metastases. During the 1940s, there was increasing use of iodine therapy for thyroid diseases, including thyroid cancer. Radiolabeled antibodies targeting human tumors in animals were reported in 1973; antibody tumor imaging in humans was reported in 1978. Since then development of new radioisotopes and new radiopharmaceuticals, coupled with improvements in technology, make therapeutic nuclear oncology an area of growth for nuclear medicine. Our aim is to project the role of Therapeutic Nuclear Medicine in different cancer and its related complication in poster presentation. These radionuclide therapy done at National University Hospital, and Singapore General Hospital, Singapore with i-131,receptor based Antibodies, Peptides and Bone-seeking radionuclides. Methods: It involved a retrospective review on the treatment of different type of the cancer and its related complications (Thyroid cancer, Non-hodgkin's B-Cell lymphoma, Neuroendocrine tumor, Liver tumor and Bone pain from metastatic disease) with radionuclides, performed at National University Hospital and Singapore General Hospital, from 2003 to 2005 in the dept of nuclear medicine. Results: Results are encouraging and it will be presented in the Poster. Conclusions: Globally increasing numbers of the cancer patients, including those with thyroid cancer, lymphoma, different form of neuroendocrine tumors, liver cancer, metastatic bone involvement with prostate and breast cancer, radionuclide therapy has already become an important component of modern medical practice. New Drugs Application (NDA) is promising form of therapy on the new horizon in the field of targeted Peptides and Antibodies therapy. Mapping of human genome is the greatest scientific achievement of this era. Molecular methodologies that were developed during human genome project, led directly to the discovery of improved molecular targets for targeted therapy. The current era moving toward increasing sophistication of radiopharmaceutical formulation, including antibodies, peptides, nano particles, fusion proteins and small organic molecules which will lead to better agents and better patterns of practice for established practice. Aim: The most widely accepted protocol for the treatment of painful bone metastases suggests to administer a weight-based activity of 153 Sm-EDTMP (SM) (37 MBq/kg). This procedure is obviously inadequate for over weighted patients, with the risk to deliver more than 2 Gy to bone-marrow. In order to easily approach to a pre-therapy dosimetric evaluation, we tried to estimate the SM uptake by a dual MDP bone scan semiquantitative study. Patients and Methods: the bone uptake of 41 (15F/26M) pts with painful skeletal metastases was studied. The week before the treatment each pt underwent MDP bone scan with a double acquisition (10 min and 5-6 hrs p.i.) under the same conditions, in order to evaluate the skeletal uptake and personalize the radioactive amount of SM for the treatment. Prior to inject MDP the patients were invited to void. 15 mins after i.v. injection the patients underwent total body scan (WB) with a double-head gamma camera, with particular attention to include the whole body in the field of view. A post-micturition acquisition was repeated 5-6 hrs later, under the same conditions. Identical acquisitions were performed 5 mins and 24 hrs after SM injection. Methods: ROIS were drawn in order to calculate the counts for each WB. The counts were decay corrected and the geometric means for opposite views were calculated. The uptake was estimated as: U=100xcnts(delayed)/cnts(early). Statistical analysis was performed. Results: MDP skeletal retention ranged from 26% to 89% (mean=64, SD=14). SM retention ranged from 38% and 93% (mean=66, SD=14). A good correlation was found between SM and MDP retention (linear regression coefficient R 2 = 0.84; y=0.95x+4.7). If two cases (who received zolendronate the day before the study) are excluded from the study (due to a markedly interference of bisphosphonate uptake), the correlation improves (linear regression coefficient R 2 = 0.89; y=0.99x+1.4). Conclusions: The dual MDP bone scan methodology is useful to predict the retention of SM in patients with painful bone metastases. This approach can lead to a personalized dosimetry in planning radiometabolic treatment to administer the highest activity of SM, respecting the constraint of 2 Gy to the bone marrow. Recent zolendronate infusion could impair bisphosphonate uptake. Aim: To investigate haematological safety after multiple doses of Rhenium186-HEDP, a betta-emmiting factor used in the palliative therapy of painful bone metastases. Patients and Methods: Aiming to that, we evaluated 23 patients with painful osseous metastases (17 men with prostate cancer, 6 women with breast cancer), mean age=71.2+/-11 years, who received fixed doses (1300 MBq) of Rhenium186-HEDP, far off other therapeutic manipulations. Of these, 13 patients (group A, mean age=70+/-13 years, 8 men) underwent multiple (2-6) radioanalgetic therapies (mean=3.3+/-1.0) and the rest 12 patients (group B, mean age=72.5+/-8.6 years, 11 men) underwent only one therapy. Haematological status (HGB, WBC and PLT count) and Karnofsky Pain Scale (KS, estimated by an established Numeric Rating Scale, values 0-100) of all patients were followed up every 15 days for 3 months after last therapy. Results: Respective pretherapeutic blood count absolute values (+/-SD) of groups A and B: HGB=12.9+/-1.5 and 11.7+/-1.3, WBC=7380+/-1870 and 7860+/-2480, PLT=220+/-76 and 280+/-63 thousand. Maximum percentile decrease of blood counts during the three month follow up period in groups A and B: HGB=6% and 7%, WBC=29% and 10%, PLT=28% and 22.5%. Paired t-test analysis did not show statistical difference in HGB values between pre-and post any radioisotopic therapy in both groups, while significant decrease in WBC count was seen only in group A (P=0.005). The PLT count was clearly decreased after therapy in both groups (P=0.012 and 0.015 respectively), but significant myelosupression was evolved only in three patients of group A (one with grade 2 and two with grade 1 myelotoxicity). Finally, patients with good pretherapeutic clinical status (KS>/=80, mean=87+/-5, N=10) had less decrease in PLT count after therapy compared to those with KS<80 (mean=57+/-12, N=13) (respective decrease=14.9+/-15.9% versus 33.4+/-17.3%, P=0.015), irrespectively of patients' age, pre-therapeutic PLT count or the number of radioisotopic therapies received. Conclusion: Rhenium186-HEDP is safe enough to be readministered several times if an acceptable haematological baseline status exists, especially in those patients who present with a more favourable pretherapeutic Karnofsky pain index.

A. Tsaroucha, G. Meristoudis, T. Liotsou, V. Giannakopoulos, C. Batsakis, A. Balomenos, J. Christacopoulou; Dept of Nuclear Medicine,''Sotiria'' Hospital, Athens, GREECE.

Introduction:The role of radionuclide bone palliation therapy in patients with prostate cancer as well as breast cancer is well established. Aim: The aim of the study was to evaluate the efficacy and toxicity of radionuclide palliative treatment in patients with lung cancer. Method: Fourteen patients with lung cancer were included in this study. They were randomized in two groups. The first group A n =7 patients received 37MBq/kgr 153 Sm-EDTMP and the other group B n=7 received 1295MBq 186 Re-HEDP. All of them had a positive bone scan demonstrating a multifocal spread of osseous disease. Blood cell counts and renal function tests were in all patients within safe limits. Two of the patients were on non steroid anti-inflammatory drugs, two on weak opioids and ten on strong opioids analgesic therapy. Pain was scored by an eight-point-rating-scale. Pain response as well as possible myelotoxicity were checked 2,4,8 and 12 weeks after radionuclide administration. The treatment was deemed effective if the pain retreated by at least two points. Results: Four of the patients of group A and three of group B experienced obvious reduction of pain. However no patient demonstrated complete pain relief. The overall pain response was 50%. The onset of the palliative effect was between 2 to 4 weeks in both groups, and its duration ranged from 4 to 8 weeks. Two of the responded patients reduced the strong opioids consumption and these two were retreated after 12 weeks . However retreatments were less effective than initial ones. Flare phenomenon occurred in two patients, one of each group. One of them eventually responded to the therapy. Mild transient myelotoxicity, concerning white blood cells and platelets, occurred in three patients, two of group A and one of group B. Conclusions: Patients with lung cancer and metastatic bone pain can benefit from radionuclide palliative therapy. Although our sample was small, radionuclide analgesic therapy in patients with lung cancer seems to be less effective than in patients with prostate or breast cancer. The two radiopharmaceuticals did not show any difference in palliative efficacy or toxicity.

Radionuclide treatment for painful bone metastases in patients with hormone-refractory prostate cancer J. Dolezal; Teaching Hospital, Hradec Kralové, CZECH REPUBLIC.

Aim: to assess the efficacy of the 153 Sm-EDTMP treatment in patients with disseminated prostate cancer with bone metastases and pain. Materials and Methods: Thirty-eight men (aged 50-83, mean 72 years) with bone disseminated hormonerefractory prostate cancer and bone pain received 153 Samarium-EDTMP. Mean applied dosage was 40 MBq per kg of patient's body weight. Karnofsky performance status, pain score (Numerical Rating Scale), analgesic score (WHO) and blood count were evaluated before and 1 and 3 months after the treatment. Results: Significant pain relief was observed in 45% and 40% of patients, mild relief in 32% and 32% and no effect in 23% and 30% of patients one and three months after administration, respectively. The pain palliation was accompanied by an improvement in mobility and a decrease in necessary dosage of analgetics. Mild and transient bone marrow suppression was observed as a side effect of 153 Sm-EDTMP treatment. None of the patients showed haematological toxicity grade 4, and only 3 patients showed grade 3 (NCI CTC). The majority of patients had haematological toxicity grade 1 or 2. Conclusion: After administration of 153 Sm-EDTMP bone pain palliation was observed in 70% of patients for three months. The haematological toxicity after 153 Sm-EDTMP treatment was mild and transient. values for group II: 63+/-19, 67+/-27, 6.3+/-3.8% and 6.7+/-4.0%. With the exception of only one patient of group I who deteriorated scintigraphically, the SSI of the rest 22 patients was unchanged. Paired t-test analysis did not show statistical difference in BSI pre-and post any radioisotopic therapy in both groups, while only in group I was seen a significant improvement in KS after the completion of therapies (P=0.036). Furthermore, patients of group A (pretherapeutic BSI=3.4+/-2.2) had insignificant KS change (from 72+/-22 to 73+/-27), while those of group B, who set out with mean BSI=8+/-3, resulted in an interestingly better clinical outcome (KS from 68+/-13 to 84+/-13, P=0.012), although no difference in age, number of therapies or blood counts were observed. Conclusion: In spite of a minimum scintigraphic deterioration in most patients throughout the follow up period, the post-therapeutical Karnofsky scores might suggest an unexpectedly favourable clinical outcome, at least in a short-term follow up period, specifically in patients who present with a more adverse pretherapeutic bone scan and who would receive multiple rather single doses of Rhenium186-HEDP. Introduction and aims: 153 Samarium-EDTMP has proved to be effective as palliative treatment in patients with difosfonate fixing bone metastases (as breast, lung, prostate cancer). Its utility has also been demonstrated in patients with osteosarcoma bone metastases, when administered at high doses (from 1 to 30 mCi/Kg). Prognosis of patients with osteosarcoma presenting bone metastases at diagnosis or with disease relapse or progression is generally very poor. Aim of this study was to evaluate the feasibility of treatment with 153 Samarium-EDTMP at the doses of 10 mCi/Kg in 6 cases of osteosarcoma with multiple bone metastases, followed by re-infusion of peripheral blood progenitor cells (PBPG) gathered after administration of 2 cycles of Ciclofosfamide and Etoposide (CE). Patients and Methods: Six patients with osteosarcoma were enrolled in the study: 4 were affected by osteoblastic forms and grading IV, 1 had condroblastic form -grade III and 1 with a round cells form. Two patients had metastases at onset (vertebral, pelvic, femoral and pulmonary) and went immediately treated with 153 Samarium-EDTMP, 3 patient was treated following the second disease recurrence (at femoral and pelvic levels), 1 patient underwent treatment after the the first recurrence (at femoral and pulmonary levels). 153 Samarium-EDTMP was administered via slow e.v. injection in a single dose of 10 mCi/Kg, followed 14 days later by re-infusion of PBPC (6.1x10 6 /Kg cellule CD34+, range 5.8-7). All patients underwent PET-CT. Results: Treatment was well tolerated by all patients and no cases of severe extra-haematological toxicity occurred. White blood cell and platelet nadir took place respectively at days 12 (range 12-18) and 22 (18-25) from administration of 153 Samarium-EDTMP. Thirty days after the administration of 153 Samarium-EDTMP one of the patients at second recurrence showed bone and pulmonary progression, the patient at first recurrence showed stable disease, on the other hand, the two patient treated at onset showed partial response (with meaningful improvement of PET scan and bone scintigraphy). Approximately five months after the radiometabolic treatment three patients are died and one of patients affected by osteosarcoma with bone metastases at onset is well (partial response) Conclusions: Although results are still preliminary, high dose radio-metabolic treatment with 153 Samarium-EDTMP appears to be well tolerated and PBPC infusion allows to control haematological toxicity. Aim: To assess the outcome results at 6 months follow up of patients with painful knee OA treated with single Y-90 RS and factors that influence the results. Methods: The RS treatment response was assessed retrospectively for 74 painful at exercise knees of 74 patients. The duration of OA symptoms was 24±9 months with 44/74 knee joints presented also pain during the night and 43/74 knees abnormal knee flexibility. Knee joints were assigned according the Steinbrocker radiological grading system (4 grade_0, 27 grade_I, 20 grade_II, 21 grade_III and 2 grade_IV). RS was performed with intra-articular knee injection of 185 MBq Y-90 silicate according EANM guidelines. RS response was assessed at 6 months in terms of a 100-point Visual-Analog-Scale (VAS) pain improvement from baseline values, of the improvement of knee flexibility and pain remission during the night. RS success rate results were classified as poor (VAS < 25), fair (VAS >=25-50), good (VAS >=50-75) and excellent (VAS >75), with excellent and good results considered as success, while fair and poor results as failure. Results: The percentage of VAS knee joint pain improvement from baseline values was 66.0±24.8 %. There was a significant difference of the VAS pain improvement in patients with the duration of disease symptoms less or more than 2 years (P=0.04), with the patient's age of less or more than 65 years (P=0.01) and with radiographic changes (P<0.001). With radiographic changes adjustment it was found that knees with no or mineral OA radiographic changes (Steinbrocker-grade 0-I) respond better than those with more advanced changes (Steinbrocker-grade III-IV) in terms of VAS improvement (77.9% versus 53.8%). The overall success rate for RS (VAS 50), was 83.8%. Failure response was 16.2%, with no response at all found on 4/74 knees. Complete response as a complete remission and a 100% VAS improvement was found on 7/74 knees. Success rate was 100% for knees with no or mineral OA radiographic changes and 90% with Steinbrocker-grade II, while the success rate of knees with more advanced changes was 79.2%. After RS treatment, pain during the night was improved on 88.6% and knee flexibility was totally improved on 65.1%. These response values were significant different from the baseline values before RS treatment (P<0.001). Conclusions: RS in patients with OA seems to be safe, without significant side effects and short time effective. Our findings implicate RS might be more beneficial in the early stages of OA. Study objectives: Examination of anti-inflammatory effect of 166-Holmium-phytate injection. Methods: Phases I-II, randomized, simple-blind, placebo-controlled comparative study using increasing dosage. 31 patients suffering from chronic synovitis, rheumatoid arthritis and seronegative spondylarthritis were examined. The protocol commenced with screening. Patients were randomly distributed into four treatment arms: Group I. Holmium phytate injectable suspension marked by 185 MBq 166Ho + 40 mg of 1 ml triamcinolone acetonide/TA/ + 1 ml of 1% lidocaine injection./Lid.inj./ Group II. 555 MBq 166Ho. + 40 mg of 1 ml TA + 1 ml Lid.inj. Group III. 925 MBq 166Ho + 40 mg 1 ml TA + 1 ml of 1% Lid.inj. Group IV. Solely 40 mg of 1 ml TA + 1 ml of 1% Lid.inj. Inflammatory activity of the affected knee-joint was tested prior to treatment, and the 14 th and 28 th days, and 3, 6, 9, 12, 24, 36, 48 and 60 months after treatment. Testing was done based on the following parameters: Measurement of swelling of knee-joint [cm]; Flexion -heal buttocks distance [cm]; Degree of knee-joint pain. Visual Analogue Scale /VAS-1-100/; Patient's opinion on inflammation of knee-joint /VAS-1-100/; Doctor's opinion on given inflammation of knee-joint /VAS-1-100/ Results: Even after 5 year period 88.2% of the findings were rated as excellent or good. 86.66% of the patients do not need another punction even after a 5 years period. We found no deviations in either haematological or chemical parameters during the study period. Administration of Holmium-166 phytate is a safe procedure. We did not detect symptoms of radiation sickness. During the study period, inflammation decreased in the group receiving 555 and 925 MBq. Conclusion: Ho-166 isotope is an effective radiopharmacy treating synovitis. Due its adventageous features it produces less radioactive damage on the organism than the traditionally used isotopes (90-Y, 169-Er, 186-Re). Due to its physical parameters it is optimal to treat large joints, and medium size joints. 166-Holmium-phytate has a: radiation type beta energy maximum: 1.84 MeV; and radiation type gamma, energy maximum: 0.66 MeV; soft tissue penetration: maximum 8.4 mm; /average: 3.3 mm /; half-life: 26.9 hours; particle size: 0.6-2 μm Study objectives: measur the synovial thickness after 166-Holmium radiosynoviorthesis by sonography. Methods: Phase I-IIA, randomized, simple-blind, placebo-controlled comparative study using increasing dosage. 31 patients suffering from chronic synovitis, rheumatoid arthritis, or seronegative spondylarthritis were examined. Patients: Gender (male/female): 12-19; Diagnosis (RA / SNSA): 21 / 10; Stage of knee joint x-ray (I / II): 7/24; Duration of synovitis (years): 7.9; Duration of disease (years): 5.72; Number of punctures before the Ho-166 treatment: 18.76; Number of steroid injections before the treatment: 18.85. The protocol commenced with screening. The patients were selected according to inclusion and exclusion criteria. Patients were randomly distributed into four treatment arms: Group I. 185 MBq 166Holmium phytate /166-Ho/ injectable suspension and 40 mg of 1 ml triamcinolone acetonide /TA/, and 1 ml of lidocaine injection 1 % Group II. 555 MBq 166Ho injectable suspension, and 40 mg of 1 ml TA and 1 ml of lidocaine 1 % Group III. 925 MBq 166Ho injectable suspension and 40 mg of 1 ml TA and 1 ml of lidocaine 1 %. Group IV. Solely 40 mg of 1 ml TA and 1 ml of lidocaine injection 1 %. There were 60 month follow-up period after the administration of the isotope. We measured the quantity of the synovial fluid and the thickness of the synovia before the treatment, and the 14 th , 28 th days and 3, 6, 9, 12, 24, 36, 48 and 60 months after the treatment. We measured the synovial thickness the following locations: In the midline, lateral and medial, by the condylus of femur medial and lateral. Results: The thickness of the synovia decreased significantly in the Group II. (555 MBq) and III. (925 MBq). After a transient improve (the steroid effect) the thickness of the synovia began to rise in the Group I. (185 MBq) and in the control group. We find a significant correlation between the synovial thickness and the clinical improvenes. Conclusions:

The 166-Holmium-phytate is an effective new radiopharmacon in the treatment of synovitis. We detect the clinical improvement by sonography. The effective dose is 555-925 MBq.

Ultrasound Monitoring of the Synovial thickness after 166-Homium-Phytate Radiosynoviorthesis. Two years results Phase III prospectiv study M. Szentesi 1 , Z. Farbaky 2 , I. Buday 2 ; 1 Semmelweis Univ., Chair of Introduction There is no consensus whether a fixed or a calculated activity of 131 I should be used for treatment of Graves' hyperthyroidism. There is no evidence that precise dosimetry leads to an improved clinical outcome. A fixed activity designed to treat the majority of patients without attempting to ablate the thyroid gland, is a simple compromise strategy. Aim The aim was to examine the quality of a method developed at our institution decades ago, based on estimating the 131 I activity one should use for treatment of Graves´ disease. This method was compared with administation of a fixed activity of 400 MBq 131 I. Material and methods Our estimation method is based on the thyroid uptake of 99m Tc-pertechnetate and the size of the thyroid gland, estimated by palpation. Sixty consecutive patients with Graves´ disease were randomised to receive either an individually estimated activity or a fixed activity of 400 MBq. In average, 308 MBq (range 260-380 MBq) was administered to 28 patients, and 29 patients received 400 MBq. Three patients did not, after all, want radioiodine treatment. The patients were followed until they had started thyroxin substitution or, if still euthyroid, typically for one year. Each time TSH, free T4 and free T3 were measured, and side effects were noted. Results Among the 28 patients who received an estimated activity, 8 (29%) were still hyperthyroid and needed further treatment. Thyroxin substitution was started in 15 patients (54 %) after an average period of 3.0 months (range 1.4-8) . Five patients were euthyroid after the treatment. Of the 29 patients given a fixed activity of 400 MBq, 4 (14%) were still hyperthyroid. Thyroxin substitution was started in 22 patients (76%) after an average of 2.8 months (range 0.5-9). One year after treatment 3 (10 %) patients were still euthyroid. In summarize, the success rate of the treatment was 71 % and 86 % in the estimated and 400 MBq group, respectively. This difference is not significant (p=0,17), but our findings are in accordance with other published studies. Conclusion The study indicates that a fixed dose of 400 MBq as well as an estimated activity in the range of 260-380 MBq give a reasonable outcome and at the same time are in compliance with the ALARA principle. However, 29 % of the patients given an estimated activity needed more than one treatment of radioiodine compared to 14 % in the fixed activity group.

This is a case of V.C., a 56 years old, female, from Las Pinas City, Philippines, diagnosed as a case of Graves' Disease. During the course of therapy, the patient had allergy to antithyroid drugs (ATDs) and beta blocker (Propanolol). She developed rashes all over the body sparing the face the day after taking her ATDs as well as Propanolol, thus all medications were discontinued. Other options, such as RAI therapy and surgery, with their respective advantages and disadvantages were fully explained to the patient who then opted to undergo RAI therapy. In our institution, we usually compute the dose based on the size of the gland and radioactive Iodine-131 uptake measurements (RAIU) rather than using fixed doses. Thyroid scintigraphy and RAIU were done which revealed poorly visualized thyroid gland and markedly diminished 24-hour uptake but normal 4-hour uptake [RAIU -4 hour uptake: 26% (NV= 15-25%); 24 hour uptake: 6% (NV= 25-45%)]. * Note: Variations in normal uptake values compared to US are due to iodine deficiency still existing in some regions. Because of the very low 24-hour uptake, we reviewed the probable causes, which can result in low uptake values. All causes were ruled out and the patient was advised to undergo two weeks of strict low-iodine diet prior to repeat thyroid scintigraphy and RAIU. Thereafter the result of repeat study showed diffuse thyromegaly with elevated uptake values indicating rapid trapping and organification processes [RAIU -4 hour uptake: 82% (NV= 15-25%); 24 hour uptake: 68% (NV= 25-45%)]. The day after the study, the patient was given 10 mCi I-131 based on the estimated weight of the gland, rapid thyroid iodine turnover ("small pool") and 24hour uptake. This was considered to be the highest allowable dose of RAI to decrease the probability of relapse and the need for re-treatment. Currently, approximately 4 weeks after the therapy, the patient is noted to have responded satisfactorily to therapy with resolution of symptoms. Aim: The aim of the study was to analyze the outcome I-131 therapy for autonomous thyroid adenomas in 361 patients observed during 16 years. Materials and method: We investigated 361 patients with Plummer's disease (M/F ratio 1:6,1; mean age 49,8 ± 12,1 years). 84,2% of these patients had an unifocal nodule, while 15,8% had multifocal toxic autonomous nodules. The patients always stopped for weeks before administration of radioiodine therapy. We administered I-131 activity of 15 ± 4,5 mCi. The mean duration of follow up was 4,36 years Results: In 340 patients (94%) a single dose was administered and the other (21 patients -6%) needed 2-3 doses. After four years 90,3% of the patients who received a single dose were euthyroid with scenografic normalization. The percentage of euthyroidism was the same after ten years. The recurrent hyperthyroidism was 6,1% -12. In these patients the mean nodular weight was 49,15 gr, the mean administered dose per gram was 171,9±26,8 μCi. The incidence of hypothyroidism was 2,6% within 0,5-7,1 years. In these patients the mean administered dose per gram nodular tissue was 177,1±37,4μCi and the mean nodular weight was 34,7±12,6gr. The nodular weight was statisticaly higher in patients who had recurrent hyperthyroidism vs hypothyroidism (p=0,001) and vs euthyroidism (p=0,002). No differences were observed in the outcome between unifocal and multifocal nodules. Conclusion: I-131 therapy is a simple, safe, effective and economical treatment of Plummer's disease. Euthyroidism can be achieved by determination of individual dose related to nodular weight and radioiodine uptake, also by preventing extranodular uptake and by evaluating more accurately the nodular weight The use of radioiodine for treatment of hyperthyroidism is based upon the radiationinduced cell changes resulting from the highly energetic beta-rays emitted by 131I. The magnitude of such effect appears directly proportional to the radiation dose. Aim: Monitoring the effect of radioiodine treatment in patients with nodular toxic goiter. Material and methods: Definitive radioiodine treatment is performed in 301 patients with nodular toxic goiter, 261 female, mean age 68,8 and 40 male mean age 68,6 .The disease duration is 48,19 months in female and 22,5 months in male. Before treatment all of the patients passed sonography, if necessary fine needle biopsy, hormonal status, radioiodine uptake test and scintigrsphy. Antithyroid drug treatment was withdrawn 7 days before radionuclide examinations. The radioiodine uptake is measured at 2, 4 and 24 hour, administered activity is 1,48 MBq. The scintigraphy was performed at 24 hour. The patients monitoring was performed at 3 rd month after treatment with clinical examination and hormonal measurements, at 6 th , 12 th and 24 th month with clinical examination, hormonal status, radioiodine uptake and scintigraphy. Radioiodine treatment was performed with dose of 185-370 MBq. Results: From 301 treated patients 261 are female with conservative treatment duration 48,19 months and this represents twice longer duration in comparison to the male.In definitively cured patients the radioiodine uptake decreased to values 34,5%, 6 months after treatment and the trend retained in the follow up controls and reaches to 72,01% compared to the initial values. In no effectively cured patients there is no significant variety in the test. The thyroid weight in the follow up period decreased with 32-48% in comparison to the initial values. Definitive treatment is determined in 70,3% at 6 month, in 81,08% at 12 month and in 83,33% at 18 month after treatment and this trend is observed in follow up tests. All of the patients received antithyroid drug therapy for 1 to 3 months followed by hormonal control and clinical examination. Conclusions:For the assessment of the treatment effectiveness and due establishment of disease relapse, the follow up period for 24 months after treatment is required.Hypothyroid status after radioiodine treatment is an indicator for definitive treatment.The variety of the radioiodine uptake and the thyroid weigh are indicators for assessment of therapy effectiveness.The absorbed radioiodine dose in the thyroid gland is 55-220 Gy . Key words: hyperthyroidism, nodular toxic goiter, 131I diagnostics, 131I therapy, absorbed dose.

The effect of radioiodine therapy on some parameters of oxidant/antioxidant balance in patients with subclinical hyperthyroidism S. S. Abdelrazek, F. Rogowski, A. Zonenberg, M. Szelachowska, A. Niko ajuk, A. Parfie czyk, P. Szumowski, B. Telejko, K. Siewko; Medical University of Bialystok, Bialystok, POLAND.

Oxidative stress plays an important role in hyperthyroidism-induced tissue damage. Increased oxidative stress, with elevated levels of free radicals, together with diminished antioxidant have been described previously in patients with hyperthyroidism. Aim: We aimed to determine whether patients with subclinical hyperthyroidism are subject to oxidative stress and whether radioiodine therapy has benefit effect on the oxidant and antioxidant status in subclinical hyperthyroidism. Material and Methods: We studied 30 patients with untreated subclinical hyperthyroidism, (25 female, 5 male), aged 23-78 years; 11 patients with multinodular goitre (MNG), and 19 patients with solitary autonomous nodule (ATN). 12 normal adult volunteers (age-and sex-matched) were studied as control group. Qualification of these patients was based on clinical features and characteristic appearance on thyroid scintigraphy and ultrasongraphy. All the patients had normal levels of serum fT3 and fT4, serum TSH levels was less than 0.1 mU/l and effective half-life measured by the use of T24 and T48 was more than 3 days at the time of treatment. Malignant changes were excluded in all nodules by fine needle aspiration biopsy. In the investigated groups, we evaluate malondialdehyde (MDA) as a marker of oxidative stress, glutathione (GSH) and glutathione peroxidase (GPx) activity as a parameters of antioxidant system before and 6 months after treatment with radioiodine. The serum fT4 fT3 and TSH were evaluated before and monthly up to 12 months after RIT, Thyroid ultrasound, and thyroid scan were done again after12 months of 131 I therapy to assess the volume of thyroid gland and thyroid nodules. The activity dose was calculated by the use of Marinelli's formula and ranged between 200 and 600 MBq. The absorbed dose ranged between 160-280 Gy, and was proportional to thyroid volume. Follow up control was done every 4 weeks. Results: Subclinical hyperthyroidism caused a significant increase in MDA level (p < 0.05) as well as a significant decrease in GPx activities (p < 0.05) and GSH level (p < 0.05) compared to euthyroidism controls subject. Achievement of euthyroidism after 6 months of radioiodine administration resulted in a significant decrease of MDA level, significant increase of GSH level and non significant increase in GPx activities. Thyroid volume reduced to about 47% (average), repeated RIT given to one patient. Conclusions: Our results confirm the imbalance of the antioxidant/oxidant status in subclinical hyperthyroid patients. Radioiodine therapy was more effective to improve these balances. Aim: The aim of this study is to evaluate the effectiveness of the fixed dose (555 MBq) of radioiodine treatment on the function and the size of toxic adenoma (TA) and multinodular toxic goiter (MNTG). Patients' population: Thirty patients (6 M, 24 F, age range 41-86, mean age 61.6) with TA and MNTG were included in the study. Twenty six patients had TA and 4 patients had MNTG. Fifteen patients had subclinical hyperthyroidism and 15 patients had overt hyperthyroidism. Eight patients were previously treated with antithyroid drugs. Method: Thyroid scan were performed, volumes of nodules were measured sonographically, thyroid hormones, TSH level and 24 h iodine uptake were determined in all patients. All of them received fixed dose of radioiodine (555 MBq). Every three months (min. 3 and max. 9 months) thyroid hormones, TSH and the volume of the nodules were measured. Results: The initial mean volume of nodules was 8.12 ml (0.79-23.42ml). After 3 (n=37), 6 (n=24) and 9 (n=10) months the volume decreased to mean 5.32 ml (0.14-20.5ml) (p<0.01), mean 3.32 ml (0.23-19.6ml) (p<0.001) and 1.63ml (0.23-3.42ml) (p<0.01) respectively. Subclinic hypothyroidism was developed in five patients during the follow-up period of nine months. Only two patients were received the second dose of radioiodine after six months because of the persistent hyperthyroidism. Overt hypothyroidism was not developed in any patient. The rest of the patients found to be euthyroid during the follow up after the initial treatment. Conclusion: Our data indicate that fixed dose (555 MBq) of radioiodine was effective in both functions and volumes of TA and MNTG in a short time of period. Aim: RAI therapy has been used for over half-a-century for the treatment of hyperthyroidism. It is extremely effective option but there are no definite methods or tests to assess the final outcome of treatment as the response varies according to a number of factors. This study was carried out to assess pulse rate at six weeks post RAI therapy as an initial clinical predictor of final outcome as documented at six months on follow up. Materials & Methods: Fifty consecutive patients referred to the department of Nuclear Medicine, diagnosed as having hyperthyroidism from July 2004 to December 2005 were included in the study. 11(22%) males and 39(78%) females with an age range of 18-78 years (Mean age 44.90) were given single dose ranging from 10mCi(370MBq)-15mCi(555MBq); mean dose 13.36mCi(494.3MBq). The baseline pulse rate for every patient was recorded twice; taken by the staff nurse and Nuclear Medicine Physician and average of the two documented. The patients were followed for at least six months post RAI therapy on an out-patient basis and assessed both clinically and biochemically (T3, T4 and TSH). At six weeks the follow up pulse rate was again assessed and correlated with the TSH levels at six months. Results: The baseline pulse rate per minute ranged from 80-130 with the mean pulse rate of 100.78 pre-therapy. The follow up pulse rate ranged from 68-116 per minute with the mean pulse rate 83.56 post RAI therapy. It was observed that if the pulse rate was > 88 per minute at six months post therapy, this was related with an adverse outcome at six months post treatment. When correlated with the TSH levels this was statistically significant applying Fisher Exact test and Chi-Square test with p-value of 0.018 and 0.002 respectively. Conclusion: Assessment of pulse rate at six weeks post RAI therapy can be used as an initial clinical predictor of final outcome at six months, however, more studies with a larger cohort of patients would help confirm this in due course. Purpose: In view of the EURATOM 96/29 regulations, a study was performed in two Greek centers, in order to evaluate radiation dose to family members of patients treated with radioiodine ( 131 I) for ablation (Group I), follow-up treatment (Group II) and hyperthyroidism (Group III), provided that they followed hospital guidelines for 15 days. The annual dose limit for the public is 1mSv/year. However, relatives helping in the support and comfort of patients are considered volunteers and dose constraints are established for them. This constraint for adult relatives (<60y) is 3mSv during the patient's treatment. Method: The radiation doses received by 30 adult family members (30 adults) of 20 patients treated with 131 I were measured using thermoluminescent dosimeters (TLD) mounted on wrist bands, for 6 days. The administered activity was 3.7GBq (100mCi), 7.4GBq (200mCi) and 592-647.5MBq (16-17,5mCi) for Groups I, II and III respectively Patient's exposure rates were also measured by a survey meter for distances 1, 2 and 3meters during the same period of 6 days. Radiation safety instructions were the same for all groups. Results: Radiation doses to all family members were below the recommended dose constraints, for the measurement period of 6 days. The estimated doses to infinity were also calculated and found to be below the recommended dose constraints. The patient's exposure rates at 1m, at the time of their release from the hospital ranged between 15-48μSv/h, 4.3-155μSv/h and 7,48-34μSv/h for Groups I, II and III respectively. Conclusion: The radiation dose to family members of all Groups is well below recommended dose constraints, provided that they comply with hospital guidelines. According to our results, 3 days of hospitalization is sufficient for Groups I and II. Papillary carcinoma of the thyroid is usually an indolent tumor with a good survival prognosis especially when small and limited to the thyroid gland. The Annual incidence of thyroid cancer per 1 million individuals in the Czech Republic is approximately 45-50 new cases, thyroid cancer is rare in children below 18 years of age -we have in our group 5% of children cancers and about 15% of microcarcinomas. Thyroid cancer is five times more frequent in females than in males, the incidence increases with age. The median age at diagnosis is between 45 -50 years. The authors followed since 1959 to 2005 a cohort of 8300 the patients suffering from differentiated thyroid carcinoma and detect microcarciomas since 1959 to 2003 (n=7200 total patients). We studied this phenomenon and discovered that this change was limited to females and to the less advanced cancers T1. The number of papillary cancers in women with more advanced stages did not change as well as any differentiated cancers in men. This unexpected finding cannot be explained by differences in radioactive fallout, and other factors should be looked for, as age, better evaluation of thyroid morphology in women. The increase of T1 cancers is remarkable, as during the years 1976 to 1985 a total of 79 new T1 cancers were diagnosed in females compared to 359 new T1 cancers between 1991 and 2001, than more than six fold increase. In patients with a thyroid carcinoma of less than 1.0 cm in diameter, which represent 15% (n=1102) of all of our patients (n=7200) form 1959-2003, the prognosis is excellent and routine RJ ablation is not indicated. However, we still prefer total thyroidectomy in these patients. Recurrent disease was detected in 5% of these patients, usually in the form of lung metastases or recurrent disease, typically during the first five years at the diagnosis. We found lung metastases after 33 years after diagnosis in one patient! The fifths version of TNM classification classified tumours into the categories T1 (0-10 mm), T2 (10-40 mm). The new sixth version of TNM classification changes that clasiffication by shifting the categories into T1 (0-20 mm) and T2 (20-40 mm). This new version thus does not allow to distinguish the patients with significantly different probability of the metastasis occurrence in the 0-20 mm category. This research was supported by AV CR 1ET100750404 and by MSMT CR 1M6798555601.

V. Voliotopoulos 1 , I. Valais 1 , M. Margaritaki 1 , V. Gianakopoulos 2 ; 1 Iatropolis Magnitiki Tomografia, ATHENS, GREECE, 2 Sotiria General Hospital, ATHENS, GREECE.

The association between thyroid cancer and hypothyroidism is considered a rare event. In the international bibliography the incidence of coexistence of thyroid cancer and hyperthyroidism is between 0,3% and 16,6%. Materials and Methods: In our clinic since now, we treated 750 patients with thyroid cancer and 10 of them was operated at firs time for thyrotoxocosis and the malignancy was detected incidentally.70%of them were men and 30%women.Among them 7 had moltinodular goiter and the rest 30% had Graves'disease.The histological examination revealed 9 papillary, 1 follicular and 1 hurthle cells carcinoma. Results: All patients received radioiodine therapy and in one patient because a high radioiodine uptake (11, 1%) and after 17 days of withdraw of T3 and a TSH level of 21, 2 ngr/ml we used the recombinant TSH (Thyrogen).In the WBS 10 days after therapy in this patient the uptake was very intense in the thyroid bed. Conclusion: The rate of incidence thyroid carcinoma in these subjects with thyrotoxocosis was similar to previous studies reported from other European countries. The ablation therapy 1 year after therapy was very successful and with no need for a new therapeutic session. Despite many years of experience in thyroid cancer treatment the optimal dose of iodine-131 necessary for successful ablation is not established. The aim of the study was to compare the rate of ablation with different doses of radioiodine. The rate of ablation was compared in four groups of patients. Statistical differences were evaluated with Mann-Whitney U-test, Kruskal-Wallis test or Pearson's chi-square exact test and a P value less than 0.05 was considered to indicate statistical significance. 466 consecutive patients with papillary thyroid cancer (404 women, median age 47 years; range 14-79 years), who have undergone total thyroidectomy were retrospectively studied. Ablative doses of I-131 were applied 4-6 weeks after the surgery. Patients were hypothyroid, with TSH more than 30 mIU/L. Patients were randomized into four groups according to 131 I administered activity, starting at 24 mCi (168 patients), then 40 mCi (125 patients), 50 mCi (65 patients), until 120 mCi (108 patients). The outcome of thyroid ablation was assessed by conventional 5 mCi whole body-scan, performed in hypothyroid state 6-9 months after ablation (first control study), and finally 12 months after (second control study). Successful ablation has been defined as the absence of residual thyroid uptake in thyroid bed. The rate of successful ablation was similar in the group of patients received 24 and 40 mCi (75% and 71.2% respectively). The higher rate of ablation (87.69% and 90.74%) was achieved in the groups treated with 50 and 120 mCi of radioiodine. In conclusion, our study indicates that a 50 mCi dose of radioiodine is a sufficient for a satisfactory thyroid ablation rate. Use of low effectively 24 and 40 mCi dose for initial ablation is justified by the convenience of administration, the lower expence and the lower whole-body radiation dose, and in our opinion this modality is convenient for group of patients with low risk of recurrent disease. Introduction: Although the differentiation thyroid cancer (DTC) has proven to be a good prognosis with significant decrease in mortality rates, many countries recently witnessed an increase incidence of this pathology. In this respect,this study aims at assessing 10 years of DTC management in national cancer centre, through a population survey. Materials &methods: 750 patients were referred to the department of endocrinology and nuclear medicine, for DTC management between1996 and 2005.All patients have undergone a surgery with total thyroidectomy even for papillary microcarcinoma followed by an iodine 131ablation. Results: This study confirms that the DTC incidence increased through the years essentially from 2001(between 2 to 3 times).The female sex is 6 times more frequent than in male (86%Vs14%) with a median age at diagnosis stage between 30 to 49 years in 49% of patients. In 64 % of the cases (33% for solitary nodule), the multinodular goiter is the principal reason for the first consultation. Even though the fine needle aspiration biopsy (FNA) was performed only in 30% of patients, 70% were malignant. The papillary histology type is 5 times more frequent than follicular type (75% Vs16%).86 % of patients have received an activity of 3.7GBq of I-131, while 9% have received 7.4GBq ,5% more than 7.4GBq as cumulative activity. After a minimum follow up of one year 78% of patients have had an undetectableTg. Conclusion: Although the increase incidence of DTC has been observed since 2001, the reasons according to our understanding are due to the early stage diagnosis using FNA, the frequent availability of neck ultrasonography and the multidisciplinary approach, rather than the fallout atmosphere of radioactive iodine or the population's exposure to thyroid radiation. As for the rest of the results, it is noticed that a patient is generally a female sex in 80% of the cases, aged between 30 to 49 years in 49%.They present a multinodular goiter in 64% with papillary histology type in 75% Aim: Well differentiated thyroid carcinoma of the ectopic thyroid tissue is a very rare entity. Our aim in this study is to determine the frequency of this clinical condition and to present the clinical experience obtained in the management of our patients with thyroid carcinoma of the ectopic thyroid tissue. Material and method: The clinical records of 1800 well differentiated thyroid carcinoma patients treated and followed in our institution between the years 1990 and 2007 were retrospectively evaluated. The carcinoma focus was found in an ectopic thyroid tissue in 11 cases. The localization of the ectopic thyroid tissue was thyroglossal duct in 8 patients, parapharengeal region in one patient, submandibular region in one patient and submental region in one patient. Results: Mean age of the patients (8F; 3M) is 43,3 years. Histopathological examination of ectopic tissue specimen revealed that 10 of the patients had papillary carcinoma and one of them had follicular carcinoma. Near total thyroidectomy was performed in all of the patients. Seven of 11 patients had a focus of well differentiated carcinoma in thyroid tissue also. The size of the thyroid tumor was between 13-35 mm in 3 cases and below 10 mm. (papillary microcarcinoma) in 4 cases, 3 of them being multifocal. Two patients had regional lymph node metastasis; there was hyoid bone and regional muscle tissue invasion in another patient. Only sub-total/near-total thyroidectomy was performed for two patients of the 4 patients whose thyroid gland was normal. For the other 2 patients with advanced disease and 7 patients who had carcinoma of the thyroid gland also; radioiodine ablation therapy was performed after thyroidectomy. Two patients were lost to follow-up. Mean remission time was 14.5 (6-42) months for the other 9 patients who are currently under follow-up (for 15-108 months) by sonographic examination and thyroglobulin level measurement at intervals. Conclusion: The occurrence of ectopic thyroid tissue carcinoma is uncommon in regard to all thyroid carcinomas. The evaluation of thyroid gland for concomitant carcinoma in the thyroid tissue leads to the incidental detection of papillary microcarcinoma in majority of these patients. However, the clinical course of the disease is favorable with a management protocol similar to well differentiated thyroid carcinoma. If we hypothesize that stunning effect arose from either the ablative action of the diagnostic I-131 dose or the early effects of the therapeutic I-131 dose , this like stunning phenomenon should concern any thyroid remnants independently to the time interval between the above iodine doses. Aim: The goal of this study was to investigate the presence of like stunning phenomenon in patients who received both diagnostic and ablative I-131 dose with a delayed time interval (>3 months) between them. Material and Methods: The study included 59 patients (5 men, 54 women, mean age 55 years) with a histology of differentiated thyroid carcinoma , disease limited into the thyroid bed and uptake 1.57±1.03. A therapeutic I-131 dose of 80-100 mCi was given 4-12 months after the 5 mCi I-131 diagnostic whole body scanning. All patients had a whole-body scan on the 8 th posttherapy day while 20 of them had it also on the 3 rd day. A quantitative estimation of the thyroid remnants was considered on the 3 rd day (Dx) for the diagnostic WBS, on the 3 rd (Rx 3 ) and 8 th (Rx 8 ) day for the posttherapy WBS. The ratio therapeutic/diagnostic (Rx 8 /Dx) concentration of I-131 in residual thyroid remnants was calculated for all patients and stunning was considered when Rx 8 /Dx was lesser than 1. The ratio Rx 3 /Rx 8 and Rx 3 /Dx were also calculated for the 20/59 patients. Results: Of the 59 patients, 31(74%) exhibited Rx 8 /Dx <1 (likestunning effect). The like-stunning population included 12/16 (75%) patients with uptake > 2%, 13/23(56%) patients with uptake between 1% and 2% and 6/20 (30%) patients with uptake < 1%. Among the 20 patients with posttherapy evaluation on the 3 rd and 8 th day, 14 patients had Rx 3 /Rx 8 >1 and Rx 3 /Dx>1, indicating a clear early curative action of the therapeutic I-131 dose and 3 patients had ratio Rx 3 /Dx<1 and Rx 8 /Dx<1 indicating a clear curative action of the diagnostic I-131 dose. Conclusion: Our results support the hypothesis that thyroid like-stunning phenomenon can be observed in patients with a diagnostic and a delayed consecutively therapeutic I-131 dose. This like-stunning effect could be the consequence of destructive effects from either the diagnostic or the therapeutic I-131 dose, mostly when the thyroid remnants are major. Objective: Studies have suggested that I-123 whole body scans (WBSs) can underestimate the extent of well differentiated thyroid cancer. We wanted to find out if I-123 WBS images provide an accurate foundation for deciding the therapeutic dose of I-131. Method: Three hundred and thirty three I-123 WBSs of 292 consecutive patients from January 2004 to March 2006 were retrospectively reviewed. All patients received total thyroidectomy for well differentiated thyroid cancer, and were on low iodine diet for at least 2 weeks, and reached TSH greater than 30 mIU/L prior to the I-123 WBS. I-131 WBSs were obtained after the patients were given high dose of I-131 (>100 mCi) for remnant thyroid tissue, local recurrence, or metastasis. The I-123 WBS and post-therapeutic I-131 WBS were performed less than 2 weeks apart, the images were reviewed for abnormal radioiodine uptakes. Results: In 298 cases, I-123 WBS and post-therapeutic I-131 WBS agreed on the extent of the thyroid cancer. However, in 35 cases, post-therapeutic I-131 WBSs detected additional lesions such as further metastatic lymphadenopathy of the mediastinum or distant metastasis to the lungs. In 22 of these I-123 WBS and I-131 WBS discrepant cases, the therapeutic dose of I-131 may have been increased had the physician known about the presence of additional lesions. Conclusion: I-123 WBS performed prior to high dose radioiodine therapy underestimated the extent of well differentiated thyroid cancer in 10.5% of the cases, and may have lead to suboptimal therapeutic dose in 6.6% of the cases. Therefore, I-123 WBS images alone may not be accurate basis for determining the dose of radioiodine therapy. Aim of the study: To determine the recurrences and disease related deaths in patients (pts) with differentiated thyroid carcinoma (DTC) treated by surgery and by radioactive iodine ( 131 I) as initial therapy. Patients and methods: Two hundred eighty DTC pts were operated and after that treated by 131 I once or several times. All pts received life-long hormonal therapy. Duration of follow-up: mean 9.1 + 5.5 years, median 8.2 years, range 2 months-26.9 years. Probabilities of the recurrences and disease related deaths were calculated by Kaplan-Meier's method and the significance of differences was determined by Log-rank test. Results: Two hundred fifty eight pts were in the remission after initial therapy; the recurrences appeared in 46 (17.8%) of them during follow-up period. The probabilities of recurrences after 5, 10 and 20 years were 10%, 20% and 30%, respectively. The significant influence on the appearance of recurrences had: the absence of 131 I accumulation in tumor, incomplete remission, initial TNM stage III and IV, pts' age >45 years and nodal metastases. The disease related deaths occurred in 27 pts (9.6% of all treated pts) during follow-up period; deaths occurred after recurrences in 13 pts (28.3% of pts with recurrences). The probabilities of disease related deaths after 5, 10 and 20 years were 6%, 9% and 17%, respectively. The significant influence on the deaths had: the initial TNM stage III and IV, pts' age >45 years, distant metastases, absence of 131 I accumulation in tumor, masculine gender and nodal metastases. Conclusion: All followed pts were initially treated surgically and by radioiodine. The appearance of recurrences progressively increased with years after initial therapy, so it is necessarily to follow-up pts till the end of their life. It is very important to treat pts until complete remission of disease is reached, to decrease the frequency of recurrences. Disease related deaths occurred more frequently after onset of recurrences; it is indispensably to treat relapses to achieve the stable complete remission, if this is possible.

The retrospective evaluation of metastatic bone disease in differentiated thyroid carcinoma Ö. Küçük, E. Özkan, E. Tokmak, P. Tarı, G. Aras; Ankara University Medical Faculty, Ankara, TURKEY.

Aim: Bone metastases(BM) are seen clinically in 4%-13% of patients (pts) with differentiated thyroid carcinoma(DTC).Due to difficult treatment, the prognosis is poor. We evaluated metastatic bone disease in our DTC group, retrospectively. Material-method: BM were detected in 20 pts out of 596 with DTC who were treated and follow-up in our clinic between 1997-2006 (age range 26-72 years; 13F, 7M). Papillary carcinoma was diagnosed in 9/20 pts and follicular carcinoma in 11/20. A total of 3.7-53.65 GBq (100-1450 mCi) I-131 was given to each patient. The duration of follow-up ranged from 6 to 156 months. I-131 whole-body scan(WBS), Tc-99m MDP whole-body bone scan, the determination of Tg and antiTg levels and/or a CT scan were carried out in the assessment of a diagnosis and follow-up of pts with BM. Results: The frequency of BM were found 3.4% in our analysis. Classification was performed according to detection time of BM. Group1; 15 pts diagnosed with primary BM, Group2; 2 pts with BM detected in post-ablative WBS, Group3; BM diagnosed in the follow-up period in 3 pts. In group1, 8/15 pts had only BM, 1/15 pt had bone and brain metastases, 6/15 pts had lymph node and/or lung metastases also. In group2; 1 pt had only BM, 1 pt had bone and lung metastases. In group3; 2 pts had bone, lymph node and/or lung metastases, 1 pt had bone, lymph node, lung and brain metastases. In the follow-up period, 3 pts from group1 and 1 pt from group3 were died. The BM were seen in 9-72 months after the diagnosis for group3. BM were persistent after the therapy on the other hand, additional new lesions were observed. Tg level was high in all pts remarkably except 2 pts (Tg-max:158226 ng/mL). One of these 2 pts with normal Tg level had high anti-Tg level (150 IU/mL), the other one had normal anti-Tg level (<20 IU/mL). 2 pts had anti-Tg levels higher than Tg levels. BM were persistent after the therapy on the other hand, additional new lesions were observed, especially in group1. Discussion: The frequency of BM has been reported 4%-13%. This ratio were found 3.4% in our analysis. We observed higher ratio of diagnosed DTC with primary BM (75%) (grup1). Its prognosis was worst than other groups. Conclusion: Tg is more important parameter than anti-Tg and the prevalence of the other organ metastases is high in DTC pts with BM. Aims: Based on the ICRP recommendations, the policy for releasing patients with differentiated thyroid carcinoma (DTC) who underwent thyroidectomy and received ablation doses of I-131, from the nuclear medicine departments should be based both on general national rules and specific regional conditions. The aim of this research was to study the kinetic, urinary excretion pattern and dosimetric characteristics I-131 to estimate the radiation doses to the public, and to check the policy for the release of these patients. Materials and Methods: Twenty-nine patients with DTC who referred to our department were selected for this study. The mean radioactivity doses administrated was 4± 0.9 GBq (range 3.7-7.4). The instantaneous dose rates were measured immediately after the administration of therapeutic radioiodine with patients in the upright position at distance of 3 meters and just before they left the department at distances of 0.5, 1 and 3 meters using a survey meter. Also, urine samples from each patient were collected every 2-4 hours for up to 3 days after radioiodine administration. Results: The maximum dose received by the nursing staff was 1.6 mSv/week, less than the dose recommended by the ICRP. The dose rate and remaining activity values of 6 out of 29 patients were higher than those of the others and this contributed to a high standard deviation. Only one of these six patients had metastases. It was noteworthy that other patients with metastases showed a moderate dose rate exposure or moderate remaining radioiodine activity in the body. On average sixty hours post administration of radioiodine, 70% of the administrated dose was excreted through the urine, 4% remained in the body and 26% decayed or excreted through other routes. Conclusion: These results indicate that family members should take into consideration the duration and the distance of being in close contact with the above patients. The time-rate curve of urinary excretion of radioactivity in all patients showed multiple peaks due to the retention and redistribution of radioiodine within the body and the enterohepatic cycle of radioiodinated thyroid hormones. Based on the study results, at least in countries as ours we strongly recommend changing the policy for release of all patients receiving radioiodine therapy except those who are capable to keep instructions properly. Patients should be discharged when radioiodine body retention and instantaneous dose rate are less than 111 MBq and 20 mSv/h at a distance of 1 m, respectively. Aim: Radioiodine therapy (rit) after a total thyroidectomy is the standard treatment of differentiated thyroid cancer (dtc). Since more than 90% of the incorporated iodine in healthy patients is cleared by the kidneys, the rit of renal failure patients (rfp) affords high requirements concerning dosimetry. Aim of this study was to determine the progression of activity in rfp and to compare the results to renal healthy patients with dtc (34 patients). Material and Methods: In the recent 10 years we treated 4 rfp with dtc. One of them was treated 3 times (2x rit + diagnostic scan (ds)), 2 twice and one patient once. Consequently the activity progresses of collectively 8 rits were documented and assessed dosimetrically. Applicated activities were between 865 and 1248 MBq (604 MBq for ds). The remaining activity was measured twice a day and immediately before respectively after the haemodialysis with an individual calibrated gamma probe. Hence the mean halflife was determined with an exponential fit on the one hand, and the integrals between the single measured values on the other hand for calculating the mean whole body dose (wbd). Haemodialysis was done on the first and third day after application. Results: The calculated halflife averages 1.8 days (1.6 -2.1). The wbd per patient averages 129 mGy (40 -180) corresponding to a mean wbd of 0.128 mGy/MBq. In comparison, the effective halflife for non-rfp averages 0.6 days (0.3 -1.1) and the wbd averages 215 mGy (71 -442) corresponding to a mean wbd of 0.052 mGy/MBq. The mean elimination of radioiodine per haemodialysis averages 47% (+/-14%). Conclusion: About 50% of the remaining activity is eliminated per haemodialysis. The effective halflife during the time interval between two haemodialysis in one patient varies depending on the grade of renal failure and should therefore be observed. The mean effective halflife for the total rit of rfp is increased 3 times compared to healthy patients. The dose per applicated MBq is enhanced correspondingly 2.5 times. Therefore, we suggest to decrease the activity for rfp with dtc to an amount of 30% of the activity, administered in non-rfp.

Retrospective analysis of patients with differentiated thyroid carcinoma (DTC) E. Urbanova, J. Vizda; Nuclear Medicine University Hospital, Hradec Kralove, CZECH REPUBLIC.

Nuclear medicine has had a major impact on the management of DTC, especially in post-operative ablation, detection and therapy of recurrence or metastases. Aim of this study was long term follow-up 25 patients ranged from 25 to 30 yrs after radioiodine therapy. Method: During the period lasting from February 1973 till December 1977 radioiodine therapy was performed for 25 pts after thyroidectomy due to DTC. Papillary carcinoma was diagnosed in 13/25 pts and follicular in 11/24 an in one pts histologically mixed type was found. Thyroid hormones treatment was done to compensate the lack of endogenous hormones and to stop TSH secretion. Follow up for all pts consisted from the WBS (whole body scintigraphy) performed after thyroid remnant ablation with 131 I. Further clinical, plain X-ray of the chest, vocal cord and US (ultrasound) of thyroid gland and neck examination and periodic serum Tg (thyreoglobulin) measurements and later WBS with 99m Tc-MIBI and rarely CT were performed. Results: Despite early detection and adequate initial treatment we observed after mean follow-up of ten yrs, three neck lymph-nodes recurrences and two pulmonary, one bone and one vocal manifestation of disease. So seven pts were retreat with radioiodine therapy. After 27 yrs seven pts showed recurrence due to pulmonary and bone metastases and five pts were follow-up for second carcinoma. Two pts died due to cardiovascular disease and one after generalisation of the disease. Completely free of disease after 30 years were 17 pts but lot of other complications were present (e.g. haematuria, hypertension, nephrolithiasis). Two patients showed one side decrease in salivary function. Maximum total administered activity of 131 I for one patient with repeated therapy for pulmonary, bone and brain metastatic process during 30 years was about 1200 mCi. Conclusion: The demonstration of distant metastases can be present after long period after beginning of the disease. For the evaluation of lung metastases in DTC, determination of Tg levels and the 131 I WBS were the most important procedures. Computed tomography is a useful addition, because 99m Tc-MIBI imaging alone may not be enough to detect lung metastases from DTC. Short and long complications of 131 I treatment should be taken into the careful consideration with the benefit for the patient with long survival.

Our first experience with low dose radioiodine ablation therapy in low risk patients with differentiated thyroid carcinoma Z. Rajkovaca 1 , J. Mijatovic 1 , M. Skrobic 1 , G. Mikac 1 , G. Vuleta 1 , A. Matavulj 2 , P. Kovacevic 2 , N. Ponorac 2 ; 1 Clinical Centre, Banja Luka, BOSNIA AND HERZEGOVINA, 2 Medical Faculty, Banja Luka, BOSNIA AND HERZEGOVINA.

The optimal dose of Iodine-131 for ablation of functioning residual thyroid tissue after (near)total thyreidectomy is controversial. The aim of this study is to present our experience with low (1.48 GBq) dose I-131 in ablation of differentiated thyroid cancer remnants in low risk patients. Material and Methods: A total of 58 patients (mean ages of 48.5 years, range 23 -72 years) with papillary and follicular carcinoma were treated first time in our Department with I-131 for ablation of a postoperative thyroid remnant after (near)total thyreidectomy. Patients with stage pT1 or pT2 N0M0 were including in the study. Patients were divided into two groups according to size of postoperative residual thyroid tissue, level of thyroglobulin and age. Group A, 40 patients received 1.48 GBq I-131, Group B, 18 patients received 3.7 GBq I-131. Six months after treatment, all patients were reassessed after withdrawing L-thyroxin for 4 to 6 weeks with I-131 whole body scan and serum thyreoglobulin measurement. A successful ablation was defined as the absence of thyroid bed activity in 185 MBq I-131 neck scan, the neck uptake of <0.3% of the administered activity and the thyroglobulin value of <5 ng/mL. Results: In group A successful ablative therapy was seen in 35 (87.5%) of patients. Of these 88.6% had papillary carcinoma on histopathology and 11.4% had follicular carcinoma. In group B successful ablative therapy was seen in 88.9% of patients. Of these 11.1% had follicular carcinoma on histopathology and 88.9% had papillary carcinoma. There were no statistically significant differences between these two groups in relation to thyroid ablation. Also, there were no statistically significant differences in thyroglobulin serum level 6 months after I-131 treatment. The remaining ones, 12.5% and 11.1% respectively, received the second course of I-131 for remnant ablation. 5/40 patients required therapy in group A and 2/18 in group B. Response to low dose I-131 was same in patients with papillary and follicular type of carcinoma. Conclusion: Our evaluation of early efficacy of adjuvant radioiodine treatment in low risk patients with differentiated thyroid carcinoma shows no differences between two radioiodine activities -1.48 GBq and 3.7 GBq in relation to thyroid ablation. We recommend the activity of 1.48 GMBq in low risk patients. Thyroid stunning phenomenon is the impairment of therapeutic 131 I uptake by normal or metastatic thyroid tissue, as a result of previous administration of a diagnostic activity of the same radionuclide. It has been demonstrated after the administration of diagnostic activities of 74-370 MBq (2-10 mCi) of 131 I. We can avoid it using 123 I in the whole-body scintigraphy. However, even the ablative therapeutic activity itself may cause stunning, because of the high radiation dose absorbed by the thyroid remnant in the first hours of the iodine accumulation (self-stunning). Aim To evaluate the occurrence of self-stunning in residual thyroid tissue after total thyroidectomy for differentiated thyroid cancer followed by 131 I therapeutic ablation. Materials and Methods A prospective study was conducted from 2005/08/09 to 2006/09/19 in 33 patients submitted to total thyroidectomy for differentiated thyroid carcinoma of follicular origin (26 female and 7 male, aged from 16 to 88, mean 48,91 ± 18,33 years). Withdrawal of levothyroxine intake, low iodine diet throughout the foregoing week and analytical studies including iodinuria were required before undertaking both diagnostic and therapeutic procedures. Cervical uptake was determinated 24 hours after oral administration of 11 MBq (300 μCi) of 123 I. Ablative therapeutic was performed 6 days later, with 131 I activities ranging from 925 to 6179 MBq (25 to 167 mCi), mean 3367 MBq (91 mCi). Cervical uptake of the radionuclide was determined 24 hours later. We used a Siemens E-Cam DCR Dual Head gamma camera, equipped with medium and high-energy collimators for 123 I and 131 I respectively, to obtain segmentary images of the patient`s cervical anterior region, as well as the 123 I capsule to be administered and a known activity of 131 I, 30 cm from the detector. Results In the diagnostic study, the cervical 123 I uptake varied between 1,1% and 29,8% (mean 6,8%). The post therapeutic uptake of 131 I oscillated between 0,42% and 17,82% (mean 4,2%). In all of the patients, a reduction in the cervical uptake of iodine ranging from -2,83% to -75% (mean -43,8%) was observed in the post therapeutic study, as compared with the diagnostic one. This reduction was found to be statistically significant (t = 5,822; p < 0,0001). Conclusions We verified the occurrence of selfstunning in all of the 33 patients subjected to ablative therapeutic with 131 I.

A. Georgakopoulos, S. Saranti, L. Iordanidou, E. Trivizaki, K. Rethymniotakis, E. Matselas, P. Koutsiouba; Metaxa's Cancer Hospital Piraeus Greece, PIRAEUS, GREECE.

If we accept the hypothesis that stunning phenomenon could be related to the curative radiation dose of iodine -131, either the diagnostic or the early therapeutic iodine-131 (I-131) action could contribute to a stunning effect production. Aim: The aim of this study was to investigate whether the diagnostic or the early therapeutic I-131 radiation dose provoke a partial ablation, giving thus the stunned appearance of the thyroid remnants. Material and Methods: 48 patients with total/near total thyroidectomy (uptake 1.52±1.13) for differentiated thyroid carcinoma received the first ablative iodine dose (50-100 mCi) within 3 months from the diagnostic 5 mCi I-131 dose. The patients were evaluated with diagnostic WBS 72 hours after the administration of 5 mCi I-131 and with posttherapy WBS 8 days after the ablative I-131 dose. Furthermore 20 of the above patients were evaluated with onemore posttherapy WBS on the 3 rd day of the ablation. Serum TSH, Tg and anti-Tg were considered in hypothyroid state. The patients were divided into 3 groups according to the uptake value. Group A(uptake >2%) consisted of 16 patients, group B (uptake 1%-2%) of 7 and group C (uptake <1%) of 25 patients. A quantitative estimation of the thyroid bed activity was performed for the diagnostic, the 3 rd day posttherapy and the 8 th day posttherapy WBS. The ratio therapeutic/diagnostic (Rx 8 /Dx) concentration of I-131 in thyroid remnants was calculated and stunning was considered when the ratio Rx 8 /Dx<1. The ratios Rx 3 /Rx 8 and Rx 3 /Dx were calculated for the 20 patients with the additional 3 rd posttherapy day WBS. Results: 25 of the 48 patients (52%) demonstrated stunning phenomenon (Rx 8 /Dx <1). Between them 16/25(64%) had a 3 days interval between the diagnostic and the therapeutic dose, 6/25(24%) had a 4-10 days interval and the rest 3(12%) patients had a 31-90 days interval. The stunned population consisted of 11/16(69%) patients of group A, 3/7(43%) of group B and 11/25(44%) of group C. Among the 20 patients with the 3 rd and 8 th day posttherapy WBS, 15 had Rx 3 /Rx 8 >1 and Rx 3 /Dx>1 indicating a clear early curative action of the therapeutic I-131 dose and other 3 patients had ratio Rx 3 /Dx<1 and Rx 8 /Dx<1 indicating a clear curative action of the diagnostic I-131 dose. Conclusion: A partial ablation could be generated by either the diagnostic or the early curative therapeutical I-131. The density of this phenomenon seems to be directly proportional to the extent of the residual thyroid tissue.

