Incidental Findings Suggestive of COVID-19 Pneumonia in Asymptomatic Patients Derived to F-18-FDGPET/CT. Preliminary Results Obtained in a Reference Single Center During the Pandemia in Spain

Aim/Introduction: The objective of the study is to evaluate the prevalence of incidental findings suggestive of COVID-19 pneumonia in a sample of patients referred for a 18F-FDG PET/CT study, asymptomatic for inflammatory lung disease, in a period corresponding to a high rate of contagion from COVID-19 in Hospital Clinico San Carlos (Madrid, Spain) We aim to contrast these findings with their real-time reverse polymerase chain reaction (rRT-PCR) result and to described radiological and metabolic findings of pneumonia Materials and Methods: Consecutive patients with whole-body (WB) 18F-FDG PET/CT from February 20th to April 30th 2020 Intravenous contrast-enhanced CT was always used except contraindications The CO-RADS criteria (1-6) was applied to classify the probability of COVID-19 pneumonia on chest CT and the maximum standardized uptake value (SUVmax) was evaluated to measure metabolic behavior of the lungs We compared these radiological and metabolic findings with rRT-PCR result (gold standard) All patients were carefully interrogated about coronavirus-like symptoms prior to PET/CT acquisition and all of them were asymptomatic All the studies were acquired on a Biograph 6 True Point PET/ CT (Siemens, Germany) following European Association of Nuclear Medicine Guidelines Results: We identified 46 asymptomatic patients with incidental findings suggestive of COVID-19 pneumonia for a total of 507 WB 18F-FDG PET/ CT studies, what it means a percentage of 9 1% The mean age was 66 4 years 54 3% (25/46) of the patients were men Among the reasons for the request, 76 1% (35/46) were oncological and 23 9% (11/46) non-oncological On 14 patients (30 4%) rRT-PCR for COVID-19 were performed consequently PET/CT findings, being positive for 64 3% (9/14) The remaining 69 6% (32/46) of the patients had no rRT-PCR for COVID-19 reports The mean SUVmax of the lung glass opacities and/or consolidations were measured, obtaining 6 2±3 7, 5 5±2 5 and 4 3±2 5 for positive, negative and non-performed rPCR, respectively Conclusion: 18F-FDG PET/CT may detect incidental finding COVID-19 pneumonia in asymptomatic patients in regions with high SARS-CoV-2 prevalence Although suspicion of COVID-19 pneumonia shows FDG uptake in most cases of our sample, the additional diagnostic value of pulmonary metabolic activity should be defined in larger series of patients Nuclear Medicine workers need to be aware of the possibility of contact with patients infected even if they are asymptomatic and should be prepared accordingly