OBJECTIVES: The purpose of this study was to develop an economic model 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 10 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 the interim analysis of phase III randomized controlled trial comparing PBT and TACE in patients with HCC. Cost parameters were estimated by using the JMDC claims database. Utilities were derived from published sources other than Japan. The incremental cost-effectiveness ratio (ICER) of PBT compared with TACE was estimated. Deterministic sensitivity analysis was performed to assess uncertainty in parameter settings.

RESULTS: Compared with TACE, PBT incurred an additional cost of JPY 848,126 and conferred an additional 0.1053 QALY. This resulted in the ICER of JPY 8,047,060 per QALY gained. Several settings such as utilities, costs and survival functions strongly affected the base case result.

CONCLUSIONS: Applying the willingness to pay threshold of JPY 6,000,000 per QALY, PBT might not be cost-effective compared with TACE in HCC. However, there is uncertainty surrounding the model inputs such as OS, PFS, utilities, and costs. Further research is required on survival benefit, utilities, medical costs of Japanese patients with HCC.