Radioiodine treatment is contraindicated in pregnancy. Still, inadvertent therapy does occur. Radioiodine was given to two pregnant women with Graves' disease and thyroid cancer respectively, both in their 20th gestational week. Routine pregnancy tests based on urinary -hCG had failed to indicate pregnancy in both cases. Methods: Estimation of doses to the foetuses and foetal thyroids. Scrutiny of pregnancy testing. Results: Doses to foetal thyroids were ablative (250-600 Gy). Total foetal dose in the Graves' patient was 100 mGy and compatible with survival, whereas a foetal dose of approximately 700 mGy together with induced hypothyroidism was fatal for the foetus of the cancer patient. Conclusions: Routine pregnancy tests (urine -hCG) may not only fail early and but also later in pregnancy.The -hCG level can be low from mid term, especially in case of a male foetus. The possibility of pregnancy should be considered in all fertile women before therapy with radionuclides or cytostatic regimens, and a clinical investigation undertaken on wide indications with determination of serum -hCG, preferably together with an ultrasound examination. More than two decades ago, the radiation absorbed dose thresholds for successful radioiodine-131 (I-131) treatment of residual thyroid tissue and lymph node metastases (300 Gy, N=30, p<0.05 and 80 Gy, N=67, p<0.01, respectively) were established by Maxon HR et al. N Engl J Med 1983. [1] . Until today, these thresholds have been frequently cited in dosimetric context related to postsurgical thyroid cancer patients. The aim of this study was to review some quantitative dosimetric works published so far, in order to explore if the initially proposed thresholds [1] ). The data were adopted from available works exactly in the form in which they had been published or presented and were statistically analyzed using 2x2 tables. Three-hundred Gy has been not statistically proven absorbed dose threshold for successful ablation of remnant thyroid with I-131 [2, 3, 4, 5, 7] . Suggested absorbed dose-rate threshold of 3 Gy/h for successful thyroid remnant ablation [4] was not proven too. The lowest study-specific thresholds for successful thyroid remnant ablation were derived as follows: 40 Gy (N=11, p<0.01) [5], 50 Gy (N=39, p<0.01) [3] , 150 Gy (N=37, p<0.01) [6], 1.6 Gy/h .AND. 100Gy (N=40, p<0.05) [7] . Further support of the latter values is the mean absorbed doses of therapeutic I-131 delivered for successful (147±128 Gy) and unsuccessful (41±16 Gy) thyroid remnant ablation (N=23, p<0.05), as presented in abstract by Haq M et al. Eur J Nucl Med Mol Imaging 2006. Quantitative in-vivo data published to date does not support a widely-accepted dosimetric approach to thyroid remnant ablation based on the threshold absorbed dose of 300 Gy. In contrast, intrathyroidal doses of I-131 in the range of 40-150 Gy appear to be evidence based cut-off values required for significantly higher success-rate of thyroid remnant ablation in postsurgical thyroid cancer patients. Aim: This study evaluates the incidence of radiation thyroiditis and its relationship with I-131 thyroid remnant uptake following I-131 adminstration for post surgical completion ablation therapy for thyroid cancer. Methods: Patients having an initial post surgical administration of either 1110 Mbq or 3700 Mbq I-131 between Jan 1992 -Dec 2006 were retrospectively reviewed. The activity of thyroid remnant I-131 on the 48 hour post administration scan was measured and correlated with neck symptoms experienced. Following review of medical records, patients were classified as having insignificant, mild or severe thyroiditis based on no treatment, NSAIDs, or steroids respectively. Statistical analysis was performed using ordinal and regular logistic regression for thyroiditis (yes/no). Results: 183 patients were included (143F,40M;16-87 years). 68 patients received 1110 Mbq and 115 patients received 3700Mbq.The mean I-131 thyroid uptake was 70.3 Mbq (Range 0-481 Mbq). 39/183 (21%) patients developed symptomatic radiation thyroiditis. Incidence and severity of thyroiditis increased with increasing I-131 thyroid remnant activity (p=<0.0001). The risk of developing any degree of thyroiditis increased by 64% for every 37 Mbq increase in activity (OR= 1.73 (95% CI 1,36-1.99). Severe thyroiditis was not seen with remnant uptake <74 Mbq while 9/30 (30%) of patients with remnant uptake >111 Mbq experienced severe thyroiditis. For patients treated with 1110 Mbq and 3700 Mbq, thyroid remnant ablation success rate was 75% and 82% (p=NS), incidence of any thyroiditis was 12% and 27% and incidence of severe thyroiditis was 1% and 8% (p=<0.05) respectively. Conclusions: Initial post surgical I-131 thyroid remnant uptake of >74 Mbq often produces significant thyroiditis. Lower initial administered I-131 activities may be desirable for low risk disease, particularly when a larger thyroid remnant is suspected. This lower initial administered dose does not appear to significantly compromise success rate of thyroid remnant ablation. 4) . After oral administration of 131-I the external whole-body dose rates were measured at a distance of 1 meter in each hospitalization day until the dose rates fall bellow the release dose rate level of 10μSv/hr. Results: The dose rate decay was biexponential for all four groups. By considering the dose rate limit of 10 μSv/h at 1 m for releasing patients, %76.4 of patients satisfied this limit after 3 days , %88.7 after 4 days and %98.8 after 5 days. There was total of three cases with hospitalization times more than 6 days because of functional thyroid reminants and widespread metastasis. The cumulated dose received by the nursing staff was 54 μSv/week, less than the dose recommended by the International Committee for Radiation Protection (ICRP). Discussion: Our data clearly showed that suitable guidelines can be derived to limit the annual dose to less than 1 mSv for children, members of the public and staff who may come into contact with cancer patient treated with radioiodine . Aims: negative diagnostic 131 I whole body scan with elevated serum Tg levels are found in 20% of patients with differentiated thyroid cancer (DTC). Empirical radioiodine treatment has also been advocated by some researchers with controversial outcomes. We performed an anterospective study to aim the answer to abovementioned dilemma and also determine the capability of Tl-201scintigraphy in these patients. Materials and Methods: We studied 21 patients with a mean age of 53 ± 14.17 years who had a history of follicular cell derived thyroid cancer (FCDTC) and elevated serum Tg levels with a negative 131I diagnostic WBS and also were treated with radioiodine. In 15 patients also whole body scan with Tl-201 was carried out. Paired T test and correlation tests were carried out. A P-values of 0.05 or less were considered to be significant. Results: The mean pretreatment and posttreatment Tg were 227.23 ± 208.50 ng/ml and 163.43 ± 282.57 ng/ml respectively. There was statistically significant difference between pre and posttreatment Tg (p value< 0.05). Eleven cases showed at least 50 % decreased in Tg value (remission group), 6 patients revealed less than 50 % decreased in Tg value (stable group) while 4 subjects demonstrated Tg increment in posttreatment Tg relative to pretreatment Tg value (progression group).There was no significant correlation between cumulative and also last I-131 doses in three groups (remission, stable and progression groups) [p value> 0.05]. In the posttreatment WBS, 10 patients showed abnormal findings in their images. In follow up scan with Tl-201, 9 out of 15 cases had positive scan. In our study at least 50 % of subjects demonstrated the reduction or normalization of serum Tg occurred in the first post-treatment follow up. Thus, our study support benefits of empiric RAI therapy of diagnostic RAI scan-negative and Tg-positive FCDTC patients .In addition, for the management of FCDTC patients who do not have RAI accumulation and have elevated Tg, other imaging modalities such as Tl-201 scan are helpful. Conclusion: We recommend RAI therapy in DTC patients with elevated Tg and negative WBS .In addition, at hospitals without access to PET, we can expect improvements in the detection of recurrence and metastasis to make a logical management after total thyroidectomy using I-131 and T1-201 as complements to each other. Objectives: For radioimmunotherapy (RIT) with Y-90-labelled monoclonal antibodies, a surrogate nuclide for assessing biokinetics is necessary as Y-90 is not appropriate for imaging. Due to similar half-life, coordination chemistry and metabolic handling In-111 is used. However, differences in biodistribution of these 2 nuclides have been reported. Here we present a method for an intraindividual comparison of blood biokinetics of In-111-and Y-90-labelled anti-CD66 antibody for RIT. Methods: For five patients (1 male and 4 female, age: median 46 years, range 21-67 years) with AML or ALL blood serum activity data were collected during dosimetry (In-111) and therapy (Y-90). The median and range of the applied activities for In-111 and Y-90 were 134 MBq (78-146 MBq) and 3107 MBq (2172-4120 MBq), respectively. A set of 18 models (sums of 1 to 3 exponentials, with various combinations of shared or non-shared parameters) was chosen and fitted to the data of each patient. Non-shared parameters means fitting the In-111 and Y-90 data with extra parameters, while shared means using a common parameter for both nuclides. All parameters, which describe later parts of the serum time activity curve were fitted non-shared, as the treatment could affect serum time activity curve. The fit parameters were calculated using a minimum sum of squares algorithm. The model which supported the data best was selected using the corrected Akaike information criterion. The models were ranked according to the Akaike weights. Results: The model when sharing the parameters of the first exponential between the In-111-and Y-90-labelled time activity curves is ranked best in four out of five patients. One patient's data were best described sharing only the half-life, but not the prefactor of the exponential. All best models were substantially supported (wi = 0.70-0.96) by the data and R2 as a measure of goodness of fit was higher than 0.97. The areas under the curves from 0 to 4 h p.i. of the best fit model of In-111 and Y-90 had a ratio of 1.02±0.03. Conclusions: The introduced method is a powerful and straightforward approach for intraindividually quantifying similarities or equality of blood serum biokinetics. This is a pivotal step in the surrogate nuclide selection process, since equality or high similarity is a necessary, although not sufficient, condition for extrapolating from a pretherapeutical dosimetry on the therapeutic radiation absorbed dose.

Introduction A dosimetric study involves many different specialists and many different steps. It starts with the labelled of the radiopharmaceutical (In 111 Cl 3 -DOTATOC) and proceeds with the administration, the collection of biological samples, the scintigraphic exams and the physic and mathematical analysis of all data collected. Aim We want to evaluate the contribution of different specialists involved in the collection data for dosimetric study before Y 90 Cl 3 -DOTATOC therapy, the mantime and instrumentation-time for all steps. Materials and methods The Biologist of Nuclear Medicine Department label the In 111 Cl 3 -DOTATOC with the help of a Medical Physicist for radioprotection. Meanwhile a Nurse make the infusion of the aminoacid to the patient. Then a Physician administer the radiopharmaceutical to the patient. Immediately the collection of blood samples starts (Nurse). The patient makes the complete urinary collection using dedicated containers that the Biologist (who directs all steps) provides to change at established time intervals. The Biologist divides all samples in test-tubes containing the same volume of liquid and then the Physicist measures them by a spectrometric system. The Tecnologist of Nuclear Medicine Units performs five whole-body scans at the patient at difference times and days. The Physicist performs the SPECT and CT applying appropriate reperies to the patients to carry out images fusion. Using compartimental models and dosimetric software the Physicist calculates residence-times and dosimetric data for critical organs and lesions. The result of all these work is delivered to the Physicians who compiles therapeutic plane. Results The patient is busy for four days. The Biologist, as director of the entire procedure, is busy for all first day and for two hours in next days. The Physicist is busy for four hours in first day, two hours in second day (for SPECT/CT) and for about three hours when all samples are collected for the data analyse. The Nurse in busy in the first and second days (when he can work in routine too). The Phisicians is busy for a few minutes the first day for administration and then for about two hours for the compiling of the therapeutic plane basing on the dosimetric data. Conclusions All the procedure is time-expensive, but the dosimetric study is an important step of the therapy with Y 90 Cl 3 -DOTATOC. To optimise the work is very important that all specialists involved are in harmony and organized. We already have performed 41 dosimetric study and we now have a consolidated organization. Aim: Peptide Receptor Radionuclide Therapy (PRRT) with Lu-177 DOTA-TATE is used for the treatment of patients with neuroendocrine tumors. The aim of our study was to determine the organ and tumor kinetics for dosimetric calculations. Material and Methods: 130 patients (aged 60+/-11 years; 57m, 73f) with metastasized neuroendocrine tumors (somatostatin expression verified before by Ga-68 DOTA-NOC PET/CT) were treated with activities of 2.5-7.4 GBq Lu-177 DOTA-TATE (1-5 cycles). On the basis of conjugated planar whole-body scintigraphies 0.5h, 3h, 24h, 48h and 72h p.i. the time-dependent whole-body, organ and tumor activities were determined and dosimetric calculations were performed according to the MIRD scheme using OLINDA software. Blood samples were drawn from 23 patients to estimate the absorbed dose to the red marrow. To describe the kinetics we used the withdrawn S358 following parameters: mean half-life and uptake (fraction of injected activity/dose, ID) which were calculated using the fit of the time-dependent activity curve to a mono-or bi-exponential function. Results: The renal uptake decreased for the first 3-5 hours p.i. with a mean half-life of 1.0+/-0.5h, followed by a second phase with a longer half-life of 65+/-17h. The maximum kidney uptake was 4+/-1%. The uptake in the spleen was with 2+/-1.8% ID stable until 24 hours p.i. and then showed a decline with a half-life of 72+/-19h. The tumor uptake showed an increase until 24h p.i. to a maximum of 0.1+/-0.1% ID per unit mass and then slowly decreased with a half-life of 77+/-25h. Liver metastases showed a higher maximal uptake (0.1+/-0.1%) as compared to lymph node metastases (0.08+/-0.07%). The blood kinetics were fitted to a tri-exponential function with large variation: half-life 1: 0.2+/-0.2h; half-life 2: 2+/-1.8h and half-life 3: 21+/-10h. The following organ absorbed doses were calculated: kidneys: 5+/-2 Sv; spleen: 7+/-4 Sv; metastases: 47+/-66 Sv (44+/-38 Sv for lymph node, and 60+/-86 Sv for liver metastases). The resulting dose to the red marrow was 0.2+/-0.1Sv. Conclusions: The relatively low organ doses compared to Y-90 labelled peptides for PRRT correlate with the low clinical toxicity of the radiopharmaceutical. The effective treatment of patients with neuroendocrine tumors using Lu-177 DOTA-TATE is confirmed by the mean absorbed tumor doses. Individual patient dosimetry should be performed due to the large interindividual variations concerning the organ and tumor doses. Aim: An individualized quantitative method to calculate activity distribution and kinetics is needed for accurate, patient-specific dosimetry for optimized internal radiotherapy treatment. Our objective is to design a clinically viable, simple procedure that will provide patient specific, quantitative and 4-dimensional (3D + time) estimate of the dose-rate absorbed from an internally delivered radiopharmaceutical. Methods: The elements of the procedure are as follows: • Quantitative reconstruction of SPECT data using patient-specific transmission or CT-based attenuation maps. Our qSPECT method includes attenuation and scatter corrections, and accounts for system resolution, and cross-talk and septal penetration when needed. • Quantitative data reconstructed from a SPECT scan are being combined with the information obtained from a series of 4-5 whole body scans (WB) in order to determine quantitative biokinetics of the tracer in tumours and critical organs. • Estimation of dose delivered to organs of interest using three complementary elements: (a) voxelized 3D quantitative activity concentrations, (b) temporal information about biodistribution of this activity, and (c) analytical calculation of the delivered dose. This calculation will be based on the known physics of photon and particle interactions and will use our analytical photon distribution (APD) method. • For repeated radiotherapy treatments, 3D dose-rate maps may prove to be particularly useful, as the final goal of this project is the determination of the reliable dose-response relationship. Materials: Simulations and phantom experiments were performed in order to evaluate the accuracy of quantitation for different isotopes relevant for oncology and to design new acquisition protocols that would provide quantitative biodistribution information in clinical setting. Investigated isotopes included Tc-99m, In-111, I-123, and I-131. Experiments used Siemens E-Cam + Profile transmission system and GE Infinia + Hawkeye CT. Activity in "tumour"-like containers placed in air and active background was measured using planar, WB, tomographic and a combination of two SPECT and five WB acquisitions. Results: The results of our studies show that in planar and WB studies the quantitation errors vary from about 10-20% to 60-80% depending on the activity distribution and the method of data processing. Our qSPECT technique results in activity estimation with errors in the order of 6-11%. Similar accuracy levels were achieved in quantitatition of activity kinetics from a combination of SPECT+WB studies. Conclusions: Improved accuracy of biodistribution quantitation obtained from a combined protocol of SPECT+WB offers new promise for patient specific dosimetry. Incorporated into our APD calculation these data will provide 4-D voxelized dose maps.

Dose assessment of salivary glands in radioiodine therapy D. Shahbazi-Gahrouei, Z. Shahi, K. Ziaei; Dept. of Medical Physics, Isfahan Uni. of Medical Sciences, Isfahan, IRAN (ISLAMIC REPUBLIC OF).

The use of radioactive iodine ( 131 I) has become an important adjunct to the treatment of thyroid cancer and hyperthyroidism. Salivary gland has the ability to concentrate radioactive iodine under normal circumstances. Salivary gland dysfunction and dry mouth are the common side effects of high-dose radioiodine therapy. The purpose of this study was to determine the absorbed dose of salivary glands. Materials and Methods: Twenty patients who were divided into two groups of 10 were studied (A group without pilocarpine and the B group received pilocarpine during treatment). The absorbed dose of parotid glands and the submandibular glands of patients was measured using thermoluminescent dosimeter (TLD) at three different times (24 hours, 8 days and 3 months after treatment). The attenuation coefficient of patients and the effects of pilocarpine were also determined. Results: In group A total attenuation coefficient was 0.335, 0.323, and 0.357 for parotid glands and the right and left submandibular glands, respectively. In group B total attenuation coefficient was 0.462, 0.482, and 0.514 for parotid glands and the right and left submandibular glands, respectively. The results also showed the dose decreases to 1 cGy after 3 and 2 half life for A and B group, respectively. Conclusions: The findings showed that the dose decreases to 1 cGy after 3 half life of Iodine therapy. The exponential coefficient attenuation of salivary glands varied between 3% to 4%. Pilocarpine should be effective to increase excretion of radioactive iodine and increases 1.5 to 2 times coefficient attenuation.

Aim: Commercially available radiopharmaceuticals for radiosynovectomy (RSO) are expensive and not always accessible for developing countries. Cost effective and safe agents are therefore needed. Herein we present the biokinetic data of rhenium-188-tin colloid (Re-Col) and phosphorus-32 colloid (P-Col) in patients undergoing RSO of the knee. Methods: In 8 patients (pts) treated with 339±102MBq Re-188 (1) in knee serial blood samples at 2, 4, 6, 12, 24, 36, 48, 60, 72 h and urine up to 72h were collected. Additional, in 5 pts treated with 82±18MBq P-32 blood measurement at 1, 2, 3, 24h and urine sampling up to 24h were studied. Median particle size range for Re-Col 5μm (range: 1-10) and for P-32 0.3μm (0.2-0.35), respectively. Results: In rabbit animal model, retention of radioactivity in the synovium for Re-Col at 24 and 74h were 96.4±11.1% and 90.7±11.2% of ID respectively. In patients undergoing RSO of the knee with Re-Col, average %ID in blood at 4, 12, 24 and 72h were 0.06±0.05%, 0.12±0.09%, 0.21±0.19% and 0.14±0.08% respectively. Total excreted activity in urine at 72h was 1.65±3.00 %ID (range: 0-8.987). For P-Col %ID in blood at 1, 2, 3 and 24h p.i. were 5.8±3. 1; 5.7±2.8, 4.4±3.3, 3. 8±3.4 respectively, and 3.7±2.0%ID in 24h-collected urine. Percent ID in blood at 24h and the area under the curve up to 24hs were significantly lower for Re-Col compared to P-Col, p<0.05 and p< 0.02 respectively. Discussion and conclusion: P-Col showed a longer retention in blood and a higher urine excretion than Re-188 tin colloid indicating a lower in-vivo stability for P-Col formulation. Data suggest that blood radiation exposure is lower for Re-Col than for P-Col. Both radiopharmaceuticals are however, suitable for radiosynovectomy. As a generator product, Re-188 provide excellent availability and can be cost effective which is however dependent on the frequency of use. P-32 as a cheep reactor product provide a good and cost effective alternative. Reference: 1. Jeong JM et al. Appl Radiat Isot 2000,52:851-5 Results of an IAEA led CRP E1.30.26 Objectives : The objective of this work was to determine normal organ mean absorbed dose and effective dose equivalent and effective dose for 11 C-PIB dosimetry in humans. Methods : 3 patients (1 female, 2 male, mean age 60.3 y) were administered with a bolus infusion of 11 C-PIB (dose range 300. 2 -377.7 MBq) and immediately scanned on a Gemini PET/CT camera. Sequential wholebody PET images, which extended from head to upper thigh, were acquired, representing 5 time points over a period of 60 minutes. Resultant images were reconstructed using an iterative single scatter simulation algorithm. Using in-house developed software, VOI analysis for each time point was performed to obtain activity concentration in normal tissue. Organs considered as source organs were brain, lung, liver, kidney, spleen, gallbladder contents and bladder contents. Using Reference Man (ICRP 23) values for organ volumes, the total activity was calculated per organ for each time point and the cumulated activity was determined from the Area Under Curve of a bi-exponential fit to the resultant Time Activity Curves. The cumulated activities were used as input to OLINDA. Results : Large accumulation of 11 C-PIB was visualised in gallbladder, liver and urinary bladder. Accordingly, the organs with the greatest mean absorbed dose (mean ± SD) were gallbladder wall (47.2 ± 14.5 μGy/MBq), urinary bladder wall (24.9 ± 11.3 μGy/MBq), liver (21.6 ± 4.6 μGy/MBq) and kidneys (12.5 ± 4.7 μGy/MBq). Effective dose equivalent (EDE) was 8.7 ± 1.7 μSv/MBq and effective dose (ED) was 5.0 ± 0.8 μSv/MBq. Of note, due to its high absorbed dose, gallbladder wall has a large contribution towards EDE, whilst not being considered in the calculation of ED. Conclusions : Organ dose estimates for 11 C-PIB are comparable to other reported 11 C ligands. analyzed and used to determinate the red-marrow-dose. The residence-time in lesions, with S-factors (MIRD), are used to calculate lesions-dose. Data are elaborated by compartimental-models to write the therapeutic plan. Patients treated with Y 90 Cl 3dotatoc have been followed for appraising the course of disease. Results We collected these average and range dose-data (mGy/MBq): red-marrow (0.07, 0.02 to 0.2); kidneys (2.34, 0.22 to 7.17); spleen (4.71, 0.03 to 28.0); liver (0.94, 0.05 to 6.47); urinary-bladder (1.47, 0.05 to 3.68); total-body (0.13, 0.05 to 0.30) . The dose to principal lesion has been calculated for 32 patients (average 23.45, 0.0005 to 238.2) . 22 patients had kidneys-dose less than lesion-dose and 29 patients had liver-dose less than lesion-dose. 20/32 patients had lesion-dose greater then red-marrow-dose, liverdose and kidney-dose. We followed 29 patients (3 patients not treated, 9 patients in progress of treatment). 23 patients had a positive results to the treatment (complete or partial result or disease stabilization) and 6 patients a negative one (progression of disease). Among 23 patients with positive results, 12 had lesion-dose greater than critical organs-dose (reached 300 Gy to lesion), for 6 patients the lesion-dose has not been calculated. Only 1 patient who reached 300 Gy in lesion had a negative responce. Conclusions The variability of the dosimetric results shows the importance to perform a personalized dosimetric-study. Follow-up showed that the patients treated till 300 Gy to the lesion had a positive result to the therapy (only one exception). Among the patients treated till the reaching of the dose-limit to the critical organs (lesion-dose less then 300 Gy), 6 had a positive result. In conclusion, the therapeutic plan wrote on the base of dosimetric-study has a real utility. Aim: The pharmacokinetics and dosimetric profile of 90 Y-DOTATOC is well known, being the kidney the critical organ. However, in end-stage renal failure, biodistribution could be altered and organs such as red marrow (RM) could be critical. The aim of this study was to evaluate the biodistribution and dosimetry of 90 Y-DOTATOC in a patient with end-stage renal failure undergoing dialysis. Methods: A female patient affected by abdominal lymphnode metastases from endocrine carcinoma, asked to eradicate her disease with 90 Y-DOTATOC in order to be enclosed in the waiting list for renal transplant. The patient suffered from renal failure since the age of 18. At 56 years old she was operated for lymphnode metastases from gastrin secreting endocrine carcinoma of unknown origin. A subsequent OctreoScan showed persistence of abdominal lymphnodes (35 mm). Gastrin: 2490 pg/ml. 111 MBq 111 In-DOTATOC were administered for dosimetry. Blood samples and planar images were obtained up to 40h p.i. Patient-specific dosimetry was evaluated by imaging analysis and actual organ masses (CT). The blood-derived method was used for RM dosimetry, considering the RM specific activity equal to that in blood. The Number of Disintegrations (ND) was obtained for all source organs; for RM, the RM specific activity equal to that in blood. The OLINDA/EXM code was used to calculate absorbed doses. Results: NDs (h) in source organs were: 0.84 (RM); 7.52 (spleen); 9.46 (liver); 35.87 (remainder of body-RB). Absorbed doses (Gy/GBq) were significantly higher than published results (mean±SD): 22.4 (vs. 9.96±6.70), spleen; 2.52 (0.89±0.68), liver; 0.36 (vs. 0.07±0.03), RM, 0.47 (vs. 0.17±0.05), total body. This confirmed a redistribution of the activity usually eliminated through kidneys, with fast and higher uptake in liver and spleen. Tumour dose was 14 Gy/GBq. The treatment was considered feasible, with RM critical organ, liver second limiting organ, spleen irradiation of some concern. The patient conservatively received 1.11 GBq. Therapy was well tolerated. Only reversible grade 1 toxicity on WBC and PLT, and grade 2 on Hb, occurred. Six months after OctreoScan and MRI showed disappearance of the lesions. Gastrin: 268 pg/ml. Conclusions: In patients undergoing dialysis, RM is the critical organ. These results showed the feasibility of 90 Y-DOTATOC therapy even in patients who would be logically excluded. In such cases, a deep analysis of the tumour dose and risk-benefit balance should guide, addressing 90 Y-DOTATOC to cases without other options.

Assessment of absorbed dose and therapeutic response of tumor in repeated high-dose I-131 anti-CD20 monoclonal antibody (rituximab) radioimmunotherapy for non-Hodgkin's lymphoma nearby tumor. The shape of 2D-ROI of tumor was determined from the MIP PET image. The volume of tumor was measured from the CT image, the % change of tumor volume before and after RIT was used to evaluate the therapeutic response. The value of CT-based tumor volume was compared with that measured by PET image at the cut-off SUV of 1.5. In tumor dose estimation, the time-activity curve (TAC) of tumor region was used, and the both absorbed fractions of beta-and gamma-ray were considered together. Results: Bi-exponential decrease was observed in fitting of TAC of tumor. The values of CT-and PET-based tumor volume were 3.8 ± 1.1cc and 3.9 ± 2.1cc, respectively, and showed the linear relationship(r=0.9053). The values of absorbed dose for tumor and the %changes of tumor volume before and after RIT were 131.6±89.5rad, were 45.4±19.3%, respectively, and did not show the linear relationship(r=-0.3312). The values of absorbed dose for tumor and the % changes of tumor volume did not show the linear relationship with the number of repeated administration(r=0.3307 and -0.1171, respectively). Conclusion: Aligning PET and planar images could estimate the quantitative values of absorbed dose to tumor. The data suggest that potentially equal absorbed dose and therapeutic response of tumor could be expected in repeated RIT with I-131 rituximab for NHL. Purpose: Gastric cancer is one of the most common cancers, and is the second most common cause of cancer related mortality in the world. The A33 antigen is a glycoprotein which is homogenously expressed by more than 95% of colorectal cancers and 55% of gastric cancer and in the normal intestinal mucosa, but not in other epithelial tissues including gastric epithelium. In order to determine the in vivo characteristics of huA33, a CDR grafted humanized monoclonal antibody against the A33 antigen, a clinical trial was conducted in patients with gastric carcinoma. Patients and Methods: Thirteen patients were entered into the study. They were assigned serially onto one of four dose levels (1.0, 2.0, 5.0, 10 .0 mg/m 2 ) of huA33. Patients with early gastric carcinoma received a single infusion of 131 I-huA33 one week prior to surgery. Biodistribution of 131 I-huA33 was evaluated by the imaging at least 3 occasions including on the day of administration and on upto 9 days. Adverse events were assessed. Ex vivo imaging and immunohistochemical analysis were performed on the samples of biopsy and surgical specimens. Results: No dose-limiting toxicity was observed and the maximum tolerated dose was not reached. Although cancer tissues with low expression of A33 by immunostaining in biopsied frozen sections did not show positive imaging with 131 I-huA33, cancers with high expression of A33 by frozen and paraffin sections in the biopsied specimen showed positive ex-vivo imaging and positive antigen expression in resected gastric cancer specimen, and the biodistribution analysis also showed tumor uptake of 131 I-huA33. Conclusions: Humanized monoclonal antibody huA33 demonstrated selective localization to gastric cancer that strongly expresses A33 antigen. These targeting characteristics of the huA33 indicate potential for the targeted therapy of advanced gastric cancer that is refractory to cytotoxic chemotherapy or recurrence after surgery, and could also be exploitable for the adjuvant therapy after curative resection of early gastric cancer. Metabolic radiation therapy is mediated by emitter labelled radiopharmaceuticals allowing lethal target radiation. Unfortunately, such medical practices using emitter radioisotopes is associated with an increase of medical staff radiation exposure in nuclear medicine department. This gives us reasons to quantify medical staff radiation in our department during 131-I lipiodol, 90-Y-colloid and 153-Sm EDTM treatments of hepatocellular carcinoma, arthritis (radiosynovectomy) and bone metastases respectively. Methods: 25 injections of 131 I-lipiodol, 11 90-Y-colloid radiosynovectomy sessions and 5 153-Sm-EDTM treatments were studied. Whole body doses (WBD) and right and left finger doses (rFD, lFD) for radiopharmacists (RP), nurses (N), radiologists (Rd) and rheumatologists (Rm) were evaluated by cylindric LiF-thermoluminescent dosimeters (TLD) placed on the waist or on the inward second finger. Results: WBD for medical staff during 2.26±0.06 GBq 131-I lipiodol injections were 2.96±2.9, 5.6±5.1 and 14.7±13.3 μSv for respectively RP, N and Rd. rFD and lFD were respectively 185.7±119 and 925.9±526 μSv for RP, 51.8±34.9 and 158.9±44.0 μSv for Rd. The use of Angioseal ® Hemostatic Puncture Closure Device deployed for haemostasis after 131-I lipiodol injections afforded a two fold decrease in Rds' exposure compared to manual compression. During the 90-Y colloid syringe filling sessions (mean activity per session: 30.3±10.1 MBq, n= 11), the WBD for RP was 10.3±15.9 μSv, rFD was 157.5±146 and lFD was 2488±3022 μSv. WBD for Rm and N performing intra-articular infusions were respectively 1.05±1.71 and 4.29±3.9 μSv per 37MBq injected. FD, normalized to 37 MBq injected, were 104.0±118 μSv (rFD) and 289.2±673 μSv (lFD) for Rm and 125.9±91.6 (rFD) and 146.0±85.7 μSv (lFD) for N. During 153-Sm EDTM syringe filling (2.40±0.2GBq) RP WBD was 0.96±2.1 μSv rFD was 55.9±20.3 and lFD was 157.9±162 μSv. N exposure during 153-Sm-EDTM administration was 28.6±25.8 (WBD) and 82.8±32.2 μSv (rFD) Conclusion: Fortunately, annual extrapolated WBD and FD doses remain under legal limits but observed values are not negligible and have to be added to those relative to 131-Iodine treatment of thyroid disorders for example. Such considerations may confirm the interest of protocol optimization, personal information and studies focusing on radioprotection.

Evaluation of factors affecting the accuracy and precision of a technique for quantification of volume and acticity with 111In SPECT. M. S. Kotzassarlidou, C. Tziaka, T. Kalathas, A. Raptou, N. Salem, A. Makridou; Theagenion Cancer Hospital, Thessaloniki, GREECE. Aim: Accurate in vivo volume and activity determination is essential in clinical research, especially for estimating organ absorbed dose during radionuclide therapy. In this study volume and activity concentration were estimated using Single Photon Emission Computed Tomography (SPECT) for volume and activity concentrations of 111-In sources between 2.5-12.5 ml and 2-9 MBq/ml. All sources were of regular geometry. The influence of voxel size, source size and shape was studied. Materials and Methods: SPECT acquisitions have been carried out by SOPHA DST XLi 2-head gamma camera over 360o, elliptical orbit and step and shoot mode, according to the following protocols: -64x64, 64 frames, 10sec/frame, -128x128, 128 frames, 5sec/frame. Pixel size [cm] and system sensitivity, [cps/MBq] of both matrix sizes for 111-In SPECT have been determined in advance. Processing was performed on Vision workstation using a Butterworth reconstruction filter (order 1, Nyquist 0.25). Attenuation correction was applied and transaxial images of one pixel thickness were obtained. The segmentation algorithm used for volume quantification was the autothresholding method. Pixel value with the maximum counts in all slices was selected and percentage (60-90%) of it was determined. Pixels of all slices with a value equal or greater than the predetermined value belonged to the source. Volume estimation was obtained by summing the number of voxels within the source contour in each slice and multiplying their total by voxel volume. Activity estimation was obtained by summing the counts of the above regions and dividing their total by acquisition time and the system sensitivity. Results: The best correlation between nominal and measured volumes by 111-In SPECT images was obtained with threshold percentage of 80% and 65% for 64x64 and 128x128 matrix size respectively. Error increases as nominal volume decreases (r=-0.718, p=0.001) for 64x64 whereas for 128x128 it increases proportionally to the threshold (r=0,883, p<0.0005). Activity estimation was best obtained for threshold percentage of 70% for 128x128. Conclusions: Autothreshold technique is effective for in vivo volume and activity quantitation of lesions with volumes greater than the system spatial resolution (i.e. Volmeas> 2.5ml). In case of smaller lesions CT is preferable for volume quantitation. Where D k is the mean absorbed dose to region k (Gy); A 0 is the administered activity (Bq); S (r k r j ) is the mean absorbed dose in target region k irradiated by source region j; j is the residence time in source region j (s), which is j = t0 t A j (t)dt / A 0 = t0 t A j (t) / A 0 dt = t0 t %ID dt. Where A j is the activity of source region j at the time of t. We calculated the mean absorbed dose of critic organ by Mirdose 3.0 software (Internal Dose Information Center at Oak Ridge Institute for Science and Education, Oak Ridge, TN), using the dynamic bladder model (4h VOID) . We summed up the resident time of lungs and tumor as the "lungs" resident time. Corrections were made for lungs masses. For the mass of tumor tissue ( m T ) we assumed unit density and employed the CT volume ( V T ) : m T =1× V T . Tumor background subtraction was attempted using CT scans to estimate true background thickness. Absorbed doses to tumor tissues (D T ) were estimated using the same approach taken for normal organs. S-factors for tumors were estimated by comparison with lungs. According to equation D T =m lungs ×(D " lungs" -D lungs )/ m T and D T =m lungs ×(D " lungs" -D lungs )/ m T , where D " lungs" , the mean absorbed dose of mixed lungs and tumor. By equation, we can easy to calculate the D T and D lungs . Results: The absorbed dose of red marrow ranged from 0.44 to 0.73Gy; thyroid, from 0.47 to 23.09Gy; ovaries, from 0.50 to 0.77Gy; testes, from 0.38 to 0.58Gy; kidneys, from 1.71~4.55Gy; liver, from 1.18 to 2.63Gy; lungs, from 1.55 to 2.74Gy; and effective dose equivalent from 0.48 to 0.80Gy. The results shows tumors with highest uptake of (2.8±2.0)%ID of 131 I-chTNT at 24h. The mean absorbed dose of tumors (within 50a) was [(8.28±2 .65), from 4.22 to 12.81]Gy, 7d reached (65±4)%, 14d reached (89±2)%, and the tumor-to-nontumor ratio (T/NT) was 3.95±1.55 (from 1.63 to 6.29). Conclusion: Repeated intravenous 131 I-chTNT is needed because single intravenous dose of 131 I-chTNT could hardly depress the growth of tumor masses. Objective: To study TGF-1 and bFGF expression in normal prostate and BPH and inhibitory effects of specially designed Sr 90 /Y 90 Applicator radiation on the expression in hyperplasic prostatic diseases. Method: 50 BPH patients were divided into two groups, the intracavitary exposure group and the hyperplasia group. All 35 patients in exposure group were treated with Sr 90 /Y 90 Applicator. 12 patients were practiced operation 4 days after the exposure, another 12 patients were practiced operation 7 days after the exposure, and the rest 11 patients were practiced operation 15 days after the exposure. 15 patients in hyperplasia group were not treated with intracavitary exposure. Expression of TGF-1 and bFGF were detected through immunohistochemical staining technique. Results: TGF-1 positive expression rates of NP and BPH epithelial cells were higher than those in correspondent stromal cells (p<0.01). No statistically significant association was found between TGF-1 positive expression of epithelium and stroma in BPH tissues and the correspondent expression in NP (p>0.05). Compared with the hyperplasia group, TGF-1 positive cell rates in BPH epithelial and stromal cells were significantly increased 4, 7 and 15 days after Sr 90 /Y 90 Applicator exposure (p<0.01). Expression of bFGF existed not only in epithelial and stromal cells of BPH, but also in normal prostatic tissues. The bFGF positive expression rates in BPH epithelial and stromal cells were higher than those in NP epithelial and stromal cells (p<0.01). bFGF positive expression rates in BPH and NP stromal cells were higher than those in corresponding BPH and NP epithelial cells (p<0.01). bFGF levels in BPH epithelial and stromal cells descent sharply 4, 7 and 15 days after Sr 90 /Y 90 Applicator exposure (p<0.01).Conclusion: Exposure of -rays from Sr 90 /Y 90 Applicator had noticeable effects to enhance TGF-1 expression and inhibit bFGF expression in BPH tissues. Objective: To investigate expressions of Bcl-2 and Bax in benign prostatic hyperplasia (BPH) tissues and influence of radiation from specially designed Sr 90 /Y 90 Applicator on Bcl-2 and Bax expressions. Method: 50 BPH patients were divided into two groups, the intracavitary exposure group and the hyperplasia group. All 35 patients in exposure group were treated with Sr 90 /Y 90 Applicator. 12 patients were practiced operation 4 days after the exposure, another 12 patients were practiced operation 7 days after the exposure, and the rest 11 patients were practiced operation 15 days after the exposure. 15 patients in hyperplasia group were not treated with intracavitary exposure. Expression of Bcl-2 and Bax were detected through immunohistochemical staining technique. Results: The Bcl-2 positive expressions in both normal prostate(NP) and BPH epithelial cells were higher than those in corresponsive stromal cells(p<0.01),while the Bcl-2 positive expressions in epithelial and stromal in BPH tissues were higher than those in NP(p<0.01).Meanwhile, the Bax expression in NP epithelial cells was higher than that in BPH(p<0.05),and the Bcl-2 expressions of epithelia and stroma in BPH were higher than the corresponsive Bax expressions(p<0.01). No statistically significant association was found between the Bcl-2 expressions of epithelia and stroma in NP and the correspondent Bax expressions(p>0.05).Compared with the hyperplasia group, Bcl-2 in BPH epithelial and stromal cells reduced sharply, and Bax positive cell rates increased distinctly 4, 7 or 15 days after the intracavitary exposure by Sr 90 /Y 90 Applicator radiation(p<0.01). Conclusion: Bcl-2 and Bax play an important role in regulation of prostatic apoptosis and the treatment of radiation with Sr 90 /Y 90 Applicator before surgery can accelerate apoptosis in prostatic tissues. The purpose of this study was the quantitative analysis of the internal contamination with four uranium isotopes in the population living near the uranium conversion facility in Port Hope, Ontario, Canada; the oldest operating uranium processing plant in the world. The urine samples of symptomatic patients presenting with symptoms of musculo-skeletal, CNS, immune system, and neoplastic disease were obtained from among a large population. Control samples were also analyzed. The urine samples were analyzed in a specialized radiochemistry laboratory by mass spectrometry, including pre-concentration of urine by co-precipitation, oxidation of organic matter, uranium purification by ion-exchange chromatography, and ICP-MS double-focusing Thermo Finnigan Neptune multi-collector. Natural uranium has a 238 U/ 235 U ratio of 137.88 and does not contain 236 U. Background total uranium concentration in the urine of humans is 7 ng/L (USA NCEH). Our results show 4 of 9 samples containing uranium of non-natural origin. One sample was highly positive for depleted uranium (DU) with a 238 U/ 235 U of 147.11 ± 1.42 and a relatively normal abundance of total uranium. This sample contained a concentration of 236 U with a 236 U/ 238 U ratio of 4.38 x 10 -6 ± 4.3 x 10 -7 indicating its reactor origin. Three samples contained detectable amounts of 236 U, one being paradoxically high with a 236 U/ 238 U ratio of 5.53 x 10 -5 ± 3.9 x 10 -6 . One of these three samples contained a higher than normal concentration of total uranium (24.8 ng/L). The 236 U in these samples indicates its origin as contamination with non-natural uranium. The remaining five samples were negative for both depleted uranium and uranium-236. The history of uranium contamination of the vicinity of Port Hope has been verified in objective scientific literature 1 . Our results suggest long-term contamination and possible adverse effects on the body burden of the current population of Port Hope. These preliminary results warrant additional multidisciplinary studies. Aim: Standard treatment of differentiated thyroid carcinoma (DTC) is total thyreoidectomy followed by radioiodine therapy (RIT) and diagnostical I-131-whole body scan (D-WBS). Radioiodine (RI) is eliminated via kidneys. In patients with DTC and end stage renal failure (ESRF) doses between 760 and 1110 MBq were administered orally. The aim of this study was to evaluate the therapeutical effectiveness of RIT using reduced amounts of RI. Material and Methods: During the last seven years 3 ESRF patients suffering from DTC were treated with RIT. One patient received four RI treatments . One patient got two RITs and 1 D-WBS and one patient received two RITs. The activity doses administered ranged between 752 and 1248 MBq for RIT and between 385 and 604 MBq for D-WBS, respectively. Hemodialysis was done on the 1 st and 3 rd day after RI administration. Serum thyroglobulin (Tg) was measured prior to and after RI applications using Tg-SRIA( Brahms, sensitivity 0,3 ng/ml) during TSH stimulation Indium 111 oxinate is a radiopharmaceutical that decays by electron capture with a half life of 67 hours, emitting gamma radiation with energies of 172 KeV and 246 KeV as well as low energy Auger electrons. Indium 111 oxinate is used in nuclear medicine for the in-vitro labelling of separated blood cells, which are then administered to patients to investigate inflammation at the sites of infection and abscesses. Because of the potential toxicity of its Auger emissions indium 111 has also been evaluated recently as a potential tumour therapy, where indium 111 has been conjugated to somatostatin receptor analogues or to tumour-specific antibodies. Aims: The aim of this investigation was to study the DNA-damaging effects and cytotoxicity associated with cellular exposure to indium 111 and to evaluate the intracellular and intranuclear doses of indium 111 required to elicit cytotoxic effects. Methods: We have investigated cellular toxicity of indium 111 oxinate in HT1080 fibrosarcoma cells and MCF-7 breast epithelial cells using the colorimetric MTT assay and the clonogenic survival assay. The results were compared with data obtained from similar experiments in which cells were treated with equimolar amounts of indium 111 oxinate that had been subjected to several weeks of decay, in order to determine the degree of cytotoxicity attributable to radioactive emissions. The single cell gel electrophoresis (Comet) assay was also used to determine DNA damage associated with exposure to indium 111 oxinate. Cellular and nuclear uptake were measured using a phophorimager or a gamma counter. Results: HT1080 cells that were subjected to 10 MBq/ml indium 111 oxinate exhibited 0.1 % cellular survival in the clonogenic survival assay compared to untreated control, while treatment with a molar equivalent of the decayed indium 111 oxinate exhibited 25 % survival compared with the same control. MCF-7 cells exhibited zero cellular survival when subjected to treatment with 5 MBq/ml compared to untreated control, while treatment with decayed indium 111 oxinate exhibited 38 % survival compared with the same control. The Comet assay showed DNA damage only at doses where cell toxicity was observed. Cellular and nuclear uptake showed that 36% of indium 111 taken up by the cell was contained in the nucleus. The results demonstrate that radioactive emissions associated with 10 MBq/ml indium 111 oxinate elicit significant DNA damage and cytotoxicity in HT1080 and MCF-7 cells. These data will allow correlation of intracellular dosage and nuclear proximity with cytotoxicity and DNA damage.

Auger electrons and it effect on cell viability. In vitro preliminary results M. Laranjo 1 , A. M. Abrantes 1 , I. Carreira 2 , M. F. Botelho 1 ; 1 Biophysics/Biomathematics Institute, IBILI-Faculty of Medicine, Coimbra, PORTUGAL, 2 Biology Institute, Faculty of Medicine, Coimbra, PORTUGAL.

Aim: Because Auger electrons cause a high energy deposition limited to the area of the decay site the ensuing biological effects may represent an alternative in cancer radiation therapy. 99mTc is the most used radionuclide in nuclear medicine. Besides its energetic gamma emission, its 6 hours half-life makes it the preferred radioisotope for patient administration. As 99mTc is also an Auger emitter, the possibility to use it not only in diagnosis but also in treatment should be investigated. In order to examine the effects of 99mTc Auger electrons in cancer cells, we investigated the survival and proliferation after exposure to 99mTc-pertechnetate. Material and Methods: Adenocarcinoma colon cells (ATCC -WiDR) developed in Dulbelcco's medium with 10% of fetal bovine serum and incubated in 37ºC, 5% CO2 atmosphere were used. 99mTc-perchnetate (85 MBq) was added to the medium during different exposure times (15, 30, 45 and 60 minutes) which resulted in absorbed doses of 0.75, 1.5, 2.2, 3 Gy, respectively. After the incubations, 99mTc-perchnetate uptake was calculated. The cell viability and proliferation were evaluated 24, 48 and 120 hours after exposure. Cell viability was evaluated by Trypan Blue exclusion test. This vital stain does not pass trough the membrane of living cells however, traverses the membrane at a death cell. With this method it is possible to estimate the ratio between living cells and death cells. To access cell proliferation we used MTT (3-[4,5-dimethylthiazol-2- yl]-2,5-diphenyltetrazolium bromide), an yellow tetrazolium salt that is reduced in metabolically active cells to form insoluble purple formazan crystals. These are solubilized by the addiction of a detergent and then quantified by spectrophotometric means. Results: Regarding uptake of 99mTc-pertechnetate it increases proportionately to the incubation time (25% for 0.75Gy; 20% for 1.5Gy; 34% for 2.2 Gy and 46% for 3Gy). The viability indicates an increase of proliferation on the first 24 hours after irradiation, but after this time it decrease progressively with the time. 48h after treatment the proliferation values were 50% for 0.75Gy; 61% for 1.5Gy; 66% for 2.2Gy and 37% for 3Gy. 120h after treatment the proliferation values were 29% for 0.75Gy; 32% for 1.5Gy; 16% for 2.2Gy and 15% for 3Gy. Conclusions: These preliminary results indicate that there are time dependent effects on proliferation and cell death.

Y. Lin 1 , W. Chang 1 , W. Lin 2 ; 1 Chunghsing University, Taichung, TAIWAN, 2 Taichung Veteran General Hospital, Taichung, TAIWAN.

The aim of this study was to investigate of various basic amino acid solutions and other compounds in order to assess their safety and their capacity to inhibit the renal uptake of In-111-DOTATOC. Materials and Methods: Male Spraque-Dawley rats (200-250 g) , in the presence of reuptake blocker, were injected with In-111-DOTATOC. At 24 hours after injection, rats were sacrificed and organs were isolated and counted for radioactivity. Results: Lysine (400 mg/kg) were resulted in more than 40% inhibition of kidney uptake, but it may induce hyperkalacmia and metabolic changes. Combination of arginine and histidine were also resulted more than 40% inhibition, nevertheless it have less side effect than lysine. Maleate (400 mg/kg) were more effective to reduce renal uptake about over 50%. Further, coinjection of colchicines (1 mg/kg), vincristine (0.1 mg/kg), noscapine (100 mg/kg), nocodazole (1 mg/kg) 5 hours before injection of In-111-DOTATOC were significantly reduced kidney uptake (respective inhibitions of 31%, 26%, 41% and 46%). Conclusions: Administration of these compounds effectively reduce kidney radioactivity in order to allow the administration of higher doses of radiolabelled somatostatin analogues for scintigraphy and peptide receptor radionuclide therapy.

Introduction Hyperthyroidism is a common disease in old cats and is preferably treated with radioactive iodine. Treatment results are good, with 90-95% of the cats becoming euthyroid. Concurrent subclinical kidney disease is not uncommon in this patient group and close monitoring of kidney function is mandatory. A recent research protocol at our institution necessitated the use of iohexol as a GFR marker to investigate kidney disease immediately prior to treatment with radioactive iodine. Since it is generally known that iohexol reduces (radio)iodine uptake in the thyroid, this study was set up to evaluate its effect on absorbed dose in the thyroid and to investigate whether this procedure influenced long term outcome of treatment. Materials and Methods 43 hyperthyroid cats, presented for I 131 -treament, participated in this study. GFR measurement using iohexol was performed in 11 patients one day before injection of I 131 . 32 cats received only I 131 and functioned as control-group. The iohexol-group received an average activity of 109 MBq I 131 (SD ± 17 MBq); the control-group received on average 111 MBq I 131 (SD ±16 MBq). Scintigraphic scans were performed 24, 48 and 120h post-therapy. A syringe with known reference activity was scanned using the same parameters. ROI's were drawn over the thyroid region, background and reference activity for all time points. Cumulative activity was calculated. A factor was obtained using MIRDOSE3.1 software converting the cumulative activity into absorbed dose, taking into account the thyroid volume. Results The mean estimated absorbed thyroid dose in the iohexol-group was 54 Gy (SD ±9 Gy), which was significantly different from the control group: 84 Gy (SD = 12 Gy) (p<0.01). Of the cats that received iohexol, a higher percentage remained hyperthyroid (18%) 3 months after treatment compared to the control group (7%). These results however did not reach significance. (p>0. 1, 2 -test) . Conclusion The administration of iohexol to evaluate kidney function reduces absorbed thyroid dose of 131 I in this small group of cats but does not seem to influence long-term outcome of feline hyperthyroidism. P60 -Monday, Oct. 15, 2007, 2:30 pm -4: Tc-MIBI were 11.2 μSv.h -1 ±2.3 and 43.1 μSv.h -1 ±11.9 respectively, at 5cm from the patients. For 201 Tl, the average dose rates at the distances of 10, 50 and 100 cm from patients 3 hours after administration were 8.3, 2.4 and 1.2μSv.h -1 respectively. These values were in close agreement to the mean corresponding value of 9.2, 2.5 and 0.9μSv.h -1 obtained by Munford et al 1989. The maximum departure dose rates at these distances were 0.14, 0.04 and 0.02μSv.h -1 .MBq -1 respectively. External doses rate of 201 Tl fell gradually, until three days after administration. After injection of 99m Tc-MIBI a rising of the external dose within 1-3 hours was seen. The maximum departure rate per unit activity at the distances of 5,10, 50 and 100 cm were 0.12μSv -1 .MBq -1 , 0.09μSv -1 .MBq -1 ,0.03μSv -1 .MBq -1 and 0.01μSv -1 .MBq -1 respectively. Significant exposure from patients after injection of 99m Tc-MIBI was limited on the few hours after administration. Maximum and average absorbed dose of nuclear medicine staff from 201 Tl were 4.6 and 2.7 μSv.h -1 , and for 99m Tc-MIBI were 18.1 and 9.8μSv.h -1 in each scan. Conclusion: Significant exposure from 99m Tc-MIBI for cardiac investigations has limited to a few hours after administration. In case of administration 201 Tl the dose rates from the patients continues to decrease until three days after injection. These data could be considered as a base for calculative exposure dose in close contact during working hours of nuclear medicine staff. .

One of the most effective treatments for thyroid carcinoma is the use of iodine-131. In recent months a number of patients with end stage renal failure have been referred to our hospital for thyroid ablation therapy. This has presented a number of challenges from a radiation protection perspective, for both the patient and the staff involved. In establishing this procedure we aim to provide an effective combination of treatments for these patients. In addition the radiation dose to all staff involved in this therapy must be considered. To date two patients in end stage renal failure, both requiring regular haemodialysis sessions, have been treated at our hospital. A multidisciplinary team was involved in establishing this procedure and helped to identify the risks involved. A dialysis facility was provided in one of our dedicated treatment rooms to enable the best possible arrangement for radiation protection purposes. All staff involved were given radiation safety training before the therapy was conducted. A member of the radiation safety team was also on hand for the duration of each dialysis session. Each patient received 3000 MBq of I-131 in capsule form with dialysis sessions conducted immediately prior to the therapy and 48 and 96 hours after administration of the capsule. Each patient was successfully dialysed on all three occasions, with no unexpected complications being noted. Dose rate measurements were performed on a daily basis, which is a routine occurrence for all our patients. Dose rates were also measured immediately prior to and after the completion of each dialysis session. All staff involved were provided with radiation monitoring in the form of whole body TLD monitors, extremity monitors and electronic personal dose meters. Our dose rate measurements show slower clearance rates, by approximately 30%, in these two patients when compared to 'standard' cases. However, this is to be expected as the main excretion route for I-131 is via the kidney. By implementing appropriate radiation safety training and methods staff doses were also able to be kept to a minimum. Maintaining the regular dialysis schedule for both these patients also allowed us to deliver an effective therapy without compromising the patient's welfare. Skin cancer is the most common cancer in humans. Many different treatments are currently used in the management of this kind of tumours, and include surgical techniques, topical therapy and radiotherapy. The healing percentage usually range from 75 to 85% by using the best therapeutic treatments. In the present paper a new therapeutic option for the treatment of squamous cell carcinoma (SCC) and of basal cell carcinoma (BCC) proposed. It consists in a superficial radiotherapy with beta emitters isotopes, characterized by the use of a synthetic resin incorporating radioactive 188 Re, that is able to perform a selective irradiation treatment of the cancer lesion.53 patients with histologically confirmed diagnosis of BCC and of SCC were enrolled for the treatment, by choosing the cases in which a relapse of the tumour was present, or in which a surgical operation would have been impossible or aesthetically unacceptable. All treatments were performed in the Nuclear Medicine Dept. of S.Eugenio Hospital, Rome. In all treated cases, an apparent clinical remission occurred in approximately 3 months; a complete healing was obtained in 100% of the treated cases, in 82 % of the cases after a single application. Neither unaesthetic scars, nor side effects, were observed. After a follow up of 12-60 months, no signs of clinical relapses were present in any of the treated patients; when a histological examination was performed, a complete tumour regression was observed.

Treatment of verruca plantaris with microwave and 32 P Application therapy Y. Ma, Y. Liu, P. Lu, G. Huang; Renji Hospital, Shanghai Jiaotong University, Shanghai, CHINA.

Aim: To study the clinical curative effect of verruca plantaris with microwave and 32 P Application and its application value. Material and Methods: 161 patients with extremity verruca plantaris were chosen by random from outpatient, out of them, the 67 patients is male and 94 is female, their average age is 36.3±17.2s ( ±SD) years old, Randomly divided them into two groups: (1) microwave treatment group have 65,the wart bodies were eliminated by microwave under local anaesthetize. (2) 96 individuals were treated with 32 P application therapy ,the liquid of radionuclide 32 P were dropped in gauze, drying them and then fixing them in corresponding focus surface for application therapy, Randomly divided 96 patients into three groups with 8 hours,24 hours,48 hours application each time, a group has 32 patients average. About 5-6 times. and once a week until the lesion recovered. The clinical reaction and curative effect were observed. Results: The clinical cure rate, recurrence rate, side effective occurrence rate and complication occurrence rate are 36.9%,53.8%,80.0% and 44.6% respectively in microwave treatment group and they are 96.9%,3.1%,37.5% and 15.6% respectively in the group of 32P application therapy. Conclusions: The characteristics of treatment of verruca plantaris, with 32P application therapy are simple method , convenient, safety , little pain, notable curative effect, it is a kind of successful effective treatment method.

Using LigandTracer® to Quantify Protein-Cell Interactions in Real-Time L. Vennstrom 1 , H. Bjorke 2 , K. Andersson 2 ; 1 Ridgeview Instruments AB, Uppsala, SWEDEN, 2 Uppsala University, Uppsala, SWEDEN.

Aim: Validate a novel biosensor (LigandTracer®) designed to detect how radiolabelled proteins bind to cell surface receptors in real-time and explore new possibilities with the biosensor. Material and Methods: Different cell lines (e.g. A431 and SKOV-3) and radiolabelled proteins (e.g. EGF and Trastuzumab) known to bind to the receptors EGFR or HER2 were used in this study. Cells and reagents were placed in LigandTracer Grey and binding traces of the protein-cell interactions were recorded in real-time without user intervention. The results were compared to data obtained from classical protocols. Results: The results obtained with LigandTracer Grey agreed with classical protocols and was highly repeatable. The time resolution in LigandTracer data was superior to the classical protocols used. Furthermore, the novel biosensor required less disposables and manual workload. Conclusion: The automated, real-time binding traces obtained with LigandTracer relieve researchers from manual workload and provides data with higher time-resolution. Apart from replacing manual protocols in protein-cell interaction measurements, this novel method opens up many new possibilities in the field of cell-based assays. P61 -Monday, Oct. 15, 2007, 2:30 pm -4 Despite of progress in pediatric oncology, metastatic neuroblastoma in children over 1year of age still remains great challenge. Nearly 90% of children in this group present bone marrow involevement. In staging of neuroblastoma , the assessment of tumoral infiltration of bone marrow is an important indicator of prognosis. For detection of bone marrow metastasis traditional staging includes bone marrow aspiration biopsy. Another method, scintigraphy with radiolabeled metaiodobenzylguanidine (MIBG), specifically taken up for cells of sympathetic origin, is now considered as the first line method for the staging and follow-up of neuroblastoma. The aim of this study was to assess the respective values of these two methods: MIBG scintygraphy and bone marrow aspiration biopsy in determination of the extent of neuroblastoma. Materials and methods: 131I-MIBG scans and bone marrow aspiration biopsy were performed at a time of diagnosis and were repeated at interval of mean 6 months (from 3 months to 8 months) during at least two years. Retrospectively there were evaluated 72 131I-MIBG scans of 19 children ( 15 stage IV, 3 stage III and 1 stage II) and were compared with the results of bone marrow aspiration biopsy. MIBG scan was divided into three groups:1-no tracer uptake in the skeleton, 2-diffuse uptake in the skeleton with or without focal lesion, 3 -focal lesion in one or more bones. Results: There was no tracer uptake in 39 MIBG scans, all of them had negative bone marrow aspiration biopsy. Focally increased uptake was seen in 19 MIBG scans but only in 5 of those 19 scans bone marrow biopsy was positive. Diffuse uptake in the skeleton with or without focal lesion was detected in 14 MIBG scans and bone marrow aspiration biopsy was positive in 10. Conclusion: MIBG scintigraphy has very high sensitivity and specificity for detection of bone marrow metastasis. To assess bone marrow involvement MIBG scintigraphy is more sensitive than bone marrow aspiration biopsy. MIBG scan seems to be very good method for staging of neuroblastoma even when bone marrow aspiration biopsy is negative. 

The study aimed to determine if the fetal anteroposterior renal pelvic diameter (RPD) is predictive of obstruction as determined by scintigraphy. Methods: Neonatal Lasix augmented(F+20) MAG 3 studies conducted over 21 months for the clinical indication of sonographically detected antenatal hydronephrosis (RPD> 4mm in mid trimester, MT, and > 7mm in the third trimester, TT) were retrospectively analysed. The sonographic MT, TT and postnatal (PN) RPD were noted. PNRPD> 5mm on the postnatal ultrasound was defined as postnatal hydronephrosis. This was based on Scott and Renwick's findings of 95% of the postnatal population falling in the 0-5mm range (Br J Urol 62:295-300). Two blinded nuclear physicians classified the scintigraphic studies as 'obstruction' or 'no obstruction' based on the half time drainage (t1/2) and frusemide washout curves. Results: A total of 40 patients (56 hydronephrotic kidneys) were identified with measurements at MT in n=31, at TT in n=50 and at PN in n=46. Antenatal hydronephrosis detected in 3/50 TT kidneys had resolved on the postnatal ultrasound. A series of one-way ANOVA's were performed separately for the right and left kidneys to compare the means of the trimester measurements for those that were obstructed on scintigraphy. Though the probability of obstruction was greater at higher RPD, in all groups, there was no statistically significant difference for the MT and TT mean RPD measurements in the obstructed versus non-obstructed group (p>.05). The mean PNRPD was found the most reliable predictor of obstruction on scintigraphy (p=.020 Rt and p=.007 Lt). The PPV for prediction of obstruction with RPD>10mm is 54% and the NPV for prediction of nonobstruction at RPD <10mm is 91%. The findings were also correlated with results of the micturarting cystourethrogram(MCU) when it was available. MCU was available in 27/40 patients and 40/56 kidneys. Vesico-ureteric reflux(VUR) was identified in 5/27 (18.5%) patients and 6/40(15%) kidneys. There was no statistically significant relationship between the RPD and presence of VUR. Conclusion: Antenatal hydronephrosis is more prevalent in the male fetus. The PN-RPD has a higher predictive value for diagnosis of obstruction compared to the MT and TT measurements, with higher likelihood of obstruction at higher diameters. The negative predictive value is 91% to S364 exclude obstruction if PN-RPD<10mm.This group of patients can hence be observed with follow-up sonography rather than subjecting them to have renogram studies. Objective: Clinical presentation of myocarditis (myo) varies from asymptomatic cases to acute heart failure. Endomyocardial biopsy (EMB) is an invasive method, therefore another procedure would be advisable, especially in children. The aim of study was to investigate of the scintigraphy with 99m Tc-Anty-Granulocyte antibody ( 99 m TcAGA) usefulness in pediatric cases with suspected myo. Methods: Between 2005 Between to 2006 aged 6,6 -17,6 yrs) with the symptoms of myo were evaluated at initial presentation and 6 month later. All pts underwent heart scintigraphy with 99m TcAGA; 10-20mCi the tracer activity was administered iv and acquisition in AP projection was performed 4 and 24 hours later. The estimation of 99 m TcAGA uptake was evaluated by calculation of the heart-to-lung ratio (HLR), value of 1,50 or more was considered as a positive result. 99 m TcAGA scintigraphy was performed in control group of 10 children with suspected enterocolitis (HLR 1, 50) . EMB was performed with immunohistchemical method in 7 pts (no consent in one case). The results of heart scintigraphy were compared with EMB. Results: The mean time from onset of symptoms of myo which included fatigue, heart failure (n=4), ventricular arrhythmias (n=4), chest pain (n=3) to diagnosis of myo was 2,52 ± 3 mo. Positive 99 m TcAGA uptake was observed in 7 pts (mean HLR 2,04 ± 0,54), in 3 cases intense (HLR>2), in 4 moderate (HLR<2) and in 1 pt borderline (HLR 1, 50) . Higher HLR (mean 2,12 ± 0,66) was found in the pts who presented within 2 mo of the onset of symptoms than in those who presented in later phase (mean HLR 1,74 ± 0,07). EMB results showed evidence of myo in 6 pts, no evidence in one case. All 3 pts with HLR>2 showed evidence of active myocarditis in EMB. Follow up 99 m TcAGA scintigraphy was performed in 6 pts (mean HRL 2,01 ± 0,53); follow up EMB in 5 pts showed evidence of persistent inflammatory process in myocardium. Conclusion: 1. 83,3% of the pts with positive heart scintigraphy showed evidence of myocarditis in EMB. 2. Intense myocardial uptake of antigranulocyte antibodies with HLR>2 strongly indicates active myocarditis. 3. Although further studies are necessary to establish its sensitivity and specificity, scintigraphy with 99 m TcAGA seems to be an advisable diagnostic method in pediatric cases with myocarditis.

Dynamic renal scintigraphy in patients with hydronephrosis E. Urbanova 1 , I. Novak 2 , J. Vizda 1 ; 1 University Hospital, Nuclear Medicine, Hradec Kralove, CZECH REPUBLIC, 2 University Hospital, Pediatric Urology, Hradec Kralove, CZECH REPUBLIC.

The aim of this study is to evaluate the kidney function before and after operation for hydronephrosis. Stenosis of proximal ureter is the most common anomaly, causing dilatation of the renal pelvis and thus hydronephrosis. In all children in our study ureteropelvic obstruction was suspected and hydronephrosis with dilatation of renal pelvis was detected by ultrasound. For functional relevance of urinary tract obstruction dynamic renal scintigraphy (DRS) was used. Material and Methods: During the past 35 months 36 children in age 1-10 years without clinical sign of infection were included in our study. Preoperative data, early and late complications and outcome were recorded. Imaging studies included urinary tract sonography and DRS, which were compared pre and postoperatively. Patients were hydrated before scintigraphy and were advised to empty urinary bladder before investigation. For DRS as radiopharmaceutical technetium 99m labeled MAG3 was used. Frusemide was administered intravenously 15 minutes after the start of examination at dosage of 1.0 mg/kg body weight to achieve forced diuresis. Scintigrams were recorded in posterior view. The zoom factor was chosen 1.5-2, matrix 128x128. Total time of examination was 30 minutes. The definition of the region of interest (ROI) for each kidney was either semiautomatic, using a ROI drown around the kidney, or fully automated. It was routine to obtain post-void images for gravity-assisted drainage. Quantitative functional parameters were interpreted in conjunction with image review and perfusion, parenchymal and excretory phases were described. An attempt was made to define the approximate limits of reversibility of stasis in affected kidney after operation, so DRS was repeated in 24 children from our study 3-7 months after the operation. Results: DRS in comparison pre and post-operation in the 18 children showed marked improvement of washout (WO). In addition the six children with WO = about 15% also showed 7 months later small improvement at scintigraphy. Conclusion: Sonography is suited to documenting the anatomical situation and can be repeated without radiation burden, but DRS can be used to assess the functional relevance of urinary tract obstruction before and after the operation. The careful attention to the technique of the examination is necessary, because there are still many controversies surrounding the physiology and interpretation of the renogram. Early diagnosis and suitable therapy of functionally relevant urinary tract obstruction are very important to avoid chronic renal damage. Aim: Glomerular filtration rate (GFR) is generally considered the best functional measure among several important functions of kidney. Cystatin C is a nonglycosylated basic protein produced at a constant rate by all nucleated cells and eliminated by glomerular filtration. Serum Cystatin C reflects renal function in children independent of age, gender, height, and body composition. Recently, cystatin C has been studied as an alternative marker of GFR and more accuracy than serum creatinine.The aim of this study was to compare measured GFR by two-plasma sample method (TPSM) with serum cystatin C level in paediatric population. Materials and Methods: The study population comprised 34 consecutive patients (21 boys, 13 girls, mean age 8.2 ± 3.8), included thalassemia (n=18), acute lymphoblastic leukemia (ALL) (n=10) and fanconi anemia (n=6). Blood samples were taken at 120 and 240 min post-injection of 37-74 MBq of Tc-99m DTPA from the contralateral arm. Slope-intercept method was used for TPSM GFR measurements. Serum cystatin C level was also measured on all patients. Results: TPSM GFR values varied between 35-150 ml/min/1.73m 2 (mean:91,9 ± 29 ml/min/1.73m 2 ). Serum cystatin C levels ranged from 0.26 to 2.04 mg/L with a mean of 1,03 ± 0.40 mg/L. There were found statistically significant negative correlation between TPSM GFR and serum cystatin C level (r = -0.45, p<0.001) . Regression analysis showed the curve equation formula as follow:GFR (ml/min/1.73m 2 ) = 129-(36 x serum cystatin C )Ninetyfive % confidence interval is: 111.6-(20.2 x cystatin C) to 146.4-(51 x cystatin C); p< 0.001. Conclusion: This study showed that there was statistically significant negative correlation between GFR value in TPSM and serum cystatin C level. Cystatin C may reflect the quantitative renal function in the paediatric population. Further studies are needed to validate this conclusion in paediatric population.

There is increasing evidence that Botulinum A toxin (BoA) might have a powerful role in the management of children with functional voiding problems. The aim of this study was to analyze radionuclide uroflowmetry evidence of effectiveness of BoA injection in treatment of dysfunctional voiding in children. Patients and Methods: Study enrolled 9 female children, 5-11 year old, with dysfunctional voiding and recurrent urinary tract infection, in whom pharmacological and biofeedback treatment failed. A dose of 500 units of Botulinum-A toxin (Dysport) was injected intrasphincterically at 4 sites in all children. Urodynamic and radionuclide uroflowmetry was performed in all children before, and 6 months after the treatment. Radionuclide uroflowmetry was performed using 99mTc-DTPA or 99mTc-MAG3 and the following parameters were analyzed: functional bladder capacity measured as voided volume plus residual urine volume, presented as a percent of predicted bladder capacity (FBC, %), residual urine volume presented as a percent of FBC (RU,%), voided time (VT,s), average flow rate expressed as voided volume divided by voiding time(AFR, ml/s), peak flow rate expressed as AFR multiplied by peak bladder emptying rate (PFR, ml/) and ejection fraction calculated as ratio of counts between peak bladder emptying rate minus minimal bladder emptying rate, and mean bladder emptying rate (EF,%). All children have been tested before and six month after the treatment using empirically designed International Reflux study modified questionnaire, regarding daytime and nighttime symptoms, voiding and bowel habits and quality of life. Results: The relative changes-each in comparison with the value before Dysport injection therapy were as follows: FBC increased by 104% versus 101% (ns), RU decreased by 14% versus 28% (p<0.05), AFR increased by 9ml/s versus 7ml/s (p<0.05), PFR increased by 18ml/s versus 14 ml/s (p<0.01), EF increased by 77% versus 67% (p<0.05) and VT decreased by 24s versus 32s (p<0.01). Significant symptom score improvement was detected six months after the treatment, being decreased by 7 versus 20. No major side effects occurred. Conclusions: Although we surveyed only a few patients, the efficacy after BoA injections in difficult-to-treat children with bladder dysfunction seems promising. Only slight improvement of bladder function parameters detected by means of radionuclide uroflowmetry with the significant improvement of urinary tract symptoms six month after the treatment could be addressed to improvement in voiding dynamics and significant reduction of postvoid residual urine volume. These results raise hope of keeping high-risk children with bladder dysfunction under conservative control longer. before and after the furosemid provocation was 2,8/min and 4,2/min respectively. In 14 cases the number of waves actually increased, and there was no change in the remaining 4 cases. In 6 cases we compared the change in ureteral function before and after reconstructive surgery. The mean peristaltic wave number before the operation was 4,3/min, and decreased to 3,2/min afterwards. Conclusion: According to previous studies, the ureter adapts to increased urine flow by increasing the transported bolus volume. In our study, megaureters adapted to the same challange by increasing the frequency, which is an indication of impaired renal drainage. The decrease in frequency following surgery may be the result of a succesful operation.

B. Ajdinovic 1 , L. Jaukovic 1 , Z. Jankovic 1 , A. Peco-Antic 2 ; 1 Military Medical Academy, Belgrade, SERBIA, 2 University Pediatric Clinic, Belgrade, SERBIA.

