OBJECTIVES: The purpose of this study was to evaluate the cost-effectiveness of proton beam therapy (PBT) for patients with unresectable hepatocellular carcinoma (HCC) compared with transcatheter arterial chemo-embolization (TACE).

METHODS: Partitioned survival model was developed to predict costs and quality-adjusted life years (QALYs) in PBT and TACE arm. Direct medical costs were considered from the Japanese payer’s perspective. Time horizon and cycle length of the model was set to 20 years and 1 month, respectively. An annual discount rate of 2% for both costs and QALYs was applied. Data on overall survival (OS) and progression-free survival (PFS) was derived from a single arm clinical trial of the “Advanced Medical Care B” for PBT and from published historical control for TACE. Costs and utilities parameters were estimated by using the JMDC (Japan Medical Data Center inc) claims database and the single arm study. The incremental cost-effectiveness ratio (ICER) of PBT compared with TACE was estimated. Sensitivity analyses were performed to assess uncertainty in parameter settings.

RESULTS: Compared with TACE, PBT incurred an additional cost of USD18,102 and conferred an additional 0.307 QALY and 0.52 LY. This resulted in the ICER of USD59,006 per QALY gained. Based on a probabilistic sensitivity analysis, the probability that PBT became cost-effective was estimated to be 70.8% under the willingness to pay (WTP) threshold of USD75,000 per QALY. Several settings such as survival functions and utilities had a relatively large impact on the base case result.

CONCLUSIONS: Applying the WTP of USD75,000 per QALY, PBT might be cost-effective compared with TACE in HCC. However, there is uncertainty surrounding the model inputs such as OS, PFS, and utilities. Further research is required on utilities and clinical benefits for Japanese patients with HCC.