Low-Dose Radiotherapy For Patients With SARS-COV-2 (COVID-19) Pneumonia

The authors propose a two-step randomized Phase II study to determine if single fraction low dose whole thorax megavoltage radiotherapy (LD-WTRT) can produce meaningful clinical benefit in COVID-19 patients. In Step 1, patients would be randomized 1:2 to standard of care without or with LD-WTRT. Patients randomized to LD-WTRT would be further randomized to either 35 cGy or 100 cGy. After 20 patients have been enrolled on each low-dose radiotherapy arm, they will be evaluated to determine the selection of the "best radiotherapy dose-arm" for the remainder of the patients. This will be done by analyzing clinical benefit, risk profile, and the dynamics of biomarker change, specifically focusing on IL-6 1. If the rate of Grade 4 toxicity is lower by an absolute rate of 15% when comparing the 35 cGy and 100 cGy arms, the arm with the lower toxicity rate will be used for Step 2 of the trial. 2. If the crude clinically meaningful event rate (CMER) which is a composite endpoint, is lower by an absolute rate of 20% when comparing the 35 cGy and 100 cGy arms, the lower CMER rate arm will be used for Step 2. CMER is defined as a composite of : 1. Rate of mechanical ventilation (MV) 2. Rate of prolonged hospital stay \>10 days (PHS) 3. Crude all-cause mortality rate at the time of analysis 3. If the crude CMER is \< 20% difference between the 35 cGy and 100 cGy arms, the investigators will determine whether there is a trend suggesting less Facility Resource Utilization Rate (FRUR). If the FRUR is 20% lower in either the 35 cGy or 100 cGy arms, that dose will be used for Step 2. The FRUR is based upon: 1. Days of mechanical ventilation 2. Days of hospitalization. 4. If both crude CMER and FRU rates do not differ by at least 20%, the investigators will evaluate the area under the curve (AUC) for IL-6 levels drawn within 24 hours before LD-WTRT and at 48 hours (2d) and 168 hours (7d) after radiation. If one of the two arms has a 20% lower serum IL-6 AUC one week after radiotherapy, the investigators will select that arm for Step 2. 5. If none of the parameters in numbers 1-4 above differ in the criteria listed, the investigators will use the lower dose of 35 cGy for Step 2.