Percutaneous Dual-Switching Monopolar Radiofrequency Ablation Using a Separable Clustered Electrode: A Preliminary Study

OBJECTIVE: To prospectively evaluate the safety and therapeutic effectiveness of dual-switching monopolar (DSM) radiofrequency ablation (RFA) for the treatment of hepatocellular carcinoma (HCC), and to retrospectively compare the results with those of single-switching monopolar (SSM) RFA in a historical control group. MATERIALS AND METHODS: This study was approved by the Institutional Review Board, with informed consent obtained from all patients. Fifty-two HCC patients who underwent DSM-RFA using a separable clustered electrode and dual-generators were prospectively enrolled. Technical parameters, complications, technical success, technical effectiveness, and local tumor progression (LTP) rates were evaluated by means of post-procedural and follow-up imaging. Thereafter, the outcome of DSM-RFA was compared with those of 249 retrospectively included HCC patients treated with SSM-RFA. RESULTS: There were two major complications (3.8%, 2/52) including pleural and pericardial effusion in the DSM-RFA group. The DSM-RFA yielded a 100% technical success rate, a 98.1% technical effectiveness rate, and a 4.3% 2-year LTP rate. In a retrospective comparison between the two groups, DSM-RFA created significantly larger ablation volume (4.20 ± 2.07 cm³/min vs. 3.03 ± 1.99 cm³/min, p < 0.01), and delivered higher energy (1.43 ± 0.37 kcal/min vs. 1.25 ± 0.50 kcal/min, p < 0.01) per given time, than SSM-RFA. There was no significant difference in major procedure-related complications (3.8% vs. 4.4%) and technical effectiveness rate (98.1% vs. 96.4%) between the two groups (p = 1.00). In addition, the 2-year LTP rate of DSM-RFA and SSM-RFA were 4.3% and 10.1%, respectively (p = 0.15). CONCLUSION: DSM-RFA using a separable clustered electrode is safe and provides high local tumor control and good preliminary clinical outcome for small HCCs, which are at least comparable to those of SSM-RFA.

Is Percutaneous Ethanol Injection Therapy Still Effective for Hepatocellular Carcinoma in the Era of Radiofrequency Ablation?

Percutaneous ethanol injection (PEI) therapy has been replaced by more-effective thermal ablation techniques that have lower local recurrence rates. However, PEI therapy remains useful in certain settings. Since PEI can be performed in any portion of the liver, PEI therapy can be valuable when tumors are located in close proximity to intestinal loops or other positions that are risky for thermal local ablative techniques. PEI therapy is also valuable in other situations where radiofrequency ablation (RFA) is difficult, including technically difficult masses that are not detected with ultrasound (US), are located in the hepatic dome, in the subcapsular area, and exophytically, or are surrounded by large vessels. PEI therapy contributes to combination therapy with transcatheter arterial chemoembolization or RFA in advanced-stage hepatocellular carcinoma (HCC), and also to the treatment of large HCC or extrahepatic metastasis from HCC. These roles of PEI therapy should be stressed for the treatment of HCCs in appropriate clinical situations. This comprehensive review of articles related to PEI therapy illustrates the recent role and indications of this therapy, which is currently valuable for HCC in the era of RFA.