key: cord-0926133-1xyn1kzg
authors: Nawwar, Ayah A.; Searle, Julie; Green, Jes S.; Lyburn, Iain D.
title: COVID-19–Related Lung Parenchymal Uptake on (18)F-PSMA-1007 PET/CT
date: 2021-06-11
journal: Clin Nucl Med
DOI: 10.1097/rlu.0000000000003812
sha: 21e36887ed4dca12ac6daa454b86552dfec87eb1
doc_id: 926133
cord_uid: 1xyn1kzg

A 70-year-old man with newly diagnosed prostate cancer underwent (18)F-PSMA-1007 PET/CT for staging. PSMA-avid primary prostatic malignancy was identified. Incidental intense patchy peripheral lung uptake was also noted. The patient tested positive for COVID-19 infection.

A 70-year-old man with prostate cancer. 18 F-PSMA-1007 PET/CT. A, MIP demonstrates intense focal uptake in the prostate consistent with the known malignancy. Moderate ill-defined uptake in the chest (arrows) was also seen. Axial CT, 18 F-PSMA-1007 PET, and fused PET/CT of the chest at 2 different levels (B-D) and (E-G) demonstrate uptake associated with patchy peripheral/ subpleural opacification. This is associated with moderate uptake on the PET component. The low-dose CT features were in keeping with COVID-19 infection, with a classic pattern of COVID-19 pneumonia bilateral, peripheral ground glass opacities. [1] [2] [3] The presence and pattern of lung parenchymal change depends on the time of imaging during the course of illness. Ground glass opacities commonly develop between days 0 and 4, peaking at days 6 to 13 and may persist beyond 24 days. 2, 4 Sixty-one percent of persistent long-term changes beyond 24 days are ground glass opacities. Also, associated uptake depends on the grade of inflammation, which is associated with variable vascular permeability. 5 In keeping with this, the patient gave a history of a positive real time-polymerase chain reaction test result for COVID-19 4 weeks before the scan. Inflammatory and infectious lung processes have been documented to demonstrate 18 F-PSMA uptake. 5,6 Similar avid COVID-19-related findings on PET/CT were described but in asymptomatic patients with other tracers including 18 F-FDG, 68 Ga-DOTANOC, and 18 F-flourocholine. [7] [8] [9] This was also described with 68 Ga-PSMA, which has the same mechanism of uptake as all PSMA-based PET tracers, including 18 F-PSMA-1007. 10 PSMA stands for "prostate-specific membrane antigen," which could be argued as a misnomer because these are not exclusively expressed on prostate cells and can be found in other tissues and conditions, such as inflammation/infection. There are limited data available explaining the exact mechanism of uptake at sites of inflammation, but it is thought to possibly also be as a result of neovascularization and increased regional blood flow/vascular permeability, delivering more PSMA ligand to the site of inflammation/infection. 5 This example of nonmalignant PSMA lung uptake highlights a cause, which may be increasingly seen in the context of the current COVID-19 pandemic and may persist even after the initial illness.

Chest CT in COVID-19: what the radiologist needs to know

Temporal changes of CT findings in 90 patients with COVID-19 pneumonia: a longitudinal study

18 FDG-PET/CT findings in COVID-19: a single centre retrospective radiological review

Time course of lung changes at chest CT during recovery from coronavirus disease 2019 (COVID-19)

Nonprostatic diseases on PSMA PET imaging: a spectrum of benign and malignant findings

E-PSMA: the EANM standardized reporting guidelines v1.0 for PSMA-PET

Incidental finding of COVID-19 lung infection in 18 F-FDG PET/CT

68 Ga-DOTANOC PET/CTwith lung involvement in the era of COVID-19 pandemic

Incidental COVID-19 pneumonia on 18 F-Fluorocholine PET/CT

68 Ga-PSMA PET/CTwith incidental finding of COVID-19 in an asymptomatic patient