Analysis of risk factors for local tumor progression after radiofrequency ablation of hepatocellular carcinoma

Objective To evaluate prognostic factors affecting local tumor progression after radiofrequency ablation (RFA) of hepatocellular carcinoma (HCC).Methods A total of 246 HCC patients (343 lesions) underwent RFA treatment in our department and were enrolled into this study.The average tumor size was 3.7 cm ( range 0.9 ～ 3.7 cm).Regular follow-up with enhanced CT was performed to evalutate the treatment results.Kaplan-Meier model and log-rank test were used in univariate analysis and COX regression model was used in multivariate analysis to identify risk factors for local tumor progression.Results The local tumor progression rate was 11.4％ (39/343 lesions),and the average time from initial RFA to local tumor progression was 12.0 months.Univariate analysis indicated tumor size ( P ＜0.001 ),close to intrahepatic vessels ( P ＜0.001),tumor boundary ( P =0.020),pathological grade( P =0.010) and CEUS before RFA ( P =0.001) as risk factors for local progression.The following factors were identified as independent prognostic factors for local tumor progression by multivariate model:tumor size (P ＜ 0.001),isolated or close to intrahepatic vessels( P ＜0.001) and CEUS before RFA(P =0.018).Conclusions Tumor size,CEUS before RFA and close to intrahepatic vessels are the most important factors for local progression after RFA.Being awaring of possible risk factors for local tumor progression may increase the treatment efficacy and help to promote the use of RFA technique. Key words: Ultrasonography; Microbubbles; Liver neoplasms; Catheter ablation