Low-Dose Radiation Therapy for Severe COVID-19 Pneumonia

Inclusion Criteria: Have had a positive test confirming the diagnosis of COVID-19; Have had clinical signs of severe acute respiratory syndrome or pneumonia (dyspnea, cough, with need for oxygen support at the time of enrollment); Have visible consolidations/ground glass opacities on chest x-ray or computed tomography; Have been on ventilator support for no longer than 5 calendar days prior to the schedule date of delivery of low-dose radiation therapy; They voluntarily participate in this clinical trial, gave informed consent and signed the informed consent form. Exclusion Criteria: Have received chest radiotherapy before Bacteria, fungi and other infections other than novel coronavirus infection; Combined with severe primary diseases such as cardiovascular, cerebrovascular, liver, kidney, hematopoietic and endocrine system or immune system diseases (the upper limit of liver function ALT and AST> normal reference value, the upper limit of Scr> normal reference value, poor blood glucose control); Mental retardation, mental disorders; Planned pregnancy, pregnancy, lactation women and during the trial; Allergy constitution or allergy to the drug ingredients and excipients of this test; Participated in other clinical trials in the recent 1 month; The Investigator does not considered appropriate to participate in this clinical trial.