The Coronavirus disease 2019 (COVID-19) is spreading rapidly throughout the world. Lung is the primary organ which the COVID-19 virus affects and leads to pneumonia, an acute respiratory distress syndrome. COVID-19 infects the lower respiratory system, and the lung’s response to this infection is recruiting macrophages and monocytes leading to inflammation, this response causes widespread damage to the lung’s airways.

The purpose of this study is to review studies of using low-dose radiation as a treatment for the inflammation of the tissue and pneumonia resulting from COVID-19. These studies were compared with the risk of developing lung cancer during performed dose for the treatment of COVID-19 in radiation therapy.

Our study focused on in vitro, in vivo and clinical reports of using low-dose radiation for the treatment of inflammation, pneumonia and COVID-19. The risk of lung cancer resulting from suggested dose in these studies was also evaluated.

From the review of articles, we have found that low-dose radiation can lead to improvement in inflammation in different line cells and animals; in addition, it has been effective in treating inflammation and pneumonia caused by COVID-19 in human up to 80%. Since suggested doses do not remarkably increase the lung cancer risk, low-dose radiation can be an adjuvant treatment for COVID-19 patients.

Lung cancer risk factors, like tobacco smoking, are highly prevalent in patients with schizophrenia. Whether these patients have a higher risk of lung cancer remains unknown.

We aimed to investigate whether patients with schizophrenia have a higher incidence of lung cancer compared with general population, in a meta-analysis.

Eligible studies were searched from PubMed and EMBASE databases to identify cases of lung cancer in patients with schizophrenia and the general population. This meta-analysis utilised the random-effects model and prediction interval was used to calculate the heterogeneity of these eligible studies. We assessed the quality of evidence with the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

There were 12 studies, totalling 496 265 patients, included in this meta-analysis. The data showed that the baseline schizophrenia diagnosis was not associated with any changes in lung cancer incidence in the overall population, with a standardised incidence ratio of 1.11 (95% CI 0.90–1.37; P = 0.31), although there was a significant heterogeneity among these studies (I2 = 94%). Moreover, there was also a substantial between-study variance with wide prediction interval values (0.47–2.64). The data were consistent for both males and females.

Up-to-date evidence from epidemiological studies indicates the lack of certainty about the association between schizophrenia diagnosis and lung cancer incidence.

The Early Breast Cancer Trialists’ Collaborative Group (EBCTCG) reported that the risks of breast cancer treatment in woman smokers may outweigh the benefits. The data used doses from published reports using a variety of treatment techniques. In our study, the risks of lung cancer and heart disease were determined from a modern era tangential-only technique.

Doses to the lung and heart were obtained for tangential radiotherapy to the breast or chest wall. The risk of lung cancer incidence and cardiac mortality were calculated by taking the ratio of our doses to those published by the EBCTG.

A total of 77 women were identified meeting our inclusion criteria. The mean combined whole lung dose was 2·0 Gy. The mean whole heart dose was 0·9 Gy. The estimated risk of lung cancer and cardiac mortality in a 50-year-old life-long smoker was estimated to be 1·5 and <1%, respectively.

Tangential only radiotherapy delivered substantially lower doses to the combined whole lung and whole heart than those reported by the EBCTCG. In this cohort, the risks of radiation induced lung cancer and heart disease are outweighed by the benefits of radiotherapy even in those that are smokers.