Radiofrequency Ablation of Hepatocellular Carcinoma

In Vivo Evaluation of a Novel Radiofrequency Ablation Electrode in Pig Livers

(1) Background: Endoscopic ultrasound-guided radiofrequency ablation (EUS-RFA) is an alternative treatment for pancreatic tumors. Currently, EUS-RFA has been trialled to treat hepatic tumors. However, little has been reported about optimal settings for EUS-RFA in patients with hepatic tumors. We evaluated the ablation effect after in vivo RFA using a new EUS-RFA electrode in a pig model. (2) Methods Four pigs were used for the in vivo test. The in vivo testing was divided into two tests based on the length of the RFA electrode (0.5, 0.7, 1 or 1.5 cm), the ablation power (30 W or 50 W), and the ablation time (10 or 15 s). In test one, ablation effect was evaluated based on the electrode length and power. In test two, ablation effect was assessed based on power and time. (3) Results: In test one, the ablation width and depth correlated with the length of the electrode and power (0.5 cm, 10 W, 10 s: width 0.46 cm, depth 0.65 cm vs. 1.5 cm, 75 W, 10 s: width 0.77 cm, depth 1.80 cm). In test two, ablation width and depth were similar when RFA was set at 1.5cm, 50 W, and 10 s or 1 cm, 30 W, and 15 s (0.65 cm, 1.14 cm vs. 0.65cm, 1.26 cm). (4) Conclusions: The relationship between electrode length, ablation power, and ablation time, and the resulting ablation effect in pig livers suggest that EUS-RFA produces effective ablation while minimizing thermal injury.

Radiofrequency ablation versus percutaneous ethanol injection for hepatocellular carcinoma: a meta-analysis of randomized controlled trials

BACKGROUND

Radiofrequency ablation (RFA) and percutaneous ethanol injection (PEI) are treatment methods for patients with early-stage hepatocellular carcinoma (HCC) who are not suitable for surgery. Although some reports indicate that RFA is better than PEI, results from previous reviews and analyses are inconsistent. Therefore, this meta-analysis was performed to more thoroughly evaluate the effects of these treatments in patients with HCC.

METHODS

A literature search was conducted using the Excerpta Medica dataBASE, PubMed, the Cochrane Library, the American Society of Clinical Oncology database, the China National Knowledge Infrastructure database, the Wanfang database, the Chinese Biomedical Literature Database, and the Chongqing VIP database without language limitations. The primary outcome evaluated was overall survival, and secondary outcomes included complete response and local recurrence. Comparisons were made between Asian and European studies.

RESULTS

Total pooled and subgroup analyses of Asian studies that included selection biases revealed that RFA is superior to PEI with respect to overall survival (hazard ratio (HR), 0.54; 95% confidence interval (CI), 0.37 to 0.80; P < 0.01) and complete response (relative risk (RR), 1.10; 95% CI 1.03 to 1.18; P < 0.01). However, no significant difference was observed between RFA and PEI in the European studies. In Asian studies, RFA was associated with a lower local recurrence rate than PEI at 1 year (RR, 0.44; 95% CI 0.20 to 0.95; P < 0.05) and 3 years (RR, 0.35; 95% CI 0.22 to 0.55; P < 0.01). However, local recurrence was significantly lower after only 3 years in European studies (RR, 0.50; 95% CI 0.32 to 0.78; P < 0.05).

CONCLUSIONS

RFA was only superior to PEI in Asian studies that included selection bias. Thus, there is insufficient evidence to support the idea that RFA is superior to PEI for patients with cirrhotic HCC. Additional large-scale, multicenter, randomized controlled trials that control for selection bias are needed to fully elucidate the optimal treatment method for HCC.

A randomized controlled trial of radiofrequency ablation and surgical resection in the treatment of small hepatocellular carcinoma

BACKGROUND & AIMS

The aim of this study was to compare the efficacy of radiofrequency ablation (RFA) with surgical resection (RES) in the treatment of small hepatocellular carcinoma (HCC).

METHODS

A total of 168 patients with small HCC with nodular diameters of less than 4 cm and up to two nodules were randomly divided into RES (n=84) and RFA groups (n=84). Outcomes were carefully monitored and evaluated during the 3-year follow-up period.

RESULTS

The 1-, 2-, and 3-year survival rates for the RES and RFA groups were 96.0%, 87.6%, 74.8% and 93.1%, 83.1%, 67.2%, respectively. The corresponding recurrence-free survival rates for the two groups were 90.6%, 76.7%, 61.1% and 86.2%, 66.6%, 49.6%, respectively. There were no statistically significant differences between the two groups in overall survival rate (p=0.342) or recurrence-free survival rate (p=0.122). Multivariate analysis demonstrated that the independent risk factors associated with survival were multiple occurrences of tumors at different hepatic locations (relative risk of 2.696; 95% CI: 1.189-6.117; p=0.018) and preoperative indocyanine green retention rate at 15 min (ICG-15) (relative risk of 3.853; 95% CI: 1.647-9.015; p=0.002).

CONCLUSIONS

In patients with small hepatocellular carcinomas, percutaneous RFA may provide therapeutic effects similar to those of RES. However, percutaneous RFA is more likely to be incomplete for the treatment of small HCCs located at specific sites of the liver, and open or laparoscopic surgery may be the better choice.