Charged particle therapy versus photon therapy for patients with hepatocellular carcinoma: a systematic review and meta-analysis.

PURPOSE: To perform a systematic review and meta-analysis to compare the clinical outcomes and toxicity of hepatocellular carcinoma (HCC) patients treated with charged particle therapy (CPT) with those of individuals receiving photon therapy.

METHODS: We identified relevant clinical studies through searching databases. Primary outcomes of interest were overall survival (OS) at 1, 3, 5 years, progression-free survival (PFS), and locoregional control (LC) at longest follow-up.

RESULTS: 73 cohorts from 70 non-comparative observational studies were included. Pooled OS was significantly higher at 1, 3, 5 years for CPT than for conventional radiotherapy (CRT) [relative risk (RR) 1·68, 95% CI 1·22-2·31; p<0·001; RR 3.46, 95% CI: 1.72-3.51, p<0.001; RR 25.9, 95% CI: 1.64-408.5, p=0.02; respectively]. PFS and LC at longest follow-up was also significantly higher for CPT than for CRT (p=0·013 and p<0.001, respectively), while comparable efficacy was found between CPT and SBRT in terms of OS, PFS and LC at longest follow-up. Additionally, high-grade acute and late toxicity associated with CPT was lower than that of CRT and SBRT.

CONCLUSION: Survival rates for CPT are higher than those for CRT, but similar to SBRT in patients with HCC. Toxicity tends to be lower for CPT compared to photon radiotherapy.