Objective: Urinary tract infection (UTI) is a common condition in children with vesicoureteral reflux (VUR), and may lead to renal damage. The aim of this study was to determine the incidence and the pattern of abnormal DMSA findings in children with hystory of bacteriologically proven UTI. Materials and methods: Standard 99m Tc-DMSA renal scintigraphy was performed in 118 children (47 boys and 71 girls, aged from seven months to seven years ), six months after the initial infection. Findings were classified according to the image appearance and relative kidney uptake (RKU) and related to the grade of VUR, sex and child's age. Results: Micturating cystourethrography (MCU) revealed VUR (78 uni and 40 bilateral) of grades I, II, III, IV and V in 2, 47, 34, 19 and 16 patients respectively. DMSA images were normal with RKU within normal limits in 48 patients and equivocal in 10 pts Findings were interpreted as abnormal in 41 cases due to scarring, and in 19 pts with decreased RKU. Bilateral scarring was shown exclusively in children with bilateral VUR. Scarring rate was significantly associated with VUR of higher degree (p<0.01) and male gender ( p<0.05). No significant difference was found between renal scarring and child's age in same gender group. Poor kidney function (RKU less than 10%) was shown in 7/118 patients. Conclusion: Renal damage on DMSA scintigraphy highly correlated with grade of VUR. A strategy to perform MCU in only patients with abnormal DMSA finding is proposed. Disordered gastric emptying is frequent and clinically important complication of diabetes mellitus (DM). The aim of this study was to determine gastric emptying rate(GER) in children and adolescents with type 1 DM, and to investigate relationship between GER and microalbuminuria in these patients. Subjects and Methods: GER with solid meals was assessed by a radionuclide method using solid meal in 33 diabetic children and adolescents and 25 age matched healthy controls. The patients were divided into two groups according to duration of diabetes as less than 5 years (Group A) and longer than 5 years (Group B). The patients ingested scrambled egg bound to 1 mCi of Tc-99m sulphur colloid bound to a scrambled egg. Images were obtained from anterior and posterior projection in a 128x128 matrix with 1.0 zoom factor. The period of data collection began as soon as the subjects finished the meal. The data were acquired for 60 s per frame, for a total of 60 min. A region of interest corresponding to the stomach was outlined to the determine the gastric counts for each image. A power exponential fit was used to analyse the time-activity curve over the stomach and to calculate the half-time of gastric emptying. Delay was recognized if GER was longer than 60 minutes. Three consecutive timed overnight urine collections were used to calculate microalbuminuria. Increased microalbuminuria was defined as a median value is greater than or equal to 7.5 μg/min. Data were evaluated using Mann Whitney U analysis, Kruskall Wallis analysis and Pearson's correlation tests. Results:

The mean values of GER were 151.72±154.46 minutes for diabetic patients and 115.42±133.85 minutes for control group; and the difference was not statistically significant (p=0.339). GER didn't differ significantly between Group A and Group B and control group (p>0.05). There was no significant difference of GER among in patients who have higher and lower microalbuminuria level (p>0.05). There was no correlation between GER and duration of diabetes and microalbuminuria (p>0.05). Conclusion: We did not detect any significant changes of GER in children and adolescents with type 1 DM. No relationship could be found between microalbuminuria and GER. Aim: Scintigraphy with Tc-99m DMSA is considered a reference method for assessment of renal parenchymal lesions and estimation of differential renal function (DRF). However, comparisons with Tc-99m MAG3 indicated certain disadvantages of DMSA such as relatively higher radiation exposure to kidney and time consumption. Tc-99m MAG3 with high tubular secretion suggests that it may be useful in infants. The aim of this study was to evaluate the performance of Tc-99m MAG3 dynamic renal scintigraphy in the detection of renal parenchymal defects and in the estimation of DRF comparing to Tc-99m DMSA scintigraphy. Materials & Methods: A retrospective review of the records between April 2002 -January 2007 indicated that a total of 29 infants (20 boys and 9 girls) aged under 1 years, underwent both Tc-99m DMSA and Tc-99m MAG3 scintigraphies within 3 weeks of each other. Parenchymal phase of MAG3 scintigraphy were compared to DMSA images for right and left kidneys, separately. The renal cortical analysis of MAG3 scintigraphy was performed on the summed image obtained from dynamic images. And also, differential function was calculated in MAG3 and DMSA studies and then compared. Results: Findings corresponded completely in 90% of patients. There was no statistically significant difference between calculated DRF on DMSA and MAG3 images. However, in the left kidney, mean MAG3 value (52.21%) tend to be higher than that of DMSA (51.48%). There is a high correlation between the DRF (r=0.91 and r=0.90; for the left and right kidney, respectively; p<0.01). Accepting DMSA is a gold standard method to assess renal cortical lesions, the sensitivity and specificity of the MAG3 cortical scintigraphy were calculated as 92% and 78%, respectively. Compared with DMSA, MAG3 was as sensitive as DMSA however lower specific than DMSA.

The results showed that most of renal parenchymal lesions detected on DMSA scans can be identified on MAG3 parenchymal scans. Both studies can be equally used for the calculation of DRF. Tc-99m MAG3 may be acquired for evaluating of renal parenchyma especially in infants because it is a feasible, useful, rapid (5 min) functional imaging method and lower radiation dose. Because of low specificity of Tc-99m MAG3 cortical analysis, Tc-99m DMSA scintigraphy have to be acquired in the definite diagnosis and management of renal cortical lesion therapy. Aim: Congenital diaphragmatic hernia (CDH) is often combined with primary hypoplasia of the pulmonary vascular bed, which is one of the most significant prognostic factors in patients with CDH. In this study, the values of lung perfusion and ventilation scintigraphies were investigated to assess the lung regarding pulmonary vascular hypoplasia in the pediatric patients with CDH. Material and methods: 8 patients (3 boys, 5 girls) were included in the study. All patients had respiratory distress within the first 6 hours of life due to CDH. Six patients had left-sided and 2 patients had right-sided CDH. All cases underwent a surgical repair of CDH in the newborn period (mean age: 3.88 days). The mean 113 ± 13 days after the operation, lung perfusion scintigraphy was carried out with 0.5 MBq/kg of Tc-99m MAA. The perfusion images were evaluated quantitatively. For quantitative analysis, the regional distribution of each lung was expressed in a percentage of total lung perfusion. Next day, lung ventilation scintigraphy was performed with 0.4 MBq/kg of Tc-99m DTPA by placing a see-through mask over the child's mouth and nose allowing them to be able to breathe as if via a nubulizer. Ventilaton images were evaluated quantitatively in a similar manner as to the perfusion study. Results: In one patient, the perfusion rate of the side of CDH was 31% and the ventilation rate of the same lung was 50%. Because of the combination of the good ventilation and restricted perfusion, it was thought that primary pulmonary vascular hypoplasia might exist in this patient. In other 7/8 cases, the mean perfusion rate was 27.14 ± 5.53 % and the mean ventilation rate was 26.14± 4.81% in the side of the CDH. In these patients, a statistical difference was not observed between perfusion and ventilation results (p>0.05). Having been considered that ventilation disorder with secondary perfusion disorder might develop, the pulmonary vascular hypoplasia could not be eliminated in these cases. Conclusion: This study reveals that the combination of lung perfusion and ventilation scintigraphies, which are objective, quantitative, non-invasive, and easily performed methods, may helpful in determining the pulmonary vascular hypoplasia in pediatric patients with CDH. Additionally, it can be suggested that these methods may be useful to evaluate the growth and development of lung affected by CDH especially during the first year of life when respratory function studies are difficult to obtain. Using the same site for tracer injections and blood sampling makes EDTA clearances more acceptable to patients and ensures that blood samples will be successfully obtained. BUT there are predicted problems from tracer contaminating the samples or saline diluting the samples. In practical terms the two important questions are (a) whether same site sampling (SSS) produces an increased rate of recognisable poor test results, and (b) whether it produces undetected bias or errors in the results. Since February 2005 307 3-sample EDTA clearance studies have been performed, of which 14 had separate sites for injection and sampling, and the remainder used the same venous access for injection and blood sampling. In addition, 18 studies from another hospital (W) that used different sites were included. A review of the results produced the following:-Recognised Problems: were noted as follows:-Venous access not obtained (5) Ward lost samples (1) patient fainted (1) Vein "blew" during tracer injection (1) tracer contamination of first sample (1) . Unrecognised Problems: were looked for by using the following quality assurance factors:-(1) The r 2 value of the log-plot fit to the data points. (2) The ratio V d / Weight. (3) The first point position relative to a line drawn only through the second and third points. The different groups studied were Group1 n=18 Hospital W and Group2 n=14 Hospital A . both of these first two groups used separate sites for the tracer injection and sampling. Groups 3 to 5 used the same site for injection and sampling, as follows:-Group3 n=96 SSS (Antecubital fossa luer) Group4 n=47 SSS (PIC line) Group5 n=27 SSS (luer in hand vein) Group6 n= 13 Any method but GFR<20ml/min. Results: with one exception, none of the QA factors showed any difference between the Groups studied. The exception was Group 6 (low GFRs), and this group showed a lower r 2 value than the others. Conclusion: The one case of sample contamination was detected by looking at the data and the routine QA values. Assessment of the QA values in the remaining data did not suggest any undetected bias in the group results. Objective: Ureteropelvic junction stenosis and vesicoureteral reflux are the most frequent entities identified by antenatal hydronephrosis. Aim: to determine the incidence and pattern of abnormal renal scintigraphy findings in postnatal investigation of children with antenatal hydronephrosis. Patients and methods: Twenty four infants (19 boys and five girls) who presented with antenatal hydronephrosis and mild to moderate hydronephrosis on ultrasound in newborn period were referred for renal scintigraphy. Ten patients with vesicoureteral reflux documented on micturating cystoureterography received DMSA renal scintigraphy and 14 patients received DTPA scintigraphy. Results: Antero posterior pelvic diameter on ultrasound ranged from 11 to 24 mm. DMSA renal scans identified congenital scars in two boys with bilateral reflux of grade V and unilateral reflux of grade III. Global hypoplasia (relative kidney uptake (RKU) less than 40%) was found in three, and poor kidney function (RKU less than 10%) in two patients. Significant obstruction was shown on DTPA diuretic renal scintigraphy in near the half of patients (6/14). Some slowing in drainage (t1/2 greater than 10 minutes) with no reduction in differential renal function was identified in three patients. Differential renal function less than 10% was obtained in one case. Conclusion: High proportion of abnormal renal scintigraphy findings was obtained (70%). Renal scintigraphy was useful in determination of underlying cause of antenatally detected hydronephrosis. Pediatric urolithiasis is very important because of its effects on the growing kidney, the significant recurrence rate, the association with urinary tract infections (UTI) and the long term outcome. In this study we aimed to determine the renal cortical state by DMSA in children with urolithiasis who had experienced UTI during follow up. Patients with urinary tract abnormalities were not included to the study. A series of 48 patients (30 boys, 18 girls) with a mean age of 82.2 ± 55.5 months and a mean follow up period of 26.6 ± 25.7 months were studied by DMSA. DMSA scar grading was performed for each subject according to Imperiale et al. Number of UTIs, the localization of the stones were noted. UTI was treated with proper antimicrobial therapy. Stone patients were treated medically according to their stone analysis or urinary metabolic analysis. 71 UTI attacks were recognized during follow up. Only 4 patients (8%) showed scars on DMSA. Scar grading was 1 in two patients and 3 in two patients. Of these four patients children with single UTI showed score 1 on DMSA and children with 3 or more UTI showed score 3 on DMSA. The localization and the side of the stones were the same in all subjects. We conclude that urolithiasis often coexists with UTI and the risk of renal injury is not low . DMSA scan evaluation is important during the follow up of these patients.

Introduction -Aim: GFR is the best measure of kidney function and is accurately measured by 51Cr-EDTA, which follows bi-exponential kinetics. As the widely applied multiple sample technique assumes a monoexponential pattern of tracer elimination, GFR is overestimated and corrections for the missing, initial, fast component of tracer clearance have been incorporated in current European guidelines. These are the linear Chantler's (CH) and the quadratic Brochner-Mortensen's (BM) corrections, diverging, however, at different GFR levels. The aim of the present study was to analyse the agreement between GFR measurements after applying the two correction methods at various GFR levels in a mixed adult population. Patients and methods: Four hundred ninety six pts (244 women), aged 52.4±15.4 yrs were enrolled in the study. Pts were referred for GFR measurement for chronic kidney disease or as kidney donor candidates, renal transplant recipients and renal transplant donors. GFR was measured with the slope-intercept, two-sample technique after i.v. administration of 51Cr-EDTA . Values were normalized for body surface area calculated according to Haycock's formula and were expressed as ml/min/1.73 m 2 . Bland-Altman analysis was applied for assessment of agreement. Results: Patients were allocated in low (<30, 139 pts), intermediate (30-90, 295 pts) and high (>90 ml/min/1.73 m 2 , 62 pts) uncorrected GFR groups. Mean (SD) uncorrected GFR values were 18.8 (6.7), 56.9 (17.4) and 104.8 (13.3) ml/min/1.73 m 2 for the three groups, respectively. After CH / BM corrections, GFR values were 17.5 (6.2) / 17.8 (6.1), 52.9 (16.2) / 48.6 (12.8) and 97.5 (12.4) / 79.5 (6.7) ml/min/1.73 m 2 for the three groups, respectively. Mean GFR differences (CH -BM) were -0.3 (0.2), 4.2 (3.5) and 18.0 (5.7) with 95% confidence limits -0.6 -0.0, -2.6 -11.0 and 6.8 -29.2 ml/min/1.73 m 2 for the three groups, respectively. -3) and Gamma camera equipped with a low energy high resolution collimator interfaced with a computer. Regions of interest (ROI) were drawn over the whole kidneys. Radioactivity-time curves were generated from the ROI. Time to peak activity (T max ), time from peak to 50% activity (T ½ ) and the uptake slope of each kidney were calculated from the renograms. The same protocol was repeated for the same animal 3 times at 3 days intervals at 2, 3 and 4°C higher temperature. Blood pressure was measured using a catheter inserted into the femoral artery connected to a recorder and renal blood flow was also measured through renal artery using an electromagnetic blood flow sensor connected to a flowmeter. Creatinine and urea in blood were measured in control and hyperthermic rabbits. Results: During hyperthermia the experimental curves shifted to the right of the control curves indicating that there was a delayed renal uptake of 99mTc-MAG-3 and clearance of radioactivity. This delay was proportional to body temperature. 

from body weight and height. Linear regression analysis was applied to assess association between variables. Results: All patients were overweight or obese, with BMI 29.7 ± 4.3 (range 25. 1 -44.6 ) kg/m 2 . GFR was 120.3 ± 20.2 ml/min. GFR was moderately correlated to BSA (0.66, p<0.0001), LBM (r=0.58, p<0.0001) and TBW (r=0.67, p<0.001) . Prediction equations were: GFR = -28.2 + 76.3 x BSA, GFR = 60.2 + 1.04 x LBM and GFR = 35.0 + 1.00 x TBW. No statistically significant difference was detected between the slope coefficients (1.04 vs 1.00) Conclusion: Despite the common beliefe, TBW is equally good to BSA or LBM as a GFR predictor in overweight or obese patients with normal renal function, thus questioning the importance of BSA normalization. As we see at these results, no significant difference was found between group I and group II, regarding the number of patients with skeletal metastases. Conclusion: Low levels (< 10 ng/ml) of serum prostaticspecific antigen can not eliminate the possibility of existance of skeletal metastases, as was expected. Even more, as the difference of the pathological bone scans between group I and group II was not significant, values of PSA 4 ng/ml cannot be considered as a safe threshold for the exclusion of the indication of bone scan. Background: The Rutland-Patlak plot is used in renography for determining relative kidney function and for separating blood background in the measured renogram. In the uptake phase the plot is a straight line, but the duration of this phase may differ from patient to patient. A good method for drawing the line in the Patlak-Rutland plot should be accurate and precise, while taking into account that data may show unusual behaviour or be noisy. Aim: This work compares three methods for drawing the line with the aim of finding a method that gives reliable results on all groups of data. Materials and Methods: Data were collected from 63 consecutive 99m Tc-DTPA renographies routinely made in the department (126 kidneys). Independent of this collection, 10 renographies were selected where at least one of the kidneys has a renogram with irregular behaviour early in the renogram, such as decrease in the renogram about 1 minute p.i., or unusually noisy data (16 kidneys with "problematic" renograms). From each renogram points for the Rutland-Patlak plot was calculated and three methods were used independently to draw the line: 1.) Manual drawing on hardcopies by three independent observers. Slope and intercept were determined afterwards. 2.) Linear regression on the first 8 points measured after 1 minute p.i. (from 1 to about 2 minutes p.i.). 3.) Points for linear regression were selected by an algorithm developed for the purpose, based on possible exclusion of early points and possible inclusion of points later than 2 minutes p.i., to reduce weighted residual variance. Results: In the group of consecutive patients (126 kidneys) Friedmann test showed significant differences among methods (p < 0.002). Pairwise comparison showed no significant difference between method 1 and 3, whereas method 2 yielded slightly lower values of slope and slightly higher values of intercept than the other two methods. Estimates on uncertainty gave similar results: No significant difference between method 1 and 3, significantly higher uncertainty estimates in method 2 than the other two methods. For the group of selected "problematic" renograms (16 kidneys) method 1 was used as reference method. Method 2 failed in a number of cases compared to the reference method, whereas method 3 showed good results. See table. Conclusion: Method 3 gives results that are accurate and precise on normal and "problematic" renograms. The method is operator-independent. Method 2 fails in a number of cases. Results: Among patients that underwent each of the three studies, no statistically differences were observed regarding age, sex, disease duration and type of lesion. 28/46 renograms (61%) were interpreted as abnormal (26 OU, 2 ON). 12/21 DMSA renal scintigraphies (57%) were abnormal and 26/89 GFR measurements (29%) were also abnormal. Conclusions: In patients with spinal cord lesion and neuropathic bladder, "functional" obstructions and parenchymal scars seem to be the most common nephrourological complications, while nephropathy detected by renogram and/or GFR measurement is found in a smaller number of patients. It is suggested that diuretic renogram and DMSA renal scintigraphy should be performed as part of the diagnostic and therapeutic management of all these patients. Patients who were booked for DTPA Renograms and EDTA clearances on the same day had those injections given at the same time, and the plasma samples were counted on a collimated Gamma Camera at the end of the day. An Excel program was used to calculate the 99m Tc-DTPA results (using times that had been recorded to correct for Tc-decay during the day). After 48 hours to allow the technetium to decay, the 51 Cr-EDTA was counted in a sample counter, and the results compared. It is sometimes difficult to differentiate peripelvical cysts / PPC / and hydronephrosis / HN /, based only on the symptoms of the patients / Pts / and the data from the ultrasonography. The aim of the study was, using dynamic renal scintigraphy, to differentiate these two entities.We have investigated 35 Pts, using 74-111 MBq 99mTc-EC. In all of them, the ultrasonographic data showed hypoechogenic area in the region of the kidneys' pelvis and it was difficult to differentiate PPC from HN. After performing renography, in 7 of the Pts, there was an "accumulation" type of the curve, in 6-a "retention" type, in 14 -the curve was with a delayed excretion and in 8normal. In all of the Pts with an "accumulation" or "retention" type of the curves, additionally a diuretic renography was performed / using 0.5mg/kg Furosemid , injected on 20 min. p.i. of 99mTc-EC /, to differentiate obstructive from nonobstructive hydronephrosis. In the latter Pts there was a quick outflow of the radioactivity from the pelvicaliceal system after the injection of the diuretic / T ½ 10 min./. Using additional imaging methods and follow up of the Pts, 22 of them with a normal or delayed excretion, finally were diagnosed as having only PPC, and from those with an "accumulation" or "retention' type -8 were with a non-obstructive hydronephrosis and 5-with an obstructive hydronephrosis, due to different reasons. Only 1 patient with PPC had non-obstructive hydronephrosis. Divided renal function of the kidneys with HN was lower -42.7% than that of the kidneys with PPC-50.1% / p<0.05 /. We consider, that using dynamic renal scintigraphy without or with diuretic, further elucidating of the diagnosis could be made and the appropriate therapy of the patient could be planed. Conclusion: The renography is a reliable tool for differentiation of the PPC from HN. Using additionally diuretic renography, not only differentiation of the obstructive and non-obstructive hydronephrosis could be made, but according to the obtained results, the following therapy could be chosen. excretory function. Aim of the study was investigation whether clearance parametric images of kidneys widen the diagnostic capacity of traditional procedures. Materials and methods: 70 individuals were studied in whom diabetes type I (insulin dependent) was diagnosed. A second group of 35 healthy volunteers served as controls. 210 individual kidneys were studied and their images and renoscintigraphic curves evaluated. In all individuals a dynamic kidney study was performed after administration of the 99m Tc-ethylenodicysteine (EC) and ERPF determined. After processing of aquired data conventional images were created by summation of scintigrams received in the phase of secretion of RF. From the same images the clearance images were created. Both types of obtained images served for the evaluation of defects of kidney parenchyma. For both types of images a 3 level score scale was used to provide semiquantitative measure of observed pathology. Renographic curves were evaluated by analyzing their shape, taking into account relative contribution of each kidney to total uptake (or ERPF). Elimination of urine from the pelvic and ureteral space was evaluated on basis of phase III of the renogram. Mean renal transit time (MTT) and mean parenchymal transit time (PTT) of the tracer were also calculated. Results: Analysis of clearance parametric images revealed that regional defects in function of renal parenchyma were more frequent in kidneys of patients with diabetes than in the controls (35,7% vs 8,6%). In conventional summation images there were no significant differences in defect frequency noted between the groups (2,9% vs.4,3%) . There were no differences between PTT and ERPF between the groups (p=0,2 and 0,4 resp). Relative uptake of EC in both groups did not differ and was within the normal range of values. There were a larger mean value of MTT and more frequent flattening of the curve in phase III in patients with diabetes than in control group (p=0,02 and p=0,001, resp.) , what could be due to the functional uropathy, seen in diabetic patients. Conclusions: 1. Clearance parametric images reveal additional information on regional function of kidneys even if other values characterizing global function of kidneys are still within the normal range. 2. Parametric clearance images should be included as a component of dynamic kidney studies.

S. Inanir, G. Ege Aktas, T. Erdil, H. Turoglu; Marmara University, Istanbul, TURKEY.

Aim: Tc-99m DMSA renal cortical scan is a reference method in determining relative renal function (RRF). Tc-99m MAG-3 is also recommended for the estimation of RRF, particularly in young children. The aim of this study was to compare MAG-3 and DMSA RRF estimations, and, to assess reproducibility of these estimations in children with unilateral hydronephrosis. Methods: We reviewed MAG-3 and DMSA scans in 19 children with unilateral hydronephrosis and a normal contralateral unit. All were imaged with 2 agents within 3 months. MAG-3 RRF was calculated using 2 different time intervals (1-2 minutes and 2-3 minutes) and perirenal C-type region of background activity. No background correction method was used in the calculation of DMSA RRF. All data were processed twice by two independent operators. Results: In the repeated estimates of MAG-3 RRF, the maximum mean differences were 0.9% (SD:1.7%) within observer and 1.4% (SD:3.3%) between the observers. Intra-method analysis showed statistically significant agreement between repeated measures of RRF for 2 agents as well as for 2 operators (intraclass correlation coefficients of early and later phase of MAG-3 and DMSA RRF values were 0.979, 0.993, 0.996 for operator 1 and 0.986, 0973, 0.995 for operator 2, respectively, p<0.001). There were significant correlations between the MAG-3 and DMSA RRF estimations (r=0.763/0.766 at 1-2 min, 0.835/0.825 at 2-3 min for the repeated measures of RRF for operator I, and 0.812/ 0.793, 0.83/0.88 for operator 2, respectively, p<0.01, pearson). When each scan was classified as normal or abnormal according to RRF values, inter-method analysis showed statistically significant agreement between MAG-3 and DMSA RRF estimations (Kappa statistic). However, a disagreement was revealed between the methods when borderline and supranormal estimates of RRF were taken into consideration. Conclusion: In children with unilateral hydronephrosis, our results indicated a close correlation between DMSA and MAG-3 RRF estimations with a good reproducibility. Renal perfusion scintigraphy using Technitium-99m is commonly performed after renal transplant to assess vascular flow to the transplanted kidney. This allows cases of vascular compromise to be detected early to minimize damage to the transplanted kidney. This retrospective study evaluates the outcomes of a series of renal perfusion scans performed in a tertiary care hospital in the post-operative management of renal transplantation. In addition, we define a renal transplant perfusion index (RTPI) as the ratio of the cumulative counts in the renal transplant to the cumulative counts in the aorta from start of the renal perfusion scan to time of peak aortic curve, and attempted to correlate the values in each patient with the eventual outcome. Over a 6 month period, all recipients of a kidney transplant and who subsequently underwent renal perfusion scan within the same admission were recruited into the study. The medical notes were analyzed for scan results and patient outcome. A scan was deemed normal if no evidence of major vascular compromise was detected, abnormal if there is a perfusion defect seen and/or there is delay in perfusion to the transplanted kidney. A patient's outcome was deemed uneventful if there were no transplant-related complications prior to discharge (i.e. vascular compromise, biopsy-proven transplant rejection or acute tubular necrosis), and eventful if complications arose. A total of 43 patients were included. 30 scans were normal, of which 1 patient had an eventful outcome (transplant rejection). Another 13 scans were abnormal, of which 9 patients had eventful outcomes (2 with vascular obstruction, 7 with transplant rejection or acute tubular necrosis). The sensitivity of this study in detecting a transplant-related complication was 90%, and the specificity was 90.6% (thus giving the likelihood ratio for a positive test as 9.6). The positive predictive value was 69.2% and the negative predictive value was 96.7%. The mean RTPI in patients with uneventful outcomes was 3.5 ± 1.56, compared to 8.91 ± 6.09 in patients with eventful outcomes. A Tc-99m renal perfusion study has become a mainstay of management after renal transplant.

This study quantifies its utility in predicting outcome after renal transplantation when done in the post-operative period. It also suggests that an elevated RTPI is associated with patients who develop acute post-transplant complications. The ectopic kidneys belong to the inherited abnormalities of the kidneys. The aim of the present study was to evaluate the function of the ectopic kidney with renal dynamic scintigraphy with 99mTc -DTPA. Materials and methods: A retrospective study of the renal dynamic scintigraphies done between 2003 to 2006 year was done. Out of 1864 renal scintigraphic examinations 15 patients with an ectopic kidney were found-8 men and 7 women with age from 15 to 70 years. In all of them diagnosis an ectopic kidney was put for the first time due to the scintigraphic examination. The scintigraphy was done on a gamma -camera Siemens according to a predefined protocol with quantitative measurements in two phases: perfusion and secretionexcretion. 222 MBq/70kg /99mTc -DTPA was injected as bolus at the very beginning a quality assessment and quantitative determinations of T max, T ½, relative function of each kidney and glomerular filtration rate /GFR/ were done. Results: In all 15 patients the ectopic kidney was found in the pelvis above the urinary bladder. In 3 patients the right kidney was ectopic and in the rest 12 the left one has an ectopic position. In 8 patients the ectopic kidney was hypoplastic. Preserved kidney function with spastic drainage were found in 2 patients. Reduced secretion, excretion and drainage were found in 10 patients. Afunction of the ectopic kidney was seen in 3 patients. Conclusion: We consider that renal dynamic scintigraphy with 99mTc -DTPA can be helpful either for diagnosis or for evaluation of the function of the ectopic kidneys Aim: To evaluate if renal pelvic dilatation is associated with dysregulation of the rennin-angiotensin system (RAS) in foetuses in the second trimester of pregnancy that could represent an early predictor of arterial hypertension development after birth.

The study consisted of 26 non-diabetic heterozygousthalassemia pregnant women aged between 25 and 30 years, on their second trimester of pregnancy (21 st to 23 rd week of gestation). The foetuses had normal development and no obvious congenital abnormalities on ultrasound. Maternal and foetal blood was collected and total rennin and active rennin were measured by an immuno-radiological (IRMA) method; inactive rennin (prorennin) concentration was calculated by subtraction of the active rennin from the total rennin concentration. Foetal renal pelvis was evaluated by ultrasound. The Mann-Whitney U test was used to compare active rennin, prorennin, and the prorennin-to-active rennin ratio between maternal and foetal blood. The same comparison was performed between foetuses with and without pelvic dilatation, as well as between their mothers. Continuous data are expressed as mean ± SD; significance was set at p<0.05. Results: A significant difference as regards prorennin, active rennin, and their ratio was observed between pregnant women and their foetuses (p<0.01). Furthermore, a significant difference was found in the prorennin-to-active rennin ratios between foetuses bearing renal pelvic dilatation and those without (p=0.004), while no significant ratio difference was found between their mothers (p=0.6). Conclusion: Dilatation of renal pelvis in the 2 nd trimester of pregnancy seems to upregulate the RAS system, with all the possible consequences of renal dysfunction and arterial hypertension after delivery; thus ultrasonographic evaluation of the foetal renal pelvis and measurements of foetal rennin should be considered.

Foetuses Prorennin (μu/ml) 571.7 ± 255.9 1620.9 ± 253.8 Active renin (μu/ml) 64.9 ± 50.4 228. Correlation with urodynamics and classification by American Spinal Injury Association (ASIA) impairment scale refluxes (VUR) and recurrent urinary tract infection. These situations can lead to scar formation in the renal parenchyma and renal failure that have serious impact on the quality of life and long term survival in this group of patients. The aim of this study was the detection by diuretic renogram of urological and/or nephrological complications in the special group of patients with spinal cord injury and neuropathic bladder. Materials and Methods: Forty-six diuretic renograms were performed in patients with normal renal function (males/females= 34/12, mean age 36,7±12,6 years, mean disease duration 6,75±5,8 years) that were referred by the Neuropathic Bladder Unit of the National Rehabilitation Center. All patients were classified according to ASIA impairment scale and underwent urodynamics. The different types of neuropathic bladder were defined according to International Continence Society (ICS) terminology. One week after the urodynamics, the diuretic renogram was performed (i.v. injections of 120 MBq Tc-99m MAG-3 and 20 mgr furosemide at zero timeprotocol F0). Our studies were classified as normal (N), OU and obstructive nephropathy (ON). Results: According to the ASIA impairment scale, patients were distributed as: A=30 patients, B=3 patients, C=4 patients, D=8 patients and E=1 patient and according to ICS, detrusor and sphincteric mechanism overactivity was revealed in 40 patients, detrusor overactivity and sphincteric mechanism underactivity in 1 patient and detrusor and sphincteric mechanism underactivity in 5 patients. Twenty-eight/46 renograms (61%) were interpreted as abnormal (26 OU, 2 ON). ON was detected in 2 males with disease duration of 31 and 17 years. No correlation was found between renogram results and ASIA impairment scale and type of neuropathic bladder dysfunction. Conclusions: Diuretic renogram revealed a great number of "functional" obstructions in patients with spinal cord injury and neuropathic bladder. The obstruction is independent of the type of neuropathic bladder. Nephropathy is the future threat. The aim of this study was to established the alleles distributions of VDR Fok I polymorphism and how one influence on intact parathyroid hormone /PTH/ level and some biochemical markers of bone turnover -serum osteocalcin /OC/ and bone alkaline phosphatase /BAP/ in predialysis patients with chronic renal failure /CRF/. Material and methods. Forty patients -22 men and 18 women with CRF were investigated. VDR polymorphism was detected about polymerase chain reaction. The serum OC was analyzed using an original kit ELSA-OSTEO and an automatic minigamma counter /Abbott, USA/. The BAP was measured with special kit "Alkphase-B" of Metra Biosystems. The level of PTH was determined with an immunoenzymetric assay. The serum and urine creatinine, total calcium, phosphorus, total alkaline phosphatase were measured according to standard methods, recommended by IFCC. The results. The distribution of allelic variation of VDR Fok I in predialysis patients were follow: 7/22.6%/ with "FF" alleles, 22/71.0%/ with "Ff" and 2/6.4%/ with "ff" alleles. The level of creatinine clearance were similar in three groups. No significant difference in serum calcium, phosphorus, alkaline phosphatase existed among groups. The intact PTH was highest in patients with "FF" alleles -204.71 ± 60.92 pg/ml versus 89.40 ± 19.57 pg/ml in patient with "Ff" alleles and 105.10 ± 19.34 pg/ml in "ff" group /p < 0.05/. The BAP in patients with "FF" alleles was higher then BAP in patient with "Ff" -36.38 ± 8.47 U/l versus 22.20 ± 1.71 U/l but the difference was not significantly. Significantly higher serum OC levels were registered in predialysis patients compared to the healthy controls -120.48 ± 15.96 ng/ml versus 14.61 ± 1.02 ng/ml / p < 0.001/. The serum OC was highest in predialysis patients with "FF" alleles -145.72 ± 16.35 ng/ml but the difference was not significantly compare to patients with "Ff' and "ff" alleles. Conclusions: 1/ We detected the follow distribution of Fok I allelic variation in our patients: 7/22.6%/ with "FF" alleles, 22/71.0%/ with "Ff" and 2/6.4%/ with "ff". 2/ The intact PTH was highest in patients with "FF" alleles and this is not due to difference of serum calcium and phosphorus. 3/ The serum OC and BAP in patients with "FF" alleles were highest but compare to patients with "Ff' and "ff" alleles the difference was not significantly Continuous ambulatory peritoneal dialysis (CAPD) is an effective mode of management for end-stage renal disease. Dialysate leakage represents a major noninfectious complication of this procedure. This technique may caused increased intraabdominal pressure resulting in hydrothorax and hernia with reported incidence of 2% to 6% and 9% to 24%, respectively. A 49-year-old male who was undergoing continuous ambulatory peritoneal dialysis (CAPD) for diabetes mellitus nephropathy had scrotal swelling on the first day of initiation of the procedure. Peritoneoscrotal scintigraphy was requested in which Tc-99m Sulfur Colloid (111 MBq; 3 mCi) was mixed into a 2-Liter dialysate bag under aseptic technique and instilled into the peritoneal cavity thru an indwelling catheter. Sequential scintigraphy revealed gradual advancement of radiotracer via the right inguinal canal and reaching the right scrotum by 26 hour post-instillation. Patient underwent right herniorapphy. One month postsurgery, peritoneal dialysis was resumed and scrotal swelling did not recur. P63 -Monday, Oct. 15, 2007, 2: Introduction: Dysphagia is a common and disabling symptom, often associated with tracheo-aspiration phenomenon, characterising different neurological and neuromuscular disorders. Amyotrophic lateral sclerosis (ALS) is the most common degenerative motor neuron disease in adults and dysphagia is the most frequent symptom. Aim: To evaluate the role of oro-pharyngo-oesophageal scintigraphy (OPES) in the diagnostic approach to patients with ALS. Materials and methods: 57 patients divided into two groups underwent OPES: group A (control group) included 17 healthy volunteers (female/male 7/10; mean age 53±25 yrs); group B 40 patients (female/male 22/18; mean age 66±17 yrs) with ALS. OPES is based on the rapid sequential acquisition of 480 images (8 frames/sec. for a total 60" examination); 10 ml of water containing 37 MBq of 99m Tc-Sulfur-Colloid are administered by a straw to patients standing in an 80° right anterior oblique position in front of a gamma-camera with a large field-high-resolution-low energy collimator. The evaluation of sequential scintigraphic images and A/T curves allows a qualitative (bolus fragmentation with multiple swallowing, naso-pharyngeal or pharyngo-oral refluxes, premature ingestion of the bolus, laryngo-tracheal aspiration) and a quantitative analysis of swallowing disorders [oral, pharyngeal and oesophageal transit times (OTT, PTT, ETT) as well as retention indexes (ORI, PRI, ERI), and tracheal aspiration percentage ( Conclusions: OPES appears to be a sensitive test in characterising different swallowing disorders that affect patients with ALS: propulsion defect (documented by increased oral and pharyngeal transit times, and retention indexes) and incoordinate swallowing (with tracheo-aspiration). OPES is a simple, non-invasive and welltolerated test which can provide qualitative and quantitative information of the swallowing phases, useful for rehabilitative and therapeutic purposes.

Juice as Sialogogue J. Hsieh; Chi Mei Medical Center, Yungkang CIty, TAIWAN.

Purpose: To assess the feasibility of using the locally popular and widely available dried sour plum as a substitute for the frequently used lemon juice in stimulated salivary gland scintigraphy (SSGS) and to evaluate the utility of parotid gland stimulated salivary excretion fraction (SSEF) as a semi-quantitative functional parameter in pre-radiotherapy and post-radiotherapy head and neck cancer (HNC) patients. Methods Eighty patients with HNC underwent SSGS and SSEF of parotid glands were determined. Patients were classified into two groups: Twenty in preradiotherapy group (PR) and 60 in post-radiotherapy group (PO). Each half of the group PR and group PO were further subdivided into two groups using different gustatory stimulus: lemon group (L) and dried sour plum group (D). In group PR, those with subjective or objective xerostomia were excluded. In group PO, patients underwent SSGS at least three months post-radiotherapy and includes only those who had completed the course of curative radiotherapy and had not received adjuvant or neo-adjuvant treatment. Results The SSEF of parotid glands greater than 50% was able to distinguish normal from abnormal salivary function in HNC patients. There is no difference between two different kinds of sialogogues L and D in both group PR and group PO using 50% as a cut-off reference for a normal SSEF. Conclusions The use of dried sour plum as substitute for lemon juice is feasible in SSGS and the finding of using 50% as a cut-off reference for a normal SSEF was able to distinguish normal from abnormal salivary function in HNC patients.

The relationship between Helicobacter pylori infection and obesity Enteroclysis and Xray angiography were negative too. Results: Twenty-three patients had positive scintigraphy with in vivo tagged RBCs and 12 patients had negative scintigraphy. GI bleeding stopped spontaneously in these 12 patients with negative scintigraphy and these patients did not undergo push-enteroscopy, intra-operative enteroscopy or surgery. Final diagnosis of our 23 patients with positive scintigraphy was determined in 17 patients (push-enteroscopy -6 patients, intra-operative enteroscopy -7 patients or by surgery -4 patients). These 17 patients had following final diagnoses: bleeding small bowel arteriovenous malformation (6 patients), uraemic enteritis with bleeding erosions in ileum and jejunum (2 patients Aim: The vanishing bile duct syndrome (VBDS), is an acquired and pathologic process that occurs in the biliary tree and is recognizable as an absence of bile duct in an individual portal tract. The underlying processes responsible for bile duct loss include immunological, infectious, ischemic, metabolic, and toxic processes. The purpose of this study was to investigate the potential role of dynamic 99mTc-HIDA hepatobiliary scintigraphy (DHBS) in the evaluation of patients affected by chronic liver disease with histological liver involvement characterized by small bile duct injury. Material and Methods: The study comprised 10 consecutive patients (9 males, 1 female), aged between 38-57 years. At diagnosis, 9 showed chronic hepatitis C virus (HCV) infection, 1 Wilson's disease. All patients underwent standard biochemical liver function tests including parameters of cholestasis gammaGT (GGT) and alkaline phosphatase (AF) and liver biopsy. DHBS was performed after i.v. injection of 110 MBq 99m Tc-iminodiacetic acid. Acquisition of images started at the moment of injection and time/frame acquisition was 20 sec for 60 min. Time-activity curves were recorded from regions of interest placed over hepatic parenchyma and main intra-hepatic biliary ducts. Quantitative analysis of the curves was performed using deconvolutional analysis and non-linear regression, measuring parenchimal and ductal time point at maximum peak counts (t max ) and t ½ of excretion. Results: A liver biopsy revealed in all patients marked ductopenia consistent with VBDS. Laboratory parameters showed GGT elevation in 2 HCV patiens with concomitant increase of AF in one of these. The analysis of quantitative data obtained by DHBS showed in all patients a slow blood clearance and excretion of HIDA documented by delayed time of parenchimal and biliary t max and abnormal parenchimal and ductal excretion T ½ . No correlation was found between HIDA T ½ ductal excretion and parameters of cholestasis. However, positive correlation between liver parenchimal/ductal T ½ and histologic scores was observed. Conclusion: The DHBS is able to assess the different aspects of hepatic function in VBDS. Although the present study includes a small number of patients, we believe that this method may be of clinical value in revealing the real hepatic and biliary function showed by correlation with histologic data. Its clinical use may be crucial in follow-up and in prognostic evaluation of VBDS patients. Aim Meckel's diverticulum is the most frequent congenital anomaly of the gastrointestinal tract, with an incidence of about 2% of the population. It is a sacculation attached to the ileum due to the failure of the vitelline duct to disappear. The mucosal lining of Meckel's diverticulum containes island of heterotopic mucosa, which may give cause to serious complications such as peptic ulcer, hemorrhage and perforation. The aim of our study was to compare scintigraphy with ultrasonography (US) in the detection of Meckel's diverticulum. Materials and methods We recruited 22 children, younger than 3 years of age, with painless rectal bleeding. All the patients underwent first scintigraphy and then ultrasound. For the scintigraphic evaluation 370 MBq (10 mCi) of 99 mTc-pertechnetate (TcO 4 -) were administered intravenously. The initial scan was made 30 min to 1 hr after the radiopharmaceutical administration. Anterior abdominal images were obtained at a frame rate of one images every 30-60 sec over the course of 30 to 60 minutes. Acquisition parameters were: single head gamma camera, parallel HR collimator, matrix 128x128, 120 frames. Activity in the ectopic gastric mucosa should appear simultaneously than that of normal gastric mucosa. Activity in the urinary tract, most often confused with for a Meckel's diverticulum, usually first appears after activity is seen in the normal gastric mucosa. For the abdominal sonography a 5 MHz convex-array probe was used. Sonographic demonstration of noncompressible, tubular, aperistaltic structure with a double-layered wall, located far from the cecum suggested for Meckel's diverticulum. All US scans were reviewed by one of the authors blinded to the scintigraphic results. Results 19 out of 22 patients showed abnormal scintigraphic findings with suggestive for Meckel's diverticulum. Ultrasound confirmed these results in 15 patients of the 19 seen by scintigraphy and was negative in 4 cases. Conclusion Ultrasound imaging is one of the most widely utilized medical imaging modality that will continue to improve the quality of healthcare in diagnostic application. However scintigraphy is easier to perform, is less operator dependent and has a better sensitivity compared to ultrasound. Also scintigraphy is noninvasive, painless, relatively inexpensive. It can be concluded that scintigraphy is still of value in the diagnosis of patients affected by Meckel's diverticulum. making of patient with HCV related hepatopathy. Our results confirm that both, painless thyroiditis and Graves disease, may occur during the treatment with IFN . In this connection, non immunogenic hyperthyroidism may be related to the acute release of hormones circulation (painless thyroiditis). A simple imaging method as pertechnetate thyroid scintigraphy allows to make a differential diagnosis between Graves disease and painless thyroiditis and is essential to address the patients towards an appropriate treatment of hyperthyroidism. Uptake (0.5-4%) fT4 (12-26 pmol/L) fT3 (3- year old (mean 52.8±11.2) 29 (23 F, 6 M) multinodular goiter patients were included to the study. After taking blood and urine samples, TcPU tests and thyroid scintigraphies were done and the patients were evaluated with thyroid ultrasound. By performing I-131 uptake measurements 4. and 24. hour uptake levels were calculated. Results: In this study, 21 of 29 patients (%72) had urinary iodine level above 100 μg/gr cre that indicates sufficient iodine intake. There was a significant negative correlation between TcPU levels and urine iodine levels as indicated in the literature. According to TSH levels, while 18 patients were euthyroid, 11 were hyperthyroid (6 subclinical, 5 overt clinic). TcPU levels were found to be higher in hyperthyroid patients than euthyroid ones, but this difference was not statistically significant. In 9 euthyroid patients there were hyperactive nodules. There was a significant positive correlation between patients' TcPU and I-131 4. and 24. hour uptake values. Conclusion: In conclusion, our patients' median urinary iodine level was 130 μg/gr cre which was sufficient. After iodinisation, high percentage (%37) of patients were hyperthyroid. We found that half of euthyroid patients had hyperactive nodules which showed the importance of thyroid scintigraphy in the evaluation of multinodular goiter patients. Correlation of TcPU and I-131 uptake levels suggest that TcPU can be used instead of I-131 uptake levels. Our preliminary results suggest that it would be important to evaluate the relationship between urinary iodine and TcPU levels in larger series of MNG patients after mandatory iodinization.

Abnormal Thyroid Function and/or with Thyroid Antibodies An important problem in nuclear endocrinology is the "blocking" of thyroid gland, which necessitates to postpone investigation, to experience adverse clinical effects of stopping medications and a delay of making diagnosis. The aim of the study was to introduce and to determine the clinical value of the scintigraphy with 99mTc-MIBI in patients / Pts / with a "blocked" thyroid. In 367 Pts / aged 38-75 years /, indicated for a thyroid scintigraphy after proper preparation, an investigation was performed with 74 MBq 99mTc-pertechnetate, 20 min. p.i. In 15 of them (4.1%), the thyroid was "blocked" and additional scintigraphy was done with 370-555 MBq 99mTc-MIBI, 15 and 120 min.p.i. It was estimated that in all Pts there was a visualization of thyroid. In 1 of them, a large "hot" nodule was visualized in the early and late image. Later on a differentiated thyroid carcinoma was proved histologically. In another 4 patients "cold" nodules on the early and late scans were detected and benign cysts were proved. Therefore according to the type of the nodule, visualized with 99mTc-MIBI and its kynetics, we could help in differentiation of the diseases, to chose the treatment option and to deretmine the prognosis of the patient. As a conclusion we consider, that a scintigraphy with 99mTc-MIBI is a useful tool in Pts with "blocked" thyroid. In addition -in patients with nodules, the investigation could help in their differentiation and therefore-a recommendation for therapy. Purpose: The aim of this study was to determine an optimal radioiodine treatment by comparing the clinical and biochemical outcome of patients with Graves disease treated with estimate doses of radioiodine to those treated with fixed doses. Material and Methods: A total of 116 consecutive patients of thyrotoxicosis treated with J-131 were divided into two groups according to the amount of J-131 administered:I group-67 patients who received estimated dose of 111-550 MBq(mean 230 MBq), II group-49 patients who received fixed dose of 300 MBq.All patients were pretreated with antithyroid drugs and were stopped one week before using radioiodine therapy.In 41,4%(48/116) patients with recurrent disease were given an additional dose(total dose 710 MBq).The outcome were followed from 6 months to 18 years(median 11,3 years). Results: At six months after single dose of radioiodine therapy, euthyroid state was achieved in 36% patients in the fixed dose group and 51% patients in estimated dose group. There was significant difference in the rate of development of euthyroid state in respect to the given dose of J-131 (p<0,05). 39% patients in the fixed dose group became hypothyroid,compared to 20% patients in estimated dose group.The median time to hypothyroidism was 26 weeks. 23% patients in fixed dose group remained hyperthyroidism six months after radioiodine therapy,compared with 29% patients in the estimated group.In that group significantly more patients who received low(150-220 MBq) doses remained hyperthyroid,compared to those who received high(<370 MBq) doses.The thyroid volume reduction was significantly (p <0,01) higher in successfully tred patients(58%) than in those that remained hyperthyroid(37%). Conclusion: There was significant difference in outcome between the two treatment regimes.Better control of thyroid states can be achieved by estimated J-131 dose,while fixed radioiodine offers an affective treatment option where is required rapid control of thyrotoxicosis and long term hypothyroidism is a recognized outcome. evaluated by visual examination (grading "high", "moderate" uptake and "no uptake") and by calculation of background radiouptake ratio (RUR) was evaluated. Results: 3 patients had a intense MIBI retention and underwent surgery: (histology revealed papillary carcinoma and folliculary folliculary carcinoma in one pat. folliculary adenoma, 4 pts. had a moderate uptake and underwent surgery too-2 pat. have benign nodule in another two thyroiditis). Using the 60/10-minute thyroid lesion to background radiouptake ratio (RUR), malignant and benign thyroid nodules could be separated with a sensitivity, specificity, and negative predictive value of 84.4%, 82.45%, and 81.33%, respectively. The mean RUR for malignant thyroid lesions was 1.67+/-0.18, whereas for benign lesions, the ratio was significantly lower, 0.32+/-0.20 (P=0.0005). Conclusions: In patients, in whom a needle aspiration cytology is not possible (hampered by antigoagulation therapy), the Tc-99m MIBI scintigraphy appears to be a useful additional diagnostic tool in the preoperative assessment of suspected thyroid nodules Differential diagnosis of the main types of hyperthyroidism is performed with the help of thyroid scan 99m Tc-99m, which brings out the size, the shape, the nodularity and the functional state of the gland. A second scintigraphy, this one with 131 I, is necessary to estimate the therapeutic activity of 131 I in hyperthyroidic patients. Both radionuclides are trapped by thyroid gland in a similar manner, however, 99m Tc is not organified. Hence, the results of both types of scans are not expected to be identical in all the circumstances. Aim The aim of this study is to evaluate and compare the correlation between the uptake of 99m Tc and 131 I in Graves disease, toxic multinodular goiter and toxic autonomous nodule, in order to ponder, in these three situations, the performance of the 99m Tc scan only, which exposes the patient to a lower radiation dose. Materials and Methods This is a retrospective study, based on a population of 100 patients, divided into 3 groups: a) 29 patients with Graves disease; b) 30 with toxic multinodular goiter; c) and 41 with toxic autonomous nodule. All of them underwent a thyroid scintigraphy 24h after administration of 1,11MBq (30 μCi ) of 131 I and a thyroid scan 15 minutes after the administration of 185 MBq (5 mCi) of 99m Tc pertechnetate. We used a Siemens ECAM DCR dual head gamma camera, with the same acquisition conditions (256 X 256 matrix), and the uptake of each radionuclide was calculated. The results in each of the 3 groups were correlationed and compared. Results In plotting the 99m Tc uptake against the uptake of 131 I, the best fit was a linear regression model for the three studied groups. The calculated coefficient of determination (R 2 ) was 0,1902 for patients with Graves disease; 0,3777 for patients with toxic multinodular goiter; and 0,5427 for patients with toxic autonomous nodule. Conclusions Our results demonstrated a poor relationship between the uptake of 99m Tc and 131 I in Graves disease, toxic multinodular goiter and toxic autonomous nodule, especially in the former. Thus, it will not be feasible to rely solely on the 99m Tc thyroid scan and exclude the 131 I thyroid scintigraphy as part of the protocol in none of these situations. Purpose: Higher levels of urokinase-type plasminogen activator (uPA) and its inhibitor (PAI-1) are linked to the poor prognosis in a variety of malignances. uPA and PAI-1 were expressed in most thyroid carcinomas, as had been measured immunohistochemically. However, no relationship between their expression and clinicopathological parameters were described. Aim of the present study was to investigate the expression and clinical relevance of uPA and PAI-1 in thyroid cancer. Patients and methods: uPA and PAI-1 in paired cytosol samples of thyroid tumor and normal tissue were determined in 23 patients using enzyme-linked immunosorbent assay and correlated to the known prognostic features. Results: Both uPA and PAI-1 concentrations were significantly higher in malignant thyroid tumors (uPA=1.342±2.944 and PAI-1=17.615±31.933 ng/mg protein) than in normal tissue (uPA=0.002±0.009, P=0,011 and PAI-1=2.333±0.338 ng/mg protein, P=0,001) with positive correlation of the two proteins in the tumors. uPA and PAI-1 were significantly higher in anaplastic vs. well-differentiated cancers (uPA P=0.014 and PAI-1 P=0.026), if extrathyroidal invasion (uPA P=0.019 and PAI-1 P=0.009) or distant metastases (uPA P=0.006 and PAI-1 P=0.003) had been present, and in tumors whose size exceeded 1 cm in diameter (uPA P=0.009 and PAI-1 P=0.035). Only PAI-1, but not uPA was significantly higher in multicentric vs. solitary tumors (P=0.012) and lymph node positive compared to lymph node negative patients (P=0.042). The differences of uPA and PAI-1 did not reach the significant level when patients with well-differentiated tumors below and above 40 years of age had been compared. Survival analysis revealed the significant impact of both uPA and PAI-1 on the Progression-Free Survival (PFS) (38.84 vs. 3.67 months for patients with low and high uPA, respectively, P<0.001; 38.2 vs. 12 months for patients with low and high PAI-1, respectively, P=0.016). Conclusions: The correlation of high uPA and PAI-1 with the known prognostic factors of poorer outcome and with lower PFS rate in patients with thyroid cancers proved that these proteins could be an additional prognostic parameter. Aim: To evaluate the changes of myocardial parameters in patients with confirmed primary hyperparathyroidism, asymptomatic for coronary artery disease (CAD).

A total of 16 patients (mean age 56.7 ± 6,2 years) with suspected primary hyperparathyroidism and no-cardiac related major symptoms (Myocardial infarction, pectoris angina) were examined using cervical planar, SPECT and dynamic, and gated rest-cardiac SPECT acquisitions. We analyzed the myocardial-rest parameters including myocardial perfusion, left regional ventricular ejection fraction (LVEF), regional motility and thickening. Acquisition was performed by obtaining early dynamic study, planar cervical images at 15 min, 45 min and 2-3 h after iv administration of 740 MBq of 99m-Tc-tetrofosmin (MYOVIEW); cardiac gated SPECT acquisition at 45 min post-injection. Results: 13 patients (81,25%) were positive for parathyroid adenoma (99m-Tc-tetrofosmin scintigraphy), and confirmed through CT/MRI and surgical exeresis with histological exam. 5/13 patients (38,46%) had myocardial parameters changes including perfusion defects, decreased leftventricular regional ejection fraction, systolic thickening and motility disorders. 8 patients (61,54%) had normal myocardial perfusion scintigraphy result. 2 out of 3 patients with unconfirmed parathyroid adenoma had normal MPS result. 1 patient have moderate perfusion defects. All the results were correlated with parathyroid hormone, calcium and phosphorus plasma and urinary levels. Conclusion: Among patients with primary hyperparathyroidism, a high percent was affected by important changes of myocardial perfusion and systolic function (38,46%). We have to underline that all these patients were asymptomatic for CAD. We can therefore conclude that Gated-SPECT is definitely a useful tool for management of patients with primary hyperparathyroidism.

Negative predictive value of undetectable Tg level in TSH suppression during the early follow-up of low-risk differentiated thyroid carcinoma A. Piccardo, S. Morbelli, P. Bianchi, F. Barbera, G. Villavecchia, M. Cabria; Ospedali Galliera, Genoa, ITALY.

Aim: is noted that TSH stimulated Thyroglobulin(TSH-Tg) alone is sufficient for early follow-up of low-risk differentiated Thyroid cancer(DTC) patients with no clinical evidence of disease after thyroidectomy and thyroid 131I ablation. Recent data indicate that serum thyroglobulin at the time of remnant ablation( ablation-Tg) can be correlated with TSH-Tg measured 12 months later and can predict persistent or recurrent disease in postoperative period. There is also consensus that, during long term follow-up, Tg measurement during thyroid hormone suppression(THST-Tg) are sufficiently sensitive to forgo further testing in a low-risk patient who is clinically free of disease and has had undetectable Tg after recombinant human TSH(rhTSH) or thyroid hormone withdrawal(THW). However only a small fraction of relapsing DTC patients, at 12 month follow-up, show undetectable TG under T4 treatment(<0.1 ng/ml). The aim of this study is to evaluate, in low risk DTC patients early follow-up, the negative predictive value(NPV) of undetectable THST-Tg measurement and undetectable THST measurement + ablationTg compared with rhTSH-Tg. Materials and Methods: we enrolled 113 patients with histologically proven DTC treated by total thyroidectomy and radioidine. In all patients we measured ablation-Tg levels. Inclusion criteria were: tumor grater than 1cm, smaller than 4 cm, limited to the thyroid, not of virulent subtype, which were completely resected with or without nodal metastases but without distant metastases, negative anti-Tg antibodies. All patients present undetectable THST-Tg at 12 month follow-up. At 1 year after radioiodine treatment, all patient underwent on rhTSH stimulated Tg assay. Results: based on rhTSH-Tg assay(>2ng/ml), histology, clinical data and long term follow-up persistent/ relapsing disease was proven in 2 patients. Tg positive(0.6-2.0 ng/ml) after rhTSH, with no evidence of disease was observed in 8 patients. 103 patients showed undetectable rhTSH-Tg. The negative predictive value of undetectable THST-Tg and rhTSH-Tg were respectively 98.2% and 100%. The ablation-Tg levels were < 5ng/ml in 81 patients. In this group the NPV of undetectable THST-Tg was 100%. Conclusion: these data seem to indicate that undetectable THST-Tg assay, evaluated by high sensitive methods combined with low ablation-Tg levels may avoid a significant number of high cost rhTSH-Tg. Further confirmation on a larger group of patients are needed. The results sensitivity and specificity of 82% and 43% respectively, however with FNA combination, the specificity of the combined procedure increased to 95%. Serum Tg measurement was detectable ( 2 ng/ml) in 31 tumor patients with a sensitivity of 80% but gave no localization information, which was important for surgical intervention. As a non-invasive imaging modality, FDG PET had a sensitivity, specificity, positive predictive value and accuracy of 63%, 75% and 88% and 65%. Conclusion: Ultrasonography of the neck is a practical modality that can be employed as first line investigation in papillary thyroid carcinoma patients with a clinical suspicion of loco-regional recurrent disease. It can be combined with radioiodine and PET findings and lead the patients to surgical intervention for a promising complete cure.

Retrobulbar 99mTc-Diethylenetriamine-Pentaacetic-Acid Uptake Predicts the Effectiveness of Immunosuppressive Therapy in Graves' Ophthalmopathy L. Galuska 1 , B. Újhelyi 1 , J. Varga 1 , L. Szabados 2 , A. Erdei 1 , I. Garai 2 , E. V. Nagy 1 ; 1 University of Debrecen, Debrecen, HUNGARY, 2 University of Debrecen, PET-CT Medical Diagnostic Ltd., Debrecen, HUNGARY.

Aim of study: In Graves' ophthalmopathy, only patients with immunologically active disease respond to immunosuppressive therapy, while those in the fibrotic stage do not. In the present series we aimed to show if 99m Tc-ethylenetriamine-pentaacetic-acid (DTPA) SPET is able to predict the success of imunosuppressive treatment. Patients and methods: 48 orbits of 24 patients with Graves' ophthalmopathy (15 women and 9 men) were studied. Patients with Graves' disease and eye signs suggestive of activity of the orbital autoimmune process (CAS 4) were entered in the study. All received corticosteroid treatment and 6 were additionally treated with orbital irradiation. DTPA SPET was performed before, and 3 to 24 months after the initiation of immunosuppressive treatment. Orbital DTPA uptakes were numerically quantified and compared before and after treatment. The calculations were performed for the entire orbit VOI as well as the anterior and posterior segments separately. The control group consisted of 34 orbits of 17 patients who had no thyroid disease. Results: In the control group, the DTPA uptake of the orbit as a whole, the anterior, and posterior segments were 7.9±2.6, 8.8±3.0 and 6.6±2.0 Bq/cm 3 (mean±SD) respectively. The upper normal reference limit of posterior segment DTPA uptake was set to the 95% percentile of the control group, 10.07 Bq/cm 3 . The mean DTPA uptake of the 48 orbits of GO patients was higher before immunosuppressive treatment than after therapy (8.92±2.31 Bq/cm 3 and 7.67±3.82 Bq/cm 3 , respectively, p=0.0003). The anterior and posterior segment values correlated with those of the entire orbit. Of the 35 orbits with an initial DTPA uptake 10.07 Bq/cm 3 in the posterior segment, 11 % has improved, while of those 13 orbits with an initial DTPA uptake above 10.07 Bq/cm 3 , 77% has improved. Conclusions: For a favourable treatment outcome, the positive predictive value of an initial DTPA uptake >10.07 was 81.25 %, while a negative predictive value of a DTPA uptake 10.07 was 89.74 %. Patients with DTPA uptake above 10.07 may be predicted as responders, while those with a DTPA uptake below this value have only low chance of benefit from immunosuppressive treatment. Aim: Marine-Lenhart Syndome (MLS) was defined as Graves`disease with autonomously functioning nodules. Currently there exist no data about the actual incidence of this desease and the results of radioiodine therapy. Methods: In a prospective trial 1110 patients with initial diagnosed hyperthyreoidism were evaluated. Physical examination, interview, ultrasound, scintigraphy and determination of T3, T4, TSH and antibodies were carried out in all patients. All patients were followed up at least one year after radioiodine treatment. Results: MLS was diagnosed in 37 patients (incience 3.3%). Following treatment with radioioidine 10 patients had normal serum TSH levels. Hypothyreoidism was present in 14 patients and hyperthyreoidism persisted in 4 patients. A newly diagnosed Orbitopathy was not observed after radioiodine treatment. Conclusion: The actual incidence of MLS was 3.3% in patients with newly diagnosed hyperthyreoidism. Treatment with radioiodine offers the chance for euthyreodism but includes a significant probability for a second therapy. The optimal method to determine iodine-131 treatment doses is to obtain time-activity curves from serial measures, after administration of a trace dose. A simplified method is based on a 24-hours I-131 uptake. It's still unclear the potential usefulness of Tc-99m scan (routinary performed during the diagnostic work-up) to estimate the iodine uptake. Aim of the study. We evaluated the possibility to use the 20-minute Tc uptake computed during standard Tc scintigraphy to reliably estimate the maximum thyroid radioiodine uptake. Methodology. We consecutively evaluated 104 patients: 52 with uni-or multinodular goiter (NG) and 52 with Graves' disease (GD). Each patient underwent both Tc scintigraphy and I-131 uptake. Tc scan was acquired with a gamma camera equipped with a LEHR-P collimator, 20 ± 5 minutes after the i.v. injection of 111 MBq of the tracer. Tc uptake was computed by measuring the syringe before and after injection under the same geometrical conditions. I-131 time/activity curve was obtained acquiring planar images with a gamma camera equipped with a HEGP collimator at several times (6 hrs, 24 hrs, >95 hrs) after oral administration of 1.5 ± 0.5 MBq. Thyroid uptake at any time was calculated according to standard methods. Statistical analysis was performed. Results. Our data demonstrate different kinetics between NG and GD. Mean iodine maximum uptake per mass of thyroid tissue (Umax) resulted similar between groups: 2.8±1.8 (NG) and 2.6±1. 3 (GD) . Mean time to reach max iodine uptake (Tmax) resulted statistically different: 21.7±7.2 (NG) and 16.0±7.7 (GD) (p<0.0001). Tc uptake mean values and standard deviation (s.d.) were 3.33 (1.73)% for NG and 8.03 (7.47)% for GD. The best fitting demonstrated a natural logarithmic correlation between Tc uptake and Umax for both NG and GD. A strong correlation was found between Umax vs. the natural log of Tc uptake. Regression coefficients R 2 were: Introduction: Interferons (IFN) are a family of naturally occurring proteins with antiviral and immunomodulatory activities. There is a wide range of thyroid abnormalities related to IFN administration. Thyroid autoimmunity has been widely reported as a side effect of IFN treatment as well as hypothyroidism and thyrotoxicosis. Methods: A retrospective analysis of 6 radionuclide thyroid studies of patients who had thyroid scans and were on interferons was done. All patients had thyroid scans obtained after IV injection of 5 mCi of Tc99m pertechnetate as well as thyroid uptake after oral administration of 9 uCi of I-131. Results: There were six thyroid studies of five patients , four on alpha IFN for hepatitis C viremia and one patient on beta IFN for multiple sclerosis were identified. Patients included 3 females and 2 males ranging in age from 45 to 50. Patients had no history of thyroid disease prior to interferon therapy. Scintigraphic diagnoses included one patient with simple goiter, one with subacute thyroiditis, one with diffuse toxic goiter and two with nodular toxic goiter. One patient developed first the nodularity then the hyperactivity in the intervening tissue later as seen on the follow up scan.Conclusion: Thyroid scintigraphy shows different Interferon Induced scintigraphic patterns and is valuable to differentiate hyperthyroidism due to Graves' like pattern from IFN -induced thyroidits.

adrenal or retroperitoneal masses preoperatively was beneficial. The number of positive cases continued to grow, indicating a more judicious referral in the recent years. Conclusion: The experience of with in-house preparation of MIBG was rewarding. The impact on clinical endocrine practice was so significant that MIBG scintigraphy had become a routine investigation for all neuroendocrine tumours in our institution.

The Aim. Data on the thyroid blood flow in healthy subjects without thyroid disease are scarce. The aim of our work was to evaluate the influence of thyrotropin (TSH) concentration on the peak systolic velocity (PSV) in a group of healthy persons. Patients and methods. We included 115 euthyroid subjects, 102 females, 13 males, aged 16 to 84 (mean, 37.8 ± 17.2 years). All subjects were negative for thyroid peroxidase antibodies (TPOAb) and thyroglobulin antibodies (TgAb). Colour flow Doppler sonography (CFDS) was performed using a 7.5 MHz linear transducer. PSV was measured at the level of intrathyroid arteries with a sampling volume of 2 mm. In each subject PSV was expressed as a mean of five measurements. Results. Mean TSH concentration in all subjects was 2.048 ± 1.282 mU/L, (min. 0.426, max. 5.415 mU/L, reference value: 0.35 -5.5 mU/L). According to their TSH concentration, subjects were divided into 4 groups: first group with TSH between 0.426 and 1 mU/L (N = 25) had mean PSV 8.5 ± 1.5 cm/s, second group with TSH between 1.001 and 1.5 mU/L (N = 26) had mean PSV 9.2 ± 2.7 cm/s, third group with TSH between 1.501 and 2.5 mU/L (N = 31) had mean PSV 9.1 ± 2.0 cm/s, and fourth group with TSH between 2.501 and 5.5 mU/L (N = 33) had mean PSV 9.7 ± 2.1 cm/s. When compared with group one, PSV was significantly higher in group four (p = 0.0167). Additionally, in all subjects a significant correlation between TSH concentration and PSV (R = 0.217, p = 0.021) was found. Conclusion. We established a significant positive correlation between TSH concentration and PSV in euthyroid subjects without autoimmune thyroid disease. The results are in accordance with the data on the stimulative influence of TSH on angiogenesis. Radioiodine and 99m Tc-peretechnetate uptakes are currently used for the assessment of thyroid function. 131 I has the disadvantages of high radiation dose due to itsemission, high energy rays and longer half life. 123 I is cyclotron produced agent and is costly. 99m TcO 4 has the advantages of quick assessments, low radiation dose and better image quality. However, both studies need preparation of patient with low iodine diet and cessation of anti-thyroid /thyroid replacement therapy. 99m Tc-sestamibi has been recently evaluated by various investigators for the assessment of thyroid function with an advantage that there is no need of such preparation. The current study was done to assess the 99m Tc-sestamibi thyroid uptake and T max . For this purpose, Nine euthyroid volunteers (Group I), 11 patients with Grave's disease (Group II), 12 patients with Hypertrophic Hashimoto's thyroiditis (Group III) and 12 patients with Atrophic Hashimoto's thyroiditis (Group IV) underwent 99m Tc-sestamibi thyroid scintigraphy. Dynamic images of thyroid were acquired for 20 minutes along with static syringe images (pre & post injection) for two seconds. Maximum uptake of 99m Tc-sestamibi was seen at 5 minutes post injection in volunteers as well as in patients in various groups. Images at 6, 10, 20, 60, 120 minutes revealed gradual tracer clearance from thyroid. In EV, 5 minutes 99m Tc-sestamibi uptake was (mean±SD; 0.10± 0.05%). In GD and HHT patients 5 minutes 99m Tc-sestamibi uptake (mean ±SD; 0.72±0.54 % and 0.36±0.25% respectively) was greater than in EV (P<0.0001 and P=0.0005 respectively). AHT patients revealed 5 minutes 99m Tc-sestamibi uptake (mean±SD; 0.09±0.04 %) lower than in EV and HHT (P=0.776 and P=0.0002 respectively). Mean 5 minutes 99m Tc-sestamibi uptake showed strong correlation with mean 20 minutes 99m Tc-pertechnetate uptake in GD patients (r=0.89) and with TSH levels in HHT patients (r=0.55). It is concluded that 5 minutes is optimal time interval between 99m Tc-sestamibi injection and calculation of thyroid uptake. 5 minutes 99m Tc-sestamibi uptake can differentiate euthyroid individuals from GD patients. No preparation with low iodine diet and cessation of anti-thyroid drugs before 99m Tc-sestamibi uptake is a great advantages which possess its role as possible alternative radiopharmaceutical for thyroid uptake calculation.

Possible use of thyroid US and thyroid Abexaminations in follow up in detecting high risk patients or early and subclinical Hashimoto thyroiditis K. Zaplatnikov 1 , W. Wiedemann 1 , M. Plotkin 2 , F. Grünwald 3 ; 1 Nuclear Medicine Clinic Nürnberg, Nürnberg, GERMANY, 2 Nuclear Medicine Department University Hospital Charite Berlin, Berlin, GERMANY, 3 Nuclear Medicine Department University, Frankfurt, GERMANY.

