Radiofrequency ablation using a multiple-electrode switching system for hepatocellular carcinoma within the Milan criteria: long-term results.

ABSTRACT

PURPOSE: To assess the long-term outcome of 516 consecutive patients treated with multiple-electrode switching system (MESS) radiofrequency ablation (RFA) for hepatocellular carcinoma (HCC) that met the Milan criteria. MATERIALS AND METHODS: We performed 522 MESS RFAs on 516 patients from December 2006 to June 2011. A total of 956 tumours that met the Milan criteria with an average diameter of 2.64 cm (range, 0.9-4.6 cm) were treated with MESS RFA. Ultrasonic contrast and serum α-fetoprotein (AFP) were measured every 2 months during the first postoperative year and every 4 months thereafter. Enhanced computed tomography was performed every 6 months. Survival was estimated using the Kaplan-Meier method. Follow-up was censored at 60 months. Multivariate analysis was performed using the Cox proportional hazards model. RESULTS: For the 956 HCC tumours, the complete ablation rate with MESS was 98.83% (510/516). During a median of 34 months (IQR, 23-52 months) of follow-up, 171 patients died and 4 were lost to follow-up (15, 30, 38 and 42 months). The cumulative incidence of local tumour progression at 1, 3 and 5 years was 0.39%, 4.96% and 6.66%, respectively, and the 1-, 3- and 5-year overall survival was 99.42%, 83.97% and 68.42%, respectively. Tumour size >30 mm was the only parameter that was predictive of local tumour progression (p < .0001). Risk factors associated with overall survival included prothrombin time >14 s, serum AFP levels >200 ng/mL and tumour abutting vessel diameter <5 mm. The complication rate was 1.74%. CONCLUSION: MESS RFA is a safe and effective method for HCC treatment. This approach results in a high local progression-free survival for HCC tumours that meet the Milan criteria.