key: cord-1008604-25bxucnj authors: Sepulcri, M.; Paronetto, C.; El Khouzai, B.; Novo, A.; Aldegheri, V.; Scaggion, A.; Fusella, M. title: Effectiveness of CBCT imaging during radiotherapy for the detection of initial COVID-19 lung disease date: 2020-05-08 journal: Adv Radiat Oncol DOI: 10.1016/j.adro.2020.04.019 sha: ba198ff512e9031a9f3d65a76ff9f6992aef5b93 doc_id: 1008604 cord_uid: 25bxucnj nan In this unique historical period affected by SARS-CoV-2 pandemic, radiotherapy treatments usually cannot be delayed or suspended. Several consensus papers regarding the delivery of Radiation Therapy (RT) in different settings and cancer histologies have just been published in order to limit the spread of COVID-19 infection in Radiation Oncology departments, suggesting to treat patients with hypofractionated schemes and to prioritise radical over adjuvant treatments [1, 2] . The development of Image-Guided Radiotherapy (IGRT) during the last two decades has allowed radiation oncologists to fix any set-up error, to verify the target position and to even perform adaptive radiotherapy, but can also be useful to assess healthy lung tissue [3] . We report the case of a 73-year old woman with recently diagnosed extensive-stage Small Cell Lung Cancer (SCLC), with metastatic liver and bone lesions. In the oncological anamnesis she had right breast cancer 15 years before, treated with surgery and post-operative radiotherapy plus 5-years of hormone therapy, with negative follow-up. She was admitted in our Hospital on the 21 st of March to start systemic treatment and was then referred for radiation therapy for two pathological vertebral lesions with an initial spread to the spinal canal. A Sars-CoV-2 test was performed at the Hospital admission and it tested negative. On the 23 rd of March the patient was send to the Radiation Oncology department for the CT-simulation in order to treat the bone lytic lesions affecting the bodies of the sixth and eleventh thoracic vertebrae. She did not have neurological symptoms, so she first started chemotherapy with cisplatin/etoposide from the 23 rd to the 25 th of March. On the 26 th she underwent radiotherapy on T6 and T11 with single fractions of 8 Gy each. The treatment was delivered on a TrueBeam STX (v2.5), with a multiple field static IMRT technique. Before treatment a Cone Beam CT (CBCT) was performed to check the setup of the patient. The acquisition protocol used for CBCT imaging was: half fan and full rotation, 125 kV and 270 mAs and half bow-tie filter applied, and no iterative reconstruction applied. The next day the Radiation Oncologist performed the offline review of treatment setup comparing the CBCT acquired in the RT treatment room with the CT-simulation. Some suspected lung areas of Ground Glass Opacities (GGOs) were clearly visible in the CBCT without any counterpart in the previous scan [ Figure 1 ]; after discussion with the Radiologist, it was decided to perform a new chest CT-scan that confirmed the previously suspected GGOs [ Figure 2 ]. In fact, the exam revealed multiple bilateral areas of subpleural GGOs, which are the primary findings on CT-scan in the early phases of COVID-19 lung infection, and also pleural effusions, a finding that may occur as a complication of COVID-19. The patient then urgently repeated the Sars-CoV-2 test that was positive, confirming the infection. On the 28 th of March she was transferred to the Infective disease COVID-19 department where she is still hospitalized when we are writing this paper. At the earliest stage of COVID-19 disease, a non-contrast chest CT-scan has high sensitivity for the detection of GGOs in the SARS-CoV-2 infection [4] and this could justify its use in the early imaging in the acute phase in selected cases. This is relevant because an early detection could improve patients' outcome for COVIDrelated pneumonia, characterized by a release of pro-inflammatory cytokines followed by activation and production of active mediators of lung inflammation, fever and fibrosis [5] . During this pandemic COVID-19 infection, the role of hypofractionated radiotherapy has constantly increased for its advantages in reducing the spread of the disease limiting patient access [1] ; in this setting the routinely use of CBCT allows Radiation Oncologists to perform customized treatments with higher dose per fraction [2] . It has already been reported the potential use of CBCT to detect early COVID-19 lung disease in an article yet to be published [6] . In this case report the patient had a first negative SARS-CoV-2 test and underwent the second one after the appearance of GGOs at the CT-scan, the day after radiotherapy, due to findings on CBCT. In conclusion, daily CBCT can be effective for early detection of COVID-19 lung disease in asymptomatic or mild symptomatic patients, helping to prevent the diffusion of this contagious disease to the care providers and other patients in the Radiation Oncology department. COVID-19 rapid guideline: delivery of radiotherapy; NICE UK guidelines Practice recommendations for lung cancer radiotherapy during the COVID-19 pandemic: An ESTRO-ASTRO consensus statement An assessment of cone beam CT in the adaptive radiotherapy planning process for non-small-cell lung cancer patients Correlation of Chest CT and RT-PCR Testing in Coronavirus Disease 2019 (COVID-19) in China: A Report of 1014 Cases Timely Diagnosis and Treatment Shortens the Time to Resolution of Coronavirus Disease (COVID-19) Pneumonia and Lowers the Highest and Last CT Scores From Sequential Chest CT Early appearance of COVID-19 associated pulmonary infiltrates during daily radiotherapy imaging for lung cancer