Effectiveness of low-dose radiation therapy in COVID-19 patients globally: A systematic review

Abstract

Background: Novel Corona Virus Disease 2019 (COVID-19) can affect multiple organs, including the lungs, resulting in pneumonia. Apart from steroids, other anti-COVID drugs that have been studied appear to have little or no effect on COVID-19 pneumonia. There is a well-known history of inflammatory disease, including pneumonia, treated with low-dose radiation therapy (LDRT). It reduces the production of proinflammatory cytokines, Interleukin-1a (IL-1a), and leukocyte recruitment. Methods: A comprehensive literature search was conducted using PubMed, Scopus, Embase, CINAHL, and Google Scholar, with keywords such as “radiotherapy,” “low-dose radiation therapy,” “low-dose irradiation,” “covid-19 pneumonia,” “SARS-CoV-2 pneumonia,” and “covid pneumonia.” with additional filters for human studies and customized articles in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses. We reviewed randomized controlled trials, quasi-experimental studies, cohort, case-control, and cross-sectional studies with a clearly defined intervention, including low-dose radiotherapy alone or in combination with any therapy to treat COVID-19 pneumonia from December 2019 to May 2021. Patients receiving standard or high-dose radiotherapy, including for other diseases, were excluded. Zotero software was used to collect and organize research from various databases, remove duplicates, extract relevant data, and record decisions. Participants’ demographics and baseline status were obtained from the full-text articles along with the intervention’s outcome/effect on patient status. Results: Four studies with 61 participants that met the inclusion criteria were included. One was a double-blind randomized controlled trial, one a non-randomized trial, while the other two were single-arm clinical trials. Low-dose radiation therapy did not show any significant improvement in COVID-19 patients. Conclusion: Only two studies included in this review demonstrated an improvement in inflammatory markers; however, patients were also given steroids or other drugs. Therefore, the confounding effects must be considered before drawing conclusions. This systematic review does not support mortality benefit, clinical course improvement, or imaging changes with LDRT.

Low-dose radiation therapy suppresses viral pneumonia by enhancing broad-spectrum anti-inflammatory responses via transforming growth factor-β production

“…Although many reviews agree on the efficacy of LDRT for treating viral pneumonia, the safety of this treatment is of great concern ( 29 – 32 ). Therefore, we investigated protection against long-term radiation-induced pneumonitis (RIP) and lung fibrosis, which are immunologically related to high levels of TGF-β expression 1, 2, 4, and 6 months after thoracic irradiation.…”

Pharmacological modulators of epithelial immunity uncovered by synthetic genetic tracing of SARS-CoV-2 infection responses

“…Whether targeted IR may reduce the impact of viral shedding in selected organs is an intriguing hypothesis that stems from this study. Low-dose radiation therapy (LDRT) has been studied as a possible treatment option during the COVID-19 pandemic, yet its effectiveness is still debated ( 41 , 42 ). Future combinations should focus on approved drugs with higher safety profiles or involve substantial preclinical testing.…”