Aim Patients with Hashimoto thyroiditis (HIT) show typically decreased echogenicity of the thyroid ultrasonography (US). In this study, we investigated the association between the US pattern, TSH values and level of thyroid antibodies (anti-TPO,Tg-Ab) in order to evaluate the usefulness of US for HIT screening. Method Included were 150 consecutive pts with suspected HIT (124 f, 26 m, mean age 47±27 yrs) and control group with 24 pts (16 f, 8 m, mean age 34±13 yrs). Blood samples were analysed for thyroid-Ab, TSH and periphere thyroid hormones. US or scintigraphy of the thyroid was performed in follow up (3 and 6 mo). Results Pat. with decreased echogenicity and high level of thyroid autoantibodes (n=90, Gr.I) had a higher mean TSH (2.95 mIU/l) compared with pts. with normal echogenicity and thyroid autoantibodes (n=31, Gr. II) (1.41 mU/l, P<0.0005). Pts. with normal echogenicity had thyroid autoantibodies too (n=29, Gr. III) with mean TPO-Ab (131±42 ng/ml) and Tg-Ab (82±35 ng/ml). Pts. with decreased echogenicity (Gr. I) had a higher level of thyroid autoantibodies (anti-TPO,Tg-Ab) than subjects from Gr. III (P<0.0001). Conclusion We found a strong association between hypoechogenicity at thyroid US and higher levels of serum TSH/thyroid ABs in pts suffering on HIT. Our results suggest that a decreased echogenicity represents a reliable sign of HIT. However, a normal echo pattern cannot exclude a HIT. This indicates a possible use of thyroid US and thyroid Ab-examinations in follow up in detecting high risk pts or early and subclinical HIT.

Application of somatostatin receptor scintigraphy in patients with thyroid associated ophthalmopathy J. Deng; Xijing Hospital, Fourth Military Med. Univ., Xi'an, CHINA.

The study aims at investigating the effectiveness of the orbital somatostatin receptor scintigraphy (SRS) with 99m Tc-OCT in curing patients with active Graves' ophthalmopathy disease and their response to the corticosteroid therapy. Method: A somatostatin analog, OCT, was labeled with 99m Tc by a direct method. The compound's labeling efficiency was confirmed by paper chromatography. The subjects of the experiment were 15 patients with Graves' ophthalmopathy (GO) and four volunteers without eye disease or Graves' disease (GD) as the control group (CG). During the study, single photon emission computed tomography (SPECT), computed tomography (CT) and the left and right lateral position planar imaging of the heads of the subjects were obtained four hours after the iv injection of 740MBq 99m Tc-OCT. Corticosteroid therapy (methylprednisolone, 10mg po tid for 1 month) was then given to all patients in the next day and lasted for one month, after that the SRS was repeated to all patients. Radioligand uptake within each orbit (O) and occipital (OC) was measured using the region of interest (ROI) method and the O-to-OC ratio was determined before and after corticosteroid treatment. Clinical activity of Graves' ophthalmopathy was evaluated before and after the treatment by calculating the ophthalmopathy index (OI). Key Results: Comparing to the O/OC ratio of the control group at the scintigraphy (1.16±0.04, P<0.05), a significant change in the O/OC ratio was observed in 12 patients with active GO between pretreatment and post-treatment (1.64±0.13 vs. 1.21±0.09, P<0.05). No significant change in the O/OC ratio was found between the CG and the 12 GO patients after post-treatment (1.16±0.04 vs.1.21±0.09,P>0.05). There was no significant change in the O/OC ratio in 3 patients with inactive GO (P>0.05) in both pre-treatment and post-treatment periods and in the CG (P>0.05). Conclusions: In those patients with active Graves' ophthalmopathy, somatostatin receptor scintigraphy showed markedly increased orbital uptake of 99m Tc-OCT. The study demonstrates that 99m Tc-OCT scitigraphy is a good indicator and able to predict the clinical response to the corticosteroid therapy in patients with GO. This method should be considered as an objective and safe method to select proper treatment therapy. the use of real-time quantitative polymerase chain reaction (quantitative real time PCR) amplification of the human epidermal growth factor receptor (EGFR) in 52 lung cancer patients and 8 cases of benign pulmonary disease and 10 healthy controls. Results Median concentration of free circulating DNA in serum of lung cancer patients, benign pulmonary disease and healthy controls was 107.6ng/mL,76.86ng/mL and 18.8ng/mL, respectively. The diagnostic sensitivity, specificity and accuracy of free circulating DNA for lung cancer was 71.2%, 50% and 68.3%, same as the diagnostic value of combinations for detecting lung cancer was 94.2%, 25% and 85%, respectively. Conclusion The free circulating DNA in the serum at diagnosis in lung cancer patients may be a new better tumor marker.

Sialoscintigraphy with 99m Tc-pertechnetate in evaluation of salivary gland function in patients after radiotherapy with head and neck carcinoma J. Niewiadomska, G. Lapinska, D. Kolataj, M. Benke, I. Kozlowicz-Gudzinska, D. Kiprian, A. Sackiewicz; Institute of Oncology, Warsaw, POLAND.

Radiotherapy in patients with head and neck carcinoma can result in temporary or permanent damage of the salivary glands. Xerostomia can exert negative effects on the patients quality of life. Aim: The aim of study was to evaluate salivary glands function in patients receiving radiotherapy due to head and neck cancer. Materials and methods: 54 patients (47 men, 7 women, aged 35-78 years) with larynx and pharynx carcinoma were enrolled in this study and underwent scintigraphy prior to radiation therapy as well as in the 6th and in the 12th month of follow-up. The patients were divided in two groups. First group consisted of 37 patients with the area of parotid glands irradiated in 70%-100%. Second group included 17 patients with the area of parotid glands irradiated in 20%-40%. In both groups 100% mass of submandibular glands was irradiated. Each patient received total irradiation dose of 6600-7000 cGy. Dynamic salivary scintigraphy was performed with single-head gamma camera SPX4 after injection of 148 MBq Tc99m-petrechnetate. Gland function was stimulated with lemon juice at 20 min of the study. UP (uptake ratio), T max (Time at the max count), MS (maximum secretion) and MA (maximum accumulation) were calculated and analyzed. Results: In both groups complete dysfunction of submandibular glands was observed in the majority of patients during 12 months after RT. In comparison with the first group, in the second the parotid glands damage was less and reversible. Among patients with retained salivary glands function, higher values of MA, MS, UP parameters were observed in cases with parotid glands irradiated in 20 -40%. Conclusions: Sialoscinigraphy is a valuable non-invasive method for assessing salivary glands function in total and for each gland separately. In patients with head and neck carcinoma, radiotherapy leads to salivary glands damage which may last up to 12 months after irradiation. Degree of dysfunction is correlated with the area of irradiation.

Peritoneal dialysis and hydrothorax E. Urbanova; Nuclear medicine University Hospital, Hradec Kralove, CZECH REPUBLIC.

Continuous ambulatory chronic peritoneal dialysis (CAPD) is an affective renal replacement therapy for patients with end stage of renal disease. Development of hydrothorax is serious but relatively less common complication. Plain radiograph shows presence of hydrothorax but cannot establish its association with peritoneal dialysis and assessing the outcome of pleurodesis procedure. Aim of this study was to show two patients (pts). with hydrothorax and CAPD. Method Both pts were undergoing CAPS for five monts. They were admitted to the hospital for breathlessness and right side chest pain. Plain radiographs showed presence of hydrothorax. Cytological examination of pleural fluid was negative for malignant cells. In view of transudative nature of pleural aspirate, a peritoneo-pleural communication was suspected. Patients were subjected to peritoneal scintigraphy to establish the communication between peritoneal and pleural cavity. Radiopharmaceutical 99m Tc-colloid (administered activity 3mCi) was injected into dialysate bag and infused through catheter into peritoneal cavity. To reach homogenous mixing of activity within peritoneal cavity the patient was asked to roll into bed. Static scans incorporating thoraco-abdominal region were acquired at frequent time intervals with dual head gamma camera equipped with LEAP collimators. Results By one hour some radioactivity was noted in right pleural space, but after two hours scintigrams were much better with ascent of activity up to apex of pleural space on the right side. Hydrothorax was present in both pts on right side due to transit of dialysate fluid through peritoneo-pleural communication. Conclusion Peritoneal scintigraphy is simple, non invasive procedure with diagnostic value in evaluating connection between CAPD and hydrothorax. Introduction. Recently, a somatic point mutation of the B-RAF gene (V600E) has been identified like the most common genetic event in papillary thyroid carcinoma (PTC), with a variable prevalence between the different series (23-62%). Its detection can be made on thyroid biopsys as well as in cytological samples obtained by fine needle aspiration biopsy (FNAB). For these reasons, it has proposed like a molecular marker in the early diagnosis of the PTC. Objectives. To know the frequency of B-RAFT1799A in operated patients of thyroid cancer. To value the utility of the detection of this mutation in the PTC diagnosis. Material and Methods. The detection of mutation B-RAFT1799A was made in 77 patients with thyroid cancer diagnosis. For the test were used fixed paraffin-embedded thyroid tissue sections coming from the surgery. 25 patients had a thyroid FNAB previous to the surgery in which also the presence of the mutation was analyzed. The techniques used for the detection of B-RAFT1799A were: DNA extraction, PCR/RFLP and mutation confirmation by sequentiation. Results. Of the 77 analyzed biopsies (63 PTC, 9 follicular carcinomas, 2 Hurthle carcinomas, 2 anaplastic carcinomas and 1 high degree sarcoma), B-RAFT1799A mutation was positive in 40,3% of tumors (31/77). According to the histologycal type, the mutation was detected in 47,6% of PTCs (30/63): 52,6% of classic variant, 33,3% of micropapillaries (4/12), 41,7% of follicular or mixed variants (5/12) and 100% of the variant of high cells (1/1). The mutation was not detected in any of the histologycal types different from PTC. Of the 25 patients who in the last had a previous PAAF year, the mutation was positive in 32% of the patients (8/25) with a FNAB previous to the surgery in the last year. Conclusions. The presence of BRAFT1799A mutation is specific of PTC and displays an elevated frequency in this group of patients. In 8 of the 25 patients with a previous FNAB in last year, a precocious and definitive diagnosis of CPT could have been given by detecting BRAFT1799A mutation in the cytology.

Waist circumference predicts silent myocardial ischemia in patients with diabetes mellitus: A myocardial perfusion study G. P. Carboni, S. Manfrini; Università Campus Bio-Medico, Roma, ITALY.

Silent myocardial ischemia (SMI) is a frequent condition in patients (pts) with diabetes mellitus but its mechanism and clinical relevance are still uncertain. Aim:We screened for SMI 34 consecutive such pts , mean age 57+-13 years , 74 % males , by rest/stress gated single photon emission computed tomography ( G-SPECT). Methods: Imaging was carried out on a dual-head gamma camera with Thallium or Sestamibi .Extent of abnormal defects ADs was considered significant when > than 10% of total LV pixels ( P ) and reversibility (myocardial ischemia) as a % of the ADs P . Visual images were analyzed with a score from 0 to 4. Relationship between imaging results and clinical parameters such first-degree family history of diabetes (71% of pts) , waist circumference ( 97+-10 cm ) , mass body index ( 27+-3 ), duration of diabetes ( 10+-6 years ) , type of diabetes ( 82 % of pts with type 2 , 18% with type 1 ) ,total Cholesterol (191+-4 mg/dl ) , LDL-Cholesterol (114+-33 mg/dl) HDL-Cholesterol ( 57+-37 mg/dl ) ,Triglycerides ( 132+-75 mg/dl ) , Hypertension ( 35 % of pts ) , Glycosylated haemoglobin ( 7+-2% ) , C-reactive protein ( 1.6+-1.3 mg/L ) , current therapy ( Insulin:in 41 % of pts ; ACE-inhibitors: in 32 % of pts ; Calciumantagonists: in 8% ; of pts ; Statins: in 44% of pts ) were then analyzed for study . All pts were also followed-up for cardiac events ( CE ) for an average time of 6 +-3 months. Results: Overall pts , 20% (7/34) revealed clear-cut SMI on G-SPECT but only 1 subject of these had a major CE after 1 month follow-up. On a logistic regression model ( Chi-square = 50 , p < 0.0001 ) , SMI was significantly associated only with waist circumference but not with the rest of clinical parameters. When data were adjusted for established risk factors and current therapy, results did not change ( p = ns for all). Conclusions: This study suggest that pts with diabetes mellitus , abnormal waist circumference indicates predisposition to an accelerate development of SMI . Stress myocardial perfusion imaging may thus indicate early appropriate prevention and treatment. The aim of this study was to evaluate the possible application of Bone Mineral density measurement using Dual Energy X-ray Absorbtometry (DEXA) in the diagnosis of transient osteoporosis of the femur. Methods: Fourteen patients were included this study (9 males and 5 females), with age range 40-55 years. All patients presented with hip pain, diagnosed by bone isotope scan and confirmed by MRI as transient osteoporosis of the proximal femur. All patients underwent DEXA scan for bilateral proximal femurs. Bone Mineral density values and T-score values were recorded. Bone density was considered normal if T-score >-1, consistent with osteopenia if Tscore was (-1) -(-2.5) and consistent with osteoporosis if T-score was < -2.5. T test was used in statistical analysis and p<0.05 was considered significant. Results: Tscores in the affected femurs were ranging from (-0.7) and (-3.7) with a mean value of (-2.2). T-scores were consistent with osteoporosis in 5 patients, osteopenia in 8 and normal bone density in one. T-scores in the controlateral femurs were ranging between (0.2) and (-2.6) with a mean value of (-0.8), with significant difference compared to affected side (p<0.5). T-scores were consistent with normal bone density in 8, osteopenia in 4 and osteoporosis in 2 patients. T-score difference between the affected and the normal side was ranging between 0-1.4, and twelve patients (86%) had a Tscore deficit in the affected side with more than 1 SD compared to the controlateral side. Conclusion: DEXA scan can detect significant drop in bone density in patients with transient osteoporosis of the femur. Although most cases didn't show T-score values of osteoporosis, still using the T-score difference compared to the controlateral femur as cutoff value may have application in establishing the diagnosis. Aim: Spondylodiscitis still remains a diagnostical problem. The aim of the study was to assess the sensitivity and diagnostic value of bone scintigraphy and leukocyte scintigraphy in spondylodiscitis detection. Material and methods: The documentation of 75 patients with clinically confirmed spondylodiscitis, who were treated at the Department of Infectious Diseases between 2003 and 2006, was reviewed. According to algorithms valid in our hospital bone scintigraphy has to be done in patients with suspected spondylodiscitis if spine on plain x-ray is inconclusive. Leukocyte scintigraphy is mainly used for detection of infective foci and in patients with fever of unknown origin. 99m Tc DPD, activity 700 MBq, was used for bone scintigraphy. Whole body scintigrams in AP and PA projections were done between two and four hours after radiopharmaceutical injection. If scintigrams were inconclusive, SPECT of suspected part of body was done. 99m Tc HMPAO labelled leukocytes, activity 450 to 500 MBq, were used for leukocyte scintigraphy. Scintigrams of the whole body were performed 30 minutes and two hours after radiopharmaceutical injection. Results: Bone scintigraphy was done just before or during hospitalization in 40 (57%) patients. At the time of bone scintigraphy 24 patients had working diagnosis of spondylodiscitis or were suspected of having spondylodiscitis. 16 patients had different working diagnosis. Radiopharmaceutical accumulation in the region with spondylodiscitis was: -increased in 38 (95%) out of 40 cases, -normal in 2 (5%) out of 40 cases. Leukocyte scintigraphy was performed just before or during hospitalization in 21 (30%) patients. 9 of them had working diagnosis of spondylodiscitis or were suspected of having spondylodiscitis. Radiopharmaceutical accumulation in the region with spondylodiscitis was:increased in 1 (5%) out of 21 cases, -normal in 12 (57%) out of 21 cases, -decreased in 6 (29%) out of 21 cases (absent activity in vertebral body), -irregular in 2 (9%) out of 21 cases (increased and decreased). The activity in the region with spondylodiscitis was normal in 4 out of 9 patients with working diagnosis of spondylodiscitis and decreased (absent) in 5 of them. Conclusions: -Bone scintigraphy is important investigation in diagnostic process in patients suffering for spondylodiscitis due to its very high sensitivity. -Leukocyte scintigraphy is without diagnostic value in patients with spondylodiscitis. The SPECT technique was confirmed to be more sensitive than the conventional planar bone scanning for the detection of reactive bony lesions in patients with back pain (1) . The newly developed hybrid SPECT/CT device can provide enhanced anatomical localization of the lesions detected on SPECT. The aim of this study was to investigate the value of SPECT/CT bone scanning in the evaluation of patients with back pain, which has not been clearly examined yet. Methods: We retrospectively evaluated bone scans of 75 patients with back pain (age 59 ± 23 years, 35 men) that had both planar and SPECT/CT images performed. Planar, SPECT & SPECT/CT scans were separately reviewed by 2 observers for bony lesion presence, location, & specific diagnosis based on each scan. The confidence in each of these assessments was categorized as uncertain, probable or certain. The final diagnosis was confirmed by surgical/pathological, radiological correlation, or follow-up for up to 20 months. Results: There were 143 lesions detected in 75 patients with final diagnosis of arthritis, degenerative disease, fracture, and normal scans. SPECT/CT findings were more accurate in predicting the final diagnosis (Lambda value 0.96, uncertainty coefficient error reduction 92%) than SPECT alone (Lambda value 0.85, uncertainty coefficient error reduction 75%). The localization certainty was significantly higher in SPECT/CT than SPECT alone (p < .05). As to lesion presence, SPECT significantly improved lesion certainty, without additional significant improvement by SPECT/CT. The diagnostic confidence in the determination of the underlying bony abnormality by SPECT/CT was significantly higher than SPECT alone (p < .05). Conclusions: While the detection of bone scan lesion is significantly enhanced by SPECT, the hybrid SPECT/CT can additionally clarify the exact location of these lesions and visualize the associated CT changes. The improved certainty of these 2 factors is the likely reason behind the superior confidence in SPECT/CT specific diagnosis of the bone abnormality in patient with back pain. Aim of the Study: Stress fractures (SF) have been considered a hazard of strenuous physical activities, such as the military training of army recruits. The aim of our study was to demonstrate the association between the findings of bone scanning and some clinical parameters of physical strain that result in bone injury in this specific group of young people. Patients and Methods: Ninety four male recruits, 18-36 years old (mean=24±5 years), under a similar training program and with suspected SF of the lower extremities underwent three-phase bone scanning after injection of 550MBq 99mTc-MDP. They were divided into various groups according to: a) Body Mass Index (BMI): (<25=normal, 25-29=overweight and >29=obese), b) duration of military service (0-2 months = recruits, and >2 months = post-trained soldiers), c) location of the primary symptoms (knees-tibiae, or feet), d) duration of pain symptoms (</=10 days or >10 days), e) pain intensity, in a 0-4 scale, where 0 = pain free and 4 = very intense pain, f) results of plain radiography (positive/negative) and g) results of bone scintigraphy (grade 0 = negative in all phases, grade 1 = positive only in the 3rd phase, and grade 2 = positive in all phases). Paired chi-square statistical tests were applied for all parameters. Results: Seventy two patients (77% of the sum) had scintigraphically positive bone pathology (21 on the leg and 51 on the feet), while the rest 22/94 (23%) had negative bone scans. SF were found at 41 patients (57%), more commonly in the feet rather than the legs (x 2 =4.94, P=0.026) and in recruits rather than post-trained soldiers (x 2 =4.62, P=0.03). Positive scintigraphic results also correlated to pain intensity (x 2 =5.29, P=0.02), although the former were not correlated to BMI, duration of pain, or the results of plain radiography. Plain radiography had sensitivity=33%, specificity=76%, PPV=83%, NPV=25% and accuracy=43% in the detection of SF, taken bone scintigraphy as "gold standard", with no correlation to any of the aforementioned clinical parameters of bone injury. Conclusions: Army recruits under the basic training program seem to suffer more severe bone lessions, located mainly in the feet, regardless of overweight or the duration of pain symptoms. Regarding bone scanning as the "gold standard" diagnostic method, pain intensity is a strong predictor of an adverse clinical condition (bone fracture rather than a milder lession)

Bone scintigraphy and Xray in detection of active osteoarthritis.Their relation to type of knee pain. A ROC analysis. Aim: Bone scintigraphy is a valuable method for detecting synovitis in knee joints with severe osteoarthritis. Both clinical symptoms and proven hyperperfusion set the indication for radionuclide synovectomy (RS). The aim of our study was to evaluate the clinical usefulness of blood pool (BP) and static scan (SS) in respect with joint pain, clinical and x-ray findings. Materials and methods: 412 knee joints of 206 patients (69±7.3years old) referred for setting indication for RS were clinically evaluated and classified by X-ray Steinboecker system and type of pain (only under stress/ both under stress and rest). Two-phase bone scintigraphy was performed according to the procedure guidelines of our department and intensity of tracer accumulation in joints was scored. To check scintigraphy or simple Xrays' ability to evaluate dolorous active synovitis complete statistical Receiver Operating Characteristic (ROC) curves were analyzed. Results: Of all knee joints studied 85.9% were painful at exercise while 10% were continuously dolorous. In general BP was positive in 80.8% and SS in 72.3%. Osteoarthritic joints were x-ray graded 8.5% as 0, 26.2% as I, 30.3% as II, 27.2% as III and 7.8% as grade IV. BP had a sensitivity of 0.91, specificity of 0.82, PPV of 0.96 and NPV of 0.59 at exercise pain and 0.97, 0.28, 0.42 and 0.95 at continuous pain respectively. All values were critically better than these of SS and Xray. Area under ROC curve for BP was larger than this for SS and for Xray (the smallest) in painful joints (0.807, 0.752 and 0.61 respectively) with statistically significant differences. Conclusion: BB scintigraphy is a useful technique for detecting active synovitis in knee joints with OA better than SS or simple Xray. Tracer accumulation is strongly related to the type of pain.

Introduction Condylar hyperplasia is a common cause of crossbite malocclusion and facial asymmetry. Treatment often includes surgery and it's necessary to know the growth activity of the hyperplastic condyles for treatment assessment. Nuclear methods are beginning very useful in this pathology. OBJETIVES The aim of our study is evaluate the correlation between histopathologic findings and uptake intensity in SPECT in patients with condylar hyperplasia. Patients and Methods Prospective study in 37 patients with clinical suspect of condylar hyperplasia and positive 99m Tc MDP SPECT. The patients with increased uptake of 99m Tc MDP in any TMJ were considered positives and were classificated in three grades of uptake. All patients were referred to surgery (condylectomy or condylar shave). An hystologic study classified the samples in three activity grades. A stadystical analysis of SPECT and hystopatological finding was done. Results Condylar hyperplasia was confirmed by hystological findings in all cases. A strong correlationship was confirmed between the uptake intensity and anatomopatologycal findings. Conclusions Condilar SPECT with 99m Tc MDP is an easy diagnostic method with high sensitivity for the diagnosis of condylar hyperplasia and is very useful to evaluate the grade of hyperplasia.

progressive condition and early surgical intervention may prevent further deformity of the hip join. Although the prognosis and treatment of these 2 conditions differ greatly, in the early stages the radiographic appearance of TOH my be confused with AVN. We will attempt to define radiologic characteristics that distinguish TOH from AVN. Patients and method: In 2 years , 5 patients (2F, 3M) were referred with acute hip pain; 1 male with bilateral hip pain in the third trimester of pregnancy (6 hips). In all patients radiographs, bone scan and MRI was performed. The diagnosis of TOH was confirmed by complete clinical recovery and normal MRI in the follow up with conservatively treatment.. Results: No patients had radiographic changes. Bone scanning showed uniformly increased uptake at the affected femoral head extending down into the femoral head in all patients. The changes on MRI were a pattern of diffuse edema without focal defects, and intact articular surface, but 1 patient with focal defect which diagnosis was AVN. Conclusion: diffuse edema pattern on MRI without focal defects and bone scanning with homogeneously increased uptake in the femoral head and neck is highly suggestive of TOH. Introduction: Reflex sympathetic dystrophy (RSD) or complex regional pain syndrome is a condition of burning pain, stiffness, swelling and discoloration of the affected limb (commonly hands and feet). Females are affected more commonly than male (3:1) . Only one in five affected patients is able to return to a normal level of functioning. Bone scan is highly sensitive (96%) and specific (98%). It is also a useful guide to prognosis. About 90% of patients with positive bone scan experienced a favorable response to steroid as oppose to 34% of those with negative scintigrams. Case Report: This is a 42 years old male presented with 6 weeks h/o severe burning sensation and pain in the left hand. He has had a laminectomy over C5-C7 about 10 weeks back. Follow up MRI revealed no nerve compression. X-rays of left hand was unremarkable. A three phase bone scan was performed with 720 MBq of Tc-99m MDP. Results: Dynamic and blood pool images revealed abnormally increased blood flow over left forearm, wrist and hand. Delayed images revealed diffusely increased tracer uptake over the left wrist, carpal, metacarpo-phalangeal and inter-phalangeal joints. A diagnosis of reflex sympathetic dystrophy was made. He was started on oral steroid therapy with analgesic for 3 months and responded well to the treatment. Conclusion: It is concluded that three phase bone scan is a safe, non-invasive, cost effective, highly sensitive and specific modality for the diagnosis of reflex sympathetic dystrophy and also a good predictor of response to treatment. Aim: FDG PET can assess the activity of several inflammatory diseases. Idiopathic retroperitoneal fibrosis (IRF) is a rare disease characterised by a fibro-inflammatory mass which surrounds the abdominal aorta and the iliac arteries and often causes obstructive uropathy. We explored the ability of FDG-PET to predict response to therapy and post-treatment relapse in IRF patients (pts). Methods: Twenty-four consecutive IRF pts (m/f:16/8; median age 58 yrs, range 9-82). The treatment was oral prednisone for 1 month and then prednisone+methotrexate or tamoxifen for 8 months. CT or MRI were performed at diagnosis, after 4 months of treatment and at the end of treatment. PET was performed in all pts before treatment, and in 13/24 pts also after the end of therapy. The treatment-induced reduction in size of IRF, as assessed by CT/MRI, was defined as absent if <10%, mild if 10-50%, and marked if >50%. FDG uptake was graded from 0 to 3+. The pts were compared with 24 controls. Results: At diagnosis, 22 (92%) pts showed a pathologic FGD uptake with 2 main patterns: diffuse (13/22 pts, 59%), and focal (9/22 pts, 41%). Diffuse pattern: 10 had grade 3+, 2 had 2+ and 1 had 1+ uptake; the reduction in size of IRF was marked in 9/10 (90%) pts with grade 3+ and 1 of 2 pts with grade 2+ and absent in 1 with 3+, 1 with 2+ and 1 with 1+. Focal pattern: 3 had grade 3+, 4 had 2+ and 1 had 1+ uptake. A marked response was observed in only 1/3 pts with grade 3+; 2 mild responses in 2/4 pts with grade 2+; no response in 2/3 patients with grade 3+, 2/4 with grade 2+ and 2/2 with grade 1+. Both pts without pathologic uptake showed no reduction. After the end of treatment, 6/13 pts had a residual pathological uptake whereas 7 had no uptake. Posttreatment relapses were observed in 5/6 pts with a residual uptake, and in only 1/7 pts without. Conclusions: The distribution and intensity of vascular FDG uptake may predict response to treatment in IRF patients; a post-treatment residual uptake heralds disease relapse. SPECT/CT may provide an incremental value to routine Indium-111 labeled WBC scintigraphy, as suggested by a recent report with a limited number of patients (1) . In this study, we verify this finding in a larger group of patients and also evaluate the different possible contributory factors to the diagnostic confidence of SPECT and SPECT/CT scans. Methods: We retrospectively evaluated Indium-111 WBC planar scans of 68 patients (age 55 ± 20 years, 39 men) with known or suspected infection that also had SPECT/CT performed. Planar, SPECT and SPECT/CT scans were separately reviewed by 2 observers in respect to infection presence, location, and the specific diagnosis based on each scan. The confidence in each of these assessments was categorized as uncertain, probable and certain. The final diagnosis was confirmed by surgical/pathological correlation; follow up scan/radiological examination or up to 18 months clinical follow-up. Results: In 10 planar images with uncertain infection location, SPECT improved 9 locations to probable sites that were further improved to 9 definite and 1 probable sites by SPECT/CT. Correspondingly, in 38 probable location sites on planar images, SPECT improved 3 locations to definite sites compared with 37 definite sites improvement by SPECT/CT. Conversely, SPECT significantly improved infection presence certainty in uncertain and probable planar subcategories, without significant additional improvement by SPECT/CT. In SPECT/CT, the specific diagnosis confidence was significantly higher when both infection presence and location site were certain, which was more frequently attained than with SPECT scans alone (45 VS 22, p < .001). Final diagnosis was categorized as non-specific/abscess, specific soft tissue infection, osteomyelitis, combined osteomyelitis/soft tissue infection, and normal/physiological uptake. SPECT/CT findings were more accurate in predicting the final diagnosis (Lambda value 0.91, uncertainty coefficient error reduction 87%) than SPECT alone (Lambda value 0.69, uncertainty coefficient error reduction 60%). Conclusions: In Indium-111 WBC scintigraphy, the infection presence recognition is improved by both SPECT and SPECT/CT, while the use of SPECT/CT leads to considerable enhancement in infection localization as well. The significant improvement in both these factors is the likely reason for the high confidence in the SPECT/CT specific diagnosis of infection. 1. Bar-Shalom R, et al. J Nucl Med 2006; 47:587-594 Objectives: In aortic aneurysm (AN) tissues, chronic aortic wall inflammation is mediated by macrophage infiltration, which is playing important role for tissue degeneration. Some studies have shown that weakening of the mechanical properties of the degenerated tissues may progress the expansion of the aneurysm. Especially, saccular ANs often expand rapidly and are suspicious for an infected aneurysm. In the present study, we hypothesized that FDG accumulated in saccular AN walls because these lesions had strong inflammatory reaction with macrophage infiltration and investigated whether FDG accumulated in saccular ANs. Methods: A retrospective survey was conducted on 17 patients with AN who underwent FDG-PET. After at least 5 h fasting, the study subjects received an intravenous administration of FDG. One hour after FDG injection, PET imaging was carried out. FDG images were visually evaluated for the presence of increased FDG uptake in the carotid arteries. We divided the 18 ANs in 17 patients into two groups (saccular-type or fusiform-type) according to the morphologic characteristics. We assessed inflammatory marker (CRP) and pathologic characteristics (atherosclerotic or inflamated) in two groups. Results: 6 of 18 ANs were divided into 6 saccular-type and 12 fusiform-type ANs. 5 of 6 saccular-type ANs were PET-positive, whereas only one of 12 fusiform-type ANs was PET-positive. There was no significant difference in the values of CRP and aneurysmal size in two groups. 10 ANs proven pathologically were divided into 4 saccular-type (2 infected, 2 atherosclerotic ANs) and 6 fusiform-type (all atherosclerotic ANs). FDG accumulated in all of 4 saccular-type ANs. Conclusion: FDG frequently accumulated in saccular-type ANs. ANs in which FDG accumulates may have a high risk of rapid expansion and rapture because these lesions are suspected to have inflammatory reaction with macrophage infiltration. Aim Aim of this study was that of confirming additional clinical effectiveness using SPECT/CT with 99mTc HMPAO-Labelled Leucocyte in infection and inflammation . Materials and Methods We studied ninety-seven patients (pts) (52 females and 45 males; mean age 58.75 ± 20.25 years); all patients underwent Labelled Leucocyte Scintigraphy for known or suspected infectious or inflammation processes: 29 pts with orthopedic implants, 28 pts with suspected osteomyelitis ,8 pts with spondylodiscitis, 14 pts with fever of unknown origin (FUO), 12 pts with inflammatory bowel disease (IBD), 5 pts with suspected septic arthritis and 1 pt with suspected vascular graft. In addition with planar and whole body protocol images SPECT /CT was performed using dual head gamma camera equipped with a low-power X ray system (Infinia Hawkeye -G.E.Healthcare ). After injection of 555 -740 MBq of 99mTc HMPAO-Labelled Leucocyte SPECT/CT images of the interesting area were obtained in all cases at 2h or 4h according with the clinical query. Final diagnosis of infection and inflammation was made on the base of bacteriologic, surgical data or clinical followup. Results SPECT/CT results proved on the whole cases 43 true-negative and 50 true -positive, 2 false -negative and 2 false-positive results. In orthopedic implants and osteomyelitis cases SPECT /CT permitted to distinguish between soft -tissue infection and bone involvement and allowed to change clinical and surgical management in 64% cases; SPECT/CT detected precise localization in ileal and ileocolonic tract in positive IBD cases. Additional value of SPECT/CT was in FUO cases since it permitted a diagnosis of renal abscess in 1 pt with polycystic kidney who previously underwent renal transplant, in another pt, abnormal focal uptake in catheter for haemodialysis and in 3 cases with liver , lung and sub-diaphragmatic abscess respectively. The overall sensitivity and specificity of SPECT/CT 99mTc-HMPAO Labelled-Leucocyte was 96% and 95% respectively. Conclusion SPECT/CT with 99mTc HMPAO-Labelled Leucocyte is a useful tool for infection and inflammation detection that provides a precise anatomy localization, expansion and tissues differentiation mainly between soft tissue infections and osteomyelitis. Furhermore, it underlines the role of 99mTc HMPAO-Labelled Leucocyte in cases of suspected abdominal-pelvic or thoracic sites of infections increasing the diagnostic accuracy of positive findings.

Objective: Hemodialysis (HD) activates neutrophils and causes increased lung retention. 99m Tc fanolesomab is a monoclonal antibody that radiolabels white blood cells and myeloid precursors in vivo. It reacts with CD 15, expressed on the surface of polymorphonuclear neutrophils, eosinophils and monocytes. Serious complications occurring < 30 min. after injection was reported in patients (pts) with compromised cardiopulmonary reserves. Lung retention of this agent has not been addressed yet. We hypothesized that there might be an excess transient retention of these invivo labeled and probably activated WBCs in the lung capillaries post HD, which may contribute to pulmonary compromise. Methods: We retrospectively and semi-quantitatively determined the degree of invivo labeled 99m Tc WBC activity on anterior (A) and posterior (P) whole body images of the 23 consecutive pts. A and P ROIs were drawn in the upper (U), middle (M) and lower (L) lung zones and over the chest wall soft tissue background and used to calculate the geometric means of conjugate ROIs (Lung uptake ratio). 6 pts without ESRD and not on HD were used as controls. Elapsed times from the last HD to imaging times were determined. Result: Mean± SD injection to imaging time: 178 ± 64 min (78-338). Of the 17 Pts with ESRD on HD, 12 had HD < 24 hr before the imaging (Group I), 5 pts had HD 24-48 before the imaging (Group II). Geometric mean lung uptake ratios for right (R) U, RM, RL, Left (L) U, LM, LL in group I were 2.28 ± 0.53, 2.75 ± 0.63, 3.07 ± 0.74, 2.36 ± 0.48, 2.95 ± 0.51 and 3.10 ± 0.75, respectively. Those values for group II were 1.80 ± 0.38, 2.17 ± 0.49, 2.46 ± 0.61, 1.62 ± 0.31, 2.02 ± 0.39 and 2.38 ± 0.48, respectively. Control ratios were 1.93 ± 0.21, 2.12 ± 0.42, 2.58 ± 0.61, 1.79 ± 0.28, 2.12 ± 0.43 and 2.47 ± 0.51, respectively. A trend of subtle increase in lung uptake ratios was noted for Group I, especially in left lung. However, differences weren't statistically significant. Conclusion: A recent HD done < 24hrs might play a role in the activation of the invivo labeled 99m TcWBCs causing prolonged lung retention in ESRD pts, which is not present > 24hrs. Despite the strong trend, lack of statistical significance in Group I pts might be due to relatively long (90-338 min) injection to imaging time and small pt population. Purpose:In this study, we aimed to investigate the role of Tc-99m HMPAO white blood cell (Tc-99m WBC) SPECT in the evaluation of bone infections in addition to Tc-99m MDP 3-Phase bone (Tc-99m 3-P) scans and planar Tc-99m WBC scans. Materials and Methods: The patients who had Tc-99m 3-P and Tc-99m WBC scans between January 2006 and March 2007 for the investigation of suspected bone infections were evaluated retrospectively. From these, 20 patients whose pathological, bacteriological, surgical data, and clinical onset showed infection were included to our study. For every patient, Tc-99m 3-P, planar and SPECT Tc-99m WBC scans were performed within one week. Our patient group consisted 12(60%) males and 8(40%) females whose ages were 10-93 (mean age was 51.5) and who had bone infections in various localizations: 11 patients (55%) had infections of foot, 6 patients (30%) had infections of knee (3 of them had knee prosthesis), 2 patients (10%) had infections of hand, and 1 patient (5%) had infection of leg. Results: The images of Tc-99m 3-P and planar Tc-99m WBC scans were evaluated together and Tc-99m WBC SPECT images alone. The results were as followings: were enrolled the study. The patients were suspected of bacterial infection due to travmatic injury (18 pts), diabetic foot (13 pts) and prosthetic surgery (23 pts). Whole-body images at 1, 4 and 24 hours after IV slow injection of 20 mCi Ciprofloxacin labelled with Technetium-99m in-house were obtained. Threephase bone scintigraphy was also performed in 42 patients in a period of 3 to 10 days. Final diagnosis was obtained by microbiological and patological examinations and clinical follow-up for a period of 1 to 3 years. Results There were 33 positive findings on Tc-99m ciprofloxacin images and 31 of them were proved to be true-positive. Staphilococci was the most common agent isolated by microbiological analysis. In one of the patients with false-positive finding, intensive bone repair was noted on bone scan images. Ciprofloxacin imaging was true-negative in 14 patients and failed to show bacterial infection in 7 patients (chronic osteomyelitis in 2, hip and knee posthesis in 2 and diabetic foot in 3 patients). The overall sensitivity, spesificity, negative/ positive predictive value and accuracy of Tc-99m ciprofloxacin imaging were 81% 88% 66%/93% and 83% respectively. Conclusion Tc-99m ciprofloxacin is a sensitive and practical procedure that can be used in detecting musculoskeletal infection. It also contrubutes to discriminate aseptic loosening and prosthetic infection and avoids unnecessary orthopaedic surgery. Along with three-phase bone scanning false-positive results can be reduced where excessive new bone formation might be the potential cause of false-positive results. Objectives: Infection of HD vascular access site is a frequent cause of mortality morbidity in HD patients. The incidence is lowest in patients with AVF. Although the prosthetic HD access (AVG and/or catheters) has been acceptable alternative to the native AVF, the patients are often plagued by more complications (i.e., infection, thrombosis). Aim of the study was to determine the accuracy of infection detection using invivo labeled Tc-99m WBC imaging in patients with AVF as HD access as compared to those with prosthetic HD vascular access (AVG, catheter). Methods: 24 consecutive patients with end stage renal disease being treated with HD and who had suspected infections were retrospectively analyzed. Two Nuclear Medicine physicians evaluated the Tc-99m WBC images in a blinded fashion. Vascular access infection was diagnosed if radiotracer uptake at the site was focal fashion and more prominent than the surrounding blood vessels. The scan results were correlated with clinical/laboratory information, cultures and outcome. Results: In 24 patients a total of 29 vascular access sites were evaluated. There were 13 AVG, 5 AVF, and 11 HD catheters. None of the AVF was infected but 60% showed collateral formation. Invivo labeled Tc-99m WBC scan showed evidence of infection in 7/13 AVG (%54) of the AVGs, compare to 4/11 (36%) of the HD catheters (P: 0.09). When compared, AVF versus prosthetic HD access (AVG + catheters), the incidence of detected infection was 0% versus 46% (P: 0.07). The sensitivity, specificity, positive predictive value, negative predictive value and accuracy for the detection of infection with the Tc-99m-WBC scan in AVGs were: 100%, 67%, 78%, 100%, and 85%. The values for the HD catheter were 100%, 86%, 80%, 100% and, 91%, respectively. Conclusions: A properly formed arteriovenous fistula is less likely than other types of vascular access to become infected. Hemodialysis catheters and arterio venous grafts had similar rates of infection. The Tc-99m WBC scan has an accuracy rate of 85-90% in detecting infection in arterio venous grafts and hemodialysis catheters i.e., prosthetic hemodialysis access. Objectives: This was an intraindividual analysis of the utility of currently available radionuclide imaging techniques: 3 phase bone (3PBo), bone (Bo), gallium (Ga), bone/gallium (BoGa), labeled leukocyte (WBC), leukocyte/bone (WBC/Bo), and leukocyte/marrow (WBC/Ma), to determine the most accurate radionuclide technique for diagnosing the infected hip prosthesis. Methods: 50 patients, 29 females, 21 males, 38-85 years old, with failed hip replacements, 43 total arthroplasty, 7 hemiarthroplasty, 4 weeks-20 years old, who completed all radionuclide imaging tests and who subsequently underwent surgery formed the basis of this retrospective study. One experienced nuclear physician reviewed all images. Diagnostic criteria for infection were as follows: 3PBo= triad of periprosthetic hyperperfusion, hyperemia, & increased periprosthetic activity on delayed, bone, images; Bo= increased activity around the shaft of the femoral component, Ga= any increased periprosthetic activity except focal activity at the tip or trochanters, Bo/Ga= spatially incongruent distribution of activity or, if congruent, Ga activity >Bo activity, WBC= increased periprosthetic activity relative to contralateral limb or surrounding normal activity, WBC/Bo= spatially incongruent distribution of activity or, if congruent, WBC activity >Bo activity, WBC/Ma= spatially incongruent distribution of activity. Imaging results were compared with surgical, histopathological and microbiological results for all 50 prostheses. Results: There were 25 infected prostheses. Final diagnoses in the remaining cases include aseptic loosening (22), failed acetabular liner (2) , and component malposition (1) . Imaging results are summarized in the For all prostheses the 3PBo scan demonstrated only moderate sensitivity and low specificity. For reasons that are as yet unknown, the test was not sensitive, but moderately specific, for diagnosing prosthetic hip infection, while in contrast, it was very sensitive, but not at all specific, for diagnosing prosthetic knee infection. Conclusions: The 3 phase bone scan is of limited utility for diagnosing infection of lower extremity joint prostheses. The test is not sensitive for prosthetic hip infection and too nonspecific to serve as a screening test for knee prostheses. Malignant otitis externa is a rare infectious disease of the external auditory canal commonly caused by pseudomonas aeruginosa. The disease may have a protracted course with extension to other bony and soft tissues structures of the skull base. Evaluation of disease extent is crucial for initial management with further evaluation required to document resolution during treatment. CT will delineate bone and gross soft tissue involvement but may be normal in early disease. MRI is useful to assess soft tissue extent of disease but assessment of resolution is difficult with both modalities. Bone scintigraphy will detect early bone involvement but remains abnormal for some time therefore is unreliable for assessment of resolution or detecting early recurrence. Gallium-67 citrate can be used to assess disease extent but like bone scintigraphy is non-specific and partly reflects bone activity. There is less published data on the use of In-111 white cell imaging which has been said to become negative before complete resolution. It is possible that this drawback relates to the imaging properties of In-111 and the difficulty of localising small low intensity foci of white cell accumulation on planar views. In three recent cases of suspected skull base osteomyelitis low intensity foci of white cell accumulation were identified on planar imaging with In-111 labelled white cells. Use of SPECT combined with 'Hawkeye' (low power CT: GE-Millenium VG) allowed accurate localisation of these foci. Dual isotope acquisition with combined In-111 and Tc-99m MDP assisted in this process as the more intense and extensive uptake by the bone agent helps to identify the initial extent of disease and which transverse slices to examine in detail on the lower count data acquired with the In-111 SPECT. In each case imaging was repeated during the clinical course of the disease to document resolution with scintigraphic findings mirroring the clinical course. Conclusion Use of In-111 combined with Tc-99m MDP SPECT and 'Hawkeye' can be useful to assess extent of disease in suspected skull base osteomyelitis on initial presentation, to monitor response to treatment and to assist in determining when to discontinue antibiotics. It is possible that this may be more specific and may present a viable alternative to Ga-67 citrate in such cases.

Careful attention to imaging parameters is required to avoid acquisition of meaningless data in view of the low counts obtained with In-111 SPECT particularly as disease resolution occurs.

The Utility of 99m- ; Conclusion: Many common diseases manifest themselves with no specific sign or symptoms, but with FUO associated to an increase of no specific marker of inflammation. Our data show that, even if, most of patients with FUO had negative scintigraphy with Leukoscan, it can help clinician to identify the cause of FUO and to decide the best therapeutic treatment.

The main etiologies of fever of unknown origin (FUO) are infections, cancers, and noninfectious inflammatory preocesses. In this prospective study, we aimed to evaluate the diagnostic role of 18F-fluorodeoxyglucose (FDG)-PET in FUO, since this substance has an increased uptake by neoplastic and inflammatory cells. Methods: The study included 23 patients (17 male, 6 female, mean age 51.3 ± 20.6 years, range 1-70 years) referred to our unit for FDG-PET study between March 2005 and December 2006. Siemens LSO HIREZ PET-CT camera was used for the record of the imaging. One hour after injecting 12-16 mci FDG, a whole body PET-CT from vertex to toe was obtained. Results: Among 23 patients studied by PET-CT, 14 (60.1%) had foci with increased FDG uptake. The remaining had normal findings. Among those patients with increased FDG; malignant neoplastic process, inflammatory process, and infection were diagnosed in 7, 6, and 1 patients respectively. Modern combination chemo-and radiotherapy have raised long-term survival of Hodgkin lymphoma (HL) to more than 80%. However, the longer follow-up has shown serious long-term adverse effects related to the treatment, including heart and lung diseases, and secondary malignancies. In order to reduce these long-term side effects, alternative therapeuties are becoming more tailored to the individual patient's prognosis. In this regard, an important predictor of outcome is the early establishment of treatment response. Conventional methods as CT scan have proven to be poorly accurate to this purpose. Recently, early interim FDG PET/CT has been reported as a strong and independent predictor of progression-free survival in HL. In particular, a positive early interim FDG PET/CT is highly predictive of progression in patients with advanced stage or extranodal disease. In the present prospective study, we collected 13 consecutive patients with newly diagnosed HL since 2004. All patients underwent initial staging with FDG PET/CT (it was positive in all patients) along with standard staging procedures, including CT. FDG PET/CT was repeated after 2 (FDG PET 2) and 4 cycles of chemotherapy, and after completion of chemotherapy (ABVD schedule). Evaluation of this last FDG PET/CT was discriminant to decide for radiotherapy in bulky disease. The follow-up range was of 4-28 months. All the FDG PET2 negative patients are in complete disease remission, except for one case (patient 2/see Table) who experienced early relapse, resistant to autologous bone marrow transplantation. She is now in disease progression and a shift in lymphocyte depletion histo-type has been documented. Results are shown in the Subtotal splenectomy is effective in decreasing both the hematologic complications of HS and infectious complications of total splenectomy. The objective of this retrospective study on 61 patients was to identify clinical and/or biological factors which could predict the rate of regrowth of the splenic remnant and influence the beneficial effect of subtotal splenectomy on red cell life span. Material and methods : Sixty one patients (M=34 ; F=27) with HS who underwent subtotal splenectomy between February 1985 and March 2005 were included in this analysis. For each patient, preoperative and postoperative clinical and biological data were collected: date of first symptoms, the clinical and biological indications for subtotal splenectomy (propensity for fatigue , number of transfusions, associated cholelithiasis, mean values of haemoglobin and reticulocyte counts), patient's age at the date of surgery. Postoperative growth and functional value of the splenic remnant were assessed by abdominal single photon emission computed tomography (SPECT). Acquisitions were performed after injection of autologous heat damaged red blood cells labelled with technetium 99m. Splenic volume was calculated on reconstructed axial slices by means of a threshold algorithm previously validated on a phantom study. Results & conclusion: Statistical analysis was done with R software. Mean values of haemoglobin, reticulocyte counts and clinical scores were compared between preoperative and postoperative follow-up periods. Median delay between subtotal splenectomy and splenic scintigraphy was 538 days (range 167-6503). Three patients developed splenic necrosis postoperatively and were dropped from the statistical analysis of predictive factors. The mean splenic volume measured by SPECT was 205 ml (range 34 ml -601 ml ; median= 166 ml). The mean haemoglobin values increased from 9.1 g/dL before surgery to 12.2 g/dL after surgery. Univariate and multivariate analyses were performed to identify the predictive variables of splenic regrowth. We describe a case of hairy cell leukemia (HCL) coexistent with non-Hodgkin's lymphoma (NHD). This combination is reported to be extremely rare with no clear demonstration of the clonal relationship between the two condition. After a previous failure of purine analogs therapy, our patient was successfully treated with rituximab resulting in normalisation of blood cell count cessation of blood transfusion and negative iliac crest biopsy. Unfortunately, the patient developed intense and persistent bone pain during the 1 st line treatment for HCL. Skeletal X-rays, whole-body CT scan and bone MRI were unremarkable and bone scintigraphy showed non-specific changes. Laboratory examinations were normal. To better evaluate these non-specific findings, a FDG-PET/CT was performed, followed by a guided bone marrow biopsy of the left femoral diaphysis. This demonstrated an aggressive high grade lymphoma, characterized by immunoblasts and polymorphous centroblasts in a diffuse pattern, expressing CD20, CD79a, CD10, Ig k for a 30 %, nuclear and cytoplasmic bcl-6 antigen, a high proliferative index (Mib-1 >90%), and ALK negative. These parameters, along with the absence of a low-grade component, were consistent with the diagnosis of primary bone marrow diffuse large B-cell lymphoma (LBCL). Shortly afterwards, LDH rapidly increased to 3780 U/L and Hb levels decreased to 9 g/dL; ESR was 120 mm, ferritin was 2857 ng/mL, fibrinogen 1000 mg/dL, 2 -M 6 mg/L. An attempt was made to assess and compare B cell clonality of both disorders using a seminested PCR approach, as previously described (1); unfortunately no major Ig H gene rearrangements could be detected in both disorders with the primer pairs used for the assay. In May 2004 the patient was started on weekly chemotherapy scheme (VACOP-B). Diffuse bone pain rapidly resolved and Hb concentration, ESR, 2 -M and LDH normalized. Unfortunately in July, six weeks after chemotherapy, she became sleepy and developed loss of memory, and central nervous system involvement with LBCL was confirmed with CSF cytology and immunophenotyping. Brain MRI showed diffuse subependimal disease. Therefore, the patient was given both intrathecal and systemic 3 rd line chemotherapy with progressive neurological improvement. However, her clinical condition showed rapid deterioration culmibnating in cessation of chemotherapy. The patient eventually died of progression of her disease in August 2004. It can be recommended the early performance of FDG-PET/CT in poorly understood bone pain to identify bone and bone marrow localization of NHD. Objective: The aim of our retrospective study is to compare the recurrence (local, regional node or distant metastasis) after sentinel lymph node biopsy (SLNB) with and without axillary lymph node dissection (ALND) in patients with breast cancer. Patients and Methods : Between May 1998 and September 2002, 277 patients with early-stage invasive breast cancer (<cT2, cN0, cM0), underwent SLNB in our institution. 167 patients were treated with ALND after SLNB and 110 patients without. All patients were classified pN+ or pN0 based upon presence or absence of metastatic lymph node by pathologic analysis. A total of 69 patients (24.9%) were pN+. The median follow-up period is 72 months (range 16-104). The site of first recurrence was classified as local, regional node or distant metastasis. Results : Recurrence occurred in 21/277 patients (7.6%). The median interval to recurrence was 38 months. Local, regional node and distant metastasis recurrence occurred respectively in 1.9%, 0% and 2.9% of pN0 patients treated with SLNB alone (N=103), and in 1.9%, 0.9% and 2.9% of pN0 patients treated by SLNB with ALND (N=105). In patients with positive nodes (N=69), regional node recurrence and distant metastasis are sensibly more frequent (respectively 1.6% and 12.9%), while local recurrence is comparable (1.6%). Conclusions : As reported by several others teams, our study demonstrates that local, regional node and distant recurrence rate in patients treated by SLNB without ALND, providing SLN is negative, is not greater than after ALND. This remains true after a long time follow-up (over 5 years). Our results support that SLNB alone in SLN-negative patients is a safe method to assess axillary lymph node status in early-stage breast cancer. (100) 105 (100) 0 (0) 0 (0) 1-3 0 (0) 0 (0) 7 (100) 55 (88.7) 4-9 0 (0) 0 (0) 0 (0) 5 (8.1) >10 0 (0) 0 (0) 0 (0) 2 (3.2) Median follow-up 66 months 77 months 56 months 74 months Median interval to 35 months 50 months 33 months recurrence Recurrence 5 (4.9) 6 (5.7) 0 (0) 10 (16.1) local 2 (1.9) 2 (1.9) 0 (0) 1 (1.6) regional node 0 (0) 1 (0.9) 0 (0) 1 (1.6) distant metastasis 3 (2.9) 3 (2.9) 0 (0) 8 (12.9) ALND, Axillary Lymph Node Dissection; SLN, Sentinel Lymph Node; ALN, Axillary Lymph Node Aim: Although it is well documented that previous excisional biopsy is not a contraindication in sentinel lymph node biopsy (SLNB), there are studies reporting problems caused by previous surgical applications. In this study we aimed to review retrospectively if there is a relation between problems encountered and presence of previous excisional biopsy during SNLB. Material and Method: A total of 167 female patients were included in the study. Seventy two of them were patients having previous excisional biopsies. 1 mCi of tin colloid was injected at 4 quadrant around areola intra/subdermally 18 hr before surgery. Patients were imaged at anterior and lateral projections and during operation SLNs were excised with the guidance of gamma probe. Results: Application difficulties were analysed in 3 main topics and were seen in 9 patients. Dilated lymphatic channels showing activity stasis caused problem in 3 patients. Leakage of the activity in a localization other than injection site was the case in 3 patients (into the biopsy cavity in 1 and in an intradermal pouche in 2 patients). Non-vizualization of SLN at first injection was the problem in 3 patients. When occurence of this problems and presence and localization of previous biopsies were compared no correlation was detected between dilated lymphatics and biopsies. Presence of dilated lymphatic channels were more often in non-biopsied patients (5/95) than biopsied patients (3/72) . Although dilated lymphatics increased operation time did not prevent detection of SLNs. All patients showing activity leakage have had biopsies within 3 weeks with periareolar insicions. Leakages formed focal activity accumulation areas mimicking SLN appearences. The real SLN could not be visualized in patient having leakage into the biopsy cavity. In other 2 patients having leakage into dermal pouch SLNs are succesfully identified. All patients with nonvisualized SLNs at first injection were patients having previous biopsies. In 2 of them with a second intraparenchimal injection done just before the operation SLNs could be detected. In the 3rd patient who had additionally morbid obesity SLN could not be identified. Conclusion: Although previous excisional biopsies do not compromise the effectiveness of the technique, especially when done with periareolar insicions it may cause problems in periareolar injection technique.

Detection of sentinel lymph nodes in breast cancer: every day practice and pitfalls G. Moulin-Romsee 1 , E. D'Hondt 1 , F. Persyn 1 , B. Van Calster 1 , S. Ceyssens 2 , P. Neven 1 , S. Stroobants 1 ; 1 KU Leuven, leuven, BELGIUM, 2 UZA, Antwerp, BELGIUM.

The SLN technique has radically changed the management of breast cancer by reducing the need for axillary lymph node dissection. Controversy and variety in every day practice however exists. We investigated the effect of different methodologies as part of an internal ISO audit. Methods: Initially, 40 MBq Tc-nannocolloid was injected peritumoral and images were acquired after 30-45 min and 2 hours (Group I, April-September 2005). Because a decreased visualisation on scintigraphy was noted (group II, January-April 2006), the procedure was adapted (group III, May-September 2006). The tracer was injected subdermal and for the 2-day protocol, the dose was increased to 80 MBq. If lymphoscintigraphy was negative after 2 hours another 40 MBq was injected periareolar. Differences in patients characteristics, visualisation and identification rate between the 3 patients groups were statistically analysed. Results: Scintigraphic visualisation and surgical identification rate was 79% and 91% for Group I, 71% and 90% for Group II and 87% and 97% for Group III. Except for age, patients' characteristics were similar (BMI, hooked wire). The odds of finding a preoperative SLN is significantly higher in group III compared to both other groups (OR=2.84) which is explained by the higher count rate of the resected SLN (p=0.0008). Other factors that are associated with a decreased detection rate are hooked wire (OR=0.416), BMI (OR=0.87) and age (OR=0.94) Discussion:

We advocate the use of a single subdermal deposit since it drains more rapidly and is easier to perform. Failure to detect a SLN is more frequently in association with hooked wire, higher age and patient overweight. When a 2-day protocol is used, sufficient dosage should be used to ensure strong signal perioperatively. Aim Axillary treatment for breast cancer can increase resistance to lymph outflow from the arm. Lymphatic collector vessels may have to pump against a chronically raised afterload, leading to lymphatic collector pump (LCP) failure and breast cancerrelated lymphoedema (BCRL). A new lymphoscintigraphic technique was used to measure LCP function in normal and BCRL arms. Materials and Methods In an Ethics Committee approved study we first measured hand to axillary lymph node transit time (t transit ) using intradermal injection of 99m Tc-human IgG ( 99m Tc-HIG, 10MBq) using -camera imaging. LCP force was assessed by placing a sphygmomanometer cuff at 60mmHg around the upper arm before injection and retention of 99m Tc-HIG distal to the cuff and absence of axillary counts at >t transit indicated inhibition of LCP function. After t transit max cuff pressure was lowered by 10mmHg steps until 99m Tc-HIG passed under the cuff and reached the axilla, indicating the pressure (P pump ) lymphatics could overcome. Results t transit was 10±7[SD]min (21 min for t transit max) in 7 healthy subjects (52±10years). LCP force (P pump ) was assessed in 16 healthy controls (54±6years) and 16 women with BCRL (60±8years, 12-56% forearm swelling). P pump was 39±14mmHg in controls, and lower at 24±19mmHg, in BCRL subjects with swollen forearms (p=0.014, unpaired t-test). Background and Aim Based on our previous experience with radioguided occult lesion localisation (ROLL) in the breast, we have recently introduced similar ROLL method for the detection of clinically non-palpable lesions in the neck with 99mTclabelled macroagregates (99mTc-MAA). Patients and methods Radioguided biopsy was performed in 9 patients (3 males and 6 females, age 27 -79 years) who had ultrasonographically proven non-palpable lesions in the neck. In 4 these were clinically suspected to be lymphoma, in 2/3 patients with papillary thyroid carcinoma (PTC) who already had total thyroidectomy and radioiodine ablation or therapy these were suspected to be PTC lymph node metastases and in 1/3 a relaps in the thyroid bed. In 1 patient repeated supraclavicular lymph-node biopsies were inconclusive, in another a primary PTC was cytologically suspected to be located in a thyroglossal duct cyst. The radiotracer (99mTc-MAA 3.7 MBq in 0.1 mL volume) was injected intratumorally under the US guidance. All the patients underwent planar scintigraphy of the neck imediately after radiotracer application -1-2 hours before surgery. The location of the injected radiopharmaceutical in the neck was marked on the patient's skin with a point 57-Co source and indellible ink. Injected activity, taken up by the neck lesions, was intraoperativelly detected and located with a gamma probe.

In all patients scintigraphy revealed intense focal uptake in the neck. All the marked lesions were intraoperativelly easily detected with gamma probe. Histopathological findings confirmed lymphoma in 4 (follicular B-cell in 2, anaplastic large cell in 1 and Hodgkin's lymphoma in 1 patient) and PTC metastases in 2 patients. In a patient with thyroglossal cyst histopathology excluded any neoplastic infiltration. In a patient in whom repeated supraclavicular lymph node biopsies were inconclusive, a radioguided biopsy revealed a metastasis of a poorly-differentiated pancreatic adenocarcinoma. In one patient with PTC and elevated Tg levels after total thyroidectomy and repeated radioiodine therapies, suspected to have a relaps in the thyroid bed, histology of a scintigraphically and intraoperativelly »hot« paratracheal lesion was negative, probably due to the fibrosis as a consequence of surgical and radioiodine therapy. Conclusion Our work suggests that intraoperative radioguided detection of nonpalpable lesions in the neck after 99mTc-MAA under the US guidance is simple and accurate method. The aim of the study was to determine the reliability of the diagnostic procedure of radioguided occult lesion localization (ROLL) and to detect sentinel lymph nodes in occult lesion localization (SNOLL) using two kinds of radiopharmaceuticals. A total of 67 female patients (mean age 56), in whom mammography, breast ultrasound, and fine needle aspiration cytology detected high risk occult lesions, were enrolled in the study. Material and methods: The day before surgery (18hrs) under ultrasound guidance 74 MBq 99mTc-MAA (from 55.5 MBq to 92.5 MBq) in a volume of 0.2 ml was injected into the center of the lesion. Usually about ten minutes after radiotracer was injected, anterior and oblique scintigrafic images were acquired. The breast contour was outlined with flexible marker 57 Co and the nipples marked with point source ( 241 Am). On the day of surgery 15 MBq of 99m Tc-nanocolloid in a volume of 0.2 ml was subdermally injected above the marked localized breast lesion. Images made twenty minutes later in anterior and anterior-oblique projection revealed a sentinel lymph node. Results: In all patients scintigraphy uncovered activity in the lesions and sentinel lymph nodes. The average lesion size of 6.2 mm was detected mammographically, and of 5.7 mm with ultrasound. Cytological findings confirmed invasive ductal malignant tumors in 38 (56.7%) and suspect in 7 (10.5%) patients. Puncture of the suspect lesion was not performed in 21 (31.3%) patients and only one patient (1.5%) had normal findings. Tumerectomy was performed in all patients. Patohistological findings confirmed malignant breast cancer in 57 (85.1%) patients, of which metastases in SLN were detected in five (8.8%). Conclusion: The obtained results show that a method of choice for a safe and quick localization of the occult breast lesion and SLN is the combination of simultaneous detection of the occult localized breast lesion with 99m Tc-MAA under ultrasound guidance and the detection of SLN with a lymphoscintigraphic subdermal injection of 99mTc-nanocolloid. Introduction: Chyluria may present as chylous clot, chylous clot retention, hematuria, flank pain, dysuria, weakness, fever and weight loss. It is a late manifestation of filariasis, a parasitic infestation endemic in South East Asia. Other associated conditions include repeated retroperitoneal infection, especially tuberculosis, trauma, genitourinary or gastrointestinal tumors, malignancy of the thoracic duct and thyroid, ureteric stone, hydrocele, inguinal hernia and pregnancy. Lymphangiography has been the main imaging modality in investigating chyluria, chyloperitoneum and chylothorax. However, it requires tedious cannulation of lymphatics, is invasive and is not readily reproducible. Lymphoscintigraphy using 99m Tc labeled colloid delineates the pattern of lymphatic drainage, is fast, non-traumatic and has no known side effects. We are reporting a case of chyluria developed after a spinal surgery in which lymhoscintigraphy was used to localize the lymphorenal fistula. Case History: 67 years old male who had a history of laminectomy over L3-L4 level and after 7 months he presented with complaint of chyluria and repeated urinary retention. On examination his vitals were normal and his CBC, LFTs and serum creatinine were within normal limits. His urine reported milky in color with enormous fat and cellular component. His ultrasound abdomen revealed right renal cyst and mild prostatic enlargement. Lymphoscintigram was performed with 37 MBq (0.5 cc volume) of 99m Tc labeled Nannocolloid injected subcutaneously as 0.25 cc aliquot in 2 nd and 3 rd interdigital spaces of both feet. 3 hr delayed whole body images revealed reduced traveling and relatively less outlined left inguinal lymph nodes, A normal flow and well outlined inguinal lymph nodes were seen in the right lower limb. There was evidence of visualization of tracer in the left kidney with appearance of para-aortic lymph nodes consistent with left sided lymphorenal fistula. A follow up cystography confirmed the appearance of chylous urine from the left ureter. Patient refused surgery. Discussion: Chyluria is a relatively common condition is South East Asia. Lymphangiography has been the main imaging modality but it is invasive and requires expertise for canulation and significant radiation exposure. Lymphoscintigraphy using Tc-99m labeled colloid is safe, non-invasive and reproducible technique and gives less radiation exposure. It is invaluable in detection of site of lymphorenal fistula and cystoscopy during active chyluria helps to determine relative severity of the involved site of urinary tract. Thus these two investigations together help determine the site of operation. Granulocyte-colony stimulating factor (G-CSF), a hematopoietic growth factor, is widely used to accelerate recovery from neutropenia after severe chemotherapy, both decreasing the risk of infection and mobilizing peripheral blood stem cells. G-CSF is commonly administrated to healthy donors to mobilize peripheral blood stem cells for allogeneic hematopoietic stem cell transplantation. Adverse events from G-CSF use in healthy donors been described in approximately 30% of cases, and are comprised predominantly of bone pain, headache, and general fatigue. Pulmonary complications caused by G-CSF include cough, dyspnea, and interstitial or alveolar pulmonary edema with mild-to-severe deterioration of blood oxygen level. Few cases of acute respiratory distress syndrome (ARDS) following G-CSF administration have been reported. The present study was designed to determine the pulmonary clearance rate of Tc-99m diethylenetriaminepentaacetic acid (Tc-99m DTPA) in healthy donors for allogeneic hematopoietic stem cell transplantation and the role of Tc-99m DTPA aerosol scintigraphy in the early detection of lung involvement. Material and Methods: Five healthy donors (2 female, 3 male; aged 25 ± 9 years) were studied. Tc-99m DTPA aerosol inhalation scintigraphy and pulmonary function tests (PFT) were performed before and after 4 days G-CSF administrations. On the basis of the scintigrams the percentage decline in activity per minute (Kep) was evaluated, which represented an accurate parameter of lung membrane permeability. Results: Increased lung epithelial permeability was observed in all of the donors after 4 days G-CSF administrations. There was statistically significant difference between two studies (1.17 ± 0.43 and 1.74 ± 0.72 for left lung; 1.24 ± 0.44 and 1.61 ± 0.62 for right lung, P<0.05, paired t test). But no significant change was observed in PFT (P>0.05). Conclusion: Our preliminary results show that subclinical alveolitis may be present in healthy donors after G-CSF administrations since it is known that an increase in the epithelial permeability of the lung is an early manifestation of interstitial disease.

Assessment of mean transit time in the engrafted lung with Xe-133 lung ventilation scintigraphy improves diagnosis of bronchiolitis obliterans syndrome in living-donor lobar lung transplant recipients T. Shinya 1 , S. Sato 2 , K. Kato 2 , S. Akaki 2 , H. Date 2 , S. Kanazawa 2 ; 1 Okayama kyokuto hospital, Okayama-city, JAPAN, 2 Okayama university medical school, Okayama-city, JAPAN.

Aim: Staging of bronchiolitis obliterans syndrome (BOS) after lung transplantation is based on declines in forced expiratory volume in 1s (FEV 1 ). Use of computed tomography (CT) has been described for early detection of BOS. The aim of this study was to evaluate the usefulness of 133 Xe ventilation scintigraphy in early detection of BOS after living-donor lobar lung transplantation (LDLLT) and to compare 133 Xe wahout imaging with CT finging for early detection of BOS after LDLLT. Material and Methods: Subjects comprised 30 double-lung recipients and 1 single-lung recipient, who had undergone LDLLT at our institution and survived >1 year. Clinically diagnosed BOS developed in 6 recipients. Declines in graft function were evaluated using a combination of 3 methods: dynamic spirometry; computed tomography; and 133 Xe ventilation scintigraphy. Findings for all transplanted lungs were compared between CT and 133 Xe washout imaging. Assessment of 133 Xe washout was assessed using mean transit time (MTT) of bi-and unilateral lungs. Correlations between MTT of bilateral lungs and FEV 1 % were evaluated. Differences between MTT of BOS and non-BOS lungs and between MTT of non-BOS and donor lungs were also evaluated on bi-and unilateral lungs, respectively. An appropriate cut-off value for MTT of bi-and unilateral lungs was set for the diagnosis of BOS. Results: In all 6 BOS cases, prolonged-washout images of engrafted lungs revealed early-phase BOS with declines from baseline FEV 1 , while only 1 BOS case could be detected using CT. A significant correlation was identified between MTT and FEV 1 % (r=-0.346, p<0.0001). MTT of bi-and unilateral lungs was significantly longer in BOS lungs than in non-BOS lungs (p<0.0001). The cut-off MTT for bi-and unilateral lungs for diagnosis of BOS were set at 62.19 s and 64.77s.Conclusion: Our data show that 133 Xe washout imaging offers excellent potential for early detection of BOS compared to early CT findings. Using 133 Xe washout imaging and MTT with radioactive tracer offers a non-invasive indication of selective ventilatory function in grafted lungs after LDLLT. MTT appears useful for identifying BOS after LDLLT and allows evaluation of graft function in bi-and unilateral lungs.

