Particle Therapy for Intrahepatic Cholangiocarcinoma: A Multicenter Prospective Registry Study, Systematic Review and Meta-Analysis

Abstract

Introduction: A prospective study was started in May 2016 to evaluate the efficacy and safety of particle therapy for intrahepatic cholangial carcinoma (ICC). To compare treatment modalities, we also conducted a meta-analysis of literature data and a systematic comparison using registry data. Methods: Patients who received particle therapy for ICC from May 2016 to June 2018 were registered. Nineteen manuscripts (4 particle therapy, 8 3D-CRT, 7 SBRT) were selected for the meta-analysis. Results: A total of 85 cases (proton beam therapy 59, carbon therapy 26) were registered. The median overall survival (OS) of the 85 patients was 22.1 months (95% CI: 12.9-31.3); the 1-, 2-, 3-, and 4-year OS rates were 70.9% (95% CI: 61.1-80.7%), 47.6% (36.8-58.4%), 37.7% (26.7-48.7%), and 22.7% (10.2-35.2%), respectively; and the 1-, 2-, 3-, and 4-year local recurrence rates were 8.2% (1.1-15.3%), 21.6% (9.3-33.9%), 33.4% (16.7-50.1%), and 33.4% (16.7-50.1%), respectively. In the meta-analysis and registry data, the 1-year OS for particle therapy, SBRT and 3D-CRT were 71.8% (95% CI: 64.6-77.8%), 59.2% (53.0-64.9%, p = 0.0573), and 47.2% (36.8-56.9%, p = 0.0004), respectively. The incidence of grade 3 or higher late non-hematological toxicity in the meta-analysis and registry data were 7.4-12% for particle therapy, 6.7-16.7% for SBRT, and 8.1-14.3% for 3D-CRT. Conclusions: Particle therapy achieved a good therapeutic effect for ICC, and a metaanalysis indicated that particle therapy is a better treatment modality than SBRT and 3D-CRT.