Low-Dose Whole Lung Irradiation for Treatment of COVID-19 Pneumonia: A Systematic Review and Meta-Analysis.

PURPOSE: Studies dating back to a century ago have reported using low-dose radiation therapy for the treatment of viral and bacterial pneumonia. In the modern era, since the COVID-19 pandemic began, several groups worldwide have researched the applicability of whole lung irradiation (WLI) for the treatment of COVID-19. We aimed to bring together the results of these experimental studies. METHODS AND MATERIALS: We performed a systematic review and meta-analysis searching PubMed and Scopus databases for clinical trials incorporating WLI for the treatment of patients with COVID-19. Required data were extracted from each study. Using the random-effects model, the overall pooled day 28 survival rate, survival hazard ratio, and intubation-free days within 15 days after WLI were calculated, and forest plots were produced. RESULTS: Ten studies were identified, and eventually, 5 were included for meta-analysis. The overall survival hazard ratio was calculated to be 0.85 (0.46-1.57). The pooled mean difference of intubation-free days within 15 days after WLI was 1.87, favoring the WLI group (95% confidence interval, -0.02 to 3.76). The overall day 28 survival rate of patients receiving WLI for the 9 studies with adequate follow-up data was 74% (95% confidence interval, 61-87). Except for 2 studies, the other 8 studies were assessed to have moderate to high risk of bias, and there were many differences among the designs of the studies, included patients, primary endpoints, outcome measurement methods, and reporting of the results. CONCLUSIONS: Despite a mild improvement in intubation-free days, WLI had no significant effect on patients' overall survival. Currently, we cannot recommend routine use of WLI for the treatment of patients with moderate-to-severe COVID-19.

Implications of Sex Difference in CT Scan Findings and Outcome of Patients with COVID-19 Pneumonia.

PURPOSE: The novel coronavirus pandemic has caused significant morbidity and mortality since December 2019. Although the role of chest CT for diagnosing coronavirus disease 2019 (COVID-19) pneumonia is still debatable, the modality has been used in scenarios of constrained reverse-transcription polymerase chain reaction (RT-PCR) testing. The epidemiologic reports indicate an unexplored difference between men and women in disease severity. We aimed to study the role of sex on disease severity and its correlation with CT findings. MATERIALS AND METHODS: Authors retrospectively studied all confirmed cases of COVID-19 with thoracic CT scans obtained at three hospitals from February 25, 2020, to March 15, 2020, in Tehran, Iran. CT involvement patterns of COVID-19 were analyzed based on sex and age of patients. RESULTS: One hundred fifteen patients (64.3% [74/115] men) were enrolled, with a median age of 57 years (age range, 21-89). Thirty patients were admitted to the intensive care unit, and 30 patients died during the hospital stay. Seventy-seven percent (37/48) of patients with unfavorable prognosis were male. Peripheral distribution of opacities was more common in men than women. When grouped by an age cut-off of 60 years, the women in the elder group had a peribronchovascular distribution pattern, and younger men showed an anterior distribution of opacities. Women younger than 60 years had significantly lower severity scores (CT-scores) (7.5 ± 6.8). Receiver operating characteristic (ROC) curve analysis demonstrated a CT-score cut-off of 14.5 to have 100% sensitivity and 91.9% specificity for predicting poor prognosis in women younger than 60 years. CONCLUSION: Opacity patterns on chest CT scans in COVID-19 are different based on sex and age, and men are at higher risk of disease severity and death.© RSNA, 2020.