Percutaneous MR-Guided Thermal Ablation for Recurrent Subcentimeter Hepatocellular Carcinoma.

[RATIONALE AND OBJECTIVES] To evaluate the technical efficacy and therapeutic outcomes of percutaneous MR-guided thermal ablation, including microwave ablation (MWA) and radiofrequency ablation (RFA) for recurrent subcentimeter hepatocellular carcinomas (HCCs). MATERIALS AND METHODS: From January 2015 to May 2024, we recruited 101 patients with 119 recurrent subcentimeter HCCs (mean diameter: 8.0±1.3 mm, range: 5.6-9.9mm), who were treated with MR-guided thermal ablation. Technical success, technical efficacy, complications, and local tumor progression (LTP) rate were evaluated after ablation. Cumulative LTP rate, recurrence-free survival (RFS), and overall survival (OS) rates were estimated using the Kaplan-Meier method.

[RESULTS] A retrospective analysis showed that MR-guided thermal ablation (MWA, n=84; RFA, n=17) was successfully executed in all cases. Technical success and efficacy were achieved in all lesions in single sessions without major complications. The mean follow-up duration was 41.1±27.1 months (median:38.0 months; range:3-105 months). The cumulative LTP rate at 1 year was 1.2%, and 5.8% at 3, 5, 7, and 9 years. The cumulative RFS rates at 1, 3, 5, 7, and 9 years were 82.2%, 44.6%, 29.0%, 23.2%, and 23.2%, respectively. The cumulative OS rates at 1, 3, 5, 7, and 9 years were 99.0%, 91.8%, 84.4%, 69.7%, and 62.0%, respectively.

[CONCLUSION] Percutaneous MR-guided thermal ablation for recurrent subcentimeter HCCs demonstrated ready visualization of lesions and ablation margins as well as high technical efficacy rate, and minimal LTP after a single treatment session.