Low-dose Whole-lung Irradiation for COVID-19 Pneumonia: Final Results of a Pilot Study

Ameri, Ahmad; Ameri, Pooya; Rahnama, Nazanin; Mokhtari, Majid; Sedaghat, Meghdad; Hadavand, Fahimeh; Bozorgmehr, Rama; Haghighi, Mehrdad; Taghizadeh-Hesary, Farzad

Introduction Radiotherapy (RT) -commonly employed in cancer management- has been considered as one of the potential treatments for COVID-19 pneumonia. Here, we present the results of the pilot trial evaluating low-dose whole-lung irradiation (LD-WLI) in patients with COVID-19 pneumonia. Methods Ten patients with moderate COVID-19 pneumonia were treated with LD-WLI in a single fraction of 0.5 or 1.0 Gy along with the national protocol. The primary endpoint was the improvement in SpO2. The secondary endpoints were the number of hospital/ICU stay days, the number of intubations after RT, 28-day mortality, and changes in biomarkers. The response rate (RR) was defined as a rise in SpO2 upon RT with a rising or constant trend in the next 2 days, clinical recovery (CR) included patients who were discharged or acquired SpO2≥93% on room air, and 28-day mortality rate was defined based on RT day. Results The median age was 75 years (80% male). Five, 1, and 4 patients received single 0.5Gy, two 0.5Gy, and single 1.0Gy LD-WLI, respectively. The mean improvement in SpO2 at days 1 and 2 after RT was 2.4% (±4.8%) and 3.6% (±6.1%), respectively, with improvement in 9 patients after 1 day. Five, 1, and 4 patients were discharged, opted out the trial, and died in hospital, respectively. Two of 5 discharged patients died within 3 days at home. Among discharged patients, the SpO2 at discharge was 81-88% in 3 and 93% in the other 2 patients. Overall, the RR and CR were 63.6% and 55.5%, respectively. The RR, CR, and 28-day mortality of single 0.5Gy- and 1.0Gy-WLI were 71.4 vs. 50% (p = 0.57), 60 vs. 50% (p = 0.64), and 50 vs. 75% (p = 0.57), respectively. Conclusion LD-WLI with a single 0.5 Gy or 1 Gy-fraction is feasible. A randomized trial with patients that do not receive radiation is required to assess efficacy of LD-WLI for COVID-19.