A Systematic Review and Meta-Analysis of Low Dose Radiation Therapy for COVID-19 Pneumonia: Learnings of 4 Years Since Pandemic.

COVID-19 caused a worldwide pandemic resulting in break of demand-supply chain in all aspects of healthcare, high mortality rates, and a constant quest for effective treatment modalities. Based on historical and recent evidences of anti-inflammatory effects of low dose of ionizing radiation, several healthcare professionals proposed low-dose radiation therapy (LDRT) along with ongoing pharmacological treatment for COVID-19 pneumonia. A positive response in a few initial studies led to systematic trials by increasing the number of patients in the range of 0.5-1.5 Gy. However, the concerns of radiation-induced risks were also raised in parallel. In the present article, we have highlighted the basis of LDRT for COVID-19 therapy. We have reviewed the available literature, specifically for outcomes on various clinical trials carried out with LDRT. Meta-analysis was performed to identify if any survival benefits are offered by addition of LDRT over pharmacological treatment alone among COVID-19 pneumonia patients. Other clinical recovery parameters such as intubation rates, oxygenation status, anti-inflammatory response have also been compared. Overall data trends favored LDRT with standard pharmacological treatment against control cohort which received standard treatment alone at all the endpoints in majority studies. LDRT addition resulted in significantly higher odds of survival than control cohort. Among critical and/or mechanically ventilated patients, LDRT did not show any promising outcomes over the control group. In conclusion, LDRT may serve as a promising complementary treatment modality with a potential of better prognosis, provided the patient selection criteria are critically identified and implemented.