Clinical outcome of medium-sized hepatocellular carcinoma treated with microwave ablation.

AIM: To evaluate the outcomes of patients with medium-sized hepatocellular carcinoma (HCC) who underwent percutaneous microwave ablation (MWA). METHODS: We retrospectively reviewed all patients with a single medium-sized HCC who underwent percutaneous MWA from January 2010 to January 2013. Technical success, technical effectiveness and complications were subsequently observed. Survival curves were constructed using the Kaplan-Meier method. The Cox proportional hazards model was fitted to each variable. The relative prognostic significance of the variables for predicting overall survival rate, recurrence-free survival rate and local tumor recurrence(s) was assessed using univariate analysis. All variables with a P value < 0.20 were subjected to multivariate analysis. RESULTS: The study included 182 patients (mean age, 58 years; age range: 22-86 years) with a single HCC (mean size, 3.72 ± 0.54 cm; range: 3.02-5.00 cm). The estimated technical effectiveness rate was 93% in 182 patients. The major complication rate was 2.7% (5/182), including liver abscess in 4 cases, and abdominal bleeding at the puncture site in 1 case. Thirty-day mortality rate was 0.5% (1/182). One patient died due to liver abscess-related septicemia. Cumulative recurrence-free survival and overall survival (OS) rates were 51%, 36%, 27% and 89%, 74%, 60% at 1, 2, and 3 years, respectively. Age (P = 0.017) and tumor diameter (P = 0.029) were independent factors associated with local tumor recurrence. None of the factors had a statistically significant impact on recurrence-free survival. Serum albumin level (P = 0.009) and new lesion(s) (P = 0.029) were independently associated with OS. CONCLUSION: Percutaneous MWA is a relatively safe and effective treatment for patients with medium-sized HCC.

Efficacy of microwave versus radiofrequency ablation for treatment of small hepatocellular carcinoma: experimental and clinical studies.

OBJECTIVE: To prospectively compare microwave (MW) ablation using a modified internal cooled-shaft antenna with radiofrequency (RF) ablation in in vivo porcine liver and in patients with small hepatocellular carcinoma (sHCC). METHODS: In an animal study, MW and RF ablations using a cooled-shaft antenna or internally cooled electrode were performed in in vivo porcine liver. Coagulation diameters of both ablations were compared. For clinical study, 42 patients with sHCC were treated with MW or RF ablation. Complete ablation (CA) and local tumour progression (LTP) were compared. RESULTS: MW ablation produced significantly larger ablation zones than RF ablation in both porcine liver and sHCC with an ablated volume of 33.3 ± 15.6 cm(3) vs. 18.9 ± 9.1 cm(3) and 109.3 ± 58.3 cm(3) vs. 48.7 ± 30.5 cm(3), respectively. The CA rate was 95.5 % (21/22) for MW ablation and 95.0 % (19/20) for RF ablation. In a 5.1-month follow-up, the LTP rate was 18.2 % (4/22) in the MW ablation group and 15.0 % (3/20) in the RF ablation group. CONCLUSION: MW ablation using a modified cooled-shaft antenna produces a larger ablation zone than RF ablation, with an efficacy similar to RF ablation in local tumour control. MW ablation is a safe and promising treatment of sHCC.