Efficacy and Safety of Stereotactic Body Radiation Therapy in Patients With Hepatocellular Carcinoma in the Caudate Lobe: A Comparative Study With Radiofrequency Ablation.

BACKGROUND: This study compared the efficacy and safety of stereotactic body radiation therapy (SBRT) and radiofrequency ablation (RFA) for hepatocellular carcinoma (HCC) located in the caudate lobe. METHODS: This retrospective study included 57 patients with caudate lobe HCC who underwent either RFA (n = 39) or SBRT (n = 18) at seven institutions in Japan between January 2016 and August 2025. Local tumor progression (LTP), distant recurrence, overall survival (OS), and changes in albumin-bilirubin (ALBI) scores were analyzed. Propensity score matching (PSM) was performed to minimize baseline imbalances between the two groups. RESULTS: The median age was 74 years, and most patients were male. No significant difference was observed in LTP or distant recurrence between the two groups in the crude cohort (p = 0.856 and 0.622), the PSM cohort (p = 0.286 and 0.907), or the curative-intent subgroup (patients with no more than three lesions, each 3 cm or less) (p = 0.827 and 0.533). Although OS did not differ in the crude cohort (p = 0.090) or the curative-intent subgroup (p = 0.060), OS was better in the RFA group than in the SBRT group in the PSM cohort (p = 0.031). No grade ≥ 3 adverse events occurred in either group. However, ALBI scores worsened significantly in the SBRT group compared with the RFA group (p = 0.012). CONCLUSIONS: SBRT achieved favorable local control with an acceptable safety profile. It may represent a valuable alternative for patients in whom RFA is technically challenging.