Systematic Review of Radiation-Based Therapies for Hepatocellular Carcinoma

Abstract Aim Despite the increasing trend to utilize radiation therapies for the treatment of hepatocellular carcinoma (HCC), there is limited analysis comparing treatment outcomes of various radiation-based therapies including selective internal radiation therapy (SIRT) to stereotactic body radiation therapy (SBRT) and proton beam therapy (PBT). This study aims to examine the heterogeneity of designs and outcomes in existing radiation therapy studies for the treatment of HCC. Methods A systematic review was performed to compare the radiation therapies for HCC including SBRT, PBT, and yttrium-90 (Y90) SIRT by searching through PubMed, EMBASE, Medline, and Cochrane library databases. The main outcomes analyzed were overall survival rates, median overall survival, and progression-free survival with additional analysis of baseline patient characteristics, including Barcelona Clinic Liver Cancer stage, Child–Pugh class, and tumor size. Results Eighty-seven studies comprising 7,462 patients were included. The pooled 1-year overall survival rates for the Y90 SIRT, SBRT, and PBT groups were 57.8, 83.1, and 78.7%, respectively. The rates of Barcelona Clinic Liver Cancer A, B, and C patients were 22.9, 32.2, and 42.5% in Y90 SIRT; 52.5, 20.2, and 25.1% in SBRT; and 36.3, 33.4, and 28.2% in PBT groups, respectively. The baseline intergroup differences were statistically significant (p < 0.0001). The median tumor sizes were 5.8, 3.1, and 4.5 cm in the Y90 SIRT, SBRT, and PBT groups, respectively. Conclusion In the management of HCC, there is substantial heterogeneity in studies investigating Y90 SIRT, SBRT, and PBT, with Y90 SIRT patients having worse Barcelona Clinic Liver Cancer and tumor burden at baseline, which likely contributes to the observed lower survival outcome.