Formal discussant of this trial, Ramesh Rengan, MD, PhD, Professor and Chair, Department of Radiation Oncology, University of Washington, and Professor, Fred Hutchinson Cancer Research Center, Seattle, commented: “My interpretation in the follow-up period is that low-dose radiation therapy is promising in terms of the time to complete recovery. However, this is a very small subset of eligible patients compared with more than 60,000 laboratory-confirmed patients hospitalized with COVID-19 as of October 2020. At the end of the summer of 2020, more than 4,000 patients with COVID-19 were enrolled in clinical trials,” Dr. Rengan stated.
“The primary cause of mortality is COVID-19–related pneumonia. Approximately 15% of patients progress to acute respiratory distress syndrome, which puts them at risk for death,” he said.
Ramesh Rengan, MD, PhD
“Mortality is associated with the cytokine storm generated by proinflammatory cytokines [interleukin-6, interleukin-1, tumor necrosis factor–alpha, interferon]. Abrogation of this storm has become a primary focus of therapeutic intervention in COVID-19 studies,” noted Dr. Rengan. “Low-dose radiation therapy has been used clinically as an immunomodulatory therapy in proinflammatory conditions, and it was studied in this single-arm phase II trial.”
Dr. Rengan continued: “Risk factors for COVID-19–related pneumonia are not yet known. Recently, a large study found that female gender and smoking were protective. It is difficult to know how to interpret matched controls, other than to say that this study is hypothesis-generating.”
Much Still to Learn
Dr. Rengan listed the following outstanding issues and questions:
“I commend the investigators who studied this group of severely ill patients with limited therapeutic options. We need to confirm these data in larger numbers of patients with at least 3 to 6 months of follow-up,” Dr. Rengan stated. “I would say this trial is important for radiation oncology because it brings our specialty into the front lines of treatment during the pandemic,” he added.
DISCLOSURE: Dr. Rengan has served as a consultant or advisor to AstraZeneca.
Whole-lung low-dose radiation therapy led to quicker recovery from COVID-19–related pneumonia in hospitalized and oxygen-dependent patients compared with matched controls treated with best supportive care and physician’s choice of anti–COVID-19 therapy, according to the results of a small trial.1...