April 27, 2020

Low dose chest radiation for COVID-19 patients

Photo of Low dose chest radiation for COVID-19 patients

Clayton B. Hess, MD, MPH, and Mohammad K. Khan, MD, PhD, are co-principal investigators on a highly innovative trial to treat COVID-19 patients with low dose chest radiation therapy.

A research team including Winship Cancer Institute of Emory University (Winship) radiation oncologists and medical intensivists (critical care physicians) has initiated a highly innovative trial to treat COVID-19 patients with low dose chest radiation therapy (LD-RT), with the goal of reducing the pulmonary inflammation that severely affects these patients and threatens their ability to breathe on their own.

Mohammad K. Khan, MD, PhD and Clayton B. Hess, MD, MPH, physician-researchers who primarily care for cancer patients, are co-principal investigators on this phase I/II trial that enrolled its first two COVID-19 patients on April 24, 2020. The first cohort in this trial will consist of five critically-ill hospitalized patients not currently on ventilators, and it is hoped that the LD-RT will reduce their risk of requiring mechanical ventilation.

The investigators were inspired by the historical use of low dose chest radiation to treat pneumonia 100 years ago, citing research from the early1900s that demonstrated improved survival as high as 90 percent in treating patients with pneumonia in the pre-antibiotic era. Khan and Hess say the research also shows that pneumonia patients got better within a few days of receiving low dose chest radiation.

Based also on the current use of LD-RT to treat a number of non-malignant inflammatory conditions, the investigators hypothesize that LD-RT can reduce the inflammatory response to COVID-19 in the lungs, counteracting what's known as the cytokine storm that is caused by the virus. Cytokines are a type of protein that can either stimulate or slow down the immune system. A cytokine storm is a severe immune reaction in which the body releases too many cytokines into the blood too quickly and can result in high fever, inflammation, severe fatigue, and nausea.

"This is an approach with over a century of experience, but we are the first to propose using low dose chest radiation in this manner," says Khan, an associate professor in the Department of Radiation Oncology in the Emory University School of Medicine. "The COVID-19 pandemic inspired us to think outside the box, and we've been working with our intensivist colleagues to launch this trial because of its potential to help patients who are desperately ill."

"We are battling a virus that causes severe acute respiratory syndrome and the challenge is to improve lung function before the patient requires intubation and critical care," says Hess, assistant professor in the Department of Radiation Oncology.

The therapy involves a single treatment with whole-lung LD-RT delivered on a quarantined linear accelerator, followed by a one-week observation period in which clinical, radiographic, and immune outcomes will be tracked for safety and benefit. Depending on the safety and benefit demonstrated by the first cohort, investigators expect to launch a second cohort of five patients. According to investigators, the inherent risks of LD-RT are low.

"The COVID-19 pandemic has presented many challenges to our world, and Winship investigators are meeting those challenges with the kind of innovative thinking that sparked this unique trial," says Winship Executive Director Walter J. Curran, Jr., MD, the Lawrence W. Davis Chair in Radiation Oncology and the Georgia Research Alliance Eminent Scholar and Chair in Cancer Research. "We expect to learn which COVID-19 patients benefit from this novel approach in relatively short order."

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