INCIDENTAL FINDINGS SUGGESTIVE OF COVID-19 IN ASYMPTOMATIC PATIENTS UNDERGOING NUCLEAR MEDICINE PROCEDURES IN A HIGH PREVALENCE REGION

Abstract

Infection with the novel coronavirus SARS-CoV-2 may remain asymptomatic, leading to under-recognition of the related disease, COVID-19, and to incidental findings in nuclear imaging procedures performed for standard clinical indications. Here, we report about our local experience in a region with high COVID-19 prevalence and dynamically increasing infection rates. Methods: Within the 8 day period of March 16-24, 2020, hybrid imaging studies of asymptomatic patients who underwent ¹⁸F-FDG-PET/CT or ¹³¹I-SPECT/CT for standard oncologic indications at our institution in Brescia, Italy, were analyzed for findings suggestive of COVID-19. Presence, radiological features and metabolic activity of interstitial pneumonia were identified, correlated with subsequent short-term clinical course and described in a case series. Results: Six of 65 patients (9%) that underwent PET/CT for various malignancies showed unexpected signs of interstitial pneumonia on CT and elevated regional FDG-avidity. Additionally, 1 of 12 patients who received radioiodine for differentiated thyroid carcinoma also showed interstitial pneumonia on SPECT/CT. 5/7 patients had subsequent proof of COVID-19 by RT-PCR. The remaining 2 patients were not tested immediately but underwent quarantine and careful monitoring. Conclusion: Incidental findings suggestive of COVID-19 may not be infrequent in hybrid imaging of asymptomatic patients, in regions with expansive spread of SARS-CoV-2. Nuclear medicine services should prepare accordingly.