18F-FDG and 18F-Fluorocholine PET/CT findings in symptomatic and asymptomatic patients with COVID-19, a French case series

Aim/Introduction: With more than 3 millions confirmed cases and more than 200 000 deaths worldwide, the COVID-19 outbreak became quickly a public health emergency of international concern Diagnosis relies-among others-on RT-PCR and chest CT showing typically multiple and bilateral patchy ground glass opacities and bilateral pulmonary consolidations (1) Some studies (2,3) have reported the glycolytic activity of these pulmonary abnormalities on 18F-FDG PET/CT in small cases series and, to our knowledge, no case wase reported to date with 18F-Fluorocholine (FCH) PET/CT The aim of our study was to illustrate FDG and FCH PET/CT findings in patients affected by COVID-19 Materials and Methods: We retrospectively reviewed the PET/CT results from 11 consecutive patients diagnosed with COVID-19 on the basis of clinical, radiological and laboratory data, between March 24 and April 30, 2020 Studies were performed for routine oncologic indications (n=8) and infectious/inflammatory disease (n=3) Symptoms, RT-PCR results and biological data were retrospectively collected if available Results: Ten of the 11 patients had CT imaging features of COVID-19 pneumonia with variable FDG-uptake (SUVmax range, 1 2 to 5 8) and a strong uptake of FCH in one patient (SUVmax = 6,3) The patient without pulmonary abnormalities was on day-13 of the infection when PET/ CT was performed We reported mediastinal lymph node involvement in 8 of the 11 patients with mild to high FDG uptake (SUVmax range, 3 4 to 8 6) and high FCH uptake (SUVmax = 5,5) Two others patients demonstrated FDG uptake in mediastinal lymph nodes that could be reported either to neoplastic involvement or to COVID-19 Four of the 11 patients were asymptomatic RT-PCR was positive in 4/6 patients Diagnosis was first suspected based on the PET/CT findings in 5 patients Conclusion: Although PET/CT is not recommended in routine practice to evaluate COVID-19 pneumonia, knowing the pattern of FDG and FCH uptake within the lungs and mediastinal nodes can help to identify infected patients, even when asymptomatic