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

Tan, Yunhua; Jiang, Jiayun; Wang, Qiang; Guo, Shixiang; Ma, Kuansheng; Bie, Ping

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.