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. (C) 2014 Elsevier Ireland Ltd. All rights reserved.