Comparison of therapeutic efficacy and safety of radiofrequency ablation of hepatocellular carcinomas between internally cooled 15-G and 17-G single electrodes

Abstract

Objective: To compare the ablation volume, local tumour progression rate and complication rate of radiofrequency ablation (RFA) for small hepatocellular carcinomas (HCCs) using 15-G and 17-G single electrodes. Methods: This retrospective study was approved by the institutional review board and informed consent was waived. We reviewed percutaneous RFA cases for HCCs using 15-G or 17-G electrodes without multiple overlapping ablations. A total of 36 pairs of HCCs matched according to tumour size and active tip length were included. We compared ablation volume and complication rate between the two electrode groups. Cumulative local tumour progression rates were estimated using the Kaplan-Meier method and compared using the log-rank test. Results: Tumour size and ablation time were not significantly different between the 15-G and 17-G groups (p=0.661 and p=0.793, respectively). However, ablation volume in the 15-G electrode group was larger than that in the 17-G group (14.4+/-5.4cm(3) vs 8.7+/-2.5cm(3); p < 0.001). No statistical difference in complication rates between the two electrode groups was found. The 10- and 20-month local tumour progression rates were not significantly different between the two groups (2.8% and 5.6% vs 11.1% and 19.3%; p=0.166). Conclusion: Ablation volume by the 15-G electrode was larger than that by the 17-G electrode. However, local tumour progression rate and complication rate were not significantly different between the two electrode groups. Advances in knowledge: RFA of HCC using a 15-G electrode is useful to create larger ablation volumes than a 17-G electrode.