Purpose

Interstitial high-dose-rate brachytherapy (iBT) and stereotactic body radiotherapy (SBRT) are local treatment options for hepatocellular carcinoma (HCC). Data comparing their efficiency and safety profile remain limited. Therefore, we aimed to compare treatment results of iBT and SBRT in HCC patients.

Material and methods

Patients with HCC who underwent iBT or SBRT between 2014 and 2024 at our tertiary center were retrospectively analyzed. Local control (LC), progression-free survival (PFS), and overall survival (OS) were evaluated. Treatment-related acute and chronic toxicities were assessed.

Results

In a cohort of 92 patients with 125 HCC lesions, 60 patients (65.2%) with 86 lesions (68.8%) were treated with iBT. The median follow-up was 21 months. There were no significant differences in LC (p = 0.73) or PFS (p = 0.27) between iBT and SBRT cohorts. To reduce confounding due to imbalances in baseline characteristics, a 1 : 1 matched sub-cohort was generated. For all patients with complete clinical data, each SBRT patient was matched to one iBT patient using a multivariable distance metric based on Charlson comorbidity index (CCI), liver cirrhosis, Child-Pugh score (CPS), albumin-bilirubin (ALBI) score, and age, resulting in two equally-sized groups with reduced baseline imbalance. After matching, the OS advantage of iBT over SBRT was no longer statistically significant. The most common acute treatment-related toxicities were grade 1 elevations of liver enzymes in the iBT group (12/60, 20%) and fatigue in the SBRT group (5/32, 15.6%). In the iBT group, two minor bleeding events and one pneumothorax occurred, but no grade > 3 late toxicity was observed.

Conclusions

Both iBT and SBRT provide effective local treatment options for HCC, achieving comparable LC and PFS, while maintaining a manageable toxicity profile. Patient selection should be guided by institutional expertise and patient preference.