Microwave Ablation Versus Radiofrequency Ablation for Treatment of Hepatocellular Carcinoma: A Meta-Analysis of Randomized Controlled Trials

There are limited and discordant results on the comparison between microwave ablation (MWA) and radiofrequency ablation (RFA) for the treatment of hepatocellular carcinoma (HCC). This meta-analysis aims to compare the two treatments in terms of efficacy and safety, based on a meta-analysis of randomized-controlled trials (RCTs). A computerized bibliographic search was performed on the main databases throughout August 2020. The primary outcome was the complete response rate, while survival rate (at 1-, 2-, 3-, and 5-year), disease-free survival rate (at 1-, 2-, 3-, and 5-year), local and distant recurrence rate, adverse event rate, and number of treatment sessions were the secondary outcomes. Seven RCTs enrolling 921 patients were included. No difference in terms of complete response between the two treatments was observed (risk ratio (RR) 1.01, 95% CI 0.99-1.02). Survival rates were constantly similar, with RRs ranging from 1.05 (0.96-1.15) at 1 year to 0.91 (0.81-1.03) at 5 years. While local recurrence rate was similar between MWA and RFA (RR 0.70, 0.43-1.14), distant recurrence rate was significantly lower with MWA (RR 0.60, 0.39-0.92). Disease-free survival at 1, 2, and 3 years was similar between the two groups with RR 1.00 (0.96-1.04), 0.94 (0.84-1.06), and 1.06 (0.93-1.21), respectively. On the other hand, RR for disease-free survival at 5 years was significantly in favor of MWA (3.66, 1.32-42.27). Adverse event rate was similar between the two treatments (RR 1.06, 0.48-2.34), with bleeding and hematoma representing the most frequent complications. Our results indicate a similar efficacy and safety profile between the two techniques. MWA seems to decrease the rate of long-term recurrences, but this finding needs to be confirmed in further trials