Subsegmental radiofrequency ablation: a novel ablation technique based on portal territory for treatment of hepatocellular carcinoma.

[PURPOSE] To propose a novel ablation technique based on portal territory (PT) namely subsegmental radiofrequency ablation (SS-RFA) and evaluate its safety, feasibility and effectiveness.

[MATERIALS & METHODS] This study prospectively included 17 patients with single HCC ≤ 50 mm who underwent SS-RFA at a tertiary medical center between October 2022 and April 2024. Before SS-RFA, 3D reconstruction and watershed analysis based on preoperative contrast-enhanced CT was first performed to find out which subsegment contain tumor, and the corresponding subsegmental Glisson pedicle to be ablated was selected. Then ablation of selected Glisson pedicle and tumor was performed successively. The safety, efficacy and feasibility of SS-RFA were evaluated.

[RESULTS] SS-RFA was performed on 17 tumor lesions (mean diameter 23.41 mm ± 8.80) and the corresponding subsegmental Glisson pedicles in 17 HCC participants (mean age 57.35 ± 10.54 years; 14 males, 3 females). Postoperative contrast-enhanced ultrasound showed an increased mean diameter of the ablation zone 48 h after SS-RFA compared with 15-30 min after SS-RFA (54.85 mm ± 2.47 vs 47.85 mm ± 1.78, <.05). Three-dimensional reconstruction based on contrast-enhanced CT 2-3 days after ablation showed lack of enhancement of the ablated Glisson pedicle and its corresponding subsegment, with an average conical necrosis volume of 50.70 ± 25.31 cm. No major complications occurred. During a median follow-up of 9.2 months (2.6-23.4), no participant died, and no local tumor progression was observed.

[CONCLUSIONS] SS-RFA based on PT is a safe, technically feasible procedure in the treatment of patients with solitary HCC ≤ 50 mm.