The Current Evidence of Intensity-Modulated Radiotherapy for Hepatocellular Carcinoma: A Systematic Review and Meta-Analysis

SIMPLE SUMMARY: Intensity-modulated radiotherapy (IMRT) is used worldwide for all tumor sites, for both curing and palliation. While evidence exists for lower normal tissue toxicity, IMRT did not show a definitive survival benefit compared to non-modulated RT. This is the first systematic review and meta-analysis to evaluate the rationale of IMRT for HCC in the liver. Although most patients had advanced-stage HCC and combined treatment were commonly used, IMRT for HCC showed similar survival with existing RT modalities and relatively low severe toxicity. ABSTRACT: Intensity-modulated radiotherapy (IMRT), an advanced RT technique, is a considerable treatment option for hepatocellular carcinoma (HCC). However, the distinguishing features of IMRT for HCC have not yet been clearly defined. A systematic review was performed according to the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses. The PubMed/MedLine, Embase, Cochrane Library, Web of Science, and KoreaMed were used to screen eligible studies focusing on treatment outcomes after IMRT for HCC until 18 April 2023. A total of 1755 HCC patients receiving IMRT among 29 studies from 2009 to 2023 were selected for the meta-analysis. The median proportion of Barcelona Clinic Liver Cancer stage C was 100% (range: 38–100%). Nineteen studies used combined treatment. Pooled rates of response and 1-year local control were 58% (95% confidence interval [CI], 50–65%) and 84% (95% CI, 70–94%), respectively. The median overall survival (OS) was 13 months (range: 5–45 months), and pooled 1- and 3-year OS rates were 59% (95% CI, 52–66%), and 23% (95% CI, 14–33%), respectively. Pooled rates of classic radiation-induced liver disease (RILD), nonclassic RILD, and hepatic toxicity ≥ grade 3 were 2%, 4%, and 4%, respectively. Although most patients had advanced-stage HCC and combined treatment was commonly used, IMRT for HCC showed similar survival to existing RT modalities and relatively low severe toxicity.