Low-dose Lung Radiotherapy for COVID-19-related Pneumonia: Preliminary Results of the Italian Mono-institutional COLOR-19 Trial

Aim: To evaluate the feasibility and tolerability of low-dose radiotherapy (LDRT) delivered to both lungs in the treatment of SARS-CoV-2-immune-mediated pneumonia in the COLOR-19 study (NCT0437747). Patients and Methods: From May 2020 to April 2021 at Brescia University Radiation Oncology Department, three patients with COVID-19-related pneumonia were treated with LDRT according to the COLOR-19 protocol. All patients were treated with a single fraction at the average prescription dose of 0.7 Gy to both lungs. Results: Three patients were enrolled (two males and one female, aged 61-81 years) and underwent LDRT. Despite LDRT being safely performed without significant side-effects, two patients died (one 81 year-old male due to septic shock secondary to Escherichia coli infection and one 79-year-old male, already in poor condition, due to worsening of COVID-19). The remaining female patient (61 years old) underwent LDRT for less severe COVID-19: her clinical condition and chest X-ray improved, and she was discharged home completely asymptomatic 27 days after hospital admission. Blood levels of C-reactive protein and ferritin generally decreased after LDRT. Conclusion: Early results of the COLOR-19 study demonstrate the feasibility of LDRT for therapy of COVID19-related pneumonia; no conclusions on the efficacy have been reached due to poor accrual.