Why is it important to report early possible COVID-19 PET/CT findings in cancer patients? Explaining with a case series.

Background: Coronavirus disease-2019 (COVID-19) causing a pandemic mostly results in mild symptoms; however, it can evolve into serious complications. It is emphasized that if the term from the recent anticancer treatment to the diagnosis of COVID-19 was short, the probability of serious events increased in cancer patients. Therefore, early detection of COVID-19 and prevention of serious events is very important. We aimed to investigate whether it is possible to detect COVID-19 early by positron emission tomography (PET)/computed tomography (CT).

Methods: We retrospectively evaluated the images and clinical findings of patients who underwent PET/CT due to malignancy and whose COVID-19 polymerase chain reaction (PCR) test were detected positive subsequently.

Results: Eight cancer patients with positive COVID-19 PCR tests were included in the study. PET/CT revealed subpleural ground-glass opacities (GGOs) showing mild fluorodeoxyglucose (FDG) uptake that could be compatible with COVID-19 in 4 of 8 patients. The number of affected lobes ranged from 1-4. All patients were diagnosed with COVID-19 by PCR test when symptoms and/or lung findings worsened on the days after PET/CT. The time interval between the last anticancer treatment and COVID-19 diagnosis in five patients was ≤7 days. During the follow-up, six of the cases (75%) needed mechanical ventilation and died later.

Conclusion: COVID-19 may be recognised early by detecting incidental findings in PET/CT, especially in asymptomatic cancer patients. Potential complications may be prevented by early diagnosis and anticancer therapy changes. Therefore, possible COVID-19 findings in PET/CT should be reported and the patient should be referred to relevant clinician.