PET and CT evaluate of pulmonary nodules in an integrated PET/CT system W. S. Huang 1 , C. Y. Cheng 1 , C. Y. Chang 1 , C. S. Liu 2 , C. H. Ku 3 , J. K. Lee 4 ; 1 Department of Nuclear Medicine, Tri-Service General Hospital, Taipei, Taiwan;, Taipei, TAIWAN, 2 Department of Radiology, Tri-Service General Hospital, Taipei, Taiwan;, Taipei, TAIWAN, 3 School of Public Health, National Defense Medical Center, Taipei, Taiwan., Taipei, TAIWAN, 4 Dept. of NM, Chung Shan Med. Univ. Hosp., Taichung, Taiwan., Taichung, TAIWAN.

Aim: The FDG PET and CT have proved useful in evaluating pulmonary lesions. This study was performed to compare the respectively diagnostic power of PET and CT in the evaluation of single pulmonary nodules (SPN). Material and Methods: A total of 117 patients with SPN and without previous history of malignancy were analyzed. Of them, 66 with known SPN, the other 51 were accidentally found from a physical check-up. Both PET and CT images were independently interpreted and were graded by the 5-point scales as described (Radiology 1996; 200:135) . Equivocal PET and CT image (grade 2) were dealt with 3 conditions: 1) dropped, 2) regrouped in to positive results or 3) regrouped into negative results. Malignant diagnosis was based on histological findings or a clinical/ radiological follow-up at least 12 m. Four comparisons were applied to assess the performance including 1) CT; 2) PET; 3) test in parallel (CT or PET positive); and 4) test in series (CT and PET positive). We used Student's t test for univariate continuous variables and the 2 test for categorical variables and Fisher's exact test whenever the expected 2 value for at least one cell was <5 (SAS version 9.13, Cary, NC). Receiver operating characteristic curves were applied to calculate the areas under the curves of interest and for comparisons (MedCalc version 8, Mariakerke, Belgium). Results: PET yields 8 equivocal results, 4 of them had negative CT that turned out to be benign lesions. The other 4 patients had both equivocal PET and CT and two of them proved to be malignant. CT revealed 17 equivocal results, 7 were confirmed by PET as malignancy, the other 5 were benign. 10 out of the 17 CT equivocal lesions turned out to be malignant. Conclusion: PET and CT play synergic role in the combined PET/CT scanner. FDG PET produced less equivocal lesions. Combining interpretation of both PET and CT information helps resolve more than half of equivocal lesions. Key Words: 18 F-FDG; PET/CT; single pulmonary nodules Running title: PET/CT in pulmonary nodules Aim: To evaluate the situation of the work-up of patients with suspected pulmonary embolism at the national level especially in relation to the use of new diagnostic methods. Method: We used a questionnaire send to all nuclear medicine departments in the Czech Republic. Questions were selected to evaluate the methodology of the lung scintigraphy from the aspect of performance, results description, use of criteria and several time and quantitative parameters. We also asked about some concomitant and concurrent examinations. Results: 36/46 (78%) departments filled in and returned the questionnaire. As to methodology, the planar images (4 or 6 to 8 views) are mostly used; only 2 departments perform only SPECT. Lung perfusion scintigraphy is available only during working hours on working days; only in 1 department also on weekends. Ventilation scintigraphy is performed only selectively. In the assessment of images, mostly standardized criteria in combination with any own are used (predominantly modified PIOPED). Radionuclide venography is performed on all but 4 departments, thrombi imaging is not available at all. The number of perfusion scans declined yearly about 2%, ventilation scans increased about 10% and venography declined about 20% between years 2003 and 2005. CT scanners with less than 4 slices are mostly available for CT angiography. Conclusion: The main drawback of lung scintigraphy is its time unavailability and predominance of planar imaging. The increase of ventilation scintigraphy could be done by the effort to increase specificity. The decline of perfusion scans is not significant, although it could be done by the low quality of CT scanners. Long lasting exposure to toluene that is commonly used in automobile and spray paints, may cause in occupational asthma. In this study, we aimed to investigate the effect of toluene on Tc-99m clearance rate of alveolar epithelium and on spirometric lung function tests in auto painters who exposed to toluene at least for ten years. Twenty-eight autopainters with a mean age of 36.4±7.2 years and a healthy group with a mean age 33.7±8.7 were included in the study. Tc-99m DTPA aerosol inhalation scintigraphy, and spirometric lung function test was administered to all subjects. Clearance half time (T½) and penetration index (PI) on the first minute image after Tc-99m DTPA scintigraphy were calculated. T½ and PI values were (48.91±19.96 and 0.36±0.04) for painters, and (35.73±6.91 and 0.34±0.034) for healthy group, respectively (p=0.034, p=0.032). There was a negative correlation between mean T½ and %FVC, %FEV1 values (p=0.043, p=0.029, respectively). Whereas, a positive correlation was observed between mean PI and FEV1/FVC, %FEF25-75 (p=0.037, p=0.045). Comparison of PEF values between painters (416.51±146.52) and healthy subjects (507.64±119.51) yielded significantly different results (p=0.038). However, T1/2 and PI did not correlate with PEF. In painters group, T½ and PI significantly differed when painters with obstruction (49.50±8.06, 0.31± 0.04; respectively) compared with painters who did not have obstruction (43.91±9.08, and 0.36±0.03; respectively) (p=0.011, p=0.011, respectively). Toluene exposure duration did not show a relationship with T½, PI and SFT. Our results indicate that toluene exposure affects bronco alveolar permeability and may cause obstructive changes that might be demonstrated by SFT. However, we could not detect any relationship of toluene exposure duration with any parameter. To show if toluene exposure duration has any affect on occupational asthma development further studies are needed.

Technetium labeled Human Polyclonal Immunoglobulin G (99mTc-HIG) scintigraphy in the early detection of pulmonary involvement in Connective Tissue Diseases (CTD) considering analgesics as the first option. If these fail, other therapeutic options can be considered, including metabolic radiotherapy with 153 Sm as the greatest exponent. Aim: Evaluate 153 Sm treatment response in patients with painful bone metastases. Material and Methods: We studied 35 patients (26 men; 9 women) with ages between 10 and 86 years old (with a mean age of 60.4 years) with painful bone metastases resistant to analgesic therapy. 37 MBq/kg of 153 Sm were administrated intravenously. Each patient remained hospitalized for 6 hours in our Nuclear Medicine Unit in a room, conditioned for Metabolic Radiotherapy Treatments. Pain was evaluated following a visual scale before and after treatment (Considering: Total Response: improvement > 4 points; Partial Response: improvement 2 -4 points; No Response: improvement 2 points). Results: In 27 out of 35 patients (77%) an effective therapeutical response was observed. 11 of these 27 effective responses (41%) showed a total pain disappearance, while in the remaining 16 (59%) the pain was partially soothed. The therapy was repeated in 2 patients, obtaining an efficient response, similar to the previous one. Treatment was effective for 8 to 16 weeks (average: 13.6 weeks). No response was observed in 8 out of 35 patients (23%), including 3 patients who suffered sudden-deaths in where the response could not be evaluated. Conclusions: Treatment using 153 Sm may result effective in painful bone metastases resistant to analgesic therapy. If the symptoms reappear, a new dose would achieve equally satisfying results. Accurate interpretation of FDG-PET images requires optimal knowledge of the normal distribution of the tracer in various anatomical structures. This distribution may change due to age, gender, and physiologic conditions. Our aim was to assess cervical spinal cord FDG-PET uptake as a function of age and gender. Methods: Head and neck FDG-PET images of 65 subjects were retrospectively assessed (21 male, 44 female; age: 21-74 years). The subjects had undergone head and neck FDG-PET imaging for a variety of reasons. The subjects did not have any evidence of FDG uptake which could interfere with measurement of spinal cord uptake. The subjects had no previous history of chemotherapy and radiation therapy. FDG uptake in the cervical spinal cord was visually evaluated. Mean and maximum standardized uptake values (SUVs) of cervical spinal cord were calculated for all subjects with visible spinal cord uptake. Subjects were separated into three age groups, each consisting of two decades, and into two groups based on gender. One way ANOVA and t tests were used for statistical analysis to calculate the differences of mean and maximum values for age groups and for gender. Results: Amongst 65 subjects, 62 had visible cervical spinal cord FDG uptake. Three did not have visible cervical spinal cord uptake. The mean SUV ranged from 1.3-2.7, the maximum SUV ranged from 1.4 -2.9. Averages and standard deviations (SD) of the mean and maximum SUVs for age groups from the youngest to the oldest were 1.71 ± 0.33, 1.79 ± 0.41, 1.89 ± 0.29, and 1.98 ± 0.40, 1.95 ± 0.45, and 2.02 ± 0.26, respectively . Averages and SD of the mean and maximum SUVs for men were 1.86 ± 0.27 and 2.00 ± 0.24, respectively, and 1.75 ± 0.37 and 1.96 ± 0.43, respectively, for women. There were no statistically significant differences between the mean and maximum SUVs amongst age groups or between genders. Conclusion: These preliminary data show that FDG uptake within the normal cervical spinal cord is not affected due to aging or gender. Further studies are required to confirm our results and to determine the significance of this observation in normal and pathological states.

Fusion of near-isotropic spiral CT to 2D nuclear medicine data to improve the accuracy of ROI delineation in hepatobiliary and renal imaging B. Corcoran, M. Carroll, M. Buxton-Thomas; King's College Hospital, London, UNITED KINGDOM.

Objective In dynamic planar hepatobiliary imaging of auxiliary liver transplants and both dynamic and static renal imaging, regions of interest (ROI) are used to generate time activity curves (TAC) and to calculate the relative function of two organs. On the hepatobiliary image it is often difficult to differentiate the native and transplant livers. In both static and dynamic renal imaging, the edges of poorly functioning kidneys are often difficult to identify. The advent of high resolution spiral CT, available through PACS connectivity, now allows near-isotropic quality orthogonal images to be reconstructed. We use the coronal anatomical data to improve the delineation of the organs. Fusing the coronal data to nuclear medicine imaging allows the more accurate ROIs to be applied in generating the TAC and the calculation of physiological divided function. Method For calculation of divided function from the dynamic data a composite image of the uptake phase is created. On a HERMES workstation, orthogonal coronal sections are generated from high resolution spiral CT (transverse slice width = 0.74 mm, slice separation = 1.48 mm). A coronal section through the liver is chosen which clearly shows the division between the native and transplant. The summed CT image is fused, using mutual information rigid transformations, to the composite NM image. Accurate ROIs drawn on the CT image are then applied to the NM image and divided function is calculated from the relative regional counts. Result The method was applied to several patients undergoing sequential post-transplant hepatobiliary imaging (99mTc-IDA) where spiral CT of the liver was available. The CT data provided greater confidence in differentiating the two functional regions of native and transplant liver. The method has also been applied to the deconvolution analysis of renograms (99mTc-MAG3) and static renal scans (99mTc-DMSA). Conclusion In hepatobiliary investigations for monitoring liver transplants, coronal images generated from spiral CT can be used to improve ROI delineation in the calculation of relative function between native and auxiliary liver regions. The method has also been shown to have a useful application in the renal imaging of poorly functioning kidneys. With promising results from ongoing clinical trials, Alpharadin™ (Ra-223) looks destined to become commonplace in nuclear medicine. This paper aims to introduce the radiation protection requirements with Ra-223 to those less familiar in working with short-lived alpha emitters and dispel some common misconceptions. Traditional teaching of radiation protection has focussed on beta-and gamma-emitting radiation due to their more common application, ease of detection and less stringent regulations for handling open radioactive sources in the laboratory. As such, alpha-emitting radionuclides have traditionally been confined to research or use in sealed sources. In some countries, alpha emitters have developed an unwarranted reputation as a dangerous form of radiation. It is important to emphasise that alpha radiation only poses a radiation risk when long-lived alpha-emitting radionuclides become incorporated into the body and irradiate a small area of tissue for a long period. Outside of the body, there is a much lower risk when working with alpha radiation compared to beta radiation and working procedures are often simpler. Alpharadin™ is an alpha-emitting radiopharmaceutical in clinical development for tumour therapy and pain palliation in patients with skeletal bone metastasis. The alpha emitter Ra-223 does not have inherent properties that make it a dangerous radionuclide. On the contrary, radiation protection parameters for Alpharadin™ offer some significant advantages when compared to traditional beta emitters (Table1).

Comparison of radiation protection parameters for Ra-223, Sm-153 and Sr-89 Aim The purpose of this study was to analyse the radiation emergency triage, treatment and hospital protection procedures in London after the contamination of Alexander V. Litvinenko with the Polonium 210 in London 2006. Identifying strengths and weaknesses allowed us to draw conclusions for improved future radiation emergency management (REM) strategies particularily for hospitals. Materials We researched numerous public documents and conducted interviews with medical professionals at various hospitals involved in the case. Methods We reconstructed the sequence of emergency management procedures such as triage and the treatment of the patient as well as radiation protection measurements taken. We then identified key characteristics and compared them with typical hospital REM procedures for radiation victims. Furthermore, we then analysed the results in the light of radiation mass casualties to detect the weaknesses of current disaster management concepts. Results The medical effects of internal contamination with the radioactive isotope Polonium 210 was not immediately diagnosed. A treatment plan was applied rather late. The single case allowed an intensive care with technical resources and a number of medical professionals to diagnose the patient which would have been impossible if the number of casualties was higher. The psychological effects of the radiological contamination remained rather unclear. The patient died a few weeks later. The received dose and exact cause of his death (radiation vs. toxicity in particular) are still disputed. Conclusion Our research shows that the contamination with radioactive isotopes in general still remains a very unusual challenge for medical professionals. Even specialist hospitals confronted with cases of radiation poisoning are quickly taken to the limits of their diagnostic and treatment capacity. Only the concentration of medical specialists and the intense usage of resources could eventually help to diagnose the illness. We can conclude that other non-specialist hospitals would perform rather inadequately if confronted with the same case and much worse if there were more casualties of that kind. Future improved emergency management strategies will strongly rely on adequate, continuous and specialised training of hospital staff, appropriate equipment as well as communication and triage among hospitals. Aim: The aim of this study is to evaluate the efficiency of the radiation protection program of a department of nuclear medicine equipped with a PET and therapy units. Material and Method: The department has a workplace monitoring system. We calculate the mean dose of the radiation exposure levels that the workers were submitted in each part of the department and compare with the whole body dosimetry, during one year. The workplace monitoring system is a TAM radiation meter system from Tema Sinergy, Italy and consists on eight Geiger-Muller detectors with a dose rate range between 0,1 μSv/h and 0,02 Sv/h and an energy sensitivity from 50 keV to 1 MeV. The whole-body dosimeters are TLD. The eight detectors are installed in: radiopharmacy, waiting room for accompanying persons, waiting room for injected patients (at two points), room for injected patients, PET radiopharmacy, PET command room, and waiting room for pts injected with 18F-FDG. The monitoring data of each main area is compiled in a 24 hour database. Results: The monitoring results, in each area per year were: Conclusions: When compared with each other, we conclude that the results match: the mean dose in the main areas where the workers usually are and the whole body values. The mean dose for the area monitoring system was 4,36 mSv/year and the mean dose for the whole body dosimetry was 2,16 mSv/year. These results are in the scope of the National legislation and the European Regulation of Radiation Protection and are demonstrative that we are working in good conditions of radiation protection. Since several years, our Department of Nuclear Medicine works with the Department of Haematology in the field of radioimmunotherapy of non Hodgkin lymphomas using antibodies (anti CD 20 ZEVALIN® Schering-Bayer, anti CD 22 Immunomedics) labelled with high activities of Yttrium 90 (Y 90) (CIS Bio International and Nordion). The manipulation of such activities of a ß-emitter can induce a great exposure of the hands of the personnel when appropriate radioprotection procedures are not applied. At the beginning, we used the radioprotection material present in our laboratory, but with increasing experience we added some improvements in our practice: -Use of a shielded suit -Use of an electric infusion pump for ZEVALIN® administration -Use of radiation attenuating gloves for ß-emitters -Use of a radioprotection kit in polymethyl-methacrylate (PMMA) supplying by Schering-Bayer -Local production of a PMMA protection box for the perfusion of the anti CD 22. Material and methods: *In 2005, an electronic dosimeter was placed under the gloves at the palm of one hand of the radiopharmacist during these steps. *In 2006, more precise studies were made with TLD chips placed at the palm and at the extremities of the thumb and the index. day, and is a minimally necessary criterion of agencies that accredit Nuclear Medicine laboratories. Tracking trends in daily QC on a monthly basis is helpful in detecting developing camera problems, which if addressed in a timely manner, will avoid unnecessary unscheduled camera downtime and maintain image quality. Increasingly, the environment in which hospitals and clinics operate is through consortiums, which, by virtue of their design, necessitate the development of standardized, uniform means of detecting and documenting problems and methods of solving these problems. We have implemented algorithms written in a version of Visual Basic on commercial nuclear medicine computers to analyze intrinsic and extrinsic flood uniformity values for a wide range of gamma camera models from various manufacturers. These algorithms use data transmitted via ethernet among 3 sites using the Dicom standard. Computed parameters include integral and differential uniformity values for full field of view and central field of view regions of interest, which are generated automatically and are tailored to each detector type. Output values are stored automatically in ASCII files, which are updated each time the analysis programs are run. The display format of flood fields is adjusted automatically for as few as 1 up to as many as 8 simultaneously displayed individually normalized flood fields for flexibility of recording floods on film. Algorithms written in Mathcad (Mathsoft, Inc.) further analyze the resultant ASCII files, segregating uniformity values for each detector of each camera in groups of monthly values, deleting duplicate records, plotting uniformity versus date curves, identifying values that exceed predetermined action levels and tabulating the number of times a detector does not meet standard criteria, prompting required attention for uniformity problems. A Microsoft Word file is generated automatically as a permanent record. These sets of algorithms have been instrumental in providing an ongoing method of guaranteeing standardized high quality imaging at different sites and facilitating certification by accreditation organizations. Aim: To fully implement alternative services that Internet offers to the easy transfer of complete patients' examinations. Prosperity of easy interchange in every day practice of Nuclear Medicine found its application through the Internet media. We use a simple and safe way to interchange images and diagnostic information between the scintigraphic acquisition and processing location and the clinical department in order to improve patient's health care and young doctors' education. We present our experience in transferring patient data, SPECT slices, 3D SPECT images in video (movies) form and animation display to medical specialists. Materials and Method: Images and patient reports are transferred and saved through dedicated software to a workstation that transform gamma-camera scintigraphic images in a PC readable format. The data are transferred to the local server PC via a Local Area Network -in which the medical system computer is also included-and are modified by Procyon Starlab GE software to BMP type image files. SPECT slices and/or 3D processed SPECT images as well as dynamic or gated studies can be send to the connected PC. Medical record data are combined with the images and movies in a hypertext file that can be sent as an attachment via an e-mailer functioning under Windows environment. The receiver side should be equipped with a similar e-mailer and can view or print patient's set of images and data through a suitable browser. The mailed series of images are characterised by diagnostic quality analogous to that of the original sets that someone can see as simple series or in a cine form of tomographic slices, dynamic studies and 3D images in a gamma camera. Results:Transfer via e-mail has been used in our center for the exchange of complete studies including data, images and movies to and from our colleagues when particular patients are concerned. Furthermore, both patients' files and educational files can be downloaded, from our department ftp location, by a unique password. Conclusion: A full patient template transfer enables the archiving of particular files from the authors' Institute database ensuring the security desired and it has been proven to be a quick and safe mean of exchange of dynamic set of Nuclear Medicine Information between physicians and scientific centers. Usual WWW connection gives the possibility of patients' data transfer as well as interchange of relative comments towards both directions. Cost effective solution has been achieved using standard hard-and software.

Picture archiving and communications system: A convenient connecting point between Nuclear medicine and Radiology for higher specifity K. F. Wurm, M. Zobel, B. Clewing; Department of Radiology and Nuclear Medicine, Göppingen, GERMANY.

Aim: Picture archiving and communication system (PACS) has become an important component of many radiological departments. The major benefit of PACS based on its ability to communicate images and reports to different physicians in a short and common modality. The aim of our study was to create the benefit for nuclear medicine results using PACS as the connecting point to additional radiological images. Material and methods: In a period of 6 months we investigated 100 patients with different bone lesions, metastases and inflammatory deseases. All patients underwent bone scintigraphy with 99mTc-HDP. All images were evaluated and adjudged. In a second view the additional informations of radiological issues using PACS were documented. Results: 76/100 patients presented an area with increased focal activity in bone scintigraphy. Using the early pictures after 10 min. additional pathological results could be detected. In correlation with radiological images using PACS 14 cases are documented as an unambiguous benign lesion, previously adjudged as a suspected area. 12/76 cases were adjudged as a benign lesion, however using PACS pathological lesion were documented. Conclusion: The progressive spread of Picture archiving and communication System (PACS) in medical imaging constitutes some of the most common changes in the radiological and hospital activities during the last decade. Using PACS as the connection point between radiological and nuclear medicine images both department have a benefit and the numbers of false positive/false negative results are reduced. PACS creates a synergy that will be otherwise only realized using SPECT/Spiral-CT Hyprid imaging.

Uptake of Technetium-99mdimercaptosuccinic acid in Cats E. Vandermeulen 1 , A. Dobbeleir 1 , H. Ham 2 , A. Piepsz 3 , T. Waelbers 4 , S. Vermeire 1 , K. Peremans 1 ; 1 Department of Medical Imaging of Domestic Animals, Faculty of Veterinary Medicine, Ghent University, Ghent, BELGIUM, 2 Department of Nuclear Medicine, University Hospital, Ghent, BELGIUM, 3 Saint-Pierre Hospital, Brussels, BELGIUM, 4 Department of Medicine and Clinical Biology of Small Animals, Faculty of Veterinary Medicine, Ghent University, Ghent, BELGIUM.

Aim: The purpose of this study was to calculate the fractional uptake (FU) of technetium-99m dimercaptosuccinic acid (Tc 99m -DMSA) in cats at 2, 4 and 24 hours and to test the influence of prone compared to supine positioning on the FU due to flexible kidney position in cats. Material and Methods: A total of 20 cats were injected with a mean dose of 146,5 MBq Tc99m-DMSA. The cats were anesthetized (induction with propofol, maintenance with isoflurane on oxygen) and anterior and posterior images were acquired in prone position at 2, 4 and 24 hours after injection. ROIs were placed over the kidneys and the geometric mean kidney activities calculated. Additionally, a second anterior and posterior view was acquired with a calibrated source positioned between the kidneys. The calibrated source activity was obtained by substraction of the activities in a large ROI on both anterior views. This was repeated for the posterior views, and the geometric mean of the calibrated source was calculated. From the posterior and geometric mean activity, the attenuation correction value can be calculated. The kidney uptake was calculated from the geometric mean of kidney counts and the attenuation value. After decay correction the uptake was expressed as a fraction of the injected dose (FU). In 10 cats these tests were repeated in the supine position. Results: The mean values of FU in cats scanned in prone position were 0.164 ± 0.071 for the left kidney and 0.151 ± 0.079 for the right kidney at 2 hours. FU values at 4 and 24 hours were respectively 0.175 ±0.076, 0.195 ± 0.074 for the left kidney, 0.162 ± 0.090 and 0.175 ± 0.080 for the right. In supine compared to prone position, a small but systematic lower FU was observed: the difference being 0.016 at 2 hours, 0.010 at 4 hours and 0.006 at 24 hours. Conclusion: Fractional uptake of 99mTc-DMSA can be calculated up to 24 hours. A small uptake increase is observed over time. Using the method of geometric mean minor differences were obtained in prone and supine position. This difference decreases at 24 h, which might indicate a higher background contribution in prone position. Organotypic slice cultures (OSC) of human brain specimens represent an intriguing experi-mental model for translational studies addressing, e.g., stem cell transplantation in neurodegenerative diseases or targeting invasion by malignant glioma ex vivo. However, long-term viability and phenomena of structural reorganization of human OSC remain to be further characterized. Here, we report the use of the positron emission tomographic radiopharmaceutical F-18-deoxyglucose (FDG) for evaluating the viability of brain slice preparations obtained either from postnatal rats or human hippocampal specimens. Anatomically well preserved human hippocampi obtained from epilepsy surgery (n = 3) and rat hippocampus slice cultures obtained from six day old Wistar rats (n = 6) were dissected into 350 μm horizontal slices using a vibratome. All slices where placed onto interphase nylon culture plate inserts, subsequently transferred into six-well culture dishes containing 1.2 ml of culture medium and kept in a humidified atmosphere at 37°C and 5% CO2 for at least 3 days. The slices were incubated with 1 -10 MBq FDG in phosphate buffered saline up to 1 h, either with or without supplementation of glucose at a concentration of 2.5 mg/ml. Radioactivity within the medium or slice cultures was measured using a gamma-counter. In addition, distribution of radioactivity was autoradiographically visualized and quantified as counts per mm2 tissue per MBq FDG (CD) for the whole slice. All experiments were carried out at least in triplicate. In rat hip-pocampal slices, FDG accumulated over 60 minutes with a doubling time of approximately 30 minutes and reached 1,300,000 ± 68,000 counts/mm2, whereas the incorporation of the radioactive label in human slices was in the order of 1,500,000 ± 370,000 counts/ mm2. The elevation of glucose concentration within the medium led to a significant three-fold decrease of FDG accumulation in rat slices and to a 2.4-fold decrease in human specimens. In conclusion, FDG specifically accumulated in organotypic brain cultures of human or rodent origin. FDG is thus suited to investigate the viability of OSC. Furthermore, these preparations open new avenues to study the factors governing cerebral FDG uptake in normal and diseased brain tissue ex vivo.

Changes in metabolism and gene expression in hepatomas expressing antiangiogenic genes U. Haberkorn 1 , J. Hoffend 1 , A. Altmann 1 , K. Schmidt 1 , A. Dimitrakopoulou-Strauss 2 , L. Strauss 2 , M. Eisenhut 2 , R. Kinscherf 1 ; Purpose: Human troponin I (TROP), the soluble receptor for vascular endothelial growth factor (sFLT) and angiostatin (ASTAT) are potent inhibitors of endothelial cell proliferation, angiogenesis and tumor growth in vivo. Transfer of these genes into tumors may induce changes not only in perfusion, but also more general ones such as changes in metabolism. Experimental Design: After generation of Morris hepatoma (MH3924A) cell lines expressing TROP, sFLT or ASTAT we quantified 18 Ffluorodeoxyglucose ( 18 FDG) uptake by dynamic positron emission tomography (PET) after tumor inoculation in ACI rats. Furthermore, expression of glucose transporter-1 and 3 (GLUT-1; GLUT-3) as well as hexokinase-1 and -2 were investigated by RT-PCR and immunohistomorphometry. In addition, changes in gene expression were measured using gene arrays. Results: FDG uptake, vascular fraction and distribution volume were significantly higher in all genetically modified tumors. Immunohistomorphometry showed an increased percentage of hexokinase-1 and -2 as well as GLUT-1 and -3 immunoreactive (ir) cells. Using gene arrays and comparing all three groups of genetically modified tumors, we found changes in expression of 36 genes related to apoptosis, signal transduction, stress or metabolism. Conclusions: TROP, sFLT or ASTAT expressing MH3924A tumors show enhanced influx of 18 FDG, which is caused to several factors: enhanced exchange of nutrients between blood and tumor, increased amounts of glucose transporters and hexokinases and increased expression of genes related to apoptosis, matrix and stress which induce an increased demand for glucose.

A. Altmann 1 , K. Schmidt 1 , J. Hoffend 1 , A. Dimitrakopoulou-Strauss 2 , L. Strauss 2 , M. Eisenhut 2 , R. Kinscherf 1 , U. Haberkorn 1 ; 1 University Hospital, Heidelberg, GERMANY, 2 DKFZ, Heidelberg, GERMANY.

Purpose: Growth of malignant tumors is dependent on sufficient blood supply. Thus, inhibition of tumor angiogenesis is emerging as promising target in treatment of malignancies. Human calreticulin (hCRET) is a potent inhibitor of basic fibroblast growth factor (bFGF)-induced endothelial cell proliferation in vitro and bFGF-induced angiogenesis and tumor growth in vivo. Experimental Design: To obtain more information about functional changes in the angiogenic process we established Morris hepatoma (MH3924A) cell lines expressing hCRET (hCRET-MH3924A). The effects of hCRET expression on proliferation and apoptosis of human umbilical vein endothelial cells (HUVECs) were measured in co-culture experiments in vitro. To evaluate changes in tumor perfusion H 2 15 O was used for positron emission tomography studies in vivo. Additionally, immunohistological quantification of vascularization, apoptosis and proliferation as well as gene array analyses were performed. Results: The in vitro experiments demonstrate reduced proliferation and increased apoptosis in HUVECs when being co-cultured with MHhCRET cells. In support, tumor growth of MHhCRET is diminished in vivo together with a reduction in PCNA staining and an increase in apoptosis as determined by immunohistology. However, tumor perfusion and blood volume are increased in hCRET-MH3924A corresponding to an increased microvessel density. Furthermore, hCRET-transfected tumors show changes in expression of genes related to angiogenesis, apoptosis, stress, signal-transduction and metabolism. Conclusions: hCRET expression leads to inhibition of tumor growth, increased apoptosis and changes in the expression of multiple genes involved in angiogenesis, stress reactions, signal transduction and apoptosis which indicates a multifactorial reaction of tumors. An enhanced microvessel density is seen as part of these reactions and is associated with increased perfusion as measured by PET. Aims Progressive improvement in the noninvasive imaging of different tumor associated antigens has lead to study a series of pancarcinoma radioligands. Among them, monoclonal (radio) antibodies for cell adhesion molecule integrin v 3 occurring on both the tumor and endothelial cells that line tumor infiltrating blood vessels has recently gained widespread support from preclinical trials in our laboratories. In this study, this effort continues by applying iodine 131 ( 131 I)-labeled monoclonal antibody to visualize and quantify the subunit 3 of integrin v 3 in three histologically different types of murine tumors. Material and Methods Monoclonal antibody anti-CD 61 (2C9.G2) against the subunit 3 of the integrin v 3 was directly labeled with 131 I using a standard iodogen method. The radiochemical purity of the resulting mAb-131 I of 99% was achieved in a reaction time just after the iodination, and 95.6 and 93.7 %, respectively after 2 and 24 hr post-labeling. The diagnostic value of the mAb-131 I radiotracer was elucidated by planar scintigraphic imaging followed by quantification of the tumor integrin subunit 3 level in male C57BL/6, C3H and BALB/c mice 3 wk after s.c. inoculation of the syngeneic Lewis lung (LLC), breast or sarcoma (L1) murine cancers, respectively. The imaging and biodistribution studies of the mAb-131 I radiotracer were done 24 hr after a single intravenous injection of 4 to 50 μg mAb-131 I in tumor-bearing mice. Results The transplanted tumors expressing the subunit 3 of the integrin v 3 were visualized on the scintigraphic images of all the examined murine tumor experimental models. On the images the liver and kidneys and the bladder were also the organs with the highest activity levels, illuminating the renal excretion pattern of the radiolabeled tracer. Muscle, brain and skin tissues had relatively low activity uptake. Biodistribution analysis, studied 24 hr after 10 μg mAb-131 I injection, revealed a quite similar profile of the tumor-to-muscle count ratio (T/M) of 9.73; 9.56 and 9.45 for LLC, breast and L1 tumors, respectively. The tumor-to-non tumor ratio (T/NT) for selected organs was increased with increasing the radiotracer dose up to 20 μg. The binding potential extrapolated from the graphical analysis of scintigraphic data correlated well with the biodistribution studies. Conclusion The present study showed that the radiolabeled monoclonal antibody, mAb-131 I that binds to the 3 subunit of the v 3 integrin, is able to target and image murine tumor tissues independently of their histological origin.

Phage display for the identification of a hepatoma binding peptide T. Prenzel 1 , A. Altmann 1 , W. Mier 1 , S. Krämer 1 , M. Eisenhut 2 , U. Haberkorn 1 ; 1 University Hospital, Heidelberg, GERMANY, 2 DKFZ, Heidelberg, GERMANY.

Hepatocellular carcinoma (HCC) is usually diagnosed at a late stage and has a high recurrence rate after resection. Increasing the concentration of chemotherapeutics in a carcinoma and thus lowering the side effects for the organism is a problem in the diagnosis and therapy of HCC. A prerequisite for a specific accumulation in the tumour are molecules with a high binding affinity for tumour cells. Due to their small size peptides are very useful tracers showing easy penetration into tumor tissues. The aim of this work was the identification of peptides with high affinity for hepatoma cells using different selection conditions. Methods: We used a 12 amino acid phage display library to identify hepatoma specific peptides. This libraray was exposed to HepG2 cells. Six peptides with the selected amino acid sequences were synthesized by solid phase peptide synthesis and radiolabelled with radioactive iodine. The properties of these peptides were evaluated by in vitro binding experiments. Furthermore, a biodistribution study was performed in tumor bearing mice. Results: Five of the six peptides showed low binding to HCC cells. The linear peptide E7 with positive binding was investigated by further studies. In in vitro binding experiments these cells showed the highest peptide binding rate after ten minutes with no evidence of internalization. Competition experiments demonstrated that binding of I-125-E7 was reduced by the addition of unlabeled peptide. E7 binds weakly to HuH7 cells and primary human hepatocytes. The half life determined in human serum was more than one hour. Peptide degradation products were isolated and characterized by mass spectrometry. We assume a a rapid deiodation and breakage of ammonium early after incubation start. Biodistribution studies of E7 in Balb/c nu/nu mice carrying HepG2 tumours revealed a two-fold higher E7 accumulation in the tumour as compared to the liver. Conclusions: The peptide E7 showed some properties that make it a possible carrier for liver cancer imaging or the delivery of isotopes or drugs to hepatocellular carcinomas. Further investigations will be necessary in order to characterise the value of E7 and its derivatives. Purpose: Histone deacetylase (HDAC) inhibitors trigger differentiation, decrease cell proliferation and induce apoptosis in tumor cells. Furthermore, they seem to act selectively to alter transcription of fewer than 2% of expressed genes. Suberoylanilide hydroxamic acid (SAHA) is a new HDAC inhibitor used in phase I/II clinical trials. In order to determine whether there is preferential tumor accumulation of SAHA we studied the uptake of the drug in 3 sensitive tumor cell lines. Experimental Design: After labelling of SAHA with iodide a MTT assay was done to assess the effects of iodination on therapeutic efficacy in different tumor cell lines (thyroid carcinoma, hepatoma, colon carcinoma). Therefafter, uptake, competition and efflux studies were done using I-125 labeled SAHA. Finally, a biodistribution study was performed in tumor bearing mice. Results: Iodinated SAHA analogs showed equal toxicity as compared to unmodified SAHA. The uptake of I-125-SAHA was time dependent with a plateau at 1 h and was inhibited by the presence of unlabeled SAHA with IC50 values around 800 nM. Furthermore, a rapid efflux was observed with a 60% decrease of intracellular activity after 10 minutes. The biodistribution study showed high accumulation in liver and kidney and a moderate accumulation in the tumor. Also a rapid washout was seen with 2.9%ID/g and 0.13%ID/g in the tumor at 1 h and 4h after tracer administration, respectively. The tumor to organ ratios were highest for brain 3 and for for 1 h and 4 h) and muscle (1.6 and 2.3 for 1 h and 4 h). Conclusions: Iodinated SAHA showed rapid efflux and no preferential tumor accumulation. For therapeutic activity tumor selective uptake may be not a necessary condition. Rather low amounts of the drug seem to be sufficient to change the balance between acetylated and non-acetylated histones in a manner that leads to differentiation, inhibition of proliferation and apoptosis.

Radiolabeling and biodistribution of PKF115-584, an inhibitor of the Wnt signalling pathway U. Haberkorn 1 , W. Mier 1 , M. Eisenhut 2 , B. Beijer 1 , A. Altmann 1 ; 1 Univ.Hosp., Heidelberg, Germany, 2 DKFZ, Heidelberg, Germany.

The Wnt signalling pathway plays key roles in cell fate specification, CNS patterning and control of asymmetric cell division. Constitutive Wnt signalling is observed in many tumors including colorectal carcinoma where >90% have an activating mutation of the Wnt canonical pathway leading to an accumulation of beta-catenin. The binding of beta-catenin to TCF4 represents a promising target for therapy and could be used for imaging of the Wnt signalling pathway. Methods: After labeling of PKF115-584, a small molecule interfering with the beta-catenin/TCF4 interaction, with I-125 we performed uptake studies in vitro using two human anaplastic thyroid carcinoma (C643 and SW1736) and two human colon carcinoma (HCT116 and CaCo2) cell lines. Efflux experiments were done with SW1736 and HCT116 cells. Finally a biodistribution study with I-131-PKF115-584 was performed in tumor bearing mice. Results: We observed a time dependent uptake with a plateau after 1 h incubation with a higher uptake in the thyroid carcinoma cell lines as compared to the colorectal carcinoma cells. No significant efflux was seen during the first 30 minutes after incubation of the tumor cells. The biodistribution study revealed different values with 5%ID/g for SW1736 tumors and 4.1%ID/g for HCT116 tumors at 1 h after tracer administration. This uptake was followed by a decrease in activity with 3%ID/g and 1.8%ID/g at 2 h and 4h for SW1736 and 2.9%ID/G and 0.9%ID/g at 2h and 4h for HCT116. Tumor-to blood ratios at 1h were 19 for brain, 4.5 for muscle and 1.6 for liver at 1h for SW1736 tumors. These remained stable until 4 h. Similar data were obtained for HCT116 tumors. Conclusions: Iodinated PKF115-584 may be used as a tracer for the visualization of Wnt signalling. However, at present its exact binding site -beta-catenin, TCF4 or the complex of both -remains to be elucidated.

Preparation and in vitro evaluation of 99mTc-HYNIClactadherin as a potential radioligand for apoptosis detection studied. They were divided into three groups randomly: ASON, SON and ASONblocked group. PCNA ASON and SON were both radiolabeled with 99m Tc after being coupled with HYNIC and were injected to the former groups respectively, and the latter were given unlabeled ASON before the injection of 99m Tc -HYNIC-PCNA ASON as control. Then scintigraphy experiments were performed on all the objects. After the last imaging session, the animals in the first group were sacrificed and their aortic arteries were removed for ex-vivo scan. Moreover, the arteries were dissected into segments for well counting, pathological examinations and PCNA staining. Results: Abdominal aortas of all the rabbits could be seen soon after the injection. However, accumulated radioactivity was observed only in the rabbits in the first group 2 hours later, and the count ratios of the lesion to the background of the abdomen were 2.75 ± 1.03 while 1.31± 0.08 for vessels of the SON group (P < 0.01) and 1.27 ± 0.03 for the blocked group (P < 0.01). The ex-vivo scan of the arteries revealed good correlation of tracer accumulation. The atherosclerotic lesions were predominantly of American Heart Association class II. The percentages of injected dose for the plaque and non-plaque vessels were 0.042±0.10 and 0.022±0.07, respectively (P < 0.001). The PCNA index was (72.25 ± 8.02) % and (3.39 ±9.28) %, respectively (P < 0.001). There is a significant correlation between these two sets of data by regression analysis(r=0.66, P< 0.05). Conclusion: 99m Tc-PCNA ASON scintigraphy can reveal the abnormally increased radioactivity of the lesions of the atherosclerotic arteries in rabbit model and it has potential to be used to diagnose the atherosclerosis noninvasively. Objective: The aim of the study was to determine the location and range of FDG uptake in knee joint and to detect the influence of aging on FDG uptake. Methods: Thirty seven patients (age range 23-82 years, 21 M and 16F) who had FDG PET which included lower extremities and who had no known disease of the knee joints were included. Maximum Standardized uptake value (SUV max) was measured by placing regions of interest (ROI) around the medial, lateral synovia, joint space, entire knee and patello-femoral joint in all the subjects. Several ROI's were placed on adjacent axial slices in the above mentioned regions of interest and average SUVmax for each region of interest for both knees was calculated for all subjects. Analysis of SUVmax was carried out for the effects of age. The correlation of knee FDG uptake with aging was also determined. Results: There is positive correlation between SUVmax measurements in all knee compartments and age where the r (Pearson correlation) measured 0.4 for all regions of the knee (p<0.05). The most affected part of the knee by age was the medial synovium where the p value was less than 0.01. The average SUVmax ± Standard Deviation (SD) for medial, lateral synovia, joint space, entire knee and patello-femoral joint was 0.75±0.2, 0.76±0.2, 0.69±0.2, 0.85±0.2 and 0.5±0.2 respectively. Conclusion: There is significant correlation between age and metabolic activity in different regions in the knee and effects of aging was noted most in the medial synovium. The increased FDG uptake in the knees with aging may be secondary to cumulative effect of weight bearing on knee joints with increasing age. The increased metabolic activity can also be secondary to inflammation associated with degenerative joint disease, the incidence of which also increases with normal aging. Further studies to investigate the role of FDG-PET in aging and related disorders such as degenerative joint disease would be of further value in clarifying the nature of our finding.

to increased metabolic activity. Brown fat occurs often in the supra-clavicular region and the increased FDG uptake can complicate the interpretation of the PET-studies. Materials and Methods: A thin, 13-year-old girl with the diagnosis of malignant melanoma was PET/CT scanned with 272 MBq 18F-FDG (intravenous injection while supine). After injection, she continued resting supine for 30 min and was scanned 60 min post injection. The scan showed an extremely high uptake in the brown fat. The scan was performed during the winter months where the patient was exposed to cold temperatures and a new scan was requested. Three months later, a new scan was performed where a more envolved pre-scan preparation was prescribed for the day of the examination. The patient was instructed to keep warm from the time she woke up and during transportation to our PET centre. After arrival, she was kept warm, 1 mg oral Diazepam was given, and she rested supine 30 min prior to injection of 293 MBq 18F-FDG and 30 min after. The last 30 min she was allowed to sit, but still kept warm and the scan was performed 60 min post injection. Results: The first PET scan demonstrated a very high uptake of FDG in brown fat in the chest and neck area and the scanning could not be optimally reported. The second scan was without brown fat uptake and was clinically relevant in following the patient's illness. Conclusion: Planning and simple preparatory procedures like keeping warm prior and throughout the whole injection/uptake process and a comfortable room temperature are important to avoid increased FDG uptake in the brown fat. Muscle relaxing medication like Diazepam can be useful if the patient is nervous or agitated. Fused PET/CT images aids in image interpretation and it is often possible on axial slices to differentiate between brown fat, muscle and lymph nodes. However, it is important to prevent uptake in brown fat as much as possible to avoid confusion between pathologic and physiologic activity. The 131-Iodine whole body scintigraphy has high sensitivity for the detention of bone, lymph nodes, and pulmonary metastasis of differentiated thyroid carcinoma, in particular when acquired after the administration of therapeutical activities. But if this scintigraphic images supplies functional information, sensible and precocious, possesses, on the other hand, slight anatomic detail, not allowing to locate the source of the pathological alteration. To get an anatomic reliable reference of areas of hyperfixation of 131I detected in the whole body scintigraphy after therapy, it might be an advantage to have a simultaneous acquisition of bone scan with 99mTc-MDP and 131I. Aim We intend to describe the technical procedure and to present some images resultant from the application of this protocol to 6 patients with thyroidectomy, for differentiated thyroid carcinoma, for localization of focal hyperfixations detected in the 131I whole body scintigraphy after ablation therapy. Materials and Methods In the whole body scintigraphys acquired 7days after the administration of the therapeutical activities of 131I, were detected focal hyperfixations of 131I in the thorax that, for its localizations, could involve pulmonary or bone structures. After 2hours of the administration of 99mTc-MDP, were acquired, simultaneously in the peak of energy of the two radioisotopes, whole body scan, segmentary images of the thorax and, in some cases, thorax SPECT. It was used a Gamma Camera Siemens E-Cam DCR dual-head, equipped with high energy collimators. Before the reconstruction of the tomographic studies, we added the corresponding plans of each isotopes. The visual analysis of the segmentary images was facilitated by the use of a software that allows to overlap the images of the two isotopes and to individually vary the brightness and contrast scales of each one of them. Results The analysis of the acquired images allowed to verify that the 131I focal hyperfixations found in the 6 studied patients were secondary lesions in the bone. Conclusion The simultaneous acquisition of bone scintigraphy with 99mTc-MDP and 131I whole body scintigraphy, in double window of energy, with the help of a processing commercial software, allowed the anatomic localization of areas of focal hyperfixation of 131I, contributing for the orientation of the patients later imagiologic studies.

In-111 labelled Octreotride and SPECT/CT image fusion from two seoarated equipments -clinical case i. paula, t. coutinho, a. fonseca, l. pereira, l. bastos; instituto portugues oncologia, porto, PORTUGAL.

Aim: In-111 labelled Octreotride (Octeroscan TM ) is used for imaging somatostatin receptor expression in tumours and their metastases. Precise location of the lesions is quite difficult and the SPECT/CT image fusion can improve accuracy and provide additional information on the anatomic location of increased uptake of Octeroscan TM . This clinical case illustrates that the registration and fusion of images from independent acquisitions by SPECT and CT can be useful in the location of increased uptake of Octeroscan TM , and shows the benefit of the resultant images when compared with the conventional whole-body SPECT. Material and Methods: We show the case of a 68 years old female patient with suspected neuroendocrine tumour. A whole-body scan with MIBG I-123 plus a whole body SPECT Octeroscan TM scan (E-Cam Siemens) and CT images (Biograph 6 PET/CT by Siemens) were acquired. The SPECT and CT scan were performed sequentially with 3 perforated PMMA markers with approximately 30 mm 3 with 2 to 3 MBq of Tc-99m, which can be seen both in transmission and emission tomographic images, attached to the skin over the bilateral iliac crests and the sternal furcula. The reconstruction of the SPECT and CT raw data as well as the manual registration and fusion of both sets of images was made with the Syngo Siemens software based in invariability of the position of the Tc99m markers relative to the patient body. Results: Whole-body scans with MIBG I-123 were negative. First Octeroscan TM whole-body scan showed only two small lesions in the upper abdomen and in the bowel. The second Octeroscan TM whole-body scan and SPECT images showed abnormal uptake sites but only SPECT/CT fusion images showed the exact location of the metastases in the upper abdomen, bowel, liver, upper mediastine and a small lesion on the right breast (suspicious of breast cancer). Conclusion: This case illustrates the benefit of SPECT/CT Octeroscan TM and the usefulness of combining SPECT and CT images from two separated devices without a dedicated SPECT/CT device. We show that SPECT/CT fusion images has a clear advantage over conventional whole-body scan and can lead to a more precise lesion location in the case of Octeroscan TM somatostatin receptor expression.

The effect of activity outside the field of view in estimation of human neuroreceptor binding with PET.

T. Shiraishi, M. Shidahara, K. Tanimoto, A. Ando, T. Miyamoto, R. Koganezawa, H. Fukuda, K. Watanabe; National Institute of Radiological Sciences, Chiba, JAPAN.

Objectives: To estimate the binding of radioligands for neuroreceptors, quantitative analysis using dynamic PET scan data of target regions with a reference region in the brain is the traditional strategy to estimate the binding of radio-ligands for neuroreceptors. In the study estimating the binding potential (BP) of dopamine D2 receptor, high activities were sometimes observed in lung, liver, gallbladder, intestine and urinary bladder, as well as in the brain. Those activities accumulated in the tissues outside of field of view (FOV) have effect on quantification of PET scanner as noise, especially on the reference region owing to non-existence of dopamine D2 receptor. In this study, we analyze the effect of the activities outside of FOV on BP value using 2D and 3D acquisitions. Methods: PET scanning was carried out using CTI-Simens ECAT EXACT HR+. We prepared the high activity (12kBq/ml) phantom used as the activity of target region and the low activity (3kBq/ml) phantom used as the activity of reference region. Both of them were filled with 68 Ge-68 Ga source, and another phantom filled with 18 F solution (220MBq) was fixed outside of FOV as the noise. After 10min pre-injection transmission scan, PET scans were performed with 2D and 3D modes under decaying the radio-activity outside of FOV. The PET scan at decaying radio-activity outside of FOV to a background was used as ideal scan. ROIs were placed on target and reference region, BP values were calculated with the ROI values. Results: The radio-activity of reference region was +1.5% higher compared to that of ideal scan in 3D mode. In 2D mode, by the contrast, the increase of radioactivity of reference region were +0.5%. As for the BP value, the decrease of BP value compared to that of ideal scan was -2.9% in 3D mode, while that of 2D was -0.7%. The coefficient of variation (CV) of BP values in 3D mode was obviously higher than that of 2D due to the radio-activity outside of FOV. Conclusion: Based on our analysis, it is clear that the BP values were underestimated due to increase of the radio-activity outside of FOV, especially in 3D mode. Furthermore, because of radioactivity outside of FOV, the BP values of 3D mode were varied widely, while BP value of 2D was stable. These results indicate that human neuroreceptor PET studies estimating BP values should use 2D acquisition mode to suppress the effect of radioactivity outside of FOV. Abstract DaTSCAN is a diagnostic tool used routinely to differentiate patients with Parkinson's disease from those with essential tremor. By using 123 Iodine labelled Dopamine Active Transporter proteins to image the pre-synaptic striatal uptake in the basal ganglia region of the brain. Data suggests DaTSCAN has 97.5% sensitivity in differentiating between Parkinson's disease and Essential Tremor Aim To investigate whether the clinical diagnosis of patients whom present with Parkinson's Syndromes would be affected depending on if the images were analysed using a qualitative or quantitative method. To assess the difference in the image interpretation of 3 separate health care professionals. Methods A blinded anonymous retrospective analysis of 50 patient studies was interpreted by; 1. Consultant Radiologist 2. Experienced Clinical Technologist 3. Trainee Clinical Technologist The results were compared with the original clinical report by a different radiologist. Each study was interpreted twice at different times, using; a) Qualitative analyses of image b) Quantitative analyses using proprietary software. Results Table 1 N/A software references to a normal range so there is no equivocal range. A mismatch was when operators report disagreed with the original report. The qualitative data shows that 2 of the 3 operators are fairly comparable with the original clinical report. The radiologist had mismatched the report with original report in 2 (4%), technologist 8 (16%) and trainee 5 (10%). The quantitative and qualitative results for the technologist show a large difference and are possibly due to the operators ROIs. The radiologist and trainee appear to have good agreement between qualitative and quantitative results. Further analysis comparing the studies original report with an abnormal quantification result hence mismatch with the original report indicated radiologist 10 (20%), technologist 20 (40%) and trainee 21 (41%). Conclusion Qualitative assessment results indicate less variability between each grade of operator and the current gold standard original report. There is a wide variability in quantification between operators and original report that is likely to represent the difference in patient ROI's. This may be due to the complexity of the software but could be improved by further training.

the clinical data, we studied the current situation on the exposure to fingers and efficacious measures to decrease and monitor the exposure. Methods: With NED (nuclear educated dosimeter: Unfors, Sweden) as a semiconductor dosimeter, first, we measured energy response and direction response as sensor characteristics and then the each medical staff in the five different clinical workplaces put the dosimeter on the index finger of their dominant hands to measure the dose. The staff's details are as follows: physician who injects RI drugs into the patients, radiological technologists who extract technetium from the Mo-Tc generator and handle RI drugs, physician who injects 18 F-FDG-PET drugs, pharmacists who test the FDG and radiological technologist who position the patients. Results: As the energy becomes higher, the response tends to be lower. It is because the energy response is a semiconductor element. Based on the result, we set a calibration constant. The direction response ended in good result except sensor-cable junction part. The finger dose of the physician who injected RI drugs was 22.36 μSv, radiological technologists handling 99m Tc 29.60 μSv per day (consultation period 20 days), physician who injected 18 F-FDG-PET drugs 51.29 μSv (80 cases, right finger 53.85μSv, left finger 47.27 μSv), pharmacists who tested the FDG 31.48μSv, and radiological technologist who positioned the patients 1.94μSv. This dosimeter can measure a real-time finger dose easily and its high sensitivity helped us to know the exposure situation effectively. (Table 1 and 2). Conclusion: This dosimeter provides a simple and effective solution to radiation protection procedures and follow-up. We measured the finger doses of nuclear medicine staff in our institute this time and found that the value ended in less than the annual limit (500 mSv per year). But, workers who use 18 F-FDG PET showed high exposure compared with no-PET case, and it should be considerd reduction of radiation exposure methods. Introduction: The dynamic renal scintigraphy used DTPA-Tc99m and captopril test constitutes a process of noninvasive functional exploration for the diagnosis of rénovascular hypertension. It permits to distinguish the hypertension induced by renal arterial stenosis from the stenosis of meeting associated with a primitive arterial hypertension. Case report: A 14 years old girl, without notable pathological antecedent, developed two months before the first consultation, a severe arterial hypertension with cephalgias and buzzing in the ears. The clinical examination objectified a breath in the left lumbar pit to the auscultation. The renal angiography objectified a stenosis of infrarenal aorta due to circumferential parietal thickening associated to renal arteries stenosis more marked in the left side. The dynamic renal scintigraphy after administration of captopril highlighted a marked collapse of the rate of tracer collecting exceeding 40% on the left side with an increase in the time of collecting on the right side testifying to a frankly positive test prevailing on the left. A transluminal angioplasty of the left renal artery and a revascularisation surgery on the right side were carried out. The evolution was marked by an improvement of blood pressure figures, which contributed to a considerable reduction of posology of the antihypertensive treatments. Discussion: The dynamic renal scintigraphy using DTPA-Tc 99m with captopril test constitutes a noninvasive process, little irradiant for patients. Its principal goal is to affirm the incrimination of the renovascular stenosis in the arterial hypertension genesis and to determine which hypertensive patients, with a renal arterial stenosis, could be treated successfully by the surgical or endoscopic revascularisation of the kidney.

Usefulness of Oro-Pharyngo-Esophageal Scintigraphy in the evaluation of inhalation into the tracheobronchial branch: a case report acquired image by count setting(100 Kcnt), that scan time of 4mm pin hole collimator was longer than 6mm pin hole collimator about 2.04 times(mean time-4mm:286.73 sec, 6mm:140.27 sec). Thyroid images by the 4mm pin hole collimator was acquired within about 5 minute except in the case of low level thyroid uptake like hypothyroidsm. We confirmed that the region of nodule was discriminated by 4mm hole better than 6mm hole through image of patient who has nodule. Even if detected count value in the 4mm pin hole collimator was 60% of 6mm pin hole collimator in the image of patient who has nodule, nodule portion of thyroid was certainly discriminated in the 4mm pin hole collimator's image. We confirmed that scan time of each diseases were needed better in 4mm hole.(hyperthyroidism -1.94 times, hypothyroidism -2.1times, goiter -1.8 times, thyroidal nodule -2.18 times) 4. Conclusion Although scan time is longer by using 4mm pin hole collimator if we adjust time and count, 4mm pin hole collimator image is more useful than 6mm pin hole collimator image. Especially, it provide useful diagnostic information in pantient who has nodule.

Racial Variations in Bone Scintigraphy: An Original Investigation R. Allie, Q. Siraj; Royal Hospital Haslar, Portsmouth NHS Trust, Gosport, UNITED KINGDOM.

By merit of its high sensitivity for early detection of bone pathology, bone scintigraphy remains the modality of choice for investigating sports injuries. This department regularly performs bone scans on military patients referred for musculoskeletal problems for the early detection of stress fractures and other musculoskeletal pathologies. For some time we have noticed that there appears to be a difference in the bone-to-soft-tissue uptake between Caucasians (whites) to Afro-Caribbeans (blacks). Bone scans of 54 military recruits (41 males, 43% blacks and 13 females, 38% blacks) were analysed. All subjects were injected and imaged according to departmental protocol using the same Gamma camera. Regions of interest were plotted over the bone and soft tissue to obtain bone-to-soft-tissue ratios. These were compared for each ethnic group. The results showed a significant statistical difference (p = 0.005) between the two groups. These findings were independent of gender, dose and waiting times. There was also a significant difference in respect to acquisition times (p = 0.004) for 500k counts. Though many options were explored, no obvious cause could be determined for this phenomenon. More research is required to shed further light on the matter; however, the various plausible hypotheses will be discussed. Aim: To learn about acute osteomyelitis as a complication in varicella and about imaging findings at different points in the course of the disease. Background: Acute osteomyelitis is a rare complication in varicella. To our knowledge only 40 cases have been reported in the litterature. Materials and methods: The clinical symptoms, findings and course of the disease are illustrated by 2 patients, a boy (18 months) and a girl (6 years) admitted to our hospital. Bone scintigraphy ( 99m Tcmethylenediphosphonate) and radiography were performed on the first or second day after admission in both patients. MR imaging was performed in the girl the 3. day. Radiograms and scintigrams were performed later in both patients. Results: The first scintigrams showed increased activity in the distal part and slightly reduced activity in the proximal part of the right humerus in the boy, and increased activity in the left tibia metaphysis in the girl. Scintigrams after 6 days in the boy showed further increased activity in the right humerus, now affecting the whole diaphysis.Scintigrams after 3 weeks were normal in the girl. The first radiograms were negative in both patients. Radiograms after 10 days showed irregular osteolytic lesions and periostal reactions in the proximal humerus diaphysis in the boy. Later radiograms showed slowly normalizing conditions. Radiograms in the girl after 1 month were normal. The MR images in the girl showed bone marrow edema in the left lateral tibia metaphysis and medial femur condyle. Both patients recovered completely after adequate treatment with antibiotics. Discussion: The scintigraphic findings in the boy could represent reactive hyperemia in the distal part of the humerus diaphysis and a transient reduced perfusion, before activity accumulation in the proximal diaphysis, where the infection was localized. Bone scintigraphy, preferably a multiphase study, is positive in osteomyelitis within 24-48 hours after onset of symptoms, with 90-95% sensitivity. Radiographs do not show significant changes the first days, even weeks, but are necessary in the follow-up. . MR imaging allows early detection of osteomyelitis, bone marrow edema appears during the first days of infection. The sensitivity is ~100%. Conclusion: Acute osteomyelitis is a serious complication in varicella and should be considered in any child with pain in a limb or joint after an episode of varicella. Successful treatment depends on early detection. Bone scintigraphy and MR imaging are sensitive methods showing pathological changes within the first days of osteomyelitis. Background/Aims. Circulatory and pulmonary complications are common in patients with cirrhosis and portal hypertension and some patients have gas exchange abnormalities that may progress to the hepatopulmonary syndrome (HPS). The prevalence of HPS is, however, variably reported from 8 to 20%, but its precise relation to the liver function is poorly understood. The aims of the present study were by means of lung perfusion scintigraphy (LPS) to assess the prevalence of HPS in consecutive portal hypertensive cirrhotic patients in relation to patient characteristics and during a 100% oxygen test. Methods.Forty-one patients (56.9±8.8 yrs,15 women and 26 men) with alcoholic cirrhosis (Child class A/B/C: 14/18/9) entered the study. All underwent a haemodynamic investigation with the determination of splanchnic and systemic haemodynamics. All had a contrast-enhanced echocardiography (CEE) and a LPS performed to diagnose extrapulmonary shunt fraction (EPSF) and HPS. In addition, measurement of Pa,O 2 , alveolar-arterial oxygen gradient (PA-a,O 2 ), lung diffusing capacity (DL,CO) and a 100% oxygen test were performed. Results. All patients had portal hypertension (HVPG: 15.5 ±6.7 mmHg). Five patients had a positive CEE and EPSF above 6%. Three of these patients had a Pa,O 2 below 10.7 kPa giving a frequency of HPS of 7%. The DL,CO was reduced in 81% of the patients and correlated significantly with metabolic liver function (GEC: r=0.39, p=0.01), splanchnic haemodynamics (post-sinusoidal resistance: r=-0.47,p=0.004; hepatic blood flow: r=0.42,p=0.012), and systemic haemodynamics (central blood volume: 0.42,p=0.006; plasma volume: 0.37,p=0.016; blood volume: r=0.42,p=0.006). Pa,O 2 was reduced below 9.7 kPa in 15% and PA-a,O 2 was above 2.7 kPa in 58% patients. PA-a,O 2 was significantly higher in patients with positive CEE, 15.5±2.2 vs 9.6±3.2 kPa than in those with a negative CEE (P<0.001). The change in PA-a,O 2 after 100% oxygen inhalation was significantly reduced in Child class C patients,-17.8±10.3 kPa, compared with Child class A and B patients( p<0.05). Moreover, the change in PAa,O 2 correlated with the EPSF fraction in the total patient population (r=-0.32, p<0.05). Conclusions. Whereas pulmonary dysfunction in cirrhosis is frequent and relates complexly to metabolic, splanchnic and central systemic haemodynamic complications, the prevalence of patients fulfilling the criteria of HPS is below 10% even in patients with advanced disease. LPS is considered a useful contribution in the evaluation of pulmonary dysfunction in cirrhosis. Aim: Emboli cause ventilation/perfusion (V/P) mismatches, usually with typical triangular character. However, in the area of middle lobe and lingula they might differ in form on sagittal tomographic images. Mismatches are sometimes observed only in these areas and they may cause dilemma in interpretation. We wanted to validate if these type of changes are caused by emboli or movement of lung position during first 20 minutes, known otherwise in cardiology as "upward creep" of the heart. Materials and method: Before perfusion SPECT, 25 consecutive patient performed two ventilation (V) SPECT. First and second ventilation studies were then compared with each other and V1/V2 quotient was calculated in order to estimate changes in lung position during the first 20 minutes. Images were validated visually and quantitatively. Change index was expressed as the fraction of the lung volume that had a quotient (V1/V2) below 0.9 or above 1.1. Results: Visual and quantitative analysis did not show significant changes in lung position due to "upward creep" that can influence false interpretation of mismatches caused by pulmonary embolism. Conclusion: V/P mismatches identified in middle lobe and lingula by SPECT are reliable for interpretation for pulmonary embolism.

Correlation between CTPA and V/Q scintigraphy in the diagnosis of pulmonary embolism S. Rep, J. Fettich; nuk.med.department, ljubljana, SLOVENIA.

Introduction: A pulmonary embolism (PE) is a blockage of a pulmonary artery caused usually by an embolus. This can be diagnosed using V/Q scintigraphy showing absent perfusion and normal ventilation of the affected lung segment or using CT pulmonary angiography (CTPA). In this case iodinated contrast medium is injected i.v. and PE is shown as filling defect of the affected pulmonary artery. Aim: The goal of our study was to detect relationship between absent perfusion showing with V/Q scintigraphy and defect of the affected pulmonary artery showing with CTPA. Patients and methods: Our study includes 20 patients with CTPA positive results for PE. CTPA and V/Q planar scintigraphy was performed within 48 hours all patients. For V/Q scintigraphy we used 133Xe (140 MBq) for ventilation and 99mTc-MAA (160 MBq) for perfusion in four projections. Lungs were divided into anatomical lobes (upper lobes, lower lobes, middle lobe and intermediate lobe). Each lobe was evaluated as having normal perfusion, ventilation/perfusion defect mismatch or match on V/Q scan, and partial or total occlusion of a segmental pulmonary artery on CTPA. The results of V/Q planar scintigraphy and of CTPA were compared. Results: Analysis of CTPA perfusion showed normal perfusion in 37.5% lobes, partial occlusion in 41.6% lobes and total occlusion of pulmonary artery in 20.9% of lobes. Ventilation was not successfully performed in 1 patient (5%). In 45% of segments ventilation was affected. Perfusion results showed absent perfusion in 20%, decreased perfusion in 49.2% and in 30.8% of lung segments the perfusion was normal. Results of both methods corresponded in 72% and did not in 28%. Conclusion: According to our results abnormalities corresponded in the 72% of segments with both methods. In 11% of segments disparity of the results was due to the fact that PE can be caused not only by complete but also by partial occlusion of the pulmonary artery. In 12 % of segments the results were false positive on V/Q mainly due to ventilatory changes (indeterminate V/Q results). In 5% of segments V/Q results were false negative most probably due to better resolution of CTPA as compared with scintigraphy.

Asynchronous appearance of double parathyroid adenomas in a patient with primary hyperparathyroidism T. Athanasoulis, A. Fothiadaki, T. Karianos, A. Tsakmakli, V. Makripoulias, F. Athanasouli, C. Zerva; "Alexandra" University Hospital Athens, Greece, Athens, GREECE.

During work up of a male patient 61 years old with a discovered raised calcium level who demonstrated primary hyperparathyroidism (PTH=1300 pg/ml and serum calcium Ca=13 mg/dl), a double phase parathyroid scintigraphy with MIBI was performed. A large area of hyperactive parathyroid gland localized at the lower left lobe of the thyroid gland. The patient was operated and a giant parathyroid adenoma was removed at the indicated location of the study which was confirmed histologically. The patient was followed up for the following two years during which his calcium and parathyroid hormone levels were normal. During a normal check up seven years later an elevated serum calcium level was found (Ca= 10, 9 mg/dl). At that time a cervical ultrasound was performed and PTH was measured. The value of PTH was 138 pg/ml confirming a mild hyperparathyroidism. A double phase sestamibi technique followed by a pertechnetate scan was used for further evaluation. An enlarged area of hyperactive parathyroid gland localized below and directly opposite of the lower right thyroid lobe extending to the upper mediastinum was discovered. An MRI was performed which confirmed the appearance of a mass (5, 5 cm x 3 cm x 2, 4 in dimensions) localized in the upper mediastinal area at the tracheo-esophageal groove with its lower border in contact with the aortic arch. A surgical removal was performed and the histological study confirmed that the removed mass was a huge parathyroid adenoma. This case report indicates that despite the fact that a parathyroid adenoma is discovered and removed, this does not exclude the possibility of asynchronous appearance of a second adenoma.

Bonescintigraphy -Adjustment of administrated activity A. Eriksson, Centralhospital, Karlstad, Sweden Background: Diagnostic reference levels (DRL) for nuclear medicine is established in Sweden by the Swedish Radiation Protection Authority, SSI. DRL is the given level of specific activity that shall not be exceeded. Currently all patients that undergoe a bonescintigraphy in Karlstad receive the same activity irrespective of weight and age. Question: Is it possible to individually adjust administrated activity by combination of age and bodyweight without loss of quality? Method and material: Adjustment of activity is done by creating an index of age divided by bodyweight. Relation of activity to index is given by a prestudy of 57 patients injected with 400 MBq or 600 MBq HDP-Tc. Results: 19 patients received standard activity 600 MBq and 23 patients got individually adjusted activity. Mean counts per image was 1,70 MCts respective 1,64 MCts. The decrease in administrated activity was 9,8% for the adjusted group. Variance of counts per image decreased from 0,14 to 0,05. Conclusion: Individually adjusted activity by this model yields same quality in the image as a standard activity. The decrease in administered activity is positive both for the staff and the patient.

Radiation protection during two decades in a nuclear medicine department S. Kristiansen, A. Nielsen; Department of Nuclear Medicine, Aalborg Hospital, Aalborg, DENMARK.

