Low Dose Lung Radiotherapy to Treat COVID-19 Pneumonia

Inclusion Criteria: * Age ≥ 50 years. * Patients have symptoms of COVID-19 infection as per WHO guidelines (e.g. cough, fever, dyspnea, etc.) for under 5 days from hospital admission. * Patients are hospitalized and meet the criteria for WHO level 5 COVID pneumonia. In addition: * SpO2 \<94% on Room Air; * Respiratory rate \>20 Breaths per minute on Room Air. * Laboratory confirmed COVID-19 infection based on PCR. * Patients need ward-based oxygen between 28 to 40%. * Patients able to provide witnessed verbal informed consent. * Patient is free of other severe medical conditions that would preclude radiotherapy treatment (e.g. severe recent CVA). Exclusion Criteria: * Pregnant or lactating women. * Presence of secondary infection with procalcitonin assessment at baseline. * Patient is generating aerosols e.g. use of CPAP device. * Hereditary syndromes known to have increase sensitivity to Radiotherapy including, but not limited to, ataxia-telangiectasia, and Njemgen Breakage Syndrome. * History of prior thoracic radiotherapy. * Inability to undergo radiotherapy for any reason as determined by the treating medical team. * Alternative diagnosis for lung compromise unrelated to COVID-19 / deemed more likely than COVID-19 related lung compromise. * Inability to consent directly. * If patient has participated in any other COVID-19 therapy study within the last month (4 weeks). * Pre-existing generalized pulmonary fibrosis. * Known prior systemic use of the following drugs within the last 6 months: Bleomycin, Carmustine, Methotrexate, Busulfan, Cyclophosphamide, or Amiodarone. * History of lung lobectomy or pneumonectomy. * Known history of pulmonary sarcoidosis, Wegener's Granulomatosis, Systemic Lupus Erythematosus, or other autoimmune disease affecting lungs. * Symptomatic congestive heart failure within the past 6 months including during hospitalization. * History of recent or current malignancy receiving any cytotoxic chemotherapy or immunotherapy within the past 6 months. * Bone marrow transplantation. * Latent tuberculosis. * Any solid organ transplant (renal, cardiac, liver, lung) requiring immunosuppressive therapy. * Septic shock and organ dysfunction. * Severe ARDS P/F ratio ≤100mmHg.