Efficacy of radiotherapy combined with immune checkpoint inhibitors in patients with melanoma: a systemic review and meta-analysis.

The purpose of this study is to review the efficacy of radiotherapy combined with immune checkpoint inhibitors (ICIs) in the treatment of melanoma and systematically evaluate the efficacy and safety of this combined treatment compared with ICIs alone. We searched a number of online databases up to 1 July 2021. Comprehensive Meta-Analysis 2.0 and RevMan 5.0 were used for summary analysis. The overall survival (OS), progression-free survival (PFS), overall response rate (ORR) and treatment adverse effects (AEs) were calculated. In total, 624 patients were included from 12 studies, including nine published studies and the results of three clinical trials. Radiotherapy combined with ICIs had a higher ORR compared with ICIs alone (35.00 vs. 20.39%). In terms of survival effect, radiotherapy combined with ICIs had no obvious advantage in OS. There was no statistically significant difference between 6-month and 12-month OS (P = 0.13; P = 0.69). There was no significant difference in PFS at 6 months (P = 0.08), but there was a significant difference in PFS at 12 months (P = 0.005). For patients with melanoma, radiotherapy combined with ICIs can improve the effective rate of treatment. Although there is no obvious OS advantage, it can improve PFS without serious adverse effects. Most of the studies included in this article are retrospective analyses, and there are few randomized controlled studies at present. Therefore, more prospective studies are still needed to explore the efficacy of radiotherapy combined with immunotherapy in melanoma.