Aim: The aim of this study was to follow the yearly radiation doses during two decades to staff working in Department of Nuclear Medicine, Aalborg Hospital. We focused on the development in procedures, the number of examinations, and the physical working environment. This includes radiation protection in general nuclear medicine and PET/CT. Materials and Methods: Data has been taken from list of examinations sent to the ministry of health since 2000 and measuring results of personal dosimetry from the same ministry since 1990. Until 1997 the department had very old and narrow quarters. When moving to new facilities in 1997 and when establishing PET procedures in December 2005, our primary goal was to increase distance between the radiation source (the patient) and the technologists in order to reduce occupational exposure. The following was taken into consideration: •Large, simple but functional rooms. •A new laboratory section with a direct hatch to the injection room. •A special waiting area for patients confined to bed. •Improved shielding in preparation settings. •Electronic personal dosimeters. •Introduction program for new staff where the main topics are: radiation protection, personal dosimeter, receiving and registration of radioactive sources and pharmaceuticals, circumstances for pregnant and breastfeeding staff and handling of radioactive waste. •Radiation protection is taken into consideration whenever changes are made or new procedures are implemented. •Dosimeter measuring results are discussed at staff meeting. Results: Among the examinations giving the highest radiation dose to the staff are bone scintigraphy, myocardial scintigraphy and PET scannings. The number of bone scintigraphies has been almost stable since 2000. The number of myocardial scans has increased from 124 scans in 2000 to 595 scans in 2006. The department started PET/CT scans in 2006 and made 416 scannings the first year. Evaluating technologists working since 1990 in nuclear medicine the average occupational radiation dose has not increased. Conclusion: We found that it is very important to develop the physical working environment currently while having focus on its functionality. Furthermore the electronic personal dosimeter, updated guidelines for procedures and introduction of new staff is significance to keep radiation dose low. This has been introduced in our department, and despite an increase in the number of scannings, the radiation dose to the staff has not increased. Cyclotrons are commonly used for production of radioactive isotopes for nuclear medicine purposes. As part of the site safety system, the nuclear process requires installation of a Stack Radiation Monitoring System (SRMS) to determine the released activity during routine operation. This SRMS requires determination of a conversion factor for converting the radiation detector readings into concentration unit. Defining the conversion factor is done mainly by calibration process of releasing a known amount of activity. It is important to have a precise estimation of the converting factor in order to enable the design of an optimal duct that shall provide maximum detection sensitivity. A computer program was developed for determining the stack conversion factor based on simulating the positron emitter isotopes free mean pass in the duct and the motion direction of the 511keV energy photons created by positron annihilation. The obtained conversion factor (by the software) is based on the radiation detector sensitivity for 511keV energy photons, the user definitions for the stack dimensions and the cross section of the duct. This algorithm is acceptable since all PET isotopes produce 511keV photons. A local calibration factor is designated to adjust the software conversion factor to the self-characteristics of the specified detector. Adjustment is done by locating a calibrated radiation source in a pre-determined location and comparing between the expected reading calculated by software and the detector actual reading. The detector readings, converted into activity concentration along with the air flow data, are used to accumulate the total activity release through the duct. The software simulation has been performed on few square and round ducts of different dimensions and the results were compared to the actual calibration releases. Results show a very high correlation between the software simulation and the actual releases. The conversion factors found to be in the range of 1CPS per 60nCi/m 3 for duct with cross section of 700cm 2 . Due to the high correlation between the simulation and the calibration releases, the simulation may now be used to estimate the design ventilation system sensitivity in order to improve the Minimum Detectable Activity and to be compatible with the restrict regulation of detecting concentration level as low as 3nCi/m 3 . This high correlation can reduce the amount of activity releases that are accumulated during the calibration process as part of the annual release activity under the site license and reduce the allowed released activity derived from the site routine operation. Introduction: The Nuclear Medicine Technologist(NMT) is the healthcare professional who is able to cover the whole range of NM procedures in the clinical routine. The period of Education is a fundamental part of the educational process and for this purpose considerable resources investment is dedicated to it. The possibility of knowing how to confront the most varied situations in Italy(I), in 27 European(EU) and Mediterranean nations, determines a professional growth in the sector. Aim: The NMT is an important part of a team of healthcare specialists; the aim of this work is to identify NMT formative processes, working situations and economical capacities. In I, Education and training is quite similar than in EU: during the initial months of the university course(average 3 years), NMTs acquire the basic theoretical elements, follow the courses which help to develop didactic, then anatomy, pathology, equipment in the radiology area(60%); at the end, NMT deals with other fields of application of the ionizing radiations. The range of tasks permitted of NMT varies from country to country, and there is considerable overlap with other professional groups. Results: According to several published reports, there are approximately 90000radiological+NM technologist in the world; 60000 of them in Europe (25%men+75%women). There are 1500 NMTs operating throughout Italian NM-PET departments. In addition to historical/cultural traditions, differences in teaching and the characteristics of university course programming create different technical procedures in NMT routine (diagnostic imaging, radiation protection, etc.); legislation is relative flexible in all countries, with 24-40 working hours per week with additional extramural NMT activity; the duties of Chief-NMT are always dedicated to management of logistic problems(80%) and financial resources(20%). Credit points must be collected by the exam for CE sessions in every countries. Italian NMT salary is 1.5 times lower than 80% of EU. Professional benefits (extra days off or special bonus) are taken into account only in the Mediterranean area or intercontinental countries. Conclusions: the training and the professional qualification of NMT represents a first step towards a governance of healthcare working activities; it's important to underline main NMT goal: one high standard of work for NMT in countries. Fundamental for the changeover of NMTs is the ability to acquire/process SPET&PET-CT images, in addition to performing quality control of NM technologies. It's in the interest of healthcare quality that NMTs take responsibility for providing of high quality service and performance in clinical routine, with professional competence and global competition. Introduction: Assuming that the modern concept of a Nuclear Medicine Department should ideally include a Positron Emitting Tracers (PET) production facility, there is a need to optimize the design of an integrated facility (here considered as the opportunity to build from the beginning) in order to allow the distinct patterns of functioning and circulation (patients, public, professionals, products, ) to occur in an harmonious and most efficient way. The purpose of this study is to integrate the ultimate concepts concerning aspects so crucial as radiation protection, ergonomics and the practicability and efficiency of the Unit, considered as a whole. Material and Methods: Starting with a bibliographic review, done according to the most recent developments on regulations and legislation, essentially at international level but also regarding eventual national particularities and following with practical knowledge, obtained from recent (real) implementation of similar units -and information shared by the responsible entities -we aim to build a complete and structured project, with an objective planning (blueprints), able to serve as basis for real implementation of an unit with an updated and optimized integrated vision of the current production and diagnostic processes. Results and Conclusions: The final blueprints of the Unit are based on studies concerning not only the previous research on current legislation, but also the current assumption of best practices and fundamental principles related to radioprotection (as the ALARA principle), production (as the cGMP rules) and diagnosis (International Guidelines). These blueprints demonstrated the practical result of that research and consist, briefly, on the obtained optimal structuring of the diagnostic side of the unit (as well as the production side) combined together in order to facilitate the necessary interaction, even if maintaining its respective independence and individual protection (compulsory condition to assure best practices) even in case of simultaneous operation.

Results: In the first patient Tg level decreased from 8.3 ng/ml to 3.0, 1.1 and 0.09 ng/ml after 1 st and 2 nd and 3 rd RI application, respectively

Conclusion: There is a significant reduction of Tg levels in ESRF patients with DTC during the course of therapies using reduced activity doses. Tg levels in all patients were lower then 1 ng/ml after the 2 nd therapy

Same-patient perfusion SPECT data were acquired by alternating between NR and BH every 15 seconds. The CT protocol was standard breath hold. These data were transferred to the LungGuide (Nihon Advanced Biologic, Japan) workstation via DICOM where non-rigid SPECT/CT image co-registration and fusion were performed using LG-IFM. Due to the small difference in displacements, BH-SPECT/BH-CT registration was taken to be the "gold standard" to which NR-SPECT/BH-CT registration was compared. The differences in the position of the the diaphragm and the bottom of the lungs and in BH CT and NR SPECT, respectively, were measured. After LG-IFM registration with, we evaluated the difference of BH-SPECT/BH-CT and NR-SPECT/BH-CT fusion images in the lung lower field. Results: LG-IFM mis-registration was observed in 5 of 40 cases (0.13 ± 0.05%) in NR SPECT/BH CT fusion images

Czech Republic -the Result of the Questionnaire

3 rd Medical Faculty

Rehling 1 ; 1 Clinical Physiology and Nuclear Medicine

positive CD10/weak GLUT-1 (13.9±4.6, n=3), negative CD10/strong GLUT-1 (11.0±0.9, n=8) were significantly higher than those of negative CD10/negativeGLUT-1 (4.3±0.9, n=3) using Kruskal Wallis test (p=0.035), suggesting that FDG uptake variation is related not only GLUT-1 but also CD10 (thus MUC2)

We present synthesis, radiochemical synthesis, and preclinical data on a series of novel radiofluorinated alkyne agents as potential PET agents for the detection of amyloid plaques. One such PET agent, AV-144 binds avidly to Abeta (A ) with a Ki = 4.5 ± 0.9 nM (vs. 125I-IMPY) and localizes specifically to A in AD brain tissue

Máthé 1 , I. Foldes 2 ; 1 Nat

Is it possible, from stress images only, to decide if a myocardial perfusion rest study is needed?

Present our experience about the unwished effects that appear during the administration of 123 I-IOFLUPANO/FP-CIT in patient with movement disorder. Material and Methods. A total of 113 consecutives patients (49% male; mean age 65.3y) were men are studied between XII/'05 to I/'07. The patients were grouped according to the clinical prescription

In 8/106 (7.55%) patients were reported pain during the injection, red flush and irritation in the zone of puncture in spite of its reinjection in another vein assuring a correct canalization. In 1/106 (0,94%) was observed slight headache with slight reddening face. Three of these patients were referred for reevaluation in a follow-up protocol (3/9; 33,3%) presenting similar reactions to the first time when the exploration was repeated. Comments. The administration of 123 I-Ioflupano/FP-CIT is a procedure of limited adverse reactions and if appear, are of slight intensity

SPECT are inaccurate for both algoritims, and that 180 degree SPET recontructed with OSEM can offer an acceptable alternative. However, 180 degree SPECT recontructed with FBP is superior for this purpose

Parisella 1 , A. Lenza 1 , F. Scopinaro 3 ; 1 Ospedale Sant'Andrea

The main component of paint thinner used in industry is toluene. Toluene can diffuse into many body fluids and tissues; and causes formation of reactive oxygen species (ROS) which are the main agents responsible for cellular damage. Antioxidant enzymes such as SOD, GSH-Px and CAT are part of the natural cell defense system against ROS mediated injuries. Matrix metalloproteinases (MMPs) play an important role in physiologic and pathologic processes, including extracellular matrix turnover, tissue degradation and repair, cell migration and inflammation. An imbalance between the expression of MMPs and tissue inhibitor of metalloproteinases (TIMPs) is believed to cause some pulmonary inflammatory diseases. Especially, the imbalance between MMP-9 and TIMP-1 expression may play an important role in airway inflammation. We aimed to investigate the alveolar clearance by Tc-99m DTPA radioaerosol inhalation scintigraphy in auto painters, to assess effects of exposure to toluene on clearance rate of alveolar epithelium and to determine the correlation between Tc-99m DTPA radioaerosol lung scintigraphy findings and MDA, antioxidant enzymes, MMP-2, MMP-9, TIMP-1 levels. Twenty eight auto painters, and control group were included in the study. Tc-99m DTPA radioaerosol inhalation scintigraphy was performed in all subjects. Clearance half time (T½) and penetration index (PI) on the first minute image were calculated. The mean T½ values and PI of toluene exposed workers were significantly higher than those of control group (P=0.034, P=0.032 respectively). The SOD and GSH-Px levels of auto painters were significantly higher than those of the control group (P=0.016, P=0.003, respectively). Conversely, CAT and MDA levels was not significantly different between groups (P>0.05). We observed a statistically significant increase (P=0.042) in MMP-9 levels of toluene exposed workers compared with the control group, whereas the MMP-2 and TIMP-1 levels of painters were less than those of control group that not reached to statistical significance (P>0.05). A positive correlation was observed between PI and GSH-Px levels (P<0.05) in the painters. There were no correlation between scintigraphic findings and other parameters in any subjects. Our findings indicate that occupational exposure to toluene in auto painters has effect on bronco alveolar epithelial permeability, which is supported by prolonged Tc-99m clearance half time and increased penetration index. We also found increase in antioxidant enzymes and MMP-9 levels. In the light of these findings, it might be concluded that long lasting toluene exposure may lead into occupational lung diseases. 

Study objectives: measur the synovial thickness after 166-Holmium radiosynoviorthesis by sonography. Methods: Phases III, prospectiv study. 30 patients suffering from chronic synovitis, rheumatoid arthritis were examined. The protocol commenced with screening. The patients were selected according to inclusion and exclusion criteria. Holmium phytate injectable suspension marked by 600 MBq 166Holmium phytate injectable suspension, and 40 mg of 1 ml triamcinolone acetonide and 1 ml of lidocaine 1%. There were 24 month follow-up period after the administration of the isotope. Inflammatory activity of the affected knee-joint was tested prior to treatment, and the 3 th and 3, 6, 12, 24 and 36 months after treatment. We measured the synovial thickness the following locations: In the midline, lateral and medial, by the condylus of femur medial and lateral. Results: During the study period, inflammation decreased. In the first two years excellent and good results were recorded in 93.3%. Two years after radiosynoviorthesis 93.3% of patients did not need another punction. The thickness of the synovia decreased significantly. We find a significant correlation between the synovial thickness and the clinical improvenes. Conclusion: The 166-Holmium-phytate is an effective new radiopharmacon in the treatment of synovitis. We detect the clinical improvement by sonography. The effective dose is 555-925 MBq. References: Margit Szentesi: Radiosynoviorthesis with Ho-166 phytate. First clinical results EANM Post-Congress Scintific Meeting. Radionuclide therapy in theory and practice. Györ, Hungary. 5. szept. 2002 . Szentesi M., 1 Környei J., 2 Antalffy M., 2 Törkö J. 2 Tóth Gy., 2 Jánoki Gy., 3 Balogh L., 3 : Study of intraarticular application of 166-Holmium IHPP in rabbits. World Journal of Nucl. Med. 1. Suppl. 2. S243. Sept. 2002 . Szentesi M., 1 Takács S., 1 Farbaki Zs., 1 Nagy E., 1 Környei J., 2 Antalffy M., 2 Törkö J., 2 Tóth Gy., 2 Jánoki Gy., 3 Balogh L. 3 Géher P., 1 Comparitive study of applying increasing doses of 166 Ho-phytate injectable suspension in chronic synovitis. (Comparative, randomized, single-blind, placebocontrolled study with increasing dosage). Eur. J. Nucl. Med. Suppl. 2. 498. 2003 . Szentesi M., 1 Takács S., 1 Farbaky Zs., 1 Nagy E., 1 Környei J., 2 Antalffy M., 2 Törkö J. 2 Tóth Gy., 2 Jánoki Gy., 3 The first article on radiosynoviorthesis was published in 1952 by Fellinger. The traditional isotopes cause whole body radiation of 10 Rad. Isotope specialists have aspired to produce an isotope incurring lower radiation loads. (Pirick, Russel, Sledge, Junsing Song) 166-Holmium-phytate produced by us: radiation type beta energy maximum: 1,84 MeV; radiation type gamma energy maximum: 0,66 MeV; soft tissue penetration: maximum 8,4 mm; average: 3,3 mm; half-life: 26,9 hours; particle size: 0,6-2 μm Study objectives: Examination of anti-inflammatory effect of 166-Holmium-phytate injection. Methods: Phases III, prospectiv study. 30 patients suffering from chronic synovitis, rheumatoid arthritis were examined. The protocol commenced with screening. The patients were selected according to inclusion and exclusion criteria. Holmium phytate injectable suspension marked by 600 MBq 166Holmium phytate injectable suspension, and 40 mg of 1 ml triamcinolone acetonide and 1 ml of lidocaine 1 %. There were 36 month follow-up period after the administration of the isotope. Inflammatory activity of the affected knee-joint was tested prior to treatment, and the 3 th and 3, 6, 9, 12, 24 and 36 months after treatment. Evaulation was based on the criteria as described by Müller, Rau and Scütte the score system was developed by the authors. Results: During the study period, inflammation decreased. In the first three years excellent and good results were recorded in 93.3%. Three years after radiosynoviorthesis 93.3% of patients did not need another punction. Administration of Holmium-166 phytate is a safe procedure. We did not detect any symptoms of radiation sickness. We found no deviations in either haematological or chemical parameters during the study period. Conclusion: Holmium-166 phytate isotope is an effective radiopharmacy treating synovitis. Due its adventageous features it produces less radioactive damage on the organism than the traditionally used isotopes . Due to its physical parameters it is optimal to treat large joints (knee) and medium size joints (hips, shoulder, elbow, wrist, ankle) . Effective dosage is 555-925 MBq. References: Margit Szentesi: Radiosynoviorthesis with Ho-166 phytate. First clinical results. EANM Post-Congress Scintific Meeting. Radionuclide therapy in theory and practice. Györ, Hungary. 5. szept. 2002 . Szentesi M., 1 Takács S., 1 Farbaki Zs., 1 Nagy E., 1 Környei J., 2 Antalffy M., 2 Törkö J. 2 Tóth Gy., 2 Jánoki Gy., 3 Background: Early and continuous prophylaxis in haemophilia is of paramount importance due to the susceptibility of the young and immature skeleton to repeated joint bleedings. In developing countries, financial aspects of clotting factor A or B replacement play a major role in patients' management. Radiosynovectomy (RSO) offers an alternative treatment option to surgical or chemical synovectomy and may reduce the need for clotting factor substitution. A.1.1. Methods: In a multicenter effort 96 patients from 4 centers underwent RSO of the knee following repeated bleeding episodes. RSO was performed applying three radiocolloid formulations (Y-90-silicate, Re-188 tin and P-32 chromic phosphate). Average age was 12.2 (range 4-18 years). Standard injected activities were 185 MBq for Y-90, 450MBq for Re-188 and 60MBq for P32. The injected activity was tailored to patients' age; 2-6 one third, 7-10 one half and 11-16 years three quarters of adult dose. Patients were referred by the haematological outpatient clinic. The frequency of bleeding episodes was documented. Prior to the RSO the frequency of knee joint bleeding was reported from patients' records. Results: With exception of one case with circumscribed and reversible skin necrosis along the injection tract or reversible swelling of the knee joint, there were no other serious side effects. Within the one month period prior to RSO, all patients had at least 3 bleeding episodes per month. Following the RSO, number of bleeding episodes dropped significantly (a total of 391 bleeding episodes during the one month prior to RSO dropping to 53 at one month, 50 at 3 months and 32 at 6 months following the RSO, X 2 < 0.001 ). During a 6 months follow-up period, 48% of the patients had no bleeding episodes (100% reduction), 38% had an 80% reduction and 14% had a 50% reduction. Based on the feedback by the children and their guardians, there was a significant improvement of the life quality attributed to improved mobility and lesser drop-out days from school. Conclusions: Our results indicate that RSO is effective in preventing joint bleeding in the paediatric population. In addition there is a significant cost benefit attributed to reducing the need for clotting factor substitution (medication cost to treat one bleeding episode 2000-4000US$ vs. 70-100USD for RSO using P-32 or Re-188). Following an initial period of scepticism, the acceptance of the procedure improved significantly. Results of an IAEA led CRP: E1.30.26 Radiation synovectomy may be indicated for the treatment of chronic synovitis. A number of factors may affect its current use, including availability, limited evidense for its efficacy compared to intra-glucocorticoid, and concerns regarding the potential long term effects of radiation exposure, particularly in younger patients. Specific chromosome-type abnormalities in peripherial lymphocytes can be useful indicators of whole-body radiation exposure. The frequency of these aberrations has been shown to increase in patients who have had radiation synovectomy using Yttrium-90 /Y-90/ by up to five times compared to baseline levers.166-Holmium-phytate /166-Ho/ is a new radiopharmaceutical currently on trial which appears to have less extra-articular leakage than Y-90 compounds. The aim of this study was to indentify any increase in specific chromosome-type abnormalities, using published criteria, in patients following 166-Ho synovectomy of the knee. 18 patients / 7 men, 10 women/ in whom the analyses were performed had a mean age 45yr range /24-72 yr./ Results: There was no increase in scored chromosome-type abnormalities after 166-Ho synovectomy. Conclusion: This study further supporth the relative safety of 166-Ho compared to oder radiopharmaceuticals. P55 -Monday, Oct. 15, 2007, 2: Aim: Use of rhTSH aided RAI therapy for differentiated thyroid cancers has increased over past few years. This study has been done to assess the clinical usefulness of rhTSH aided RAI therapy for patients of differentiated thyroid cancers administered RAI for either residual remnant ablation (RRA) or irresectable and metastatic disease. Materials and Methods: 12 patients (9 females; 3 males) 14-68 years (Mean age 33.75); of differentiated carcinoma of thyroid given rhTSH aided RAI therapy for either RRA or irresectable and metastatic disease from October 2003 to February 2007 were included in the study. 10 patients had Papillary carcinoma while 2 had Follicular carcinoma. 7 patients had stage I, 2 stage II, 1 stage III while 2 had stage IV disease. 7 patients were given rhTSH aided RAI therapy for RRA while 5 had either irresectable or metastatic disease. 11 patient's TSH did not rise adequately after surgery or due to functioning metastatic disease while 1 opted for rhTSH aided therapy because of the problems associated with Thyroxine withdrawal. RAI given ranged from 100mCi(3700MBq)-170mCi(6290MBq); Mean dose 140.42mCi(5195.54MBq). All the patient's baseline TSH, Thyroglobulin (Tg) and Anti-Thyroglobulin (Anti-Tg) levels were recorded. 0.9mg I/M injections of rhTSH were given at Day 1 & 2 and TSH levels recorded 24 hours post injection. RAI therapy was given if TSH level was >30μIU/ml. All patients underwent whole body scan prior to discharge. Patients were followed at 3 months interval on outpatient basis. The mean follow up was 23.5 months. If the valid Tg levels came down to negligible levels at 3 months complete response (CR) was documented; if Tg levels reduced significantly but not negligible, was termed as partial response (PR), if no significant difference noted; stable disease (SD) and if increased progressive disease (PD). Results: 10 patients had valid Tg levels. The baseline Tg levels ranged from 0.5->30000ng/ml. The baseline TSH levels ranged from 0.718-10.8μIU/ml. After the rhTSH injection the TSH levels rose to (34.8-96.9 ) after first injection and (33.1->75) after the second injection. All patients are alive; 5 patients had CR, 4 had PR while 1 had SD. 2 patients were too soon to assess at the time of review. The Overall Response Rate was 90%. Conclusion: rhTSH aided RAI therapy yields good results with an appreciable response rate, therefore it can be used for effective therapeutic administration of RAI for both RRA and in cases of irresectable or metastatic disease.

Detection of ectopic gastric mucosa in Meckel´s diverticulum by 99m Tc-pertechnetate disodium scintigraphy in patients with the lower gastrointestinal bleeding, retrospective study J. Dolezal; Teaching Hospital, Hradec Kralové, CZECH REPUBLIC.Aim and Background: to present our twelve-years experience with the perfusion 99m Tc-pertechnetate disodium scintigraphy of Meckel's diverticulum in patients with lower gastrointestinal bleeding. Gastric mucosa may be presented in Meckel´s diverticulum and associated with the peptic ulcer disease and the lower gastrointestinal (GI) bleeding and the 99m Tc-pertechnetate scintigraphy can help to make diagnosis of ectopic gastric mucosa. Material and Method: one hundred patients -22 adults (14 males, 8 females, aged 18 -78, mean 26 years) and 78 children (39 boys, 39 girls, aged 1 -17, mean 8 years) underwent 99m Tc-pertechnetate scintigraphy. All patients had melaena or hematochezia with anaemia. The morphology imaging and the endoscopy were negative in all patients. The dynamic scintigraphy of the abdomen was started immediately after i.v. administration of 99mTc-pertechnetate. The static image of the abdomen was done after it. As necessary the SPECT was added to improve sensitivity, specificity and better spatial specification. Results: Four patients (two boys -two-and ten-years-old, one girl -four-years-old and 24-years-old male) had positive scintigraphy. All patients underwent surgery and Meckel diverticulum with ectopic gastric mucosa (by histology) was detected. GI bleeding stopped spontaneously in patients with negative scintigraphy. These patients did not undergo intra-operative enteroscopy or surgery. Conclusion: 99m Tc-pertechnetate scintigraphy can help to detect ectopic gastric mucosa in the abdomen and improve a management of patients with lower gastrointestinal bleeding. Aim: Rapid detection and localization of the bleeding sites are important factors for the clinical management of patients with active hemorrhage. The aim of this study was to assess the accuracy of technetium-99m (Tc-99m) labeled red blood cell (RBC) scintigraphy in patients with suspected gastrointestinal bleeding. Material and Methods: Between December 1997 and August 2002, we selected 95 patients (53 women and 42 men, age range 18-87 years) with clinical suspect of gastrointestinal bleeding consecutively referred for Tc-99m RBC scintigraphy. The results of Tc-99m RBC scintigraphy were compared with those of oesophagus gastro duodenoscopy and angiography. Results: Tc-99m RBC scintigraphy was positive for active gastrointestinal bleeding in 39 (41%) patients and negative in 56 (59%) patients. Gastrointestinal bleeding was confirmed by other procedures in 31 of the 39 patients (79% true positive rate) with positive RBC scintigraphy (by oesophagus gastro duodenoscopy in 26 patients and by angiography in 5 patients). In 23 (74%) of the 31 true positive patients, RBC scintigraphy demonstrated active bleeding already in the early (within 30 min) phase of the study. In the remaining 8 patients (26%), RBC scintigraphy resulted positive only after delayed (between 3-15 hours) acquisition. Therefore, the acquisition of delayed images increased the sensitivity of the method. In 8 of 39 patients with positive RBC scintigraphy, gastrointestinal bleeding was not confirmed by other procedures (20% false positive rate). Among the 56 patients with negative RBC scintigraphy, the lack of gastrointestinal bleeding was confirmed by oesophagus gastro duodenoscopy and/or angiography in 39 patients (70% true negative rate). Among the remaining 17 patients with negative RBC scintigraphy, 14 patients had gastrointestinal bleeding by oesophagus gastro duodenoscopy and 3 by angiography. RBC scintigraphy had a sensitivity of 64 %, specificity of 83%, positive and negative predictive values of 80% and 69%, respectively. Conclusion: Tc-99m RBC scintigraphy is a useful and safe non-invasive test for the diagnosis and the management of patients with suspected gastrointestinal bleeding. In particular, the possibility to re-image patients over an extended period is helpful in identifying intermittent bleeding sites.

Radionuclide Assessment of Gastric Emptying in Relapsing-Remitting Multiple Sclerosis B. G. Chaushev, A. Klisarova, P. Bochev, N. Deleva, B. Ivanov; MBAL St.Marina -Varna,Bulgaria, Varna, BULGARIA. Aim Assessment of gastric motility disorderders in relapsing-remitting Multiple Sclerosis (MS) using dynamic scintigraphy of gastric emptying by 99mTc. Material and Method Evolution of gastric emptying was performed in 15 patients with MS (8 males and 7 females), aged 30,6± 6,33 years, with 6,5± 3,7 years of disease duration. The diagnosis MS was defined according to McDonald's criteria. The clinical impairment was rated according to the Expanded Disability Rating Scale (EDSS). None of the patients have subjective complaints, suggestive of gastroparesis. At the time of the study all patients were in remission and free of corticosteroid treatment. Dynamic gastroscintigraphy was carried out in the morning after evening fast, with 8-12 hours abstention of tobacco, drinks and medication influencing gastric motility function. The patients was took breakfast consisting of semi-solid food, labeled with 1 mCi / 37 MBq / Tc-99m SC. Parameters of the protocol included 5 frames. The first image was achieved at 0 minute and the next ones were achieved after 30 minutes interval during two hours or until stomach evacuation goes above 50%. The time needed for semi-emptying of stomach was determined from all received images. We were drawing region of interest, which includes the whole stomach from all projections. Time-activity curve that represents the movement of radioactivity in region of interest was generated and half emptying time was calculated (with up to 60 minute's normal range). Results Our results demonstrate delayed gastric emptying in more than half of the patients (53%) with values ranging from 37,7% to 49,2%. We found gastric motility disorders in patients with more pronounced functional deficit, as assessed by EDSS. Sex, age and disease duration have not a significant impact on gastric emptying. Conclusion Autonomic dysfunction is an integral part of the pathological process in MS with involvement of almost all somatic systems. Dynamic scintigraphy of the gastric emptying in MS provides possibilities to evaluate the gastric motility. The evacuatory disturbances are an essential factor, impacting on the health status and on the quality of life. They appear even in patients without subjective complaints and with relatively mild neurological deficit. Key words: Multiple Sclerosis, gastric emptying, dynamic scintigraphy Introduction: Tc-99m MIBI which is widely used in nuclear cardiology, is excreted via the hepatobiliary system thus enabling to make comments concerning this system of elimination. The nonalcoholic fatty liver disease (NAFLD) which is associated with mitochondrial dysfunction and has the potential to progress to cirrhosis has recently been drawing attention with its increased incidence due to predisposing factors such as obesity and diabetes (DM) . Aim: In this retrospective study, MIBI findings in normal and obese patients (pts) groups and the influence of accompanying risk factors on these findings were investigated using the rest images of myocardial perfusion scintigraphy (MPS). Method: Regions of interest (ROIs) of the liver (L) and right lung (RL) were drawn in the anterior projection using the rest MPS images of the pts referred to our department for coronary artery disease (CAD) work up. The liver index (L/RL) was calculated using the ratios of average counts obtained from the related ROIs. The body mass index (BMI) was calculated with the help of the medical records at the time of the MPS. The presence of DM and hyperlipidemia (HL) was investigated from the pts' medical records and history. The pts who had a known liver and/or lung disease, those who smoked or drank alcohol, with a low LVEF or perfusion defects on rest MPS images were excluded from the study. Finding: The data of a total 249 pts (159 females, 90 males, average age: 60,49±11 years, height: 1.63±0.1 m, weight: 77,22±15 Kg) were analysed. No significant change was observed in the L index with respect to an increase in BMI in the overall assessment of the study group (r:0.008, p:0.9). The cases with BMI>30 and DM (n:38, L index 2.5±0.77) showed a significant degree of decrease in their L index (p:0.029); while in the cases with BMI>30 and had only HL (n:29, L index: 2.88±1.12) a significant change was not detected (p:0.57). Conclusion: In the study group the liver uptake ratio of MIBI was significantly decreased in the presence of both obesity and DM as compared to normal individuals. However, similar findings were not observed in the presence of only obesity or obesity and HL. Although histopathological verification is a must, these findings suggest hepatocyte dysfunction in pts with NAFLD who has similar pts characteristics. the present findings need to be confirmed in prospective studies that enable kinetic analysis of hepatic function with simultaneous histopathologic analysis. P64 -Monday, Oct. 15, 2007, 2:30 pm -4 The aim of this work has been to evaluate the results obtained by radioguided parathyroid surgery in patients diagnosed of primary hyperparathyroidism due to parathyroid adenoma (PA). Methods. Inclusion criteria: Patients diagnosed of primary hyperparathyroidism, a previous positive 99mTc-MIBI scan (including SPECT or SPECT/CT), pathological diagnosis and clinical/biochemical follow-up > 9 months.According with these criteria we have included in our study 49 patients. Radioguided parathyroidectomy was performed between February 2004 and July 2006. The day of surgery, a low dose (136-222 MBq) of 99mTc-MIBI was injected and a planar scan was performed in order to draw a cutaneous mark in the localization of the PA. The interval between tracer injection and surgery was determined on the basis of the previous scan, ranged between 20 m. and 2 h. On surgical theatre an intraoperative hand-held gamma probe was used. In all cases we determined intraoperatively PTH levels and performed a pathological diagnosis. A radioguided removal of the PA, reduction of intraoperative PTH levels > 60% and a pathological diagnosis of PA were used as criterions for successful excision of the abnormal gland. Results. In 48 patients (98%) radioguided removal of the PA was achieved. In 37 patients the PA was eutopic (1 double adenoma) and in 11 ectopic. Scintigraphic localization of the PA was concordant with surgical localization in 46 patients, in two was nonconcordant (2 eutopic adenoma), and in 1 the PA was non detected on surgery. Radioguided surgical technique was minimally invasive in 38 patients, unilateral or bilateral cervicotomy in 10 (5 previous cervical surgery, 2 nodular goiter, 1 double adenoma, 1 four glands revision and 1 non surgical detection) and sternotomy in 1 (ectopic mediastinal adenoma). Biochemical follow-up revealed normocalcemia in 47 patients and persistent hyperparathyroidism in 1 (2%). Conclusions. Radioguided parathyroid surgery is a safe and effective method in the surgical treatment of primary hyperparathyroidism due to PA. We achieved a 98% of surgical detection with a 2% rate of hyperparathyroidism persistence/recurrence. Aim: Although total thyroidectomy is accepted to be the main component of the therapy in differentiated thyroid carcinoma (DTC), completion thyroidectomy (CT) is a controversial issue due to its morbidity potential. The aim of this study is to evaluate the efficacy of CT with the aid of gamma probe, using I-131. Materials and Methods: 152 patients (109 female, 43 male; mean age: 42, range: 17-75) who had undergone CT, between April 2003 -January 2007, with the help of gamma probe, after labelling with I-131 were enrolled in this study. The patients have undergone the primary operation with the diagnosis of either benign multinodular or solitary nodular goitre, and DTC was diagnosed in the operation specimen. The patients, while not under thyroid hormone replacement therapy in the 6 th week or later after the operation and with TSH<30 mU/L, remnant thyroid tissue 2 grams and/or suspicious malignant findings in the remnant tissue due to ultrasonographic examination, were evaluated by the council of thyroideal diseases of our hospital, and CT was decided. 0.1-0.2 mci. I-131 was given orally to the patients 48-72 hours prior to surgery, and thyroid scintigraphy were obtained on the operation day. CT were performed with the guidence of gamma probe. 127 patients underwent bilateral, and 25 unilateral remnant thyroid tissue resection. Results: Preoperative mean remnant thyroid tissue mass was measured ultrasonographically to be 7,8±1,6 grams. Intraoperative mean ratio of thyroid activity to background activity(T/BG) was detected to be 13,1±3,3 and the mean ratio of thyroid bed activity to background activity after the excision (TB/BG), 1,5±0,2. (p<0.001). Mean operative time was 72±8 minutes. TSH levels were > 30 mU/L in all patients after the 6 th week and no remnant thyroid tissue was detected in 143 patients either by ultrasonography or scintigraphy. While the mean TSH level of the patients was 8,4±3,4 mU/L preoperatively, it was 61,9±20,7 mU/L postoperatively (p<0.001). Malignancy in the remnant tissue was detected in 38 (25,3 %) patients. 5 (3,2%) patients had transient hypoparathyroidism and 2 (1,3%) had transient recurrent laryngeal nerve palsy postoperatively. None of the patients had persistent hypoparathyroidism and recurrent laryngeal nerve palsy.Conclusion: In patients with DTC who had undergone subtotal thyroidectomy or lobectomy in the primary operation, CT with the guidence of gamma probe after labelling with I-131, is a safe procedure with minimal complications.

I-123 ADAM SPET in athyreotic patients with and without suppressive thyroxine therapy. Aim: to evaluate the added diagnostic value of SPECT imaging over planar imaging of parathyroid scintigraphy performed in primary and secondary hyperparathyroid (HPT) patients. Materials and Methods: 136 patients with primary HPT (no. 94) or secondary HPT (no. 42) underwent pararathyroid localising imaging in our centre, and then were operated on by the same surgical equipe. Parathyroid scintigraphy consistsed of a double-tracer 99m Tc-Pertecnetate (150 MBq)/ 99m Tc-Sestamibi (550 MBq) subtraction scintigraphy plus perchlorate per os (400 mg) accordingly to Rubello's protocol (EJNMMI, 2003; 30(2) :189-2); SPECT imaging was obtained immediately after planar imaging using the following parameters: acquisistion, elliptical orbit, 60 x 2 steps, 30 sec./step, 128 x 128 matrix, processing, filtered back projection and Butterworth filter using different cut-off levels and order calues depending on the location, depth and uptake of the parathyroid enlargement. High resolution -10 MHz -ultrasonography (US) was also routinely associated. Results: Sensitivity in localising parathyroid enlargements using double-tracer subtraction scintigraphy, SPECT alone, and US were: 90%, 84%, and 62% in primary HPT, and 56%, 68%, and 75% in secondary HPT. Interestingly, combining double-tracer scintigraphy and SPECT information sensitivity rose up to 94% in primary HPT (instead, in this series, US did not improve sensitivity, even if allowed a better location of the parathyroid enlargement in some cases). On the other hand, US allowed a mild increase of sensitivity in patients with secondary HPT. This was related to the fac that US was able to detect some very small parathyroid enlargements which were not seen at scintigraphy. However, it has to be underlined that US gave 14% false positive results in comparison to 2% of scintigraphy, especially in secondary HPT patients. Conclusions: On the basis of our data, it seems reasonable to argue that the combination of planar double-tracer subtraction scintigraphy and SPECT is an optimal pre-operative localising procedure in primary HPT patients. Conversely, in secondary HPT patients, neither scintigraphy nor US showed a very high accuracy: a combination of all these methods in secondary HPT could be recommended.

Tc-99m radio-guided completion thyroidectomy in patients with differentiated thyroid carcinoma Aim: Completion thyroidectomy (CT) is crucial in patients with differentiated thyroid carcinoma (DTC) who had either subtotal thyroidectomy or lobectomy as the initial operation. Whether CT is associated with an increased complication risk is controversial. The aim of this study is to evaluate the efficacy of Tc-99m radio-guided surgery with gamma probe in performing CT. Materials-Methods: 27 patients with the histopathological diagnosis of DTC after the initial operation, with the tumor diameter 1 cm, TSH < 30 mU/L, remnant tissue > 2 g. in ultrasonographic examination and/or suspicious malignant foci in the remnant thyroid tissue, and undergone CT with the aid of gamma probe using Tc-99m were enrolled in this study retrospectively. On the operation day, 3-5 mci, 0.5 mL Tc-99m pertecnetate was injected through the forearm 10 minutes prior to the incision, and bilateral remnant tissue resection was performed with the guidence of gamma probe. Results: Intraoperative mean ratio of thyroid activity to background activity(T/BG) was detected to be 9.3 ± 2.3 and the mean ratio of thyroid bed activity to background activity after the excision (TB/BG), 1.3 ± 0.3. (p<0.001). Mean operation time was 74 ± 9 minutes. TSH levels of all patients one month after the surgery were >30 mU/L and no remnant thyroid tissue was detected either by ultrasonography or thyroid scintigraphy, except in two patients. Preoperative mean TSH level of the patients was 7.3 ± 3.1 mU/L, while it was 61 ± 16.4 mU/L postoperatively, (p<0.001). Malignancy in the remnant tissue was detected in 5 (18.5 %) of the patients. Transient hypoparathyroidism occured in 1 ( 3.9%) patient postoperatively. Persistent hypoparathyroidism or recurrent laryngeal nerve damage occured in none of the patients. Conclusion: in patients with DTC who had undergone subtotal thyroidectomy or lobectomy in the primary operation,Tc-99m radio-guided CT is a safe procedure with minimal complications.

The diagnostic value of Tc-99m MIBI gated myocard perfusion SPECT in detection of silent myocardial ischemia in asymptomatic patients with type II diabetes mellitus Aim: In this study, we aimed to evaluate the diagnostic value of Tc-99m MIBI gated myocard perfusion SPECT (MPS) in the detection of coronary artery disease (CAD) and silent myocardial ischemia (SMI) in the patients with asymptomatic Type-2 Diabetes Mellitus (DM). Material and Methods: For this purpose, 35 patients with Type-2 DM and 15 volunteers without any cardiac symptom as a control group were included in this study. Exercise tolerance test (ETT), echocardiography and Tc-99m MIBI gated MPS were performed to the patients and volunteers. Computed tomography coronary angiography (CTCA) was performed in the patients with coronary ischemia or infarct detected in Tc-99m MIBI gated MPS. Biochemical analyses lipid profile of the patients and the volunteers were evaluated for the risk of CAD. The results were analyzed and compared visually and statistically. Results: The data of the present study revealed that silent myocardial ischemia was found at a high rate (25.71%, n=9) in 35 patients with Type-2 DM. Severe CAD in CTCA was detected in four of nine patients with ischemia or infarct in Tc-99m MIBI gated MPS (44.4%). Left ventricular diastolic dysfunction in echocardiography, ischemic pattern in ETT and high risk of CAD according to biochemical analysis were detected in the same four patients. At the end of statistical evaluation, we found that Tc-99m MIBI gated MPS showed significant correlations with CTCA, echocardiography, ETT, HbA1c, risk of CAD and diabetic age in diabetic patients with CAD. Conclusion: In conclusion, we propose that Tc-99m MIBI gated MPS is a reliable and non-invasive method, which can be used to detect silent myocardial ischemia and CAD in the patients with Type-2 DM. were subjected to 22 PET studies. All patients were treated previously with total thyroidectomy and 131 I treatment. The routine protocol during the follow-up included 131 I whole-body scan (WBS). Thyroxin treatment was withdrawn (four weeks) and patients were on an iodine-free diet before WBS. Tg, anti-Tg antibodies, FT 3 , FT 4 and TSH were determined. Patients with negative WBS and elevated Tg or with suspicion of recurrence were subjected one week later to a PET study. PET findings were verified by pathology report or other imaging techniques (CT, MRI, ultrasound) . Results: At the time of the PET study, mean thyroglobulin values were 106 ng/ml (5-400 ng/ml). In three cases, the value was <1ng/ml but there was suspicion of recurrence based on clinical examination. TSH values were always >50 μUI/ml and antithyroglobulin antibodies were negative. PET detected disease in 17/22 studies (77%), localized as follows: 12 cervical lymph nodes, 7 mediastinal lymph nodes, one lung metastasis and one bone metastasis. PET findings were verified by CT scan in 11 cases and by ultrasound and MRI in 6 cases. In all cases, presence of disease was confirmed by postoperative pathology report. PET was negative in 5 studies; four patients remained disease-free in the follow-up, and lymphatic metastasis was confirmed intra-operatively in one patient. Conclusion FDG-PET localized the metastasis in 17/22 (77%) of the studies performed in patients of DTC variants with poor prognosis (tall cell or Hürthle cell carcinoma), modifying the subsequent therapeutic approach to these patients.

The role of 99mTc-pertechnetate thyroid scintigraphy in hyperthyroid HCV positive patients treated with interferon (IFN ) Background: The occurrence of thyrotoxycosis in the course of therapy with IFN for HCV related chronic hepatitis is well known. However, a differential diagnosis between painless thyroiditis and Graves disease is needed to provide a proper clinical management of patients with thyroid disfunction and liver disease. Aim: To determine the value of pertechnetate uptake in the thyroid gland of patients with low TSH serum levels found in the course of treatment with IFN or within one months from drug withdrawal. Patients and Methods: Thyroid scintigraphies of 21 patients (17 f; mean age 44 yrs) treated with IFN and with low TSH values (mean TSH serum value: 0.07±0.13 mU/L; normal range: 0.26-5.0 mU/L) were retrospectively evaluated. Thyroid images were obtained at 20 minutes after intravenous injection of 111 MBq of 99m Tc-pertechnetate and the tracer uptake value was calculated as percentage of injected activity (normal range: 0.5-4%). Results: Pertechnetate uptake values were out of normal range in 16/21 patients; 13 of them had a low uptake value (A) and 2 had an uptake over the normal upper limit (B). A normal uptake value was seen in the remaining 6 patients (C) whose circulating hormone levels were into a normal range (see Table) . Discussion and Conclusion: Although hypothyroidism is considered the most frequent thyroid disease in the course of IFN therapy, the differential diagnosis of different forms of thyrotoxicosis has an important role in the clinical decision The aim of this study was to compare the effectiveness of fixed and calculated dose I-131 treatment efficiency in patients with Graves disease. Materials and Methods: We retrospectively analysed 139 patients with Graves disease who treated with radioiodine in a manner of calculated or fixed dose approach between the years of 2000-2006. Study group consisted of 31 male and 108 female patients (range: 19-78, mean age: 44±14,46 years old). Mean follow-up interval was 15±15 months. Twenty four patients excluded from the study due to failure in follow-up. One hundred and fifteen patients received single dose I-131. Sixteen of these 115 patients received I-131 via calculated dose and 99 fixed dose approach. Mean doses for both groups were as follows: 9±4.4 mCi for calculated dose group (range 3-17 mCi); 9±2.6 mCi for fixed dose group (range 3-20 mCi). The criteria for successful therapy was defined as euthyroidism or hypothyroidism after radioiodine therapy and, the existence of hyperthyroidism six months after therapy was considered as unsuccessful therapy. Results: For 16 patients who recieved calculated doses success ratio was %44 [hipothyroid (%31), euthyroid (%13)] after treatment. Success ratio was %65 [hipothyroid (%57), euthyroid (%8)] for 99 patients who recieved fixed doses. Hipothyroidism occured 1-27 months (mean: 6±5,6) after treatment. 16 patients recieved second doses and success ratio in this group was %80 [(hipothyroid (%53), euthyroid (%27)]. One patient whose thyroid volume was 127 g, recieved third dose and after total 60 mCi RAI-131 finally patient was euthyroid. Although the difference in success ratios and frequency of hipothyroidism weren't statistically significant, success rates and frequency of hypothyroidism was higer in fixed dose group. This statistical problem may be related to small number of patients in calculated dose group. Low success ratio in the calculated group can be a consequence of low dose/gr factor (100 mikrocurie per gram). Conclusion: Our results were in agreement with literature with respect to success rate and frequency of hipothyroidism in Graves' disease with fixed dose of radioiodine. Success rates can be improven by using higher dose/gr factors in calculated group. Aim: 131I-MIBG scintigraphy is shown to be useful in imaging of neuroendocrine tumours. A technique of in-house iodination of MIBG, developed in our department in 1993 was found to be very cost-effective. Our experience in 131I-MIBG scintigraphy with the tracer prepared in-house was analyzed. Materials and methods: Records of 131I-MIBG scintigraphy, carried out in our department between 1994 and 2006 were reviewed. Results: A total of 714 studies were performed during this period. There was a significant increase in the number of scintigraphy studies in the latter half of this period -265 during 1994 to 2001, and 439 during 2001 to 2006 . The clinical indications were pheochromocytoma and paragangliomas (261 cases), carcinoid tumours (47), neuroblastoma (88), medullary thyroid carcinoma (56) and others (262), with more of neuroendocrine tumours in the latter half of study period. Evaluation of Aim: HIV patients receiving HAART may develop body fat changes and low mineral density (BD), but whether these conditions are related is unclear. We further investigated whether a relationship exists between osteopenia/osteoporosis and lipodystrophy (LD)/lipoatrophy (LA) in HIV patients on HAART. Methods: Sixtyfive male patients, aged 31 to 53 yrs, with HIV infection HAART (treatment duration: 39.8±12.3 mths) were consecutively studied; all cases had normal BMI (range: 18 to 25); 21 patients had LD, 14 LA while 30 had no fat changes (NFC). There was no percentage difference between the 3 groups in HIV infection and HAART duration and in CDC stage, while the percentage of LD which included protease inhibitors (PI) in their HAART regimen was significantly higher than both LA and NFC patients. In all cases we measured by DEXA (Hologic QDR -4500 A) BD (g/cm 2 ) in lumbar spine, with t-score calculation according WHO criteria, and fat mass (FM; g) both in trunk (T) and appendicular (A) regions with T/A ratio calculation. Results: Globally, 44/65 (67.7%) patients had low BD values, with osteoporosis in 14 (21.5%) cases and osteopenia in 30 (46.1%); the frequency of osteoporosis was higher in LD patients (38%), than in LA (14%) and NFC (13.3%), but with significant (p<0.05) difference only between LD and NFC. BD was lower in LD than in LA and NFC, but not significantly. T-FM was significantly (p<0.01) higher in LD than in LA and NFC, and A-FM was significantly lower in LA than in LD (p<0.05) and NFC (p<0.01) with no difference between the latter two. T/A was significantly higher in LD (1.86±0.48) than in LA (1.4±0.3) and NFC (1.14±0.38) as well as it was in LA than in NFC. T-FM correlated negatively with BD and T/A positively with PI therapy duration. Conclusion: Bone mass loss, even osteoporosis, may occur in HIV patients on HAART with significantly higher frequency in PI treated patients who had lipodystrophy with T fat accumulation, in our cases. An inverse correlation seems to exist between T-FM and BD in HAART patients, but it is unclear whether the pathogenetic mechanism leading to T fat accumulation and bone mass loss is common. Aim: Body fat changes are common in HIV infected patients receiving HAART, mainly if protease inhibitors (PI) are present in their regimen, but the pathogenetic mechanism is still unclear. We evaluated quantitatively body fat composition in HIV patients treated with HAART to ascertain both fat loss and fat distribution changes in order to identify possible therapeutic and host related associated risk factors. Methods: We enrolled 136 HIV patients receiving HAART, 87 M and 49 F; according CDC stage, 54 patients were stage A, 44 stage B and 36 stage C. At clinical examination, fat changes were present in 76/136 patients (FC) and absent in the remaining 60/136 cases (NFC). In all patients we measured by DEXA (Hologic QDR -4500 A) fat mass (FM; g) in whole body (W), trunk (T), peripheral regions (P), arms (A), legs (L) and calculated T/P ratio and total weight (TW). We also measured BMI, CD4 counts and HIV RNA and determined CD4 count nadir and rise from nadir and HAART duration, including PI, NRTI and NNRTI. Results: We found significantly lower values of WFM (p<0.01), PFM and LFM (p<0.00001) in FC than in NFC; AFM was also lower in FC, but not significantly. Moreover, TFM and T/P were higher in FC than in NFC, but significantly (p<0.00001) only for T/P. No significant difference was ascertained in TW, BMI and in CDC stage between the 2 groups of patients. FC patients had significantly (p<0.00006) longer HAART duration in respect of NFC (42.6±8.9 vs 33.8±5.4 mths), in particular PI and NRTI duration; significantly higher current CD4 count (p<0.02) and CD4 rise from nadir (p<0.006) were also ascertained in FC than in FNC, while nadir showed no difference. WFM, PFM and LFM negatively and T/P positively correlated to PI and NRTI therapy duration. Conclusion: In HIV patients on HAART fat loss with distribution changes, mainly involving peripheral regions, may occur, significantly higher in FC and in NFC. The PI and NRTI longer exposure and the better immune recovery, both conditions affecting adipocite metabolism, could represent probable risk factors for fat loss in our FC cases, to be considered in HAART patient follow up. Aim The glomerular filtration rate (GFR) is measured frequently in cancer patient receiving cytostatics, because some of the pharmaceuticals are excreted by filtration in the kidney and some may also be nephrotoxic. The treatment dose of a few specific drugs is adjusted and calculated in relation to GFR and may be discontinued if GFR decreases severely. In Denmark, GFR is assessed by plasma clearance of 51 Cr-EDTA ( 51 Cr-labelled ethylenediaminetetra-acetic acid), which is a highly reliable method, but indeed also time consuming. Due to the frequent need of GFR-estimation it appears relevant to look for a more simple method for estimating GFR. In this study we therefore explored the possibility of replacing 51 Cr-EDTA (GFR) by an estimate (eGFR) from plasma creatinine, sex and age of the patients according to . Material and Methods Cancer patients having a least four 51 Cr-EDTA measurements performed in 2005 were included in the study. Information concerning gender, age, weight, diagnosis, chemotherapy, plasma creatinine and GFR were obtained from the files and eGFR was calculated using the Cockroft-Gault formula. Results In 2005, 48 patients (13 women and 35 men) were subjects to at least four GFR measurements. Mean age was 47 years (range 21-77 years) and the diagnostic profiles included: sarcoma (36%), cancer of the bladder (27%), germ cell tumors (13%), cervical cancer (8%), lung cancer (4%), unknown primary (4%) and various (8%). All patients were treated with nephrotoxic chemotherapy such as cisplatin, carboplatin and ifosfamide. On average, GFR decreased continuously from the first to the last measurement: 97, 90, 84 and 81 ml/min (16%). eGFR, however, first increased and then decreased with no difference between the first and last values: 101, 104, 108 and 104 ml/min. As a consequence, the ratio GFR/eGFR decreased significantly from 0.99 to 0.82. Conclusion: In patients receiving nephrotoxic cytostatics GFR and eGFR agreeded at the first examination but a 16% fall in GFR was not detected by the eGFR. Consequently, plasma clearance of 51Cr-EDTA can not be replaced by eGFR from plasma creatinine and the Cockroft-Gault formula in these patients if the aim is to calculate the specific dose as accurate as possible in order to monitor the toxicity of the various treatment strategies and to ensure the highest efficacy. [1] The variation in age, body habitus, glycemia level, duration of uptake period and partial volume effects are important factors that influence the SUV level. The purpose of this study was to quantitavely assess the differences of SUVbw (SUV measurement based on body weight) in normal tissues (blood, hepatic parenchyma, spleen, kidney, bone marrow, muscle, stomach, brain) and to evaluated the degree of correlation with body weight and age. Materials and methods 35 consecutive patients having 18 FDG-PET/CT studies were evaluated retrospectively (19 M and 16 F mean: 61 ± 12.57 y.o. and body weights ranged from 48 to 120 mean: 75 ± 16). Approximately 1 h after injection of 5 MBq/kg of 18F-FDG, whole-body CT images were acquired without contrast media. A whole-body emission PET scan was performed with 3 min acquisition per each bed position (PET/CT: Discovery STE, GE). ROI were placed at the same level with no know abnormality. Mean SUVbw were compared, and the correlation between FDG uptake and body weight, patient age was assessed by using the Pearson correlation coefficient test. Results The mean SUVbw values for cerebellum, kidney, stomach, liver, bone marrow, spleen, blood and muscle were 7.21 ± 2.21, 2.46 ± 0.86, 2.24 ± 0.73, 2.03 ± 0.41, 1.92 ± 0.56, 1.79 ± 0.43, 1.52 ± 0.32 and 0.73 ± 0.21. Body weight correlated well with mean SUVbw (blood r = 0.49, p < 0.01; kidney r = 0.46, p<0.01; spleen r = 0.37, p = 0.03; stomach r = 0.36, p = 0.03; bone marrow r = 0.33, p = 0.05; liver r = 0.32, p = 0.06; muscle r = 0.3, p = 0.08; cerebellum r = 0.21, p = 0.24) The SUVbw showed no significant and very weak correlation with age ranged from r = -0.25, p = 0.15 (kidney) to r = 0.14, p = 0.44 (spleen). Discussion Although there was a wide variance in the SUVbw, it showed a strong significant positive correlation with body weight in blood, kidney, spleen, stomach and bone marrow. The best correlation between glucose consumption and body weight was observed when the SUVbw was > 1.52 ( blood) with exception of cerebellum. The SUV bw showed no significant correlation with age. Conclusion SUVbw are weight-dependent indice for FDG uptake in tissues. There are however some notable differences between the r correlation coefficient with regard to the selection of normal tissues. Aim: To investigate the diagnostic potential of a new semiquantitative sacroiliac index in bone scintigraphy, as a method to distinguish chronic, non-infectious, inflammatory sacroiliac disease (CILBP) from low back pain of mechanical/non-inflammatory origin (MLBP) in young males. Patients and Methods: We studied a relative homogenous population sample of 133 young males, aged 18-36 years, including the age when many sacroiliac diseases emerge. Of these people, 32 (group A) had CILBP, verified by clinicolaboratory and other imaging procedures, 29 (group B) had MLBP similarly verified, and the rest 72 (group C) had been scintiscanned for reasons irrelevant to sacrospinal disease. All of them were also subgrouped by age criteria. After planar static bone scanning, two rectangular and symmetrical regions of interest (ROIS) were drawn onto the bottom third of the sacroiliacs, as well as a third one which encompassed the whole L4 vertebra. Finally a non-dimensional numerical value called "r" was created for all patients, by the equation r = total counts/total pixels of the "hottest" of the two sacroiliac ROIS divided by the counts/pixels corresponding to the L4 values (r = SI/L4). Results: The statistical analysis showed negative correlation of r with age in all three groups (P=0.04 for group , 0.012 for group and 0.05 for group C). Regardless of age, the mean value of r of group's B patients (1.53 +/-0.12) appeared significantly lower (P=0.002) than group's A (1.66 +/-0.17) and unsignificantly higher (P=0.12) than group's C (1.49 +/-0.14), while group's A mean value of r also appeared significantly higher than group's C (P<0.0005). Conclusions:

the SI/L4 ratio seems to decrease with ageing -at least in the young ages-, irrespectively of the presence of CILBP, and its clinical potential seems to be helpful in the distinction of patients with CILBP from both the normal people and from patients with MLBP. To our knowledge, there is no other study of this semiquantitative index in young male adults with CILBP using the above methodology, but a larger population sample would still be necessary so to accurately standardize the normal value range of SI/L4 ratio.

F. Marafi, A. Syed, A. Esmail, A. Elgazzar; Mubarak Al-Kabeer Hospital, Jabriyah, KUWAIT.Aim: Post-polio syndrome causes new weakening in muscles previously affected by the polio infection and in muscles that seemingly were unaffected. Patients present with musculoskeletal pain, weakness, and fatigue that probably result from overuse and misuse of muscles and joints. The objective of this study is to review patterns of poliomyelitis on bone scintigraphy. Material and methods: Bone scans of 6 adult patients, five females and one male, aged 35 to 51 years, known to have paralytic poliomyelitis were studied. Five patients had unilateral while one has bilateral disease. Patients' complains included knee, shoulder, neck and/or back pain. All the patients underwent three-phase bone scan acquired 5 minutes (blood pool) and 3 hours (delayed) post-intravenous injection of 25 mCi of Tc99m MDP. Studies were reviewed by two nuclear medicine specialists and findings were recorded. Results:The following patterns were recognized: (1) Markedly decreased blood pool activity in all affected limbs particularly distal to the knee (both limbs in the patient with bilateral disease), (2) Deformed ipsilateral hemipelvis with relatively reduced radiotracer uptake in all patients with unilateral disease with minor degree of asymmetry in the patient with bilateral disease, (3) stress changes in the contralateral lower extremity illustrated by relatively increased radiotracer uptake diffusely in the bones of the lower extremity and (4) degenerative changes of multiple joints (shoulders, knees, ankle and spine). Significant scoliosis was only noted in the patient with bilateral disease. Conclusion: Bone scintigraphy shows several poliomyelitis related findings predominantly due to skeletal asymmetry with unilateral disease. Awareness of the characteristic scintigraphic findings is important to avoid misdiagnosis on bone scan which can help also in the follow up of post poliomyelitis changes. Purpose: To examine the observer variation for bone scintigraphy in the detection of occult scaphoid fractures in daily practice, using only the early bone scanning images. Methods: One hundred subsequent bone scans of patients with a suspected scaphoid fracture but negative initial radiographs were prospectively included to calculate the inter-and intra-observer variation. Three nuclear medicine physicians independently evaluated all bone scans at two different points in time with a three months interval. The observers filled out a blinded scoring sheet for each patient. They scored if a scaphoid fracture was present or not. In addition they scored the presence or absence of another fracture. The inter-and intra-observer variation was analysed using the kappa statistic. Results: The inter-observer variation showed substantial agreement for a scaphoid fracture and almost perfect agreement for another fracture. The intraobserver variation showed almost perfect agreement for both a scaphoid fracture and another fracture. Conclusions: In the present study early static images of bone scintigraphy for suspected scaphoid fractures showed very little inter-and intraobserver variation. In addition, expertise does not seem to have a negative influence on the results. This enhances the possibility of using bone scintigraphy in daily practice.

Aim: To determine normal limits for quantitative 99m Tc-HDP three phase bone scintigraphy regarding flow distribution at ankle and mid foot level. Materials and methods: 62 consecutive patients referred to bone scintigraphy and without known pathology in the legs or hips were included. 51 patients were eligible, 29 females and 22 males. The population was divided into three groups according to age; less than 50 years (n=17), between 50 and 69 years (n=20) and older than 70 years (n=14). Quantitative three-phase bone scintigraphy was performed in all patients. First phase consisted of a dynamic planar uptake in anterior projection immediately after a bolus injection of 700 MBq 99m Tc-HDP with a matrix size of 128 by 128 pixels with a LEGP collimator, dorsal view, and recording of 120 frames at two frames per second. A processing protocol with standardised size ROIs was used to quantify flow distribution at ankle level and in the mid foot using the area under the curve for each ROI during the first ten seconds of initial bolus passage. Results: Blood flow distribution at ankle and mid foot level for the three age groups is presented in table 1. Conclusion: We suggest the normal range for distribution of blood flow at ankle level determined by quantitative three phase bone scintigraphy to be 36/64 (i.e. mean + 2SD). Since variation in blood flow at ankle and mid foot level increases with age most probably because of uneven development of arteriosclerosis and various joint diseases, normal ranges for blood flow distribution at ankle level is wider among people older than 70 years. At mid foot level the normal range for blood flow is as wide as 20/80. The reference levels presented have been produced with the intention to quantify blood flow distribution at ankle and mid foot level among patients with various pathological conditions in particular Charcot foot. Aim: The aim of this study was to determine whether there is a difference between the left and the right proximal femur bone mineral densities (BMDs) and, therefore, whether it is necessary to measure BMD of the femur bilaterally in determining bone loss. Material and Methods: This study was performed on 399 subjects (353 women, mean age 55 ± 11 years; and 46 men, mean age 54.9 ± 15 years). BMDs of both hips (femoral neck, trochanter, intertrochanter and ward's area) were measured using dual energy X-ray absorptiometry (DEXA) (QDR_4500-Hologic densitometer). The statistical software SPSS version 10 for Windows (SPSS, Inc, Chicago, IL) was used for statistical analysis. A paired t-test was used to assess the right versus left (R-L) differences in BMDs of the said regions. The results of BMD measurements were expressed in units of grams per square centimeter (g/cm²) as means (M) and standard deviations (SD). The 2-tailed Pearson correlation was used for correlation analyses between R-L BMDs. Results: The mean femoral neck and trochanter BMDs in total subjects were higher in the right leg than the left (0.787 ± 0.130 vs. 0,768 ± 0.129, p< 0.001; and 0.637 ± 0.117 vs. 0.629 ± 0.115, p< 0.005, respectively). Similar results were also obtained in females (0.784 ± 0.129 vs. 0,767 ± 0.126, p< 0.001; and 0.633 ± 0.115 vs. 0.624 ± 0.113, p< 0.005, respectively). In males, a significant right versus left BMD difference was found only in femoral neck (0.810 ± 0.136 vs. 0,779 ± 0.146, p< 0.005). There were significant correlations of BMD between all the right and the left femoral regions (p< 0.001). Conclusion: Although BMDs of the right and the left femoral regions were strongly correlated, there were significant R-L differences of BMD in femoral neck (in males and females) and trochanter (in females). Therefore, bilateral femur BMD should be taken into consideration in evaluating a possible bone loss.Aim: The purpose of this series of cases was to describe clinical findings and patterns of the triple phase bone scans in young patients with clinical examination suggesting medial tibia stress syndrome (MTSS) or "shin splint", term frequently used synonymously with this disorder. Material and Methods: This study included seven patients (11 limbs) selected retrospectively with clinical examination suggesting MTSS that underwent plain radiographs and triple phase bone scintigraphy (TPBS) with Technetium-99methylene diphosphonate dimmer (MDP) during the period from June/2006 to February/2007. Patients generally reported diffuse tenderness along the posteromedial edge of the tibia and complained of exercise-induced pain after starting physical activity. Results: Five patients had bilateral symptoms and two had unilateral pain. Mean duration of symptoms was about 6.1 weeks. There were 6 male and 1 female. Age ranged from 19 to 35 years old (mean value=24.71). Patients included 4 runners (2 military recruits and 2 recreational runners), 1 professional basketball player, 1 recreational soccer player and 1 recreational gymnast. All the patients related exercise-induced pain in the beginning of activity. One recreational runner related an unbearably pain when he continued the activity. Radiographs were normal in all patients. Perfusion and blood pool images of isotope bone scans were normal in all cases. Delayed bone scintigraphy showed characteristic longitudinal linear uptake in 4 limbs (2 patients) and focal uptake (longitudinally spindle-shaped uptake) in 7 limbs (5 patients). Conclusion: In this study, all patients with clinical examination suggesting MTSS had scintigraphic abnormalities. Most of them had focal uptake (longitudinally spindle-shaped uptake) in the bone scan. It was an unexpected finding once MTSS pattern most usually found in other studies is longitudinal diffuse uptake (double stripe sign, tubular pattern or longitudinal linear uptake), more related to bone remodeling. In the current study, most patients were recreational athletes. This fact suggests that many of these problems result from poor or misguided training regimens. Bone scintigraphy was an important tool to confirm the clinical diagnosis of MTSS and exclude other causes of lower leg pain such as stress fracture, nerve compression syndrome and extertional compartment syndrome. Accurate diagnosis is essential in early phase after the onset of pain to establish specific treatment and ensure return to sports activity. Transiet osteoporosis of the hip (TOH) is an uncommon condition. It presents with progressively worsening hip pain gradually increasing without history of trauma. There is a characteristic discrepancy between substantial clinical disability and minimal physical findings. This condition is characterized by a predictable bening course, with complete clinical recovery. Unlike TOH, avascular necrosis (AVN) is a Introduction-Aim: Early diagnosis of osteomyelitis (OM) in the diabetic foot reduces the need for amputation, but detection is difficult. Coexisting disorders such as soft tissue infection and Charcot arthropathy (CA) may obscure the clinical and radiological manifestations of OM and bone biopsy is not routinely performed. The aim of this prospective study was to evaluate the efficacy of Tc99m-HMPAO-labelled leucocyte scan (HMPAO-LS) for the diagnosis of OM in the complicated diabetic foot, in comparison with other commonly used diagnostic modalities. Patients and methods: Forty five diabetic patients with clinical suspicion of OM in 54 pedal sites were enrolled in the study. All patients had pre-existing pedal abnormalities including pedal ulcers (n=36), CA (n=27), and toe or foot amputation (n=21). C-reactive protein levels (CRP), ESR and white blood cell count (WBC) were measured at inclusion. All patients underwent plain radiography, three-phase Tc99m-MDP-bone scan (MDP) and HMPAO-LS. Tc-99m-sulfur colloid bone marrow scan (BMS) was additionally performed in 6 patients to interpret abnormal leucocyte uptake in CA. Spatially congruent bone/leucocyte findings were interpreted as positive for OM. Incongruent HMPAO-LS /BMS indicated OM superimposed on CA. Diagnosis was confirmed by long-term clinical and radiological follow-up or bone biopsy. Results: Among the 54 pedal sites investigated, 26 foci of OM, 6 cases with acute Charcot arthropathy (ACA) and 22 sites with simple soft tissue infection (STI) were diagnosed. Patients with OM had higher CRP compared with those with ACA or STI (24.6 vs 10.3 and 7.5 mg/L , p<0,05). WBC and ESR were not significantly different among the three groups of patients. Plain radiography was insensitive (34.6%), but very specific (96.4%) while three-phase bone scan was extremely sensitive (100%), but not specific (10.7%) for the diagnosis of diabetic foot OM. The sensitivity, specificity and accuracy of HMPAO-LS were 95%, 88% and 91.1%, improved to 95%, 100% and 97.8% respectively with the addition of BMS. Conclusion:Among laboratory tests, elevated CRP is better marker of OM in the diabetic foot compared with leucocytocis or elevated ESR. Plain radiography is the least sensitive imaging method for early diagnosis of OM and bone scan is the least specific method for detecting OM in patients with pre-existing pedal abnormalities. Tc99m-HMPAO-labelled leucocyte scan is the most accurate radionuclide method for the diagnosis of OM in the diabetic foot. The addition of bone marrow scan improves the specificity of leucocyte scan for diagnosing OM superimposed on CA. Aim: In the large-vessel vasculitis, in particular Takayasu arteritis (TA), clinical signs and laboratory tests are not good markers for evaluating the vascular disease activity. Aim of this study is to evaluate if FDG-PET can have a role in assessing the inflammatory activity and the extent of the disease in patients (pts) with TA by a correlation between 18F-FDG uptake, acute-phase reactants and the clinical outcome. Material and Methods: We studied 28 consecutive pts with large-vessel vasculitis in steroid treatment (m/f 5/23; age 52±15yrs; 23 TA and 5 Giant Cell Arteritis). A total number of 37 PET studies was acquired. FDG uptake was evaluated using a visual score (0-1-2-3), in 7 different vascular areas and a total vascular score was calculated.PET was performed at the same time of the evaluation of acute-phase reactants [erythrocyte sedimentation rate (ESR), C-reactive protein (CRP) and interleukin-6 (IL-6)] and assessment of disease activity according to the Kerr criteria. Results: The frequency of elevated ESR was higher (p 0.049) in presence of vascular FDG uptake (50%) than in absence of uptake (16%). ESR was higher (p 0.026) in pts with vascular FDG uptake (33±22) than in pts with no uptake (20±13). The PET score was significantly (p 0.019) higher in pts with high ESR (5.7±4.2) than in pts with normal HSR (2.7±2.9). The correlation of PET score was significant with ERS (R=+0.41 p 0.013) and IL-6 (R=+0.48 p 0.037) and not with CRP (R=+0.20 ns). The PET score was significantly higher (p 0.011) in pts with active disease (6.6 ±4.6) than in pts with inactive disease ( , colon carcinoma=3, kaposi sarcoma=2, lung tumors=2, anal carcinoma=2, myeloma=2, cervical carcinoma=1, HCC=1, brain tumor=1) underwent FDG PET/CT studies to identify areas of HIV replication and/or tumor increase. All 123 HIV-positive patients had a combined PET and CT body scan (Discovery LS PET CT, GE Healthcare, Milwaukee, WI, USA) from the base of the skull to the pelvis with [18F]fluorodeoxyglucose (FDG) and 5 patients also had brain studies with FDG. FDG accumulations (visual and quantitative) were rated, on a per patient basis, as true positive(TP) or true negative(TN), and false positive(FP) or false negative(FN), based on final clinical data. Results: 44/123(36%) HIV-positive patients had proven malignancies (NHL=32, HL=8, lung cancer=1, anal cancer=1, brain tumor=1, HCC=1) in cytology/histology and conventional diagnostic imaging procedures (CT, MRI, abdominal US, thorax X-ray). In this context, overall sensitivity (TP/TP+FN), specificity (TN/TN+FP) and accuracy (TP+TN/TP+TN+FP+FN) of PET/CT scanning with FDG was: 84%, 58%, 69% respectively for diagnosis of NHL diseases; 100%, 69%, 81% respectively for diagnosis of HL and 80%, 44% and 64% respectively for diagnosis of other neoplastic diseases. Moreover, nodal FDG uptake showing active HIV replication areas was well identified in 18/123 HIV-positive subjects, and lung infections were correctly diagnosed in six more HIV-positive cases. The standardized uptake values (SUVmax) over nodal lesions from lymphoma (NHL plus HL) were in the range of 3.4-21 and in active HIV replication were in the range of 1.5-2.5. Conclusion: In our patient series, FDG PET/CT scan misjudged in the separation of malignancy from infection in some cases. However, PET/CT provided accurate localization of malignant and infective disease allowing biopsy of specific sites. Even if abnormal FDG uptake occurs in subjects' nodes with detectable viral load, evaluating active lymphoid tissues during HIV infection from malignant lymphomas was possible.

The effect of recent hemodialysis on invivo labeled 99m Tc WBC lung retention in patients with end stage renal disease (ESRD)Aim: Several clinical studies are evaluating the therapeutic potential of delivery of various progenitor cells (PCs) for treatment of injured hearts. The only noninvasive in vivo imaging method for evaluation of homing of transplanted haematopoietic PCs (HPCs) used so far was labelling the cells with 111In-oxine. The aim of our study was to evaluate radiolabelling of CD34+ haematopoietic PCs with 99mTc-exametazime and to examine use of radiolabelled cells to monitor myocardial homing. Materials and Methods: Human HPCs were mobilized with granulocyte-colony stimulating factor and collected by aphaeresis. CD34+ cells were enriched with an immunomagnetic separation device (Isolex 300i). Amount of collected CD34+ cells per patient varied between 78 to 497 million. A fraction of of the cells (20-27%) was radiolabelled with 600MBq of 99mTc-exsametazime and incubated for 20 min at room temperature. To remove unbound radioactivity, the cells were washed with cell free media. Cell viability was assessed by Trypan Blue exclusion assay before radiolabelling and 5 and 150 min after labelling. Labelling stability of HPCs was assessed 150 min after cell labelling. 87-205 MBq of radiolabelled cells was injected into open coronary vessel through a micro catheter. SPECT images were obtained 2 and 16 hours after HPC injection. Results: Labelling efficiency of HPCs was up to 40.2% depending on the amount of cells available for radiolabelling. According to trypan-blue staining, viability of radiolabelled HPCs before and immediately after the labelling was 82.9% and 83.2% respectively, whereas viability 150 min after labelling was 61%. Labelling stability of HPCs 150 min after cell labelling was 60.8%. SPECT images obtained 2 and 16 hours after HPCs injection enabled us to evaluate the arrangement and percentage of transplanted HPCs accumulated in the heart muscle. Additionally it was possible to evaluate their migration and accumulation in the reticuloendothelial system of the liver, spleen and bone marrow. Conclusion: We can conclude that 99mTcexametazime labelling of HPCs is feasible, and in vivo imaging with SPECT provides a non-invasive method for sequentially monitoring cell trafficking with good spatial resolution.

Red cell mass, plasma volume, blood volume and their deviations from expected normal values in patients with end stage chronic renal disease. Results: PVK was correlated (r 2 :0.7 p<0.001) with PCV and BMI in all patients especially in men (r 2 :0.92). RCVK in all patients was also strongly correlated (r 2 :0.77 p<0.001) with PCV and BMI. RCVK in men is affected only by BMI (r 2 :0.74 p<0.01), while in females both PCV and BMI's influence reach statistical significance. In general, DRCV and DPV are strongly related to BMI and PCV (r 2 : 0.78 and 0.6 respectively). In men PCV and W predict DRCV and DPV (r 2 :0.8 and 0.9 respectively) whereas in female subjects only DRCV is strongly correlated (r 2 :0.9 p<0.01) with PCV and W. Serum Fe seems to have a predictive role in DRCV and DPV estimation. No other significant correlation among biochemical parameters (urea, creatinine, PTH), total duration of dialysis and blood volumes was found. Conclusion: Not only radionuclide measurement of blood volumes but their promt estimation as well from the above equations has an important role in decision making in patients at ESRD providing a applicable estimation of their anaemia. Aim: To assess the contribution of an integrated SPECT-CT (Infinia-Hawekeye 4, GE Healthcare) in patients undergoing 99m Tc-radiolabelled blood cell imaging. Material and Methods: 39 consecutive patients underwent 99m Tc-radiolabelled blood cells imaging. Among them, 11 patients had 99m Tc-red blood cell imaging (RBC) for suspicion of liver or spleen hemangiomas (n=9), and for suspicion of splenosis (n=2); additionally, 28 patients had 99m Tc-HMPAO-white blood cell imaging (WBC) for detection of active Crohn's disease (n=15), and for suspicion of infection (n=13). Following the routine protocol, a low-dose unenhanced SPECT-CT study (2.5mA, 140kV, Eff.D 2mSv) was performed. SPECT-CT findings were compared to planar and SPECT results. Final reports were correlated to morphological imaging, clinical and surgical reports. Results: In the RBC group, 7/11 patients had a positive study suggestive of liver or spleen hemangiomas (n=5) and splenosis (n=2). SPECT-CT was particularly useful for appropriate differentiation between physiological uptakes and pathological uptakes (vessel hot spots vs. liver lesions), as well as for precise anatomic localization of functional splenic remnants. All liver lesions >1.5cm were assessable on the low-grade CT, but liver or spleen lesions <1cm were not always distinctly detected. In some patients, respiratory motion artifacts also impaired the CT quality. In the WBC group, 10 patients had a positive study suggestive of infection on planar imaging. SPECT-CT was particularly helpful for a more accurate diagnosis of osteomyelitis vs. soft tissue infection (n=9), or for confidently ruling out a liver abscess (n=1). In 12 patients with Crohn's disease (CD), SPECT-CT allowed better anatomic localization of disease extent, and exclusion of intra-luminal bowel activities. In 1 patient, SPECT-CT helped identify an entero-cutaneous fistula from ileostomy; in 6 patients with active CD, the low-dose CT showed a colon wall thickening with a lumen narrowing matching a hot spot on the SPECT part. Conclusion: In 99m Tc-radiolabelled blood cell imaging, a low-dose multi-slice SPECT-CT, the Infinia-Hawkeye -4, was found useful for improving the interpretation confidence, and thus, the diagnostic accuracy. Aim: Behcet's disease (BD) is a multisystem disorder characterized by vasculitis, and consists of a triad of recurrent ulcers of the oral and genital mucosa with relapsing uveitis. The prevalance of pulmonary involvement varies in the range of %1-10 in various studies and its complications are severe and life threatening. We aimed in this study to investigate the changes of pulmonary epithelial permeability of patients with BD using 99m Tc-DTPA aerosol scintigraphy. Material and Methods: Twenty-one non-smoking patients with BD (8 females, 13 males; mean age: 38.67±8.86 years) and 15 healthy voluntary non-smoking controls (8 females, 7 males; mean age: 50.87±12.45 years) underwent 99m Tc-DTPA aerosol inhalation scintigraphy and pulmonary function tests. Subjects inhaled 1480MBq of 99m Tc-DTPA for 4 minutes in supine position. Scintigraphic data were recorded dynamically (1frame/min) in posterior projection on a 64x64 matrix for a 30 min period using with a double headed gamma camera (Infinia, GE, Tirat Hacermel, Israel) equipped with a low-energy all purpose parallel hole colimator. Half time of 99m Tc-DTPA clearance (T 1/2 ) were calculated by placing a mono-exponential fit on the curves. Penetration index (PI) was also calculated by dividing the peripheral total counts by the sum of the peripheral and central total counts on the first minute image, in order to quantify the distribution of the inhaled aerosol. Results: The clearance half time of 99m Tc-DTPA radioaerosols in BD's patients (24.81±6.2 min) were faster than in normal control group (46.47±22.33min) (p=0.002). There was also a significant difference between PI of patients with BD (14.66±3.01) and that of controls (20.56±6.10) (p=0.0005). No correlation was found between the mean T 1/2 values of 99m Tc-DTPA clearance and the spirometric measurements except FEV 1 in BD patients (r=0.48; p=0.03). PI were correlated with FEV 1 in BD patients (r=-0.44; p=0.048). Conclusion: Lung epithelial permeability of the patients with BD was found significantly lower than that of normal subjects. The result of this study demonstrated that the assessment of lung epithelial permeability using 99m Tc-DTPA aerosol scintigraphy could predict the presence of lung involvement in patients with BD. .

Detect of pulmonary emobolism in patients with deep venous thrombosis using 99m Tc -Technegas/ 99m Tc-MAA lung scan S. L. Chen, B. L. Li, W. Liu, Y. Gu; Institution of Nuclear Medicine,Zhongshan Hospital,Fudan University, Shanghai, CHINA.

The existence and severity of pulmonary thromboembolism(PTE) was still one of the major clinical concerns. The aim of this study was to assess the use of lung ventilation/perfusion (V/Q ) scan in the investigation of PTE, and compared the results of lung ventilation/perfusion (V/Q ) scan with CT angiography (CTA) or MR angiography (MRA). Methods: A total of 85 patients with deep venous thrombosis (DVT) underwent V/Q planar scan and chest X-ray , CTA or MRA were performed also. The modified Prospective investigation of Pulmonary Embolism Diagnosis(PIOPED) diagnostic criterion was used for interpretation of lung scintigraphy. According to the data of perfusion-ventilation scintigraphy, the patients was consider with a high pretest probability of pulmonary embolism, intermediate probability of pulmonary embolism, low probability of pulmonary embolism, lower clinical probability of pulmonary embolism or normal. the patients with a high pretest probability, intermediate probability and low probability were positive, lower probability and normal patients were negative. Results: Among the 85 patients, 29 patients with a high clinical probability of pulmonary embolism (34.1%) by 99mTc -Technegas/ 99mTc-MAA Lung Scan, 7 patients with a intermediate clinical probability of pulmonary embolism (8.2%), 6 patients with a low clinical probability of pulmonary embolism(7.1%), 1 patients with a lower clinical probability of pulmonary embolism (1.2%), another 42 patients were normal(49.4%). Pulmonary embolism was detected in 42 of the 85 patients (49.4 percent). Compared with the data of lung V/Q scan detect and CTA or MRA examination In the patients with clinical probability of pulmonary embolism, 76% patients showed different blood vessel abnormality findings between lung V/Q scan defect and CTA or MRA. We found that in patients with partly pulmonary embolism, the blood flood could pass away the stricture artery. So the perfusion scan of the patients maybe was normal, the perfusionventilation scintigraphy couldn't found pathological vascular disease. Moreover, when the small pulmonary embolism was in the laterale or outboard segment of the lung, CTA or MRA maybe mistake diagnosis and the perfusion-ventilation scintigraphy could found pathological vascular disease. Conclusions: Lung V/Q scan was a considerably effective technique to detect PTE. The combination of V/Q scan and CTA (or MRA) could provide more comprehensive and accurate diagnosis information. And a larger outcome study is needed.

Comparison of ventilation-perfusion scintigraphy and contrast enhanced computed tomography in patients with pulmonary embolism K. F. Wurm, T. Zelesny, U. Wacker, A. Hentz, F. Dammann; Department of Radiology and Nuc. Med., Göppingen, GERMANY.Aim: Ventilation-Perfusion scintigraphy has been the main imaging modality used in the evaluation of patients with suspected acute pulmonary embolism. Since the introduction of multi-slice devices computed tomography has been used as an equivalent imaging method. The aim of our study was to correlate the results of ventilation-perfusion scintigraphy with spiral CT pulmonary angiography. Material and Methods: We evaluated 40 patients (23 women, 17 men, mean age 62 years) with suspected acute pulmonary embolism (symptomatic patients and increased D-dimer blood test). All patients underwent computed tomography and ventilation-perfusion scan. Scintigraphic examinations were obtained with two head gamma camera, using Tc-99m labelled human albumin microspheres. Spiral CT scans were performed with the use of radiological contrast and multi-slice device. We compared the results of these three investigations. The sensitivity and specificity were evaluated. Results: The ventilation-perfusion scintigraphy presented matching results in 21 of 40 cases. 16 of them presented an identical issue in computed tomography. In 19 of 40 cases we found a mismatch of ventilation-perfusion study. In 15 cases computed tomography could confirm a positive acute lung embolism. The sensitivity and specificity of lung perfusion scan in detecting lung embolism was 89% and 82%. Computed tomography revealed a sensitivity and specificity of 92 and 95 %. Conclusion: The results of ventilation-perfusion scintigraphy confirm a high sensitivity for diagnosis of lung embolism. In correlation computed tomography presented a similar sensitivity with additional specific informations. Both modalities shall be accepted further on as an important diagnostic tool for patients with suspected lung embolism.

Pfeifer, N. Millman, J.Mortensen; Rigshospital, Universityhospital of Copenhagen, København Ø, DENMARK.A 49-year old woman, suffering from stridor and dyspnoe was diagnosed with tracheobronchial amyloidosis of transthyretin type (ATTR). Pulmonary involvement in ATTR is uncommon. According to the patient's symptoms and for prognostic reasons it was important to rule out cardiac amyloidosis as frequently seen in ATTR. The usefulness of 99m Tc -aprotinine scintigraphy in detecting extra abdominal lesions of amyloidosis and especially early cardiac involvement has previous been shown (1) . Thus, the patient was evaluated with 99m Tc -aprotinine whole body scintigraphy supplemented with single photon emission tomography (SPECT) and computer tomography of the chest using the VG Hawkeye GE hybrid system. There was a close correlation between a) the scintigraphic findings of amyloid deposits in the central airways and b) the wall changes of the right upper bronchus as seen on the low quality CT (Hawkeye) and c) the right upper lobe atelectasis shown on chest x-ray. No extra pulmonary amyloid deposits were found. Conclusion: 99m Tc -aprotinine scintigraphy with SPECT/CT detected amyloidosis in the central airways that correlated closely to the clinical and histological findings. Reference: (1) Objectives: The purpose of this study was to evaluate the usefulness of Tl-201 Chloride/Tc-99m MIBI, for the investigation of lung lesions, after comparison with CT and histological findings. Methods: Scintigraphy with Tl-201 Chloride and Tc-99m-MIBI was performed in 24 patients [19 men, aged 48-80 years and 5 women aged 66-78 years] with radiographic findings lung nodules, suspicious for malignancy. Factors of the early and delayed static scans (hot, warm or cold uptake), the early and delayed retention indexes, the blood flow and the tumour retention index were obtained from Tl-201/Tc-99m-MIBI scintigraphy. Tumour retention indexes were classified into three grades; slightly (>0.9), moderately (0.9-0.8) and severely (<0.8) decreased. Grade of tissue differentiation of tumour (well, moderately or poorly differentiated) and tumour size (T1 T4) were examined. Scintigraphic indexes and tumour characteristics were compared. Results: The early static scan and tumour size showed a correlation with the blood flow index. However, the delayed static scan did not show any relationship with blood flow index and tumour size. The tumour retention index with Tc-99m-MIBI had a tendency to decrease in malignant tumours, and showed a significant correlation with the grade of tissue differentiation of the tumour. Regarding Tl-201 Chloride we obtained a 88.8% sensitivity, 80% specificity, 87% accuracy, a 94.1% positive prognostic value and a 66.6% negative prognostic value. Conclusions: The tendency of the tumour retention index to decrease in Tc-99m-MIBI scintigraphy might imply the malignancy of the nodule investigated and would be an additional useful parameter for the accuracy of the diagnosis.

Introduction: In patients with CTD, the early detection of the pulmonary involvement is mandatory. Pulmonary Function Tests (PFTs) are considered to be valuable noninvasive diagnostic modalities. Among them, carbon monoxide lung diffusion (DLCO) reduction that is consistent with pulmonary fibrosis and microvascular damage is widely considered as the earliest and most sensitive index for the evaluation of pulmonary involvement. In previous studies we proposed the usefulness of HIG scintigraphy in the evaluation of lung involvement in CTD. The aim of our study was the evaluation of HIG lung scintigraphy, in the early detection of the pulmonary involvement in CTD patients. Methods: Fifty-two non-smoking patients suffering from Scleroderma, Rheumatoid Arthritis or Systemic Lupus Erythematosus (males/females 8/44, mean age 54.8 years, mean duration of disease 8.4 years) and referred to our institution for detection of possible pulmonary involvement were included in this study. Patients were submitted to PFTs (DLCO, forced vital capacity [FVC] and total lung capacity [TLC]) and HIG scintigraphy within a week. For semiquantitative interpretation of HIG scintigraphy, a region of interest (ROI) analysis was performed on the posterior view (sum of the mean activity for each lung divided by mean left ventricular activity / 2 = average score). The average score was correlated with PFTs. Pearson's correlation coefficient r was calculated. A probability P<0.05 (two-tailed) was considered to indicate statistical significance. Results: PFTs abnormalities were detected in 40 patients (DLCO reduction in 39, FVC reduction in 13 and TLC reduction in 19 patients). A statistically significant negative correlation was detected between HIG scores and each one of the PFTs [DLCO (r=-0.46, p<0.001), FVC (r=-0.42, p=0.002) and TLC (r=-0.43, p=0.002)]. In 14 patients isolated DLCO reduction (normal FVC and TLC) was detected. HIG scores were greater in these patients comparing to them with DLCO within normal range (0.58 vs. 0.51, P<0.01). Discussion and Conclusion: DLCO reduction was the commonest pulmonary function abnormality in our patients. The isolated DLCO reduction might be attributed to pulmonary microvascular damage and increased membrane permeability, which constitutes one of the possible 99mTc-HIG uptake mechanisms. By this pathway, HIG lung scintigraphy seems to be useful in the early detection of the pulmonary involvement in CTD patients. Aim: The aim of the study is to documentate intraoperative gamma probe applications in neck surgery in our hospital. Material and Method: Between January 2006-March 2007 with the guidance of intraoperative gamma probe 17 patients underwent parathyroidectomy, 9 well differentiated thyroid cancer patients; complementary thyroidectomy, 2 medullary thyroid carcinoma patients; recurrent tumor exicion and 1 carcinoid patient; tumor excision. Before parathyroidectomy 20 mCi of Tc99m-MIBI was injected and during 2 hours static images were obtained every 10 minute in order to detect maximum parathyroid/thyroid uptake. At the operation day according to this optimal timing 1 mCi Tc99m-MIBI was injected. For complementary thyroidectomy 500 μCi I -131was given per orally 24 hours before the surgery and patients were imaged at 4-8th hour following I-131 injestion. In medullary thyroid carcinoma patients 1 mCi of Tc99-DMSA(V) and in carcinoid patients 1 mCi Tc99m-MIBI was injected 10 minutes before the operation. Results: In parathyroidectomy patients during operation except 1, ideal timing for peak parathyroid/thyroid uptake ratio was reached. Obtained parathyroid/thyroid ratios were quite variable and changed between; 1.5-37. In complementary thyroidectomies thyroid/background ratios were between; 10-90. Tumor/background ratio was 3-6.5 in medullary carcinoma and 5.8 in carcinoid. Conclusion: Optimization of injection time before surgery is very important in radioguided parathyroidectomy. This can be reached with the cooperation of departments of surgery and nuclear medicine. In parathyroidectomies, complementary thyroidectomies and in various tumor excisions beside a guidance potential, gamma probe help surgeons to instantly verify accurate removal of the targeted tissues. Graft-versus-host disease (GVHD) is common compication of allogeneic bone marrow transplantation (BMT) in which functional immune cells in the transplanted marrow recognize the recipient as "foreign" and mount an immunologic attack. The chronic form of graft-versus-host disease (cGVHD) is defined as that which occurs after 100 days. Chronic GVHD demages liver, skin and mucosa, and the gastrointestinal tract like in acute GVHD (aGVHD), but also causes changes to the connective tissue of the skin and exocrine glands. Function of salivary glands, as exocrine glands, is very often observed in patients suffering from cGVHD. Aim:The aim of this study was to evaluate the function of major salivary glands with dynamic salivary gland scintigraphy (DSGS) in hematologic patients suffering of cGVHD after allogenic BMT. Methods: DSGS was performed after iv. injection of 370 MBq Tc99mpertechnetate, with gamma cammera above parotid (PG), submandibular salivary glands (SG) and oral cavity (OC). DSGS lasted 60 minutes (one frame-one minute), with per os stimulation in 40. minute with ascorbic acid tablete. Time-activity curves (TAC) were generated over PG, SG and OC as regions of interest. Activity in OC was estimated on static scintigram 90. minutes after iv. injection.Using TAC and scintigrams, DSGS findings were graded from 1 to 4 according to Shall at all. ( SCT grade 1-normal finding, SCT grade 2-moderate function damage, SCT grade 3serious function damage, SCT grade 4-very serious function damage). DSGS was performed in five patients, seven to ten months after allogenic BMT. Two pts. were male and three female, aged from ninetheen to thirty nine years. Three patients suffered from acute leucaemia and two from mielodisplastic syndrome. Results: Three pts. suffered from aGVHD and all pts. were diagnosed as having cGVHD in skin, mucosa and liver. Four pts. had feeling of dry mouth (xerostomia). All pts. with xerostomia had patological scintigraphic finding: two pts. had SCT grade 2 and the other two SCT grade 3. In pts. without xerostomia scintigraphic finding was negative. Conclusion: This preliminary results sugests that DSGS, as objective test, can detect disfunction of salivary glands in patients suspected of chronic graft-versus-host disease, improving diagnosis and forehand therapy of cGVHD. Bone metastases are a frequent complication in oncological patients, and can deteriorate their quality of life by the appearance of bone pain, and, to a less degree, fractures or medular compression. Bone pain treatment is multidisciplinary, Aim: objective of this study is the evaluation of the staff radiation extremity exposure from preparation and application of 90 Y-Zevalin (activity/patient<1.184MBq) in our hospital. Material and Methods: data from the first 9 therapeutic administrations were considered. The chemists performed the radiolabelling at a high protection standard in a dedicated hot cell, using shieldings in Plexiglas for vials and syringes, tele-tongs and an automatic dispensing system. Technicians were involved in activity dose preparation only before buying the current dispensing system. Physicians administered the radiopharmaceutical through slow activity infusion (duration nearly 15 min). All operators wore both latex and anti-X gloves. Thin-layer TLDs (LiF:Mg,Cu,P) were fixed to the fingertips to measure the local skin dose, Hp(0.07), at the position with the highest risk of exposure to adequately protect the hands. 10 TLDs were given to the chemist and the technician, while 4 to the physician. Results: as for the chemist fingertips, the 75 th percentile of the dose distribution (Hp(0.07)) is 0.583 mSv/GBq, while the 95 th is 2.657 mSv/GBq. For each radiolabelling the sum of all fingertips adsorbed doses was performed. The mean of these values is 6.82+/-1.23 mSv/GBq. The medians of the radiolabelling fingertips doses range from 0.08 to 0.63 mSv/GBq, while the means range from 0.18 to 2.05 mSv/GBq. The ratio between the highest and the lowest absorbed dose to the fingertips is extremely variable per radiolabelling, observing values from 11.2 to 247.3. Technician doses are lower than the chemist ones, ranging from 2.5% to 77.8% compared to the latter. As for the physician the medians of the fingertips doses range from 0.22 to 1.87mSv/GBq/administration, while the means range from 0.19 to 1.90mSv/GBq/administration. Conclusion: when working at low radioprotection level, the exposure of the staff might exceed the annual skin dose limit of 500mSv. It is due to carry out an extremity monitoring with fingertips dosimeters suitable to betaradiation, stated the high risk of the method. Aim: Radionuclides have been used worldwide for diagnosis and treatment. Their use in Brasil have started in 1955 and have been increasing progressively, benefiting thousands. Scintigraphic methods have significant role in brazilian physicians practice. Despite its great importance, nuclear medicine's image was tarnished by nuclear disasters as Chernobil (1986) and Goiania (1987-brazilian disaster linked to radiotherapy). Those events boosted fear in public opinion concerning the use of radiation in medical procedures, even those that utilize small amounts of it like nuclear medicine. This work aims to evaluate how widely spread is knowledge about nuclear medicine among its patients, to find out their personal view and fears about procedures and specially if fear of radiation is usual. Materials & methods: After reading and accepting informed consent, adult patients underwent a multiple choice questionnaire. Research took place in a private service of NM in Teresina, Brazil during January-March 2007. Results: 525 patients were interviewed, 268 women and 257 men, ages ranging from 18 to 94 years old. Most patients (77.1%) have never undergone a nuclear medicine procedure before; 316 (60.2%) had never even heard about this medical field. From the 209 (39.8%) that already knew something about nuclear medicine, 92 (44%) received information from relatives or friends. Patients under 18 years old were not asked to answer the questionnaire. A great majority (80.8%) believe that the exam will be useful in solving their health problem. Besides, 27% think it is a very advanced procedure and 14.9% declared insecure due to their lack of information. Only 149 (28.4%) patients reported to have some kind of fear; 66 (44.3%) from them said to be afraid of bad result; 38(25.5%) feared it could be painful and only 18(12.1%) were afraid of exam's radiation. Others kinds of fears, as allergic reactions, injection, suffocation, distressed 83(55.7%) of the patients. Conclusion: Although many had already heard about this kind of procedure, lack of information is still usual among them. Therefore, greater efforts for public diffusion of social benefits of nuclear medicine are needed. Fear of bad result is the most frequently mentioned, probably because it may represent life-threatening situations as bone metastasis and coronary insufficiency. Twenty years after brazilian main nuclear accident (Goiania), fears of radiation seem not to be very important among patients.

M. Gerhardt, T. Pulawska, S. B. Søndergaard, B. Zerahn; Herlev Hospital, Copenhagen County, Herlev, DENMARK.

To evaluate the effect of music composed with the purpose of being calming, on heart rate and motion artefacts during image acquisition in rest and stress myocardial perfusion scintigraphy. Material and Methods: 124 patients referred for myocardial perfusion imaging on the suspicion of ischemic heart disease were included in a randomised cross over study. Only studies with successful gating during both rest and stress image acquisition were included. 50 patients listened to music during acquisition of rest images and not during stress image acquisition and 51 patients did vice versa. The study comprised 50 women and 51 men. The music played is named MusiCure and composed with the purpose of creating a relaxed atmosphere. The music is non vocal, slow in tempo and performed with acoustic and electric instruments and nature sounds. Heart rate was registered before and after each image acquisition. Motion artefacts were evaluated by two independent specialists in nuclear medicine using a semiquantitative four point scoring system. After each image acquisition the patients filled in a questionnaire with their evaluation of the calming effect of music/no music, whether they liked the music played or if they would prefer to select the style of music played, and if they would prefer to listen to music during the acquisition or not. Results: During stress image acquisition there was a significant decline in heart rate of -3.2 (±5.3) bpm, (p=0.008) among patients who did not listen to music. This decline in heart rate was significant for women alone; -4.2 (±5.9) bpm, (p=0.01) but not for men; -2.4 (±4.7) bpm, (p=0.3). Regardless of music being played or not there was no significant effect on heart rate during rest acquisition and there was no difference in the frequency or severity of motion artefacts. 92% of the patients preferred to listen to music during image acquisition, and 51% would prefer to select music of their own choice. 79% of the patients declared that the music had a calming effect, 17% no effect, and 4% found it to be distressing. Conclusion: Listening to music during acquisition for myocardial perfusion imaging after stress prevents a decline in heart rate in particular among women and has not any adverse effects on the frequency and severity of motion artefacts. A vast majority of patients preferred to listen to music during image acquisition, although half of the patients preferred to select the music style themselves. Flood field uniformity quality control (QC) is an essential function that must be performed daily before a gamma camera can be placed into clinical service for that Purpose. Clinical audit (EC Directive97/43/Euratom): Systematic examination or review of medical radiological procedures which seeks to improve the quality and the outcome of patient care through structured review whereby radiological practices, procedures and results are examined against agreed standards for good medical radiological procedures, with modification of practices where indicatedand the application of new standards if necessary. Implementation of MED directive. Clinical Audit shall be arranged to supplement the self-evaluation of practices. Objective must be that Clinical Audit be carried out every 5 years to cover all essential radiological practices in health care. Ten points of interest to be covered by clinical audits are defined in the degree. Introduction In any medical investigation the result standards in terms of sensitivity, specificity and accuracy are expressed. For stress myocardial perfusion scintigraphy (sMPS) in ideal non-selected population these values are all around 90. According to the references they can be much lower in compromised group of patients. To assure appropriate work quality every diagnostic laboratory should periodically perform the quality control of the whole laboratory as well as of every individual results interpreter . Aim Aim of the study was to control the quality of sMPS results reading in our nuclear medicine laboratory in a compromised group of patients. The whole laboratory as well as every individual interpreter was controlled. PATIENTS Retrospectively the sMPS readings of 351 pts, 270 (77%) men, 81 (23%) women, mean age of 59±10 y (31-84), were compared to the results of coronary angiography. 144 (41%) pts suffered recent MI, in 37 (11%) pts CABG and in 104 (30%) PTCA was performed. Methods The sMPS results, denoted as positive or negative, were compared to the results of coronary angiography. By their comparing, sensitivity, specificity and accuracy of sMPS were expressed for the whole group as well as for the individual readers of scintigrams. Results Conclusion: The great difference in diagnostic accuracy among the readers of scintigrams was found. These results were a good reminder of the whole group and especially of certain individuals for approving the quality of their work.

Advantages and problems of digital documentation and reporting in nuclear medicine O. Nickel, A. Helisch, M. Schreckenberger; Klinikum der J. Gutenberg-Universitaet, Mainz, GERMANY.Aim: Archiving and online reporting with digital documentation (without hardcopy) requires certain technical prerequisites and an adapted workflow. As well the image display on the workstations used for reporting as the image archive are to be optimised for easy and fast access, a good report quality and a safe long-term availability of the archived data. Material and Methods: All the image data from our modalities (5 gamma cameras, 1 PET scanner, 1 Ultrasound) are sent by DICOM transfer immediately after acquisition to the department PACS system "TomoMagine"(BS Industrieelektronik, Germany). The reporting physicians use windows workstations with two monitors for text and images. Quality control of the image monitors is done by test images (e.g. SMPTE). All images can be displayed with the TomoMagine viewer, which was developed especially for nuclear medicine: SPECT and PET slice data can be viewed interactively with 3D navigation in 3 planes and MIP projections; overlays of PET/CT or SPECT/CT can be displayed as well. All image data of a patient can be loaded online in a short time by using the archive database. 24 hours after acquisition the images are sent automatically to the central PACS system of the hospital; this system distributes the patient studies to the department servers of the referring physicians. Results: The image management of a digital archive has some problems compared to a conventional archive with film or paper hardcopies: The monitor and graphics mode for image display must be able to display all relevant levels of grey. Some LCD monitors that we tested were bad or even useless in this respect. A document on paper or film can be easily removed, an electronic document, which has been sent to a RIS/PACS, may have already been copied to several places; therefore its elimination can take very much effort. By the temporary storage of images in a local image archive and delayed transfer to a central PACS this problem can be minimized. The use of a local image archive improves the speed of access to the image data compared with a central PACS, the redundant archiving (local and central) increases the long term data security. Conclusion: The use of a local image archive in nuclear medicine, together with a centralized PACS can improve the workflow during reporting and image archiving.Aim: Lactadherin binds with high affinity to phosphatidylserine exposed on the surface of apoptotic cells. It is the aim of this project to synthesize 99mTc-HYNIClactadherin and to measure its ability to bind to apoptotic HL60 leukemia cells. Materials and methods: Bovine lactadherin was isolated from milk, conjugated with HYNIC and labelled with 99mTc using tricine as the coligand. The conjugate was separated on a Biosep-SEC-S 3000 HPLC column and stability studies with and without BSA carrier was carried out by TLC. HL60 cells (Human Leukaemia cell line) were made apoptotic using etoposide. Multiple cell aliquots were added different amounts of 99mTc-HYNIC-lactadherin. The procedure was repeated with untreated HL60 cells to evaluate 99mTc-HYNIC-lactadherin binding to non-apoptotic cells.Results: The amount of conjugated HYNIC per protein molecule was determined spectrophotometrically to be 4. The relatively low yield of the HPLC purification (19 ± 2 %, n=3) relates to the fact that lactadherin most likely adhered to the column. The stability tests showed that in the presence of BSA the RCP only decreased from 94 % to 92 % during a five hours period. The non-stabilized solution plunges from 90 % to 35 % RCP during the same period. A significant difference in binding activity between apoptotic and control cells (136 ± 6.6 %) was achieved with a 99mTc-HYNIClactadherin concentration as low as 11.6 nM. Furthermore, the difference in binding to apoptotic and normal HL60 cells reached a plateau at 30.9 nM label resulting in an 320 ± 16.9 % increase. When native lactadherin was added in excess the radioactivity in the pelleted apoptotic cells dropped to 2 ± 0.14 %. This strongly suggests that the binding of 99mTc-HYNIC-lactadherin to apoptotic cells is mediated by the same mechanisms as for unlabeled lactadherin. Conclusion: 99mTc-HYNIC-lactadherin has been synthesized, tested for stability and in vitro biological binding activity. The data clearly show that the compound is a potential imaging agent for apoptosis recognition.

Aim: Annexin V is known to bind to phosphatidylserine which is exposed on the outer surface of the cell membrane of cells undergoing apoptosis. It has been shown that bovine lactadherin a milk fat protein isolated from milk has affinity to phosphatidylserine and apoptotic cells as well. In vitro binding studies of 99mTc-HYNIC-lactadherin indicate that it binds to apoptotic cells. We want to present the results of the biodistribution studies in mice and tracer kinetic studies in pigs of 99mTc-HYNIC-lactadherin and 99mTc-HYNIC-annexin V. Materials and methods: Normal mice were injected with approximately 1 MBq in 100 ul of 99mTc-HYNIClactadherin or 99mTc-HYNIC-annexin V and sacrificed after 10 min, 1 h or 3 h. The animals were dissected and major organs were collected in counting tubes and the distribution of radioactivity was measured. Tracer kinetic studies in pigs were done by a combination of non-invasive scintigraphy and katheterisation. Results: The biodistribution studies in mice showed a relatively fast blood clearance. The relative uptake of 99mTc-HYNIC-lactadherin (n = 3)/99mTc-HYNIC-annexin V (n = 3) 1 h post injection was 5.1±0.3/6.1±0.3 in blood, 84.0±0.4/18.3±2.4 in the liver, 4.6±0.5/2.4±0.4 in the spleen and 6.3±0.8/73.2±3.0 in the kidneys. Accordingly, scintigraphy in pigs showed high liver uptake of 99mTc-HYNIC-lactadherin (n = 3) and high uptake of 99mTc-HYNIC-annexin V (n = 3) in the kidneys. Renal extraction of 99mTc-HYNIC-lactadherin was about 3% whereas the extraction of 99mTc-HYNIC-annexin V fell from 17-1% 2-120 min p.i. Conclusion: These tracer kinetic studies in mice and pigs showed that 99mTc-HYNIC-lactadherin is mainly taken up by the liver in contrast to 99mTc-HYNIC-annexin V which is mainly taken up by the kidneys. These results combined to the apoptosis recognition ability of 99mTc-HYNIC-lactadherin makes this radiotracer a potential new imaging agent for apoptosis in different organs with an advantage to 99mTc-HYNIC-annexin V for imaging apoptosis in the kidneys. Transport and phosphorylation of F-18-Deoxyglucose (FDG) in the tumor cells determine the kinetics of the tracer and the accumulation. However, experimental data gave evidence that other processes like angiogenesis may have an impact on the tracer kinetics. This study is focussed on the combined evaluation of PET and angiogenesis related gene expression. Methods: Dynamic PET FDG studies were performed in 25 patients with colorectal tumors within two days prior to surgery. Volumes-of-Interest (VOI) were used to obtain time-dependent tracer concentrations from the tumor region and a reference area. VOIs over the descending aorta were used to retrieve FDG total blood concentration data. A two-tissue-compartment model was fitted to the data and the transport constants k1-k4 as well as the fracional blood volume (vessel density, VB) were calculated using the evaluation software PMOD (PMOD Technologies Ltd., Adliswil, Switzerland). Tumor specimen as well as specimen from a reference area(normal colon) were obtained by surgery and quantitative gene expression data were obtained by gene array analysis using the U133A gene chip (Affymetrix Inc., Santa Clara,CA,USA). PET and gene array data were evaluated with the GenePET module of PMOD. Results: A quantiative data evaluation was performed in 25 patients, comprising 32 specimen of tumors and normal colon tissue. SUVs were highly variable between 0.9 and 19.4 SUV for this collective. Angiogenesis related genes were enhanced by a factor of 2.9, when tumors and normal colon were compared. Classification analysis demonstrated that 5 angiogenesis related genes provided the best discrimination between malignancies and reference tissue. The correlation/regression analysis demonstrated significant correlations (p<5 %) for the SUV, fractal dimension (heterogenity of the tracer), k1, k3, and the FDG influx. Summary: Angiogenesis has a significant impact primarily on the kinetic data (k1, k3), but also on the global FDG uptake. A detailed analysis of the FDG kinetics can help to classify the grade of angiogensis in primary colorectal tumors. 

Fifteen patients between ages 37 and 70 years of age (mean 54 yrs), with stage IIa-III recurrent cervical carcinoma treated with radiation therapy or chemotherapy and radiation therapy were enrolled. MR was performed on a 1.5 Tesla Scanner (GE Scanner), the CT and PET was performed in a PET/CT scanner, (GE Discovery ST). MR scans were performed for radiation planning tumor delineation and PET CT's were performed for ruling out nodular metastasis. MR and PET/CT scans were done with a time interval less than 60 days. PET and CT were coregistered during acquisition in the PET/CT scanner. MR volumes were co-registered with the CT part of the PET/CT using 5-6 internal anatomical fix points. The GTV were retrospectively delineated on transverse sections of CT (center 0 HU; width, 300 HU and tumor consistent criteria like contrast enhancement) and MR (T2 weighted) scans independently by two physicians with training in radiology and nuclear medicine, working in a blind fashion. GTV's were evaluated with different modalities on a single integrated Eclipse planning system (Varian Medical systems). GTV was autosegmented on PET scans using a lower activity level defined as 50% of maximum activity corrected for regional background Results: The preliminary results demonstrated that on average GTV defined in PET smaller than in both CT and MR.The final result will be demonstrated at the meeting. Conclusion: The combined PET/CT scan demonstrates an easy and observer independent definition of GTV for radiotherapy. The size of GTV was found smaller compared to determination by MR and CT. Aim: CD10/neutral endopeptidase (CD10) and intestinal-type mucin (MUC2) are known to associate with colorectal carcinogenesis and local invasion. The purpose of this study is to investigate the relationship between clinicopathological factors and FDG uptake in PET-CT in colon cancer, focusing on the expression of CD10 and MUC2. Methods: In this study, 25 patients (61.9±13.6 year old 10 women, 60.7±13.6 year old 15 men) with colon cancer were contiguously selected from April to September 2006. Preoperative PET-CT was performed in all of them. To determine the relationship between clinicopathological factors and standardized uptake values (SUVs) in colon cancer, we analyzed the tumor differentiation, tumor size, lymph node metastasis, vascular invasion, lymphatic invasion, and the expression of MUC2 and CD10, in paraffinated tissue using immunohistochemial stain. In addition, the expression of hexokinase (HK-II) and glucose transport (GLUT-1), and cell proliferating activity using Ki-67 were evaluated. Results: All of the 28 cases studied were positive for GLUT-1, specifically 6 of GLUT-1 weak positive and 19 of GLUT-1 strong positive. There were 14 cases of CD10 positive, 17 cases of MUC2 positive. CD10 showed negative correlation with MUC2 (rho=-0.65, p<0.001). MUC2 expression exhibited the positive correlation with Ki-67 (rho=0.37, p=0.067). There was no statistical significance among SUVs and various clinicopathological factors such as tumor differentiation, size, lymphatic or vessel invasion, lymph node metastasis, Ki-67, and HK-II. Furthermore, no clear correlation was found between

A very simple animal model of liver infection consists of the intraperitoneal injection of Clamidia Pneumoniae, which results in an activation of hepatic Kupffer cells in 30% of the animals. This Kupffer cells dis-regulation can be associated to primary biliary cirrhosis. Aim of this study was to assess the predictivity of FDG Small Animal PET for the early identification of reactive animals, possibly identifying not only the peritoneal inflammation caused by the injection but also the liver Kupffer cells activation and behaviour (are they originated from the peritoneum or from the liver itself?). We used 7 adults Balb/c mice (10-11 weeks) which were intraperitoneally injected with purified C. Pneumoniae elementary body suspension (the inoculum preparation contained 2.0x10^7 inclusion forming units). 2,7,10 and 20 days after, the animals underwent a FDG Small Animal PET (GE, explore Vista). We administrated 20 MBq of FDG via the tail vein. Uptake time was 60 min, acquisition time 20 min. Images were reconstructed with OSEM 2D iterative reconstruction. Animals were considered positive if a visual abnormal FDG uptake was present in the abdomen and/or in the liver. We found that 3/7 animals had a positive PET scan 2 days after inoculum within the peritoneum. 7 days after inoculum all these animals presented an increased peritoneal FDG uptake, which disappeared 10 an 20 days after inoculum. The other 4 animals had negative scans 2,7,10 and 20 days after inoculum. No hepatic signs of inflammation were detected in any of the animals. These results reflect the biological behaviour of this animal model previously reported in literature (World J Gastroenterol, 2006 Oct 28; 12(40) ) which shows an inflammatory response in about 30% of the subjects. This inflammation, probably connected with the liver reaction, could be very early detected by FDG PET (those that were positive intraperitoneally). However, this imaging method was never able to identify the liver Kupffer cells activation. These preliminary data indicates that, although predictive for reactive animals, FDG Small Animal PET is not the most appropriate technique to in vivo evaluate Kupffer cells movements and behaviour. A reporter gene-reporter probe method or a in vitro cell labelling tracking method may be more accurate to fully in vivo understand the Kupffer cells behaviour.Aim: Differentiation between cancerous growth and inflammatory reaction may be sometimes difficult. The glucose analogue, 2-18 F-fluoro-2-deoxy-D-glucose ( 18 F-FDG) accumulates in the areas of high glucose metabolism, such as rapidly growing tumours or active inflammatory foci. However, 18 F-FDG is specific neither for cancerous growth nor inflammation, thus causing false-positive findings. Vascular adhesion protein 1 (VAP-1) is a human endothelial protein whose cell surface expression is induced under inflammatory conditions, thus making it a highly promising target molecule for studying inflammatory processes in vivo. We hypothesized that positron emission tomography (PET) with Gallium-68-labeled 1,4,7,10-tetraazacyclododecane-N',N'',N''',N''''-tetraacetic acid conjugated synthetic peptide targeted to VAP-1 ( 68 Ga-DOTAVAP-P1) could be feasible for differentiating tumours and inflammatory foci.

We compared the biodistribution of 68 Ga-DOTAVAP-P1, 18 F-FDG, 11 C-choline and 68 Ga using experimental rat model. 11 C-Choline is a marker for cellular proliferation and it has been extensively used for PET imaging of prostate cancer. Free 68 Ga also accumulates in both the tumours and inflammatory foci. To establish an in vivo model, athymic rats were s.c. implanted with human BxPC-3 pancreatic adenocarcinoma cells and sterile skin/muscle inflammation was caused by turpentine oil. Dynamic 2h PET imaging and ex vivo organ distribution measures were performed 24h after induction of inflammation. Results: Our results revealed that the 68 Ga-DOTAVAP-P1 was able to visualize inflammation better than tumour and it was more inflammation-selective than other tested tracers. The difference between 68 Ga-DOTAVAP-P1 vs. 68 Ga and vs. 11 C-choline was statistically significant (P<0.001). The most tumour-selective tracer was 11 C-choline. The difference between 11 C-choline vs. 68 Ga and vs. 68 Ga-DOTAVAP-P1 was statistically significant (P<0.001). However, 18 F-FDG showed the highest target-to-background ratios (Table) . Conclusion: Our results indicate that 68 Ga-DOTAVAP-P1 targeting VAP-1 was capable of differentiating tumour from inflammatory foci in our animal model and it was almost as sensitive as 18 F-FDG for inflammation imaging. A minority of tracers developed for scintigraphic detection of infection and inflammation could theroretically discriminate bacterial infection from sterile inflammation. However, for some of these tracers these claims could not be confirmed. Recently, the radiolabeled thymidine kinase (TK) substrate 1-(2'-deoxy-2'fluoro-beta-D-arabinofuranosyl)-5-iodouracil (FIAU) has been proposed as an agent to image bacterial infections, based on presence of endogenous TK in bacteria. In the present study, we investigated [I-125]FIAU targeting in rats with bacterial and sterile inflammation. To prove that FIAU uptake was TK-mediated, E. coli TK-negative bacteria were generated and inoculated intramuscularly (im) in rats and FIAU uptake was studied. Methods. FIAU was labeled with I-125 using the trimethyl tin precursor. Aim: Angiogenesis is a prominent feature of rheumatoid synovitis. v 3 integrin is expressed at high levels on the synovial formation of new blood vessels in rheumatoid arthritis. Synovitis in rabbits could be suppressed by blocking this integrin with cyclic RGD peptide based v 3 antagonists injected directly into the joint. The multi-pinhole (MPH) single-photon emission computed tomography (SPECT) technique and In-111 labelled cyclic RGD peptide (111In-DOTA-E-[c(RGDfK)]2) allows to detect vascular joint alterations in arthritis-mouse-models. Methods: MPH-SPECT-measurements were performed under short general anaesthesia in collagen-induced-arthritis (CIA) mice, which had arthritis of front and back paws. All mice were independently scored macroscopically before starting the studies. Control mice were compared with the MPH-analysis of arthritis-mouse-models. SPECT data was acquired with a conventional gamma camera (PRISM 2000 S, Philips) which was outfitted with a new constructed MPH-collimator (12 pinholes with a diameter of 1.5mm). After the injection of 35.6±14.2 MBq (mean±SD) In-111 labelled RGD peptide, a dynamic measurement between 0 and 60 minutes p.i. was performed. Results: The high sensitivity of the MPH-Technique allowed the dynamic visualisation in the uptake of RGD peptide in the ankles and other organs of the mice. MPH-SPECT allows to detect all arthritic lesions (n=7) and a quantitative analysis. The regional evaluation showed that after 6 minutes, the percentual accumulation 1 h p.i. in the inflamed paws was 0.34%±0.27% while in healthy control mice (n=5) a significant lower uptake of 0.09%±0.03% was measured (p(1)=0.0047, Mann-Whitney). No significant difference was observable in the knee joints between healthy and arthritic mice. Conclusion: The results of our studies suggest a correlation between arthritic inflammation and accumulation of cyclic RGD peptides in CIA animals in vivo. The MPH-SPECT technique in combination with a cyclic RGD peptide can be used as a diagnostic instrument for imaging joint pathologies and for an accurate and quantitatively precise monitoring of therapy studies.

Aim: Image quality using the specific serotonin 2A-receptor radioligand 123 I-R-91150 is variable in dogs. Since the P-glycoprotein is expressed in the blood-brain barrier, amongst many other organs, we wanted to evaluate the effect of ketoconazole, a Pglycoprotein modulator, on the brain uptake of this radioligand in dogs. Materials & Methods: Three 7-year-old healthy female Beagle dogs were included. Two SPECT scans were performed; one baseline scan and one scan after administration of ketoconazole. Ketoconazole was administered orally during 3 successive days; two days before scanning at a dose of 100mg/kg, one day before scanning and the day of scanning at a dose of 50mg/kg. The radioligand 123 I-5-I-R91150 was injected (mean 166 MBq) intravenously 90 minutes prior to acquisition. Acquisitions were performed under general anaesthesia (premedication with medetomidine, induction with propofol and maintenance with isoflurane in oxygen). Acquisitions were performed with a triple head gamma camera (Triad, Trionix), equipped with LEHR hole collimators. Images were reconstructed with HOSEM iterative reconstruction and application of a Butterworth-postfilter (cut-off, 1,2 cycles/cm, order 8). ROI's were drawn over eight cortical regions (left and right fronto-, temporo-, parieto-, and occipito-cortical area) and one global subcortical region. The uptake in the cerebellum (area void of serotonin 2A-receptors) was used as a reference for non-specific binding in addition to free ligand. Radioactivity measured in the cortical areas was assumed to represent the total activity. The binding index was operationally estimated as (mean counts/pixel in regional cortex)/ (mean counts/pixel in cerebellum). Results: On visual inspection a clear improvement was noted after administration of ketoconazole. The mean counts/pixel in the total brain was 85,3 ± 40,6. After administration of ketoconazole the mean counts/pixel in the total brain was 96,4 ± 43,1. The mean serotonin-2A binding index of the baseline scan in the frontal cortex was 1,47 ±0,01. After administration of ketoconazole, the mean serotonin-2A binding index increased to 1,93 ± 0,16. This is a mean increase of 31,7%. Conclusion: The results of this study demonstrate a trend towards an increased brain uptake of serotonin 2A-receptor radioligand 123 I-R-91150 after use of ketoconazole. Despite clear improvement of image quality, no statistic conclusions can be taken due to a low number included subjects. Further investigations are necessary to confirm these preliminary findings.

Aim. To determine possibilities of quantitative imaging of the mouse thyroids using the NanoSPECT/CT small animal imaging system. Materials and Methods. Phantom and in vivo measurements were made with the NanoSPECT/CT device. Phantoms of two point sources distributed in homogenous flood source of cylindrical for were created. 99mTc and 131I isotopes were used to fill in radioactivity. 99mTc activities ranged from 2 MBq in points to 40 MBq, 131I activities ranged from 0.3MBq to 3 MBq. Flood activities were between 10-40 MBq. In vivo imaging of 3-3 mice with the respective isotope was performed using activities of 99mTc of 10-40 MBq injected iv. or 3-5 MBq of 131I.Imaging was done 30-60 minutes post inj. Thyroids were then removed from mice and measured in a welltype counter and compared to standard activities to determine real activity. Results. ROI-quantified voxel activities were the same in the measured phantoms and the calculations of two digits post zero. In vivo results were the same with an error of 6% with 99mTc, with 131I the error depended on the signal intesity and count-noise ratio. Conclusions. NanoSPECT/CT allows the correct absolute quantification of activity located in voxels both in vitro and in vivo if a good signal-noise ratio can be obtained. Objective: Poor in vitro and in vivo delivery is limiting the use of oligomers for imaging and therapy. Streptavidin (SA) may be used as a convenient link between biotinylated antisense radiolabeled oligomers and transmembrane carriers added to improve delivery provided that antisense and carrier function is not compromised thereby. Methods: Nanoparticles with 20 mer uniform phosphodiester (PO) or phosphorothioate (PS) DNAs against the mdr1 mRNA or a 25 mer phosphorodiamidate morpholino (MORF) against the survivin mRNA were linked to SA along with cholesterol, a 10 mer tat or 10 mer polyarginine carrier. The 99m Tc radiolabel was always on the oligomer. Results: As evidence of unimpeded carrier function, the MORF/SA/tat and MORF/SA/polyarginine nanoparticles accumulated 10 fold more than the MORF/SA and the naked MORF controls after 12 h in survivin+ MCF7 cells while all PO nanoparticles showed increased accumulations at all times with compared to without carriers in three mdr1+ cells but not so the PS DNA nanoparticles because of its high protein affinity. Evidence of antisense targeting were the statistically higher cellular accumulations of the antisense MORF nanoparticle than the sense MORF nanoparticle control and statistically higher accumulations of the PO DNA nanoparticle in the three cell types in order of their mdr1 expression levels. In xenografted mice, the PS DNA/SA/tat and PS DNA/SA/cholesterol nanoparticles were accumulated in all tissues including tumor much higher than the PO nanoparticles. These results show that the high protein binding affinity of the PS DNA was expressed despite the presence of the SA. Conclusions: The preparation of oligomer carrier constructs was greatly simplified over covalent conjugations by using SA as a linker. The SA linker had no apparent detrimental influence on the function of the carriers or antisense oligomers. These observations suggest that SA provides a convenient means of linking oligomers, carriers and, eventually, antitumor antibodies without compromising properties. The aim of this study was to investigate the effect of food and time on intestinal activity in technetium 99m tetrofosmin stress myocardial perfusion scintigraphy. Based on a pre-study sample size calculation, we estimate the study population to comprise a total of 150 patients. Patients were recruited at a single center and underwent a two day exercise-rest Tc-99m tetrofosmin single photon emission computed tomography (SPECT) imaging. Patients were randomized to food or no food (450 ml of water and two slices of white bread with butter versus no drink or food) versus early or late SPECT (within 15 min from injection of tracer versus 30-60 min after injection of tracer) in a 2 x 2 factorial design. Patients with abnormalities on their stress test also had a rest SPECT. The food/time allocation used for the stress test was used for the rest as well. Rest data will be reported separately. Patients were randomized in blocks of four. Most patients received adenosine pharmacological testing with moderate (25W) bicycle exercise. Frequency of intestinal activity was assessed visually on SPECT images on 3 different planar projections. Inferior myocardial wall and abdominal activity adjacent to the myocardium was evaluated visually on a 5-point semi-quantitative scale, ranging from no to severe intestinal overlay and a final accept/repeat SPECT decision. Evaluation was performed by a trained observer blinded to the pre-SPECT details. The primary endpoint is the percentage of accepted first time SPECT in each cohort in the intention to treat population. Secondary endpoints include proportion of approved first time scans in each cohort as per actual time and food (per protocol analysis), intestinal activity according to method of exercise testing, and time from injection to final acceptance of the scan (including repeat scans). An interim analysis has been planned at 75 patients (estimated to be late April, 2007). The final results will be presented at the meeting. The aim of study was to explore the possibilities of the use of DICOM standard (Digital Imaging and COmmunications in Medicine) in our Department. We used it in comparison of new commercial software package (4DM SPECT) with the existing (QGS) for the quantification of left ventricular ejection fraction (LVEF). LVEF values obtained with 4DM SPECT, 8 and 16 frames/cycle were also compared. Material and methods: twenty patients (9 male, 11 female, mean age 57 ys) referred to stress and/or rest gSPECT study with 99mTc MIBI, were enrolled. Studies were performed with two detector camera system (ECAM), first with 16 frames/cycle, and immediately after that with 8 frames/cycle for each patient, according to the recently published EANM/ESC procedural guidelines for myocardial perfusion imaging (gSPECT, high count study), with total duration of 26 minutes (13 minutes for each study). After the reconstruction, the 16 and 8 frames/cycle data were processed with 4DM SPECT program. Original 8 frames studies were also copied from eSOFT to ICON working station, using the DICOM key, where reconstruction and QGS processing was performed. Mean LVEF values were compared, and statistical significances were checked with paired t test. Results: 4 DM SPECT-8 fr 4 DM SPECT-16 fr QGS -8 fr Mean LVEF % (range%) 68 % (57-76%) * ** 71 % (62-82%) 63 % (54-73%) * p<0.01 between 8 and 16 fr 4DM SPECT **p<0.01 between 8 fr 4DM SPECT and QGS Mean LVEF values obtained with 8 frames 4DM SPECT were 5% higher than with 8 frames QGS program. Difference between 8 and 16 frame mean LVEF values in 4DM SPECT was smaller, but both results turned to be statistically significant (p<0.01). Conclusions: DICOM transfer from one to another working station was successful in all cases. Significant differences between 16 and 8 frame 4 DM SPECT study were found, and between 8 frames studies obtained with two software programs. Since more prominent differences were found with different programs, it can be concluded that LVEF values should always be processed with the same software package, especially when follow up of patient is needed. The DICOM successfully enabled the comparison of the two software packages.

Aim: Both stress and rest examinations are usually performed to diagnose ischemia or infarction in the left ventricle. If the stress study is performed first and the images show normal findings, it might be unnecessary to perform the rest study. The aim of this study was to evaluate if it is possible to avoid rest studies in some patients without making false negative interpretations. Material and method: The gated-SPECT studies performed using a two-day nongated stress/gated rest 99m Tc-sestamibi protocol from 532 consecutive patients were investigated. The patients had a mean age of 62±11 years, and 49% were men. Myocardial perfusion scan was performed for the diagnosis of CAD in 421 patients and for management of known CAD in 107 patients, previous myocardial infarction in 79 patients and previous revascularisation in 98. Visual interpretation by one experienced physician at the time of clinical reporting was used as the gold standard for the scintigraphic presence of myocardial infarction or ischaemia. Rest, stress and gated images as well as clinical information were available for this interpretation. Only the stress images (slice images and polar plots) were examined independently by 2 physicians and 3 technologists regarding the question if a rest study was needed or not. Results: The clinical evaluation of the rest and stress images by the experienced physician showed normal findings, i.e. no signs of infarction and ischaemia, in 360 cases. The five observers decided that rest was unnecessary in 70, 135, 87, 94 and 43 of these studies respectively. A false negative classification, i.e. rest study not necessary in a case were the gold standard interpretation was infarct or ischaemia, was found in 1, 3, 0, 2 and 0 cases respectively. Conclusion: The results show that it is possible to avoid rest studies in a significant number of patients with no or only few false negative interpretations.Technologists and physicians did not differ substantially in the interpretations.

H. Lehtinen, A. Sonkki; University Hospital of Turku, PET Centre, Turku, FINLAND.The Aim of this poster is our practical experiences of cardiac CTA and perfusion studies performed at Turku PET Centre, Finland. Coronary CTA combined with the cardiac perfusion study is one of the best and most reliable non-invasic tests in diagnosis of CAD. The study provides seamless team work with many occupational groups like Medical Laboratory Technologists, Physicians and the Physicists. The radiographer's role is to prepare patients, inform them of the study and do the scan. Materials and Methods. At first we prepare the patient for the cardiac study. The patient fills an interview form where we will see his current medications, possible former reactions to contrast agents, allergies, diabetes and kidney diseases. While the patient lies down we observe heart rate, check blood pressure and set an intravenous cannula. Optimal heart rate is stable and under 60 bpm. If it's above 60 bpm the physician gives beta-blockers intravenously. Oral nitrate spray is given to each patient before the scan. CTA demands breath holds so it's good to exercise this with the patient before the study. The scanner used is GE VCT 64-slice PET-CT scanner. Cardiac CTA consists of a calcium score scan and a coronary scan with contrast media. We use an automatic dual head injector system for injecting contrast media and NaCl bolus chaser. The CTA scan is then followed by the perfusion studies with 15 Olabelled radio water, first basal perfusion and then adenosine stress perfusion. During the perfusion studies we monitor ECG and the blood pressure according to our protocol. After the study we observe the patient for awhile and advise him to drink a lot because of the possibility a nephrotoxic reaction due to iodine-containing contrast. Conclusion. Cardiac CTA combined with PET perfusion is an excellent example of a multimodalitystudy, as the anatomic information of CT images is combined with the functional information of PET. It has been very challenging, exciting and rewarding to do these studies.

Standard Indicator of SESTAMIBI Regional Washout in the Myocardium Purpose: In recent years, it has been shown that washout of MIBI is observed in myocardial ischemia lesions, and a method for its evaluation is discussed. We obtained the standard indicator for regional washout from early and delayed MIBI images and evaluated its usefulness. Method: In 14 healthy volunteers without abnormalities, such as cardiac diseases, hypertension or electrocardiographic abnormalities, SPECT images were acquired one hour after intravenous administration of 740 MBq of MIBI of (early image), and subsequently, three times, up to five hours (delayed image 1, delayed image 2 and delayed image 3). To draw a polar map from each sequential SPECT image, the regional washout rate obtained from the mean count in three areas of the myocardium was plotted, and the gradient was calculated with the approximate equation. Results: Comparison of gradients in the linear approximation and exponential approximation from the early image to delayed image 3 in each area showed no significant differences ( and RCA=-4.549±0.621, showed significant difference (p< 0.05) for the LAD and LCX, but not for the other vessels (p=ns). The respective r 2 were 0.9303, 0.9295 and 0.9145, with no significant differences among the three (p=ns). As for correlation between the linear approximation and exponential approximation, the linear approximation approached 1 more closely than the curve approximation, however, no significant difference was observed. Conclusion:It was suggested that the regional washout of MIBI in healthy myocardium would decrease with a gradient of linear or curve approximation. Since there was no significant difference between the approximated line and curve, evaluation of the gradient with the linear approximate expression may provide a constant gradient, and therefore, it can be used as an indicator of the washout rate.

T. Iimori, T. Fujibuchi, H. Sato, K. Sawada, Y. Uchida, T. Kawata, M. Fujita, S. Shindo, y. Kuwabara; Chiba University Hospital, Chiba, JAPAN.Background and Purpose: By 99m Tc -MIBI Scintigraphy, a myocardial morphologic assessment (hypertrophy or enlargement) and functional assessment are also enabled as well as myocardial perfusion evaluation, and they contribute to the assessment of myocardial viability. Recently, there are some reports that accumulation and clearance of MIBI are related to severity of heart failure. Therefore, we evaluated the utility of scatter correction for precise energy count in calculating H/M (Heart/Mediastinum) value of MIBI in the planar image. Method: 1) Phantom simulation study: In the phantom, myocardial region was filled by 0.123MBq/ml with MIBI, liver region was filled with 0.025MBq/ml of MIBI, and mediastinum was filled by water. We imaged the phantom with static collection (preset time; 200,000 counts, matrix; 512*512), and repeated with the different main window widths and sub window widths in order to determine the appropriate window width for scatter correction by TEW. We used NMSE (normalized mean square error) for their evaluation. 2) Clinical evaluation: With the appropriate windows determined by the phantom, we measured H/M value of MIBI in 54 patients with heart failure (43 male, 11 femail, mean age 54.8±15.5 years), and compared with raw data for the relation with the clinical data such as ejection fraction (EF). Since 123 I-MIBG imaging is well-established as a gauge of CHF, effect of scatter correction by TEW in MIBI was also evaluated for the correlation with 123 I-MIBG. Result: Main window width with 140KeV±10% and sub window width with 122KeV±2.5% were appropriate in scatter correction by TEW by the phantom study, respectively. 2)Correlation coefficient between H/M value and EF in patients with CHF was r=0.12 without scatter correction, and it improved to r=0.25 with scatter correction. Correlation coefficient with H/M value and 123 I-MIBG H/M value were r=0.62 without scatter correction, however, it increased to r=0.90 with scatter correction. Conclusion: We proposed appropriate windows for the scatter correction in cardiac imaging by 99m Tc-MIBI by phantom study, and proved its utility by applying to the clinical cases. Background: Stem cells represent one of the new therapeutic possibilities for severe co ronarydisease, the effect being tested in many trials. Most centers use intracoronary injections, but some recommend intramyocardial injection, to obtain maximal homing and retention of the cells in the ischaemic myocardium. Details about differences between these administration techniques are completely unknown. The purpose of the present study was to examine the retention of In-111 labelled human stem cells injected into porcine, left ventricular (LV) myocardium. Methods: In-labelling was performed as previously described by our group (EJNM 2006 (EJNM , 33:1171 (EJNM -1177 . The labelled cells (2) (3) (4) were injected into the pigs (35-40 kg) via a cardiac catheter into the LV walls in 10 small depots (total volume injected = 2 cc). Subsequent static gamma camera images were obtained (170 and 245 keV dual window, MEGP collimator) over the next 6 days to monitor the clearance of the labelled cells from the myocardium. On the second day 100 MBq sestamibi was given iv. after the planar image and cardiac SPECT performed 30 min later. The energy windows for SPECT were 25% around 155 and 245 keV. Results: It was easy to localize, in the homogenous sestamibi visualization of the LV myocardium, the remainder of 2-4 MBq In-111, distributed in 2-5 hot spots, in the apex, posterior wall, septum etc. By the daily planar "pure" In-111 images the retention of the indium could easily be calculated after correction for physical decay: (day 2, 3, 4, 6). Discussion and conclusion: This technique with a lower energy window centered around 155 keV during SPECT, permitting only part of the general myocardial activity uptake to be visualized as a background. It nicely demonstrated the myocardial localization of <1 MBq In-111 activity accumulations from labelled stem cells injected into the heart of 35-40 kg pigs. Introduction LVEF, EDV and ESV are good clinical indicators of left ventricular function and volumes, routinely measured by echocardiography (ECHOC). In former decade the Emory Cardiac Tool Box (ECTB) was developed, a toll for assessing left ventricular function and volumes from gated SPECT myocardial perfusion scintigraphy (GSPECT). GSPECT myocardial function assessment provides an important incremental information. Aim of the Study The aim of the present study was to validate the accuracy of the ECTB in assessing LVEF, EDV and ESV from GSPECT using ECHOC as a reference values. Patients and Methods 44 consecutive patients, 29 males and 15 females; mean age 63+/-12 y, range 39 -87 y, with suspected or known coronary artery disease were examined using 99mTc-MIBI GSPECT (8 gates/cardiac cycle) 60 min after tracer injection at stress. The GSPET data were reconstructed using an automatic algorithm employing filtered back projection (FBP) and further analyzed by Emory cardiac (EC) toolbox. All patients underwent two-dimensional (2D) M-mode ECHOC in the same diagnostic evaluation. 

Optimization of myocardial FDG-uptake in F18-FDG PET-CT by a standardised hyperinsulinemiceuglycemic clamp protocol and acipimox K. Krommes, G. Pleschberger, V. Meyer, H. Kässmann, C. Pirich; Salzburger Landeskliniken, Nuklearmedizin, Salzburg, AUSTRIA.

The assessment of myocardial viability by F-18 FDG PET has become a standard procedure in nuclear cardiology. Metabolic imaging of the heart requires designated protocols that reflect alterations in substrate metabolism under ischemic conditions. It was the aim of the study to analyse the efficacy and practicability of a standardised hyperinsulinemic-euglycemic clamp protocol in clinical routine. Method: Cardiac F-18 FDG imaging was studied in 68 patients from 2005 till February 2007. 52 patients were non-diabetic (76 %) and 16 patients were diabetic (insulin and non-insulin dependent; 24 %). Every patient was given a dosage of 250 mg acipimox on the study day. The hyperinsulinemic-euglycemic clamp protocol differentiates between non-diabetic, diabetic non-insulin-dependent and diabetic insulin-dependent patients. For each patient group, there is a predefined pattern for application of oral glucose or/and insulin (maximum single insulin dose 8 IU) according to the blood glucose level. Results: According to our protocol the following procedure was necessary in our patients: • No insulin / no glucose: 1 patient • No insulin / glucose: 28 patients • Insulin / glucose: 30 patients • Insulin / no glucose: 9 patients 58 patients needed glucose, of whom 54 patients (93 %) got 75 g glucose and 4 patients (7 %) got 37,5 g glucose. After glucose application, 28 patients (48 %) required no insulin, and 30 patients (52 %) needed insulin to lower the blood glucose level. 39 of 68 patients were given insulin, 30 of them after glucose application and 9 patients without glucose. In detail, 29, 6 and 3 patients received respective dosages of 4, 6 and 8 I.U. insulin. One patient was given 26 I.U. insulin. Diagnostically adequate imaging quality was achieved in 64 cases (94 %) and even in 14 of 16 diabetics (88 %). Cardiac FDG-PET imaging of 2 patients was not successful due to vomiting of the oral glucose drink. Conclusion: For metabolic imaging of cardiac glucose consumption by means of F18-FDG PET-CT a strategy combining the use of acipimox and the hyperinsulinemic-euglycemic clamp protocol is feasible and results in adequate imaging quality in the vast majority of patients. The protocol is even successful in a diabetic population. Aim: In our department, myocardial perfusion scintigraphy (MPS) is usually performed using a 2-day rest-stress 99m-Tc-sestemibi protocol. With more referrals and wishes of additional procedures for routine and research purposes there is a growing pressure on the staff and a waiting list seems inevitable. We examined if resource utilization could be improved by applying the Lean concept originally introduced by Toyota for optimizing automobile production. Material and Methods: Implementations of Lean has as its core five concepts: 1. Specify value in the eyes of the customer; 2. Identify the value stream and eliminate waste; 3. Make value flow at the pull of the customer; 4. Involve and empower employees; 5. Continuously improve in the pursuit of perfection. In terms of MPS, concepts 2-4 were applied. First, we established an "AS-IS" flow diagram, which required a) an interview guide, b) interviews of secretaries, booking, laboratory technicians, and physicians, c) sketching of a so-called swimming lane diagram, and d) the "AS-IS" flow diagram. From the "AS-IS" diagram it was easily seen which activities could be combined, reduced, or eliminated. Based on these observations a "TO-BE" diagram eliminating all "waste" could be established in a process involving and empowering all relevant employees. Results: The "AS-IS" diagram identified the following pre-scan steps as candidates for a change: i) non-appearance of patients, ii) measurement of body weight and height, calculation of body mass index and sestamibi dose, iii) preparations and check of patient dose, iv) positioning of intravenous cannula and dose injection, v) check of medication and withdrawal of relevant drugs before stress acquisition, and vi) entering of informations into a working sheet and the patient protocol. Similarly, the following post-scan steps were candidates for a change: vii) information to the patient of preparations for the succeeding stress examination, viii) precautions on day-2 in case these instructions had not been followed. Conclusion: These and other simple changes, which could eliminate or streamline the many extra procedures, lightened the pressure on the personnel, made the working rhythm more fluent and stable, and yielded extra time for patient care as well as the conductance, processessing, and finalizing of each single MPS study. In this way, the "low hanging fruits" were collected. In addition, a further gain could be obtained in at least ¼ of the patients by converting the sequence rest-stress to stress-rest and leaving the rest study undone in case the stress study was normal. Aim: Gated myocardial SPECT provides an estimate of left ventricular ejection fraction (LVEF). Most commonly gating is performed with 8 frames per cardiac cycle although 16 frames per cycle may provide more accurate estimates of left ventricular function. The aim of this study was to compare same day repeatability of left ventricular ejection fraction using 8-frame or 16-frame gated SPECT. Method and Materials: In patients referred for routine myocardial SPECT a 16-frame gated SPECT study (study A) was performed 1 hour after injection of 600 MBq 99mTc -MIBI. A second 16-frame gated SPECT study (study B) was performed immediately after without the patient leaving the gamma camera. 8 frame studies were constructed from 16 frame studies. Gated studies were processed with QGS software. Repeatability is reported as the mean difference (study A -study B) ± 1.96 SD. Results: 15 repeated studies (7 stress and 8 rest studies) were performed in 11 patients. In study A, 16frame studies produced significantly higher LVEF than 8-frame studies (mean LVEF 66.5%, vs 61.9%, p < 0.0001). Repeatability of LVEF in 8-frame and 16-frame studies were 1.7 ± 9.9% and 2.6 ± 10.8% respectively. The difference in LVEF was not statistically significant in neither 8-frame nor 16-frame studies. In stress studies LVEF was significantly lower in study B than in study A (repeatability 3.4 ± 7.0% [p = 0.02] in 8-frame studies and 4.4 ± 9.8% [p=0.03] in 16-frame studies). In rest studies no change in LVEF was observed (repeatability 0.1 ± 11.5% in 8-frame studies and 1.0 ± 11.2% in 16-frame studies). No correlation between difference of LVEF and change of heart rate, perfusion defect size, EDV or ESV was observed Conclusion: There is significant variability of same day left ventricular ejection fraction measured with gated SPECT. Repeatability seems not to be affected by frame rate, but appears to be poorer in stress studies than in rest studies. These observations should be taken into account in serial evaluation of left ventricular function with gated SPECT studies. . Recently there has been an increase in the number of acute chest pain and pre-surgical patients (pts) with cardiac risk factors treated at community hospitals in the U.S. Many of these pts require immediate cardiac care which has significantly added to hospital stays and health care costs. Yet both federal and state reimbursements for institutions seeing these patients have decreased. Aim: to develop a patient care pathway and PACS ( picture archiving and communication system ) to maximize immediate care for cardiac and pre-surgical patients while reducing the patient's hospital stay when possible. Length of hospital stay was recorded for all uncomplicated cases. Method: This project was a cooperative effort among the cardiology department, hospital administration, stress laboratory, cardiac care floor and nuclear medicine. A Tc-99m gated myocardial perfusion imaging (MPI) was performed on all low and intermediate risk chest pain and pre-surgical patients within 24 hours of admission and preliminary results were provided to the attending physician within 2 hours of completion of the test. 450 patients (261 females, 189 males) with an age range of 18 to 95 years (mean = 64) underwent a one day rest and stress (exercise or pharmacologic stress with Adenosine or Dobutamine) gated SPECT MPI. A rest/stress dose of 370MBq/1.11GBq (10/30 mCi) of Tc -99m Tetrafosmine was used. A Siemens E-Cam gamma camera with 4D MS SPECT Software was used to reconstruct orthogonal views. Results: 373 pts (83%) had negative MPI findings and were discharged with 24 hours of the exam. 31 pts (7%) had positive MPI findings and were immediately sent to coronary angiography and discharged within 2 to 3 days post MPI. 37 pre-surgical pts (8%) with negative MPI findings went to surgery within 24 hours. 9 pts (2%) with positive MPI results went on to have CABG. Conclusions: All low and intermediate risk chest pain pts were discharged within 24 hours of MPI which represents an improvement over past hospital stays for these pts. Pre-surgical pts with negative MPI results were immediately sent to surgery. These data suggest a significant reduction in hospital costs and stays. Introduction: Even if Filtered Backprojection (FBP) methodology still has a very well established role in routine image processing in Nuclear Cardiology, actually, with the general improvement of computational power available, an increasing number of Nuclear Medicine Departments worldwide tend/is interested on the use of Iterative Methods (IM). With this paper, it is intended to expose some main considerations, always with clear practical purposes, sharing our own studies and experiences. Material and Methods: The first part of the study consisted on the analysis of the different possibilities available within the current software options brought widely available by the furnishers of equipment. Once concluded, sessions of practical tests started: the main goal was to establish the relative practicability of the options predefined on the first part of the study. Hence, we used one group of 10 different myocardium perfusion scintigraphic studies, which had been processed with the distinct methodologies previously defined. We have compare data related with the processing operation itself for each case, with main focus on parameters as the time spent (from the operators as well as the system's immobilization, for instance) and complexity (here considered as essentially related with the degree of operator's intervention). In order to establish the clinical value of each methodological option, the resultant images were evaluated by 5 independent physicians, according to different criteria, always based on its clinical value. Conclusions: It had been clarified and justified what seems to be the best option for the use IM in routine image processing, in the specific case of MPI. Introduction: It is worldwide very common that patients who will undergo a myocardium perfusion scintigraphy are requested to be in fasting condition. Even if this idea is generally accepted, the scientific evidence underlying this requirement seems to be far from objective and/or consensual. The main goal of this work is to contribute for the study of in vivo biodistribution and pharmacokinetics of 99mTcsestamibi with and without fasting. Material and Methods: The same normal volunteer was imaged twice under different physiological conditions: the first study was done without fasting and the second one in fasting condition. Anterior projections of thoracic and abdominal regions were acquired during 120 minutes, starting immediately after intravenous injection of the tracer. Regions of interest in myocardium, liver, gallbladder and proximal intestine were drawn and a related timeactivity curve was then obtained. Data was compared and correlated with the normal gastrointestinal tract physiology. Results and Conclusions: Biodistribution and pharmacokinetics of 99mTc-sestamibi under those distinct physiological conditions had appeared slightly different, particularly in the case of organs such as the liver and the gallbladder. Based on the obtained results, the authors assume first, the need to study further this subject and, secondly, maybe there is a need to review patient preparation procedures in the specific context of myocardium perfusion imaging. Objectives: FDG-PET has suboptimal sensitivity in the diagnosis of brain metastases (BM). The presence of such metastases may result in cerebellar asymmetry (CA) of FDG uptake or Crossed cerebellar diaschisis (CCD). Previously, CCD has been studied qualitatively to describe the neuronal dysfunction of the cortico-pontocerebellar-system caused by supratentorial BM. We aimed to evaluate the potential added value of semiquantitative analysis of CA in the diagnosis of BM by comparing cerebellar uptake in patients (pts) with and without BM as well as in normal volunteers (NV) Methods: A total of 73 subjects studied: 18 NV and 55 cancer pts including 30 without BM (G1) by MRI and 25 with BM (G2) as confirmed by MRI, PET or histopathology. PET/CT scans of all subjects were retrospectively reviewed and one symmetric ROI in bilateral cerebellar (cbl) cortex was drawn. Differential values were calculated as 100 -(SUV1/SUV2), whereby SUV1/SUV2 corresponds to the cerebllar hemisphere with the lower/higher SUVmean, respectively. Differential values of groups NV and G1 were used to determine the cut-off for CA determined as mean -2x standard deviation. Mann-Whitney and t-tests were used for statistical analysis. Results : Differential values of NV and G1 showed no significant difference (mean 3.1 +/-2.4 vs. 2.6 +/-1.7, p = 0.474) with values ranging from 0-7.9%. Cut-off for CA was determined as differential values 6.7%. 10/25 pts (40%) in G2 were found to have CA suggesting affection due to BM. 3/13 pts (23%) with unilateral supratentorial (ST) metastasis showed contralateral CA consistent with CCD (frontal, parietal, occipital) which is compatible with published data. Three pts demonstrated CA ipsilaterally to ST foci (frontal, temporal/parietal occipital). Despite bilateral ST foci, 2/3 pts developed CA. 2/4 patients with cbl metastasis revealed CA caused by ipsilateral foci whereas 2 pts with bilateral cbl foci showed no CA. BM could be identified by PET/CT in 21/25 pts (84%) as increased or decreased FDG-avidity. PET/CT failed to identify BM in 4/25 patients (16%) which however could have be decreased to 3 (12%) if evaluation of CA was used. Conclusions: Detection of CA in FDG PET may indicate the presence of BM, and thus may have an added value in the diagnosis of BM, particularly if semiqunatitative measurement is used instead of subjective visual assessment. Prospective validation of our findings is needed. Measurement of SUV as a means to evaluate glucose metabolism in solid tumours may aid in defining response to treatment. Aim: We have evaluated FDG-SUV changes during neoadjuvant chemo-radiotherapy in LARC patients, in comparison with pathological response determined at surgery performed at the end of treatment. Methods: Thirty-three patients undergoing a novel treatment regimen have been evaluated with FDG PET during treatment. Baseline PET studies were obtained from neck to pelvis for staging purposes. Scans obtained after 12 days of treatment and presurgically were carried out only on the pelvis. SUV corrected for body weight was obtained for each study. Maximum SUV values and average SUV values were obtained by drawing an irregular three-dimensional region of interest which semiautomatically defined the tumor area based on preset threshold values. Values were recorded for the three studies and changes compared to treatment outcome which was defined on pathologic evaluation of surgical specimens at the end of treatment and scored on a five level tumor regression grade scale (TRG). Results: In 55% of tumours a complete or near-complete regression was observed at the end of treatment. In the remaining patients considered non-responders only partial or no regression was observed. Baseline SUV showed no correlation with the overall outcome. Conversely, a strong correlation was observed between SUV values measured 12 days after the start of treatment and the pathological response (TRG). The most important factor in predicting tumor response was found to be the early SUV change (variation between the baseline and the 12 day scan). The SUV values measured on the pre-surgery scan were not as predictive of the overall outcome. We could define a cutoff value of the early average SUV change that predicted treatment response in 100% of patients, whereas for early maximum SUV change this was correct only in 31/33 patients. Conclusions: FDG-PET is an effiecient and powerful tool for monitoring changes of tumour activity during the course of treatment. In particular, the early changes occurring shortly after beginning of treatment allow a very efficient evaluation of response which is more accurate for average SUV compared to maximum SUV.

Evaluation of dispersion of SUV obtained by different PET system; preliminary cylinder phantom study H. Otake 1 , Y. Takahashi Purpose: SUV (Standardized uptake value) is a useful tool for the evaluation of the uptake of FDG in tumor lesion, however, reliability of its accuracy in different condition such as different camera or institution has not been evaluated enough. In our study, SUVs obtained by five PET systems with different acquisition condition and reconstruction method were compared by phantom study. Materials and methods: Five cameras, SET-2400(Shimadzu), Acquiduo(Toshiba), Biograph LSO(Siemens), Discovery (GE) and Gemni (Philips) were used. The same amount of radioactivity of F-18 was filled in a cylinder phantom with the size of 200 mm tall and 200 mm in diameter (Type-3, Anzai-Sogyo, Tokyo, Japan ). In phantom filled with same concentration of F-18, different sized round spots (8, 12, 14, 18, 22, 27mm) filled with F-18 solution containing activity corresponding to SUV 2.5 were placed in equal interval. SUV of different spots were measured and compared with background. SUV were calculated using formula by Kubota et al. Max SUV obtained by ROI methods was used as a representative value. 3D acquisition method and image reconstruction by FORE-OSEM method was applied. Results: Minimum detectable size were different in each PET system. SUVs by CT attenuation correction PET system were higher than those by external radiation source. In routine condition, maximum difference of SUV was 45.7%, whereas, 22.6% in condition under image reconstruction. Conclusion: For the early detection or follow up of cancer patients, contribution of FDG-PET is recently recognized and the number of study are increasing rapidly. However, we should pay attention about the follow up PET study by different PET camera, which may show different SUV value. As shown in our study, maximum difference of SUVs by different camera was 45.7%, therefore, precise information of each PET study such as name of PET camera, acquisition condition and reconstruction method is recommended to be added to each results. Aim: It is now a well know fact that the interpretation of abdomino-pelvic images in PET/CT can be altered by normal tracer fixation or accumulation in different organs and anatomic structures, such as the bowel, the ureters or the bladder. The purpose of this presentation is to show the advantages of the administration of furosemide and laxatives to the patient, as part of the preparation for a late second image acquisition when in presence of equivocal findings in first acquisition. Methods: We present six examples of PET/CT (Siemens Biograph 6 HiRez) whole-body image acquisitions performed 60 minutes after the i.v. administration of approximately 370 MBq of 18 F-FDG, adjusted according to the patient body weight. Images were visually analysed after iterative reconstruction using the common parameters for these patients. When equivocal 18 F-FDG foci were found along the course of urinary or intestinal tract, a second late abdomino-pelvic image acquisition (approximately 3h later) was performed after administration of furosemide (20-40 mg) and/or laxatives (sodium citrate and sodium laurilsulfoacetate). The second late images were then compared visually with the correspondent first acquisition ones. Results: We show a comparative study of the images acquired before and after administration of furosemide and laxatives to remove equivocal 18 F-FDG activity. As can be seen, the late images acquired post-furosemide and post-laxative administration, show enhanced information when compared with the first abdomino-pelvic PET/CT evaluation. This clearly allowed a more accurate distinction between physiologic and pathological 18 F-FDG uptake, improving the diagnostic accuracy.Conclusions: The administration of furosemide and laxatives and late image acquisition in PET/CT, after equivocal first diagnosis, due to retention of 18 F-FDG along the intestinal and urinary tracts, proved to be of great utility in the above mentioned examples. In conclusion, this presentation shows the usefulness of this simple, non-invasive interventional procedures in ruling out suspected tracer fixation that is otherwise difficult to evaluate. Objectives: To assess the value of a image fusion and change protocol for early detection of disease progression or recurrence. Each patient underwent pre-surgery imaging with In-111 Octreotide , I123 MIBG and spiral CT and post surgery imaging with In-111 Octreotide , I123 MIBG and spiral CT at approximately 6 monthly intervals post surgery. SPECT and whole body imaging (wbi) with In-111 Octreotide is carried out at 24 and 48 hours pi . I123 MIBG SPECT and wbi is performed at 4 hrs and further wbi at 24 hours pi. Methods: A composite data set comprising the 24hr, 48 hr Octreotide, 4hr MIBG and CT transaxial images is created by mutual information based image fusion for each patient's follow up imaging sessions. Change detection is carried out between the Octreotide SPECT 24hr and 48hr image sets to detect and eliminate significant changes corresponding to normal physiological excretion e.g. in the gut. Remaining areas of stable, significant uptake are reviewed in the context of the co-registered 4hr MIBG SPECT and CT data. Pre -surgery and any previous post-surgery composite data sets are fused and compared to the current data to detect areas of significant change and potential areas of tumour recurrence or progression. Results: Of the 12 patients included to date, 6 exhibited stable disease, 4 demonstrated disease progression and 2 disease recurrence . Conclusion: The advent of accurate image fusion software and ready availability of CT through PACS has enabled the development of comprehensive image protocols for follow up imaging in patients with neuroendocrine tumours. This image fusion and change detection protocol is also directly applicable to patient data acquired with new hybrid SPECT-CT systems. 

With the improvement of gamma cameras systems and software, SPECT has become a usual practice in most nuclear medicine departments. However, the development of other techniques in Nuclear Medicine conditioned the impact of new advances in SPECT methodology. SPECT provides significant technical challenges for the Nuclear Medicine Technologist, concerning to data acquisition and image processing and reconstruction. Many new advances in SPECT methodology are becoming available, such as whole body SPECT acquisition and iterative 3D reconstruction (3D OSEM). Whole body SPECT acquisition is a new technique of image acquisition, allowing the 3D visualization of whole body. The application of this method is especially important in bone studies, excluding additional planar views, and improving the recognition and identification of lesions. The aims of this study are to describe the benefits of SPECT imaging based on whole body acquisition in bone studies and iterative 3D reconstruction (in relation to backprojection and the most widely used iterative reconstruction method, 2D OSEM) and analyse the impact, advantages and limitations of this methodologies, essentials to produce highest quality scans and reduce some image artefacts. Material and Methods: The acquisition of whole body SPECT was performed on a dual-head camera (Siemens e.cam signature), using low-energy and high resolution collimators. A 20% energy window centered on 140keV was used for data acquisition. Imaging was performed with the patient in supine position. Images were acquired as 128×128 matrices with use of a 360º arc. For each of the 5 positions considered, 32 projections were acquired, each 15 seconds in duration with a non-circular orbit, step and shoot mode. Tomographic images were lately submitted to different reconstruction methodologies. Results and Conclusions: The whole body SPECT acquisition applied to bone studies is an effective, relatively cheap and easy to apply technique, that consume a short period of time (40 minutes), allowing the 3D visualization of whole body, advantages that guarantees its superiority by themselves in relation to conventional whole body bone scan. In concern to reconstruction of the data, iterative 3D reconstruction algorithm provides significant improvements in image quality due to higher spatial resolution, lower noise, reduction of distortions and artefacts, improved image contrast and more accurate and easier to interpret images compared to backprojection and conventional iterative 2D reconstruction method. Aim: Oblique projections have been suggested to enhance sentinel node (SN) detection in breast cancer by supplementing anterior projection (AP) and lateral projection (LP). SN close to tracer depots can be especially difficult to detect. This may be remedied by moving the breast before acquiring AP or LP to increase distance between injection site and axilla. However, in some patients movement of the breast may be inadvisable, e.g. to avoid hook-wire displacement in patients with nonpalpable tumours. We wanted to compare a 45° anterior oblique projection (AO-45) with AP and LP to investigate if this improved scintigraphic detection of SN in patients, where the breast could not be moved due to a hook-wire. Furthermore, we wished to test the influence on observer confidence. Material and methods: All women with non-palpable breast cancer scheduled for SN procedure and hook-wire implantation in 2006 were eligible (n=75). Fifteen were excluded: reinjection of tracer S402 (n=6), contamination artefacts (n=2), bilateral tumours (n=1), non-available images (n=3), non-available surgery results (n=2) and multiple wire-implantations (n=1). 99mTc-Nanocoll (2 x 10 MBq) was administered using both a peritumoral and a periareolar injection. Scintigraphic images were obtained using a single-headed gamma camera (Mediso, Hungary) equipped with a low energy high resolution collimator. Dynamic images in AO-45 were obtained for 20 minutes after injection and a summed image from 15-20 minutes comprised the early AO-45. Following dynamic acquisi-tion, successive 5-minutes planar images were acquired in AP and LP. Late images in AO-45 and AP were obtained successively starting 85 minutes after injection. For each patient, the five images were reviewed randomly and independently without knowledge of other projections or the number reported and confirmed by surgery. Results: In all 60 patients, one or more SN were identified, in 11 patients (18%), one or more were positive for metastases. In 47 patients (78%), AP was sufficient. We found additional SN in AO-45 alone in 3 of 60 patients (5%); one was positive for metastasis. In another 10 patients (17%), AO-45 also showed additional SN, but these were also visualized in LP. In the former 47 patients, AO-45 improved observer confidence in 14 (23%) and in the latter 10, observer confidence was improved with AO-45 in 6 (10%). Conclusion: Adding oblique projections to standard AP and LP for SN detection in non-palpable breast cancer demonstrated a few more detected SN, and improved observer confidence in one third of the patients. To ascertain whether imaging patients at 6 hours post injection will demonstrate SLN(s) if the initial 3 hour image is negative. Method: Sentinel lymph node (SLN) images are usually acquired the day before surgery. Four injections of 10 MBq 99m Tc nano-colloid in 0.5 ml are injected peri-areolar. The nipple area is then massaged for 5 minutes. 3 hours post injection anterior, lateral and oblique images are acquired on 256 matrix with LEHR collimator. A cobalt flood source is used to outline the patient. If no nodes are seen on the 3 hour image a further 10 minute oblique image is acquired at 6 hours, again on 256 matrix with LEHR collimator. At surgery, 2 ml of Blue Dye is also injected peri-areolar. Results: 10 out of 302 patients (<4%) demonstrated no nodes at three hours. 2 patients went to surgery before delayed images could be acquired. Of the remaining 8, 4 (50%) images indicated nodes at 6 hours. Of the 4 patients, with negative images at 6 hours, 3 had low activity nodes found at surgery using a gamma probe and in 1 patient the nodes were detected with blue dye only. Conclusion: Imaging at 6 hours post injection can improve the SLN localisation if the 3 hour image is negative.

Interdisciplinary databases for evaluation of nuclear medicine procedures M. Móldrup 1 , W. Vach 2 , P. Hóilund-Carlsen 1 ; 1 Odense Universitetshospital, Odense C, DENMARK, 2 University of Southern Denmark, Odense C, DENMARK.

We have established interdisciplinary databases the stem of which are nuclear medicine procedures in heart disease and cancer. Using our database for breast cancer as an example we present its important characteristics and our experiences with it. Material and Methods: The database includes prospective and chronological data from mammography, nuclear medicine, surgery, pathology, oncology, and clinical genetics. Its purpose is to ensure that all patients are included, check the quality of the sentinel lymph node (SLN) procedure, evaluate its usefulness in terms of a constantly high identification rate, reliable detection, and treatment of extra-axillary SLNs, and long term follow-up with regard to axillary and distant recurrences. All parties agreed upon purpose, rules, and which data should be recorded for each patient. We created the questionnaire sheets with a common lay-out suited for typing of data, e.g., yes or no. All questions must be clear and unequivocal allowing simple answers only. Each panel must have blanks for crosses or numbers, not text. Spaces for "unknown" or "not done" are mandatory to ensure all questions are considered. In each department a contact person collects and controls data before submission to us, where they are checked once again by a controller before typing. In collaboration with the Statistical Research Unit we have established an organization ensuring creation of proper webbased databases, relevant questionnaires, control of submitted data sheets, typing (twice) of data, error correction, etc. Patient ID is converted to a serial number to ensure anonymity. A set of basic data are available to all parties at all times. All can have their own data within a fortnight. Interdisciplinary data are provided after application. An updated set of all data is available twice a year. Results: The database has created a positive and unique collaboration between departments. All parties can check the entire patient course, including waiting and procedure times. It has become clear what is good and less good, if there are patterns of non-visibility of SLNs, reoperation, rates and appearance times of lymphedema, effects of treatment, new procedures, etc. Conclusion: Interdisciplinary databases yield closer collaboration and better understanding between parties. The fact that each department has its own questions means that data are much more comprehensive, detailed, correct, and up-todate than in nationwide cancer databases. Datasheets and controllers are still necessary to ensure data reliability. Nucl. Med. 27, 235-238 (1986) ]. We use 3 computer-controlled modules in connection with an automatic dose dispenser. The modules are installed in pharmaceutical class B cells surrounded by a class C laboratory. Materials & methods: All the 900 batches were analyzed according to the European Pharmacopoeia (EP) to verify: •Radiochemical purity (HPLC, TLC); •pH (pH indicator strips); •Sterility (all the batches has been sent to an external GMP compliance laboratory); •Bacterial endotoxins (turbidimetric method); •Chemical purity (HPLC); •Radionuclide purity (NaI detector); •Half-life (measuring the activity at different times in a dose calibrator); •Residual solvents (GC-based method for measurement of residual methanol, acetone, ethanol and acetonitrile. Detections limit was 25 μg/ml for all 4 solvents); • Kryptofix 2.2.2 (method developed by Mock et al [Nucl. Med. Biol. 24; 2:193-195, (1997) ]; •Bubble point of sterilization filters. Depending on the requested amount of activity for in-house scheduled scans and of external costumers requests, we usually bombarded 1.6 ml of [ 18 O] H 2 O for 50 to 100 minutes at 30-35 μA beam current with a PETtrace Cyclotron and using alternatively two targets. [ 18 F] Fobtained by (p,n) reaction is transferred to the automated synthesis modules, which synthesise [ 18 F] FDG within 25 minutes. Furthermore 3 minutes are required to empty the target and additional 20 minutes are necessary for the Automatic Dispensing Unit to dispense activity in vials for QC, back-up and sterility in addition to vials for a variable number of costumers. All the samples are filtered (at 0.22 μm) into sterile evacuated collecting vials in pharmaceutical class A environment. Results:The number of rejected batches over 900 was 33 and was due either to mechanical problems as leakage of fittings, tubes and valves or to solvent-/radiochemical impurities exceeding the EP limits. None of the batches was positive to sterility or pyrogenicity tests or presented problems due to the radiochemical purity or half life. Conclusion: Based on our experience we conclude that solvents impurities represent a crucial point in FDG production and great attention must be focused on an accurate method for residual solvents detection. Background: Immunoscintigraphy is an attractive tool for tumor and other imaging purposes, with Iodine ( 123 I / 131 I) and 111 Indium(In) as popular isotopes for radiolabelling. I-labelling may be obtained by the iodogen and other methods, In needs some chelator, e.g. DTPA. The Aim of this study was to produce and evaluate, in an experimental mouse model, a good labelling technique for in vivo use of a specific monoclonal antibodies (MoAb) against a human breast cancer (BC) antigen, MUC-1. Materials and Method: 131 I and 123 I labelled anti-MUC-1 (MUC) MoAb were synthesized by the iodogen method. After one sephadex purification step free 131 I or 123 I were <5%. The I-MUC was then injected into BC xenograft tumors in 5 mice. As control a nonsense I-labelled MoAb, anti-TNP, was injected into other mice with the same BC tumors. By gamma camera monitoring and well counting of the tumors the retention of the MoAb were compared. 111 In labelling of polyclonal IgG Ab modified with DTPA-anhydride were done 11 times, before labelling MUC. DTPA-anhydride was suspended in dichloro-methane (DCM) to avoid hydrolysis. Just before adding the IgG solution, DCM was evaporated with nitrogen. IgG-DTPA was then separated from DTPA-anhydride by gel chromatography before adding 111 In-citrate. Results: Iodine-: In the first series of BC xenografts 131 I labelled MUC was retained longer than anti-TNP (p<0.05), both according to imaging and well counting. However, in the following 2 identical mouse tumor series, radio-iodine was rapidly removed from MUC anti-TNP in the xenografts, and high iodine uptake was noted in the thyroid gland. Indium: labelling efficiency of IgG-DTPA varied from 40 to 90% (mean 70). Generally, but not always, purification with one sephadex column increased purity to >90%. The In-MUC has not yet been tested in an in vivo mouse model. Conclusion: In vitro labelling with iodine is generally simple, but in vivo stability of I-labelled antibody must be carefully evaluated since de-iodination in vivo often occurs. Inlabelled antibodies are, according to literature, usually stable in vivo, but chelatorbased In-labelling procedures may be a greater challenge for a reproducible production of a highly purified, radiolabelled antibody. Aim: A radiation detection system for target monitoring was designed, developed and optimized for its use as a diagnostic tool for cyclotron startup, maintenance and operational needs. The system was installed for monitoring the radiation levels next to the cyclotron target during and after bombardment. The system permits a rapid assessment of the quality of any particular run in which isotopes are produced as radionuclides for pharmaceutical labeling. Cyclotrons are produce short-lived positron-emitting isotopes that are used as research tools in identifying physiological mechanisms and in diagnostic procedures for numerous medical problems with the Positron Emission Tomography (PET) instrument. The short half-lives characterizing the positron-emitting isotopes necessitate that they be produced at the desired activity, as rapidly as possible, so that they will be available for the scheduled procedure. This raises a need for automated control sensors that can monitor the production process. Method: A computerized radiation detection system was developed for monitoring the radiation levels next to the cyclotron target, during and after the isotope bombardment in an attempt to show that a particular cyclotron run might be faulty. The system utilized a BGO scintillation detector focusing on measuring the photons at the energy window of 511 keV; and a Geiger Muller detectors design for measuring the gross gamma radiation. The system monitored the radiation levels throughout the production run as well as the activity before and after the transfer procedure, when the measurement of isotope activity takes place. The installed system input on-line the results into computerized software, and used as part of an overall diagnostic and control tool of the bombardment run. Results: The target radiation detectors provided an early warning of a malfunction or an irregular run. This information could lead to operational decisions in order to prevent delay in the production and availability of the isotope. The system predicted and quantified accurately the actual amount of radioactivity being produced, thus it assured quality control during isotope production. The system also helped in troubleshooting target problems immediately after their occurrence and identified the stage at which the malfunctioning took place. Conclusion: The results obtained from the developed system indicated that such a measurement tool can serve as a powerful instrument for sensing various target conditions. This can be translated to an awareness of problems in the early stage during isotope production, and provide early notification to the cyclotron operator that a particular run is malfunctioning. Aim At present, most Nuclear Medical Departments have instrumentation that allows them to perform tommographic studies in a continuous circular method. With the present work, we aimed to compare quality of images obtained by Simple Photon Emission Tomography with two approaches, continuous circular and step-and-shoot circular acquisitions. Material and Methods For both methods, continuous circular acquisition and step-and-shoot circular acquisition, we tried to establish associations between acquisition parameters (independent variables) -number of projections for each detector, time for each projection; and measurements of image quality (dependent variables) -noise, contrast, resolution and sensitivity. The experimental series was defined using a non probabilistic method by convenience, with sixteen studies of a Jaszczak fantom, model ECAT/DLX/P, in which eight studies were acquired in a continuous circular mode and the other eight in circular step-and-shoot mode. The statistical analysis was performed with package SPSS version 14. Results The percentage of noise was inferior in studies in continuous circular mode, the contrast measured with the 4 spheres gave identical results in the two acquisition methods, the resolution was higher in step-and-shoot mode and the detection sensitivity was higher in continuous circular mode. Conclusion We conclude that the tommographic acquisition in continuous circular mode presents identical image quality to the one in step-and-shoot circular mode. The quantification of low activity in plasma of a Positron Emission Tomography tracer is performed in PET research to derive a kinetic model for a particular biochemical process. To define the kinetic model, the concentration of radioactivity in the parent compound present in the plasma must be measured at several time points. A radio-HPLC is used to measure low levels of radioactivity in a compound throughout rapid sequential experiments with the nearby presence of another compound causing a high background level. Both the measured compound and the background level are caused by compounds labeled by a positron emitter isotope. The time separation between the parent compound and the metabolite one is limited, therefore optimization of the measured volume and its geometrical configuration can improve the Minimum Detectable Activity. Improving of the MDA is important for achieving a better reliability and validity in measuring biochemical processes with PET. The research was based on an analytical study, followed by software simulation and feasibility experiments for increasing the measuring sensitivity of an HPLC metabolite radiation detector. As a first analytical step a mathematical model for the coincidence measurement probability from a PET tracer radioactive compound was developed. By using this model, an estimation of the number of coincidence counts was made, and its influence on detection sensitivity from the system configuration parameters was assessed. Results of the mathematical model were compared to those obtained by software simulation.. Finally an experiment was performed under similar conditions those in the mathematical modeling and software simulation. A high correlation between the mathematical modeling and the software simulation was found. The results indicated that an optimum for the measured volume and its geometrical configuration can be found. A curve representing the measured coincidence counts as a function of volume was obtained from the experimental results. The experiment validated the analytical study, showing that optimization can be achieved for each case based on the time separation between the parent compound and the metabolite one. A new method for improving the MDA for the data acquisition during kinetic modeling, based on optimizing the measured volume seen by coincidence detection configuration is suggested. The MDA is defined by both the signal and the background levels. The S404 reduction in the sensitivity for the signal measurement is negligible compared to the reduction in the background level, and is achieved by increasing the distance between the measured parent compound and the metabolite one. 

We have developed a simple image registration method for 99m Tc-MDP planar bone scintigraphy and x-ray images in patients with suspected scaphoid fracture. This method is based on immobilisation of the wrist in a vacuum pillow equipped with three multi-modality fiducial markers ( 57 Co-source collimated by a punched coin, 2.5 cm) during image acquisition followed by computer assisted semi automatic image registration (CASAIR). The aims of this study were to investigate the feasibility of the vacuum pillow to immobilize the wrist and to evaluate the accuracy of CASAIR. Materials & Methods: Wrist movement between two examinations was assessed in five healthy individuals. A small metal disk ( 1.3 cm) was taped radially to the volar side of the carpus. Two x-ray images were acquired with the wrist immobilized in a vacuum pillow equipped with three fiducial markers. Between the two acquisitions the subject walked around for about 5 minutes. The two images were registered with CASAIR and the distance between the centres of the metal disc on the carpus in the two images picture was measured. Accuracy of multi-modality image registration with CASAIR was estimated from 19 clinical fusion images. The distance between the centres of each fiducial marker on the X-ray image and scintigraphic image was measured. Results: Mean wrist movement as evaluated by consecutive Xrays was 0.8 mm (range 0 mm to 1.4 mm ). Accuracy of CASAIR was 0.4 mm (range 0.2 to 0.7 mm). Conclusion: The vacuum pillow provides a feasible and accurate method of immobilisation of the wrist and image registration with CASAIR provides very accurate image registration of nuclear medicine and X-ray images. In consideration of the size of the scaphoid bone the magnitude of misregistration with the proposed method has no clinical impact. Introduction:In routine practice of SPECT acqusition,the image acquisition time per projection is a cause of concern eventually leading to increased overall acquisition time of a clical study.The present study was therefore undertaken to optimize the overall aquisition time irespective of whether FBP or OSEM reconstruction technique is used.The objective of the study also included comparative evaluation of the images obtained by either reconstruction techniques. Materials and Methods:The raw image data were retreived from DST-XL Sopha Gamma Camera work station and were then subjected reconstruction using both FBP and OSEM technique on Xeleries work station.The aquisition time was also manipulated to 15 seconds per view from 30 seconds per view/projection.The reconstructed images were obtaine for reduced acquisition time keeping all other parameters identical nad by using both reconstruction techniques.The reconstructed images were blinded for independent evaluation by two nuclear medicine physicians in the nuclear medicine department of the institute. Results and Conclusions:The overall image information and quality remained unchanged even after reducing the acquisition time from 30 seconds to 15 seconds per projection irrespective of whether FBP or OSEM reconstruction method was used for skeletal images.In addition the intercomparison of FBP and OSEM reconstructed images revealed that the image information was better delineated in OSEM reconstructed images as compared to FBP reconstructed images. The image optimization in terms of reduction in acquisition time without any loss of image information would help reducing overall study time in SPECT aquisition.In addition use of OSEM reconstruction technique appears to be the order of the day in image processing and would provide improved image information delineation. The generally used filtered back projection(FBP)method is likely to be influenced by high accumulation, especially in the liver and biliary system, and it is often difficult to reduce the waiting time for imaging with a Tc preparation. In this study, reduction of artifacts using the projection mask method was studied. Method: A model was prepared to generate artifacts from the liver using a cardiohepatic phantom. Mask processing of 100 counts was applied to SPECT images acquired over 360 degrees at intervals of 6 degrees and the obtained projection data of 60 slices other than the myocardium. A similar mask processing was also applied to clinical cases after AMI and compared. For analysis, decreases and variations of the counts were measured with a polar map and a circumferential profile curve (CPR) on a short axial image. Results: In the phantom, a significant difference in the count was observed (p< 0.001) between normal processing and mask processing, that is, the average count was 47.49 for normal processing and 41.93 for mask processing. Variances in the area with visually observed artifacts with the CPR were 5.08 for normal processing and 4.02 for mask processing, indicating smaller variations with the mask processing. The counts and variances in an area with visually observed artifacts in clinical cases were 8.68 and 27.14 respectively, which were significantly reduced to 7.85 and 18.72 by mask processing (p< 0.001). Conclusion: The projection mask processing method is an effective means for removing artifacts from the liver and the gallbladder, and imaging may be available from the early period after myocardial injection of the 99mTc tracer. Aim: In PET study, the coincidence count rate (CR) in the imaging of standard image quality phantom (IQ phantom) is different from that of the actual clinical data. Therefore, clinically optimal injection dose cannot be estimated using the data of IQ phantom. In this study, we made an anthropomorphic pelvis phantom (pelvis phantom) which can provide the CR equivalent to clinical data and investigated whether the optimal injection dose could be estimated using this pelvic phantom. Materials and Methods: The pelvic phantom was made by putting high radioactivity area imitating the urinary bladder in the IQ phantom and by using bone-equivalent material for pelvic bone model. At first, the images of the pelvic phantom were acquired changing its radioactivity using both 2D and 3D acquisition modes. Obtained CRs were compared to those of pelvic images of actual patients. Then, single photon ratio (SPR) indicating the maximal NECR was determined in the pelvic phantom imaging. Using this SPR, the SPR obtained from patients' data was normalized. The optimal injection dose of FDG per kg of body weight was calculated according to the relationship between SPR and the injected dose. Results: The good correspondence was shown between CR of pelvic phantom data and that of clinical data when SPRs were 2.6 to 3.9Mcps for 2D imaging, and 6.0 to 10.7Mcps for 3D imaging. The SPR at the maximal NECR in the pelvic phantom imaging was 12.4Mcps in 3D acquisition whereas no peak was found in 2D mode. The optimal injection doses calculated using SPR in 3D imaging were 282MBq and 400MBq for the body weight of 40 kg and 80kg, respectively. These results were empirically acceptable. Conclusion: The imaging of pelvic phantom showed the CR similar to human bodies, indicating that the statistical quality of the obtained data in human studies can be estimated by this phantom. And, using SPR of this phantom, the optimal injection dose per body weight could be simulated in 3D imaging. Introduction: Phantoms for the determination of the size of pixels should be big, rectangular, homogeneous and easily available. However, they must not "jut out". The NEMA homogeneity phantom can meet these requirements if its position is adjusted to whole body scanning. Material and Methods: The NEMA phantom was filled with 1 GBq of 99m-TcO4 and placed on the examination table with its long edges parallel to the examination table. A square tile of 31.5 cm was put on top of the phantom and was aligned to one of the short edges of the NEMA phantom to facilitate a comparison of the resulting defect with that of a static image. Pixel numbers were determined by applying rectangular ROI to the edges of the phantom and of the tile. By this, the numbers of pixels of the x-and y-axis could be determined and compared with the length and width of the phantoms. We compared the data of a Prism 2000 camera with those of an LFOV camera that had not been approved yet by our hospital at the time when we did the exams. We did a static scan and two whole body scans (180 and 100 cm) with both cameras. Results

tile 315 

The accuracy of OSEM and FBP reconstruction algorithm for the determination of the thyroid volume: A fantom study A. Ergulen, G. Durmus-Altun, F. Ustun, S. Erol, S. Cıldavil, S. Berkarda; Trakya University, Edirne, TURKEY.Background_Individualised dosage models are frequently applied for radioiodine therapy in patients with Graves' hyperthyroidism. In these dosage schemes the thyroid volume (TV) is an important parameter. Iterative reconstruction algorithms produce accurate images without streak artifacts as in filtered backprojection. They allow improved incorporation of important corrections for image degrading effects, such as attenuation, scatter and depth-dependent resolution. The aim of this study was to compare the accuracy of OSEM and FBP reconstruction algorithm for the determination of the TV in fantom study, and to comparing estimted TV 360 and anterior 180 degree SPECT acquisition Methods and Results_The OSEM (It:2, Sbs:4) and FBP (BW cut-off:0.5, order 6) algorithm was employed in reconstruction. At quantitative analysis 360 and anterior 180 degree 131-I thyroid SPECT , the volume of thyroid were calculated for 20%-30%-40% uptake levels of wather-filled thyroid fantom. For estimation of TV, linear regresion analysis was eployed and final regresion equations were generated for each acqusitions and filters. The thyroid images were filtered, and after applying a threshold method an automatic segmentation algorithm was used for the volume determinations. The best estimation of TV was observed on 180 degree SPECT acquisition and FBP algoritims. Estimated TV(ml)=56+(0.002 * calculated TV)-(0.23 * average count of thyroid); R:0.99, R 2 :0.98, p:0.01, SE of estimation: 0.158). th predicted TV was 49.8+/-0.83 ml (min:48.97, max: 50.93) and SEE of pTV was 0.118+/-0.038 ml. Conclusions_The comparisons with OSEM and FBP indicate that thyroid volume estimations with 360 Aim High resolution scintigraphy ( HRS) can be useful in radio-guided surgery (RGS) and small animal imaging. Devices are generally based on arrays of sensible elements: room temperature semiconductor arrays or scintillating crystals arrays that can be coupled with position sensitive photomultipliers (PSPMT). Here we describe a small Field Of View (FOV) portable cameras based on 1 and 4 inches 2 PSPMT. Materials & Methods These cameras show a peculiar crystal-collimator-PSPMT matching that allows the exact positioning of all the scintillating elements inserted in the square holes of a parallel Tungsten collimator. This arrangement ensures no crosstalk of rays or light among crystals. The scintillation light emerging from each crystal is revealed by a PSPMT (H8500 or R8520-00-C12). The anodes allow event positioning through the reconstruction of the maximum of the multiplied charge distribution by the centroid algorithm. Data are then selected with an appropriate energy window and transferred to a workstation. We studied the spatial resolution and the homogeneity of two cameras both equipped with 2.4x2.4x5 mm 3 CsI (Tl) crystals and a 25 mm long collimator. A thin Plexiglas container filled with 99m Tc was used to check homogeneity and pixel identification. A Derenzo phantoms with the diameter of the holes ranging from 2 to 4 mm was positioned at contact, at 1, 2, 3 cm distance from the collimator and filled with 99m Tc to assess the camera spatial resolution. Results The energy resolution was 19.1 % FWHM of the 99m Tc peak over the whole FOV area. Both cameras showed homogeneity within ± 5% between max and min pixel counts. Pixel identification showed average peak to valley ratio of 20:1. Spatial resolution was 3.3 mm at 1 cm, 4.9 mm at 3 cm, 6.0 mm at 5 cm and 10.9 mm at 10 cm distance. Conclusion Measurement of resolution were performed to foresee the working conditions of HR cameras. Actually when nuclear physicians show to surgeons sentinel nodes or parathyroid glands, they are on contact with the source or at few cm distance. Both detectors were used for RGS and showed hot nodes less than 2 mm large and distant 2.5 mm each other. In several instances a spot detected as single node by Anger camera showed the presence of two near nodes. Aim The aim of our study is to evaluate the correlation between the bone density measured with Quantitative US technique (QUS) and with Dual X-ray Absorbiometry (DXA). Material and methods We studied 12 patients (47-57 years; mean: 52). Bone status was assessed by quantitative ultrasound, using DBM Sonic 1200 (IGEA, Italy), which measures amplitude-dependent speed of sound (Ad-SoS [m/s]) and bone densitometry by the use of UNIGAMMA PLUS/COMPACT (L'ACN, Italy), which measures bone mineral density. We correlated the T-score parameters obtained in QUS e in DXA scan. "T-score" compares the patient's BMD with the young-normal mean BMD and expresses the difference as a standard deviation (SD) score. The QUS was performed in menopausal ambulatory in Gynaecology Department, measuring the bone tissue at the metaphysic of the proximal phalanges of the last four fingers of the non-dominant hand. After the ultrasound bone densitometry, the women underwent the DXA scan of lumbar spine (L2-L4). The BMD is calculated in g/cm 2 . We had exposed T-score as diagnosis of normality, osteopenia and osteoporosis according to World Healt Organization normal range. Results According the WHO definitions, osteopenia was found in 7 patients and normal bone density in 5 patients with Quantitative US technique . With DXA method, osteopenia was found in 7 patients, normal in 4 patients and osteoporosis in 1 patient . Conclusions Concordance was found between the bone density measured with QUS and with DXA in 8 patients, while 4 patients results were discordant. Some studies in literature showed an agreement of 0.2-0.8 between QUS methods and DXA In our study the agreement between the diagnosis in QUS and in DXA is 0.47. It agree the literature data. Our intention is to continue this study, extending the case study. Aim: Neuroendocrine tumors may be treated by peptide receptor radionuclide therapy. In order to target somatostatin expressing tumors DOTATOC was coupled to a ßemitter Yttrium-90 (Y-90) or Lutetium-177 (Lu-177) which results in a high radiation dose in the tumor tissue. The elimination of the peptide occurs via the kidneys. Y-90-DOTATOC shows tubular reabsorbtion and accumulates in the kidneys. Therefore, a major complication of Y-90-DOTATOC-therapy is the radiation-induced nephrotoxicity. In this study we determined the effects of Y-90-DOTATOC-therapy on renal function with Tc-99m-MAG-3 scintigraphy. Methods: 29 patients (19 m; 10 f) between 28 and 78 years (average: 57,5 years; median: 62 years) have been examined. All patients received a minimum of three DOTATOC-therapies in combination with a nephro-protective amino acid infusion according to the Heidelberger Standard Protocoll. The dynamic scintigraphy was carried out from dorsal position (Multispect 2, Fa. Siemens) with a weight dependent application of Tc-99m-MAG3. Between the 21st. and 50th. minute p.i. a blood sample was taken at the opposite arm. The blood was centrifuged and 1 ml serum was measured in a Gammacounter using repeat determination. The evaluation of the tubular excretion rate (TER) was done on a Xeleris Workstation. The TER of any examination was normalized using a specific patient standard. The average after the second, third and forth therapy was verified with the T-test procedure and deviations from average were analysed. Results: After the second and third therapy there was no significant change in renal function with a probability of p=0,19 (n=29) after the second therapy and p=0,25 (n=20) after the third therapy. A significant aggravation of the renal function was shown in 11 patients p=0,001 (n=11) after the fourth therapy. In 3 of 11 patients the TER was pathological. Conclusions: Three cycles of Y-90-DOTATOC therapy are well tolerated by the kidneys, and a significant reduction of renal functions were not observed. However a significant reduction of the TER was found after the 4th cycle in some patients. However, the renal function dropped into the pathological range in 27.2% of these patients. We conclude that the risk of a nephro-toxicity by a Y-90-DOTATOC-therapy is negligible during the first 3 cycles. After the 4th cycle of Y-90-DOTATOC therapy, a reduction of renal function may occur, but the clinical relevance is low. This presentation will outline some of the additional duties that may be encountered by a Nuclear Medicine Technologist (NMT) working in the field of RIT research. Radioimmunotherapy is being increasingly used, particularly in the treatment of haematological malignancies. A stem cell transplant with prior RIT involves input from a range of specialities such as Oncology, Haematology, Nursing, Radiopharmacy, Physics, Imaging, and Laboratory services. It is vital that the multidisciplinary team works in harmony to deliver this service. The large number of staff members involved adds complication to making patient appointments and has led to some overlapping of roles in order to offer a continuous service. RIT is a complex and evolving technique and many procedures will be new to a Nuclear Medicine Technologist entering the field. The additional duties performed by a NMT at Southampton include coordination of patient appointments for RIT clinical trials, performance of ELISA assays, quality control of radio labeled antibodies by HPLC and ITLC, administration of dosimetric and therapeutic infusions, assistance with dosimetry calculations and Bremstrahlung imaging. These duties will be illustrated with reference to a clinical RIT trial currently being undertaken at this institution. Aim The aim of this study was to determine the radiation dosimetry of no-carrieradded (NCA) 123 I-metaiodobenzylguanidine (MIBG) compared to carrier-added (CA) 123 I MIBG, in the same subjects. Materials and Methods Nine healthy subjects were injected with 185 MBq NCA 123 I MIBG and on a separate occasion with CA 123 I MIBG. Anterior and posterior whole body (WB) scans were made with a dual-head camera at 30 min, 1.5, 2.5, 4.5, 6, 24 and 48 h post injection to obtain organ timeactivity data. Blood samples were collected at the same time points in order to determine activity in the total blood volume. Urine was collected in five portions up to 48 h in order to monitor the excretion. One set of regions of interest (ROIs) was drawn for ten source organs and different background regions on the WB scans, and then applied to each WB scan. The counts in the ROIs were corrected for background. The geometric mean net counts were calculated, and corrected for attenuation, efficiency, decay, and expressed as a percentage of injected activity. Curve fitting was applied to the time-activity data to obtain the total number of disintegrations in each source organ, from which the absorbed doses to all organs was calculated (Olinda/EXM software). The effective dose (mSv/MBq) and effective dose equivalent (mSv/MBq) were then determined. Results The effective dose of NCA 123 I MIBG was equal to CA 123 I MIBG (0.029±0.002 mSv/MBq vs. 0.029±0.002 mSv/MBq, respectively; p=0.181). The effective dose equivalent of NCA 123 I MIBG corresponded with that of CA 123 I MIBG (0.025±0.002 mSv/MBq vs. 0.026±0.002 mSv/MBq, respectively; p=0.055). The myocardial wall showed 25% more uptake for NCA 123 I MIBG compared to CA 123 I MIBG. The radiation dose to the myocardium was thus higher for NCA 123 I MIBG compared to CA 123 I MIBG (0.035±0.006 mSv/MBq vs. 0.029±0.004 mSv/MBq, respectively). Conclusion No essential differences were found in absorbed dose between NCA and CA. The higher myocardial uptake of NCA favours the use of NCA over CA for the assessment of myocardial imaging.

Characteristic evaluation of a real-time semiconductor dosimeter and measuring finger dose in nuclear medicine departments T. Fujibuchi 1 , T. Isobe 2 , T. Iimori 1 , Y. Uchida 1 ; 1 Chiba university hospital, chiba-shi, JAPAN, 2 Kitasato university, Sagamihara-shi, JAPAN.Background and Purpose: Workers who use radiation sources in the nuclear medicine field have the highest risk of exposures to their fingers. Until now, TLDs have been the only reliable dosimeter to measure finger doses. However, the usage of TLDs is complicated, its procedure is time-consuming and it is used in other fields as well. In this study, we measured finger doses by using a semiconductor dosimeter for the nuclear medicine examination and evaluated its sensor characteristic. After having Aim: the tracheo-bronchial inhalation is the most invalidating symptom shown by patients with neurological disease and it is the most frequent cause of death. Oro-Pharyngo-Esophageal scintigraphy (OFES) allows both functional and semiquantitative study of the various stages of swallowing. Material and Methods: We studied with OFES a woman who underwent to high dosage radiotherapy treatment for rhinopharyngeal carcinoma. The patient developed progressive and ingravescent dysphagia, with ipomobility of the right arm. The patient, placed in a 80° right anterior oblique upright position, in front of a large-field-of view gamma-camera, was given a single 5 cc bolus o water labelled with 37 MBq of 99M Tc-nanocolloid. Eight images/sec are acquired (0.125 sec/frame) for one minute, with dynamic acquisitions using a 64x64 matrix and zoom 1 of the visual field from oral cavity down to epigastric area. Two second after the beginning the patient is invited to swallow the liquid in a single time and a static image lasting 60 seconds is then acquired at the end of examination, to evaluate the presence of tracheo-bronchial aspirate. For the presence of massive inhalation the study was completed with a SPET-Tc. The parameters analysed were: Oral, Pharyngeal and Esophageal Transit Time, Oro-Pharyngeal and Esophageal Retention Index, percentage of tracheo-bronchial aspirate. The study was performed at the time of diagnosis, after the treatment by positioning the low pressure cuffied tracheostomy tube and finally after functional laryngectomy. Results: OFES shows a massive tracheo-bronchial inhalation at first study with ritention of bolus in the both lungs and a lengthier oral and pharyngeal transit times and an increase in the oro-pharyngeal retention index. A SPET-Tc confirms the pulmonary aspiration and shows a sovra-elevation of the right lung as consequence of inhalation. The OFES performed after positioning of the cuffied tracheostomy tube shows absence of inhalation in tracheo-bronchial tract after oropharyngo-esophageal transit of liquid bolus with a presence of small aspiration in the right lung in tardive acquisition. The cuffied tracheostomy tube was changed with a standard tracheostomy tube and the OFES shows again massive tracheo-bronchial inhalation. Then the patient was submitted to functional laryngectomy. A scintigraphic study performed subsequentely shows absence of tracheo-bronchial inhalation. Conclusion: OFES in neurological patient is a simple, inexpensive, non invasive and reliable technique that shows the presence of bolus inhaled and quantifies tracheobronchial aspirate. OFES is a useful and accurate tool to monitoring the response to medical and/or surgery therapy.

Ger on Children with Recidive Bronchitis(RB) M. Hudournik; General hospital celje, Celje, SLOVENIA.Aim: In this examination we are finding how frequent GER as a cause for RB. Materials and methods: In this examination have been included 80 children (53 men, 27 women) in an age from 2 mounts to 14 years. Doctor's notes for these children have: RB (35 children), vomiting (23), cough (14) and allergy (8). The images of these children has been taken in lying position after a normal meal. Radiofarmac was Tc-99m-LYOMAA (dose upon 7,4 MBq -37 MBq), which has been to apply through the nasogastric tube or to drink up. Gamma camera was set up behind the patient. The field of view includes the mouth, sternum and abdomen. Images are generated every 30 s for 1 h on 64x64 matrix. After 2-3 hours we have taken delay images of lungs to find out the aspiration Tc-99m-LYOMMA in to the lungs. Results: From all (80) in this examination included children has had 22 (27,5%) GER and from this 22 has ha dan aspiration in the lungs. In examination has confirmed with diagnosis, RB 37%, vomiting 26%, allergy 12% and cough 14% GER. Children average age with RB diagnosis has been 2,9 years . Most children (18) with RB has been 1-2 years old, 39% of them has had a GER. Conclusion: Frequency of GER on children with RB is 37%, especially with children at approximate age 2 (39%). Introduction: The collaboration problems that arise from the observation and care of patients could be codified to Nursing Interventions Classification (NIC), to obtain finally results codified agreed to Nursing Outcomes Classification (NOC). These collaboration problems, interventions (NIC) and results (NOC) applied to patients referred for treatment of hipertiroidism could identify and develop interventions to optimize ant obtain the wished results so the patient feels more comfortable in the visit to our Service. Methodology: Since 2004 the nursing in our service are explore these aspects in the daily care of patients (approximately 8 patients weekly), and have been identified the collaboration problems that usually presents this type of patients. The most frequent were: administration of radionuclides, informed consent, radioprotection advices, nursing registry, discard pregnancy in women in fertile age. Once identified these collaborations problems an interventions, codified according the NIC criteria are applied: Administration of oral medication (2304), agreement with the patient (4420), Support in making decisions (5250), Identification of risks (6610), Documentation (7920), advise before conception (5247). All patients fulfilled a report (survey form) about the satisfaction for the care received in the Service. This form was complimented at 90% of patients. All patients facilitated a satisfaction survey when they left our service, which was answered for the 90% of them. Results: After application the interventions we had a satisfactory results in 85% of patients. These results codified agreed the NOC were: Behaviour of fulfillment (1601), Well-being (2002) , Knowledge: prescribed activity (1811), Knowledge: preconception (1822). Conclusions: The use of the methodology according NANDA criteria could diminish the collaboration problems in patients referred to treatment with I-131. we acquired image that used ORBITER GAMMA CAMERA with pin hole collimator. Also we acquired the thyroid phantom and the 4-Q bar phantom image to compare resolution. The patient image aquired by 300 sec or 100 Kcnts. and phantom image acquired by 500 Kcnts. We calculated Thyroid/BKG ratio from the image that is setted with 300sec. and then compared scan time from the image that is setted with 100 Kcnts. Additionally, we investigated that the time required of each diseases(hyperthyroidism, hypothyroidism, goiter, nodule).

When we acquired image by time setting(300sec), using 4mm pin hole collimator and 6mm pin hole collimator, that result of Thyroid/BKG ratio was as low as 1.89 times in 4mm pin hole collimator(ratio -4mm:21.64, 6mm:40.89). And we

The relative high number of persons who daily attend to Nuclear Medicine Departments is an important factor regarding disease transmission. Although the permanence of these people in the facilities is usually quite short in time, there is always the possibility to transmit or receive infectious agents (both through organic material or airborne transmission). The goal of this work is, firstly, to "make the diagnosis" of the present situation, identifying what kind of infectious agents are present at Nuclear Medicine Departments (and if different NM Departments present different profiles, according to their characteristic turnover of patients), and, secondly, to suggest appropriated technical solutions for their control/elimination, when possible (otherwise, at least, to obtain their minimization). This abstract relates with the first part of the work (as it is still on progress). Material and Methods: As a first step, it was performed the characterization of the present situation, via an adequate analysis/detection of the main pathological agents (focusing only on bacteria and fungi) present in the diagnostic equipment, as well as in other important "hot spots" in a Nuclear Medicine Department, where the spreading of these agents was believed to be more prone to happen (such as keyboards). It had been collected and microbiologically analysed bacteriological samples from those pre-established spots in several distinct Nuclear Medicine Departments. The information collected is actually being related to the different kind of scintigraphic studies that are performed in those Departments (and/or the different "specific profiles" of the Departments itselves). The cleaning methodology (agents used and respective frequency) used in these Departments is being taken into account and related with the results obtained. Results and Conclusions: According to the results obtained, it had been possible to identify the main infectious agents and to make the "point of the situation" in distinct profiles of NM Departments, being believed that this should be the starting point to further studies, now aiming to identify methodologies able to control the incidence of Nosocomial Infections related with NM Departments. 3 Ben-Gurion University of the Negev, Beer-Sheva, ISRAEL.

The 18 O Oxygen isotope is widely used in cyclotron targets for the production of the 18 F positron emitting isotope. The latter's rapidly increasing use in medical imaging generated a need to improve the diagnostic tools for controlling the cyclotron production of 18 F and 18 O during the enrichment process. A highly reliable measurement of 18 O concentration is important for the 18 O manufacturer to validate its purity, and for the 18 F producer, to assure that that it is produced with the required activity and quantity at the end of the cyclotron run. This work describes a process that can validate the concentration of these isotopes and that should prove useful to both parties. The manufacturing of 18 O water involves several stages to obtain the final required concentration of 18 O (98.5%). By carrying out isotopic analysis repeatedly throughout these stages, the concentration of each isotope can be validated. A radiation detector was used to measure the gamma field for different levels of 18 O enrichment during the production of 18 F. The gamma radiation dose rate and the accumulated dose were measured for a target loaded with recycled water, or 98% enriched 18 O water, or 16 O water. The detector readings from the nuclear interaction in the cyclotron target were compared to the measured beam current, the existing indicator for the bombardment. The variations in the radiation level were calculated and compared to the different levels of 18 O activity in the water, obtained repeatedly throughout the enrichment process, to establish a relationship. The isotope analysis test during enrichment enabled the manufacturer to maintain the 18 O enriched water concentration level in the short run, and the 18 O production quantity rate in the long run. The water enrichment was not reflected by the accumulated beam current when measuring cyclotron protons; however the calculated ratio between the radiation level and the accumulated beam current gave a factor of up to 2.4 during the target water bombardment at the various stages. This study presents a comprehensive solution for monitoring and validating 18 O enrichment during the manufacturing stage, as well as the production of 18 F. The isotopic analytical test enabled malfunction identification at the early stages of the 18 O manufacturing process which assured quality and quantity. During the bombardment, the beam current did not indicate any difference in the level of enrichment. However, the radiation monitoring system provided a useful tool for distinguishing between different enrichment levels during the production runs.

Calibration of I-131 in Dose Calibrators Routinely Used in Nuclear Medicine Departments S. Tastan 1 , N. Kucuk 1 , E. Ibis 1 , E. Turkoglu 1 , K. Kir 1 , A. Soylu 2 ; 1 Ankara University, Ankara, TURKEY, 2 MONROL A.S, Ankara, TURKEY.Introduction: A dose calibrator is one of the most important instruments in a nuclear medicine center since it is crucial to give the right amount of activity to the patient. The calibrator is a well-type ionisation chamber, which has long term stability and can measure activity to the desired level of accuracy. However, it is sensitive to even small changes in geometry, container type, density and volume of samples. Material & Method: In this study ,which is part of a Project supported by the IAEA as a CRP,performance tests of BIODEX ATOMLAB-100 dose calibrator were performed according to " IAEA Technical Report Series No: 454" . The calibration was done by using an I-131 standard solution provided by the IAEA to all participants of the project in various countries. The solution was 178 MBq/ 5 mL in a 10R Schott Vial with Teflon-coated stoper and aluminium uncrimped seal,uncertainity (3 %, k=2) . Correction Factors were calculated for the 10R vial, 5 mL syringe and the vial which is routinely used in our laboratory . During the transfer to syringe/vial, necessary amount of carrier solution was added to bring final solution to original mass. Results: Calibration factors were 1.027, 0.982, 1.029 respectively 10R Vial, 5 mL syringe and routine vial. GUM ( ISO Guide to the Expression of Uncertainty in Measurement) were used to analyse all uncertainty components. The table demonstrates correction factors with the calculated uncertainities. Conclusion: This study demonstrated that dose calibrator measurements are sensitive to small changes in container type and geometry altough total mass is the same. In many countries don't have national measurement laboratories. Therefore, it is important that performance tests, calibrations and audits of radioactivity measurements in radiopharmacies and clinic so that measurement errors can be avoided.Correction factor with uncertainities 10 R Vial 1.027 x Activity ± 0,0187 k=1 Routine Vial 1,029 x Activity ± 0,0583 k=1 5 mL Syringe 0,982 x Activity ± 0,0583 k=1 Introduction. Usually the patients coming for the first time to our Diagnosis Unit for a PET study show a high degree of unknown about details of that. This fact induces a high degree of anxiety that could be assessed in nursing diagnosis according NANDA classification. On basis this diagnosis could be planned nursing interventions (NIC). Objective: To evaluate nursing diagnosis of anxiety and the effectiveness of the application of interventions (NIC) according to NOC criteria in patients who are going to perform a PET study. Material and Methods: From I/'05 to VI/'05 110 patients have been studied for first time using PET, under suspicion of malignant disease. For this purpose, patients with alteration of conscience level are excluded. The degree of anxiety is evaluated by means a numerical scale LIKERT type, before and after the application of the plan of care. Results: After the application of the nursing care plan a 10% of patients reduce in 3 points the anxiety level, in 65% this reduction is of 2 points and in a 5% in 1 point according LIKERT scale. Conclusions: The application of the nursing plan of care in patients, who first perform a study PET, diminished the level of anxiety in a significant proportion.

High performance liquid chromatography evaluated the stability of Levofloxacin and Stannous Chloride for Injection X. Q. Zhou, G. X. Cao, R. J. Zhang, X. F. Qin; jiangsu institute of nuclear medicine, Wuxi, Jiangsu Province, CHINA.Aim: Levofloxacin is a sort of broadspectrum antibiotic which is often used to treat infectious diseases at present. The method about determination content of Levofloxacin tablet using spectrophotography was reported. 99m Tc-Levofloxacin is a new specific infect imaging. We prepared Levofloxacin and Stannous Chloride for Injection by freeze-dry. It is most important for radiopharmaceutical. We determined the concentration and evaluated the stability of levofloxacin in Levofloxacin and Stannous Chloride for Injection for the first time. Methods:The concentration of levofloxacin and the concerned substance in Levofloxacin and Stannous Chloride for Injection were determined by reverse High Performance Liquid Chromatography (HPLC). The stability of Levofloxacin and Stannous Chloride for Injection and the radiochemical purity were examined under the different conditions of light, temperature, humidity. We used citric acid and acetonitrile (79:21) as mobile phase, adjusted pH to 4.0 using triethylamine. The mobile phase was pumped at 1 ml/min through the Lichrospher C18 (4.6×250mm,5μm) at room temperature. The detective wavelength was 293nm and the sensitivity was 0.01AUFS .The number of theoretical plates was exceed 2500 using the model 600 high performance liquid chromatograph and 2487 UV detection (Waters Aim: To guarantee presentation of all studies from PACS to a particular examination on a given imaging modality (in our case PET) after a query from HIS. Material: PET Ecat Accel (Siemens, Erlangen, Germany), DICOM Modality Tool Kit (The OFFIS Computer Science Institute, Oldenburg, Germany). Method: HIS is interconnected with PACS via unique identifier (on PACS side with the seek key "Accession Number") for selecting all image data for particular examination on given imaging modality. The imaging modalities without the possibility to write down this unique identifier to a corresponding data item (most often if native image format is used -e.g. ecat7 for PET Ecat Accel) can usually use the data item only for a unique "Study ID". Now there arises a problem if it was necessary to make additional studies for a particular examination, as the previous image study would be unwantedly overwritten. The only possible solution is simulated modification of "Study ID" for additional studies. For the purposes of proper archiving and selecting all the studies appertaining to a given examination on PACS it is necessary, after the conversion of the native image format to DICOM, to write down backwards in the blank data item "Accession Number" the original unmodified value. On the basis of the above mentioned was for simulated "Study ID" generation modified before now designed DICOM modality worklist in the form of an intranet application. After the conversion of the native image format ecat7 to DICOM on the evaluating workstation Esoft Siemens are the image data going to PACS received by a temporally PACS running on hospital intranet server. Here is reconstructed backwards the original value of the "Accession Number" from data item with simulated "Study ID" and is at once written into the corresponding blank data item in the format DICOM. The data repaired in this way are resent to target PACS and after their successful archiving deleted from temporally PACS. Results: Such solution allows medical staff to make very simply additional studies on scheduled imaging modality for a given examination such that all of them could always be presented after a query from HIS. Conclusion: The methods with the usage of free software tools may not always be easy to perform but sometimes are the only possible. Moreover, they are in some cases the cheapest option. Aim: Vaccination using dendritic cells is a new therapeutic approach for patients with disseminated malignant melanoma. This phase I-study examines safety and migration of alpha-type I dendritic cells versus PGE2 dendritic cells in patients with malignant melanoma. Methods: The treatment consist of vaccination with the patients own dendritic cells, which are injected intradermally or directly into the lymph nodes. At the onset of treatment we are looking for the migration comportment of radiolabeled dendritic cells generated by 2 differently preparation processes. At present six patients with malignant melanoma in stages III and IV (AJCC,1) were included. Alpha-type I dendritic cells and PGE2 dendritic cells were radiolabeled with approximately 1.4 MBq 111 In-Oxin. Thereafter, a minimum of 1 x 10 6 alpha-type I dendritic cells were injected intradermally of the right upper leg, and the same amount of PGE2 dendritic cells into the left upper leg. Migration was investigated by dynamic examination during 30 min. Furthermore, static scans were performed inguinal for another 10 min. with and without shielding of the injection area. Additionally, whole body scan, including 4 radioactive standards (activities 0.04 MBq -0.4 MBq) were performed with a scan speed of 10 cm/min. Late scans were acquired 24 hours and 48 hours after injection. Results: Scintigraphically, lymph nodes were visualized at 24 and 48 hours after injection. Positive lesions were semi-quantitatively analysed by drawing regions of interest (ROI) above the injection area, inguinal lymph nodes and radioactive standards. After correction for half-life, 79 (± 4)% after 24h and 55 (±7)% after 48h of the initial activity was found in the injection area of both cell types. Mean of ratios (counts in lymph nodes/ counts in injection area) of alpha-type I dendritic cells were 0.72 after 24 hours and 2.11 after 48 hours. For PEG2 dendritic cells, the ratios were 1.35 after 24 hours and 3.75 after 48 hours. In all 6 patients, differences in migration of both cell types were not significant (p=0.27). Conclusion: Alpha-type I DC have a lower tendency to migrate than PGE2-DC in vivo, but the differences observed are not significant. Our data do not provide information about the stimulating behaviour of dendritic cells for an antitumor tumor reaction. Up to now, the optimal type of dendritic cells is not synthesized. However, the cells used in this study show potential for further clinical studies.