Are there overlapping clinical features between thoracic radiotherapy side effects and covid-19 pneumonia? Radiation pneumonitis outside the radiation ports: Three case reports.

Respiratory involvement of COVID-19 infection, with presentations ranging from a mild flu-like illness to potentially lethal acute respiratory distress syndrome, is the main clinical manifestation in adults. Chest imaging shows a pictorial fashion of images due to the severity and stage of the disease, starting from focal nodular or mass-like opacities with air bronchogram to areas of ground glass consolidation or whited out lung. However, during the COVID-19 pandemic, CT findings could yield confounding reporting in the case of cancer patients previously treated with thoracic radiotherapy (tRT) due to atypical radiation pneumonitis occurring outside the radiation ports. Hypersensitivity pneumonitis and radiation-induced bronchiolitis obliterans organizing pneumonitis (RT-BOOP) are accounted for in this report.