No-Touch vs. Conventional Radiofrequency Ablation Using Twin Internally Cooled Wet Electrodes for Small Hepatocellular Carcinomas: A Randomized Prospective Comparative Study

Abstract

Objective This study aimed to compare the efficacy between no-touch (NT) radiofrequency ablation (RFA) and conventional RFA using twin internally cooled wet (TICW) electrodes in the bipolar mode for the treatment of small hepatocellular carcinomas (HCC). Materials and Methods In this single-center, two-arm, parallel-group, prospective randomized controlled study, we performed a 1:1 random allocation of eligible patients with HCCs to receive NT-RFA or conventional RFA between October 2016 and September 2018. The primary endpoint was the cumulative local tumor progression (LTP) rate after RFA. Secondary endpoints included technical conversion rates of NT-RFA, intrahepatic distance recurrence, extrahepatic metastasis, technical parameters, technical efficacy, and rates of complications. Cumulative LTP rates were analyzed using Kaplan-Meier analysis and the Cox proportional hazard regression model. Considering conversion cases from NT-RFA to conventional RFA, intention-to-treat and as-treated analyses were performed. Results Enrolled patients were randomly assigned to the NT-RFA group (37 patients with 38 HCCs) or the conventional RFA group (36 patients with 38 HCCs). Among the NT-RFA group patients, conversion to conventional RFA occurred in four patients (10.8%, 4/37). According to intention-to-treat analysis, both 1- and 3-year cumulative LTP rates were 5.6%, in the NT-RFA group, and they were 11.8% and 21.3%, respectively, in the conventional RFA group ( p = 0.073, log-rank). In the as-treated analysis, LTP rates at 1 year and 3 years were 0% and 0%, respectively, in the NT-RFA group sand 15.6% and 24.5%, respectively, in the conventional RFA group ( p = 0.004, log-rank). In as-treated analysis using multivariable Cox regression analysis, RFA type was the only significant predictive factor for LTP (hazard ratio = 0.061 with conventional RFA as the reference, 95% confidence interval = 0.000–0.497; p = 0.004). There were no significant differences in the procedure characteristics between the two groups. No procedure-related deaths or major complications were observed. Conclusion NT-RFA using TICW electrodes in bipolar mode demonstrated significantly lower cumulative LTP rates than conventional RFA for small HCCs, which warrants a larger study for further confirmation.

2022 KLCA-NCC Korea practice guidelines for the management of hepatocellular carcinoma

“…It showed a lower LTP rate compared to conventional tumor-puncturing RFA. 507,508 A prospective multicenter study also found improved local tumor control after no-touch RFA for HCC. 509 However, further investigation is warranted to evaluate whether no-touch RFA would also enhance the survival outcomes after treating pa-tients with HCCs.…”

Comparison of Ablation Performance between Octopus Multipurpose Electrode and Conventional Octopus Electrode

“…First, as there are two electrodes with adjustable active tip lengths the system can be used for no-touch ablation. Several recent studies have demonstrated better local tumor control of liver malignancies with this approach than conventional tumor puncture techniques, either through percutaneous or laparoscopic approaches [ 27 28 29 ]. Second, since the active tips of the two electrodes are adjustable from 1 cm to 3 cm with a 5 mm step variable, Octopus MP electrodes could be useful in treating asymmetric and ovoid-shaped tumors, especially those with variable diameters that require active tips of different lengths.…”

2022 Korean Liver Cancer Association-National Cancer Center Korea Practice Guidelines for Local Ablation Therapy of Hepatocellular Carcinoma: What’s New?

“…Moreover, tumor feeding and draining vessels are destroyed in the earlier period of RFA, preventing tumor spread via the blood vessels. In two recent RCTs and a prospective multicenter clinical trial, compared with conventional tumor-puncturing RFA, no-touch RFA provided a lower LTP rate [ 24 25 26 ]. However, further investigation is warranted to evaluate whether no-touch RFA enhances survival outcomes after treating patients with small HCCs.…”