Carbon-ion radiotherapy versus radiofrequency ablation as initial treatment for early-stage hepatocellular carcinoma

Carbon-ion radiotherapy (C-ion RT) has shown potential as a curative treatment for patients with hepatocellular carcinoma (HCC). However, no reports have compared the effectiveness of C-ion RT and radiofrequency ablation (RFA). This study aimed to compare clinical outcomes between C-ion RT and RFA for patients with early-stage HCC.

Medical records of consecutive patients with HCC (single lesion ≤5 cm or two to three lesions ≤3 cm) who received either C-ion RT or RFA as initial treatment were retrospectively reviewed. Propensity score matching (PSM) was used to adjust for clinical factors between both groups.

A total of 560 patients were included, among whom 69 and 491 received C-ion RT and RFA, respectively. After PSM (C-ion RT, 54 patients; RFA, 95 patients), both groups were well balanced. Carbon-ion radiotherapy had significantly lower cumulative intrasubsegmental recurrence rate after PSM compared to RFA (p = 0.004) (2-year, 12.6% vs. 31.7%; 5-year, 15.5% vs. 49.6%, respectively). However, no significant difference in cumulative local recurrence rate, stage progression-free survival, or overall survival (OS) was observed between both groups. In the RFA group, 6 of 491 patients (1.2%) showed grade 3 adverse events, whereas no grade 3 or higher adverse events were observed in the C-ion RT group.

Carbon-ion radiotherapy provided a lower cumulative intrasubsegmental recurrence rate, but a comparable cumulative local recurrence rate, stage progression-free survival, and OS compared to RFA. Thus, C-ion RT appears to be one of the effective treatment options for early-stage HCC when RFA is deemed not indicated.