Radiofrequency ablation compared with microwave ablation for the treatment of liver cancer: a meta-analysis.

Question Radiofrequency ablation (RFA) and microwave ablation (MWA) are the main ablative methods utilized in the treatment of hepatic lesions. Although efficacy of RFA has been evaluated in several studies, effectiveness of MWA and comparison between the two approaches remain unclear. Aim of the survey is to compare MWA with RFA in the treatment of liver cancer. Methods The systematic review and meta-analysis were conducted according to the PRISMA guidelines. A systematic search of MEDLINE (PubMed and Ovid) and the Cochrane Central Register of Controlled Trials was conducted for studies published from 2010 onwards. For all outcomes of interest, meta-analyses for the Odds Ratio (OR) have been performed. A random-effects model was used for the meta-analyses. Complete ablation (CA), local tumor progression (LTP), intrahepatic distant recurrence (IDR), and complications were analyzed. Results Fifteen studies with a total of 2169 patients were included in our analysis. The meta-analysis found non-significant difference in CA rates between MWA and RFA (OR, 1.10; 95 % CI, 0.78 – 1.55; p = 0.5898). Specifically, for the four randomized clinical trials (RCTs), meta-analysis outcomes remained consistent with the main overall results (OR, 1.28; CI, 0.54 – 3.05; p = 0.5706). Rates of LTP were comparable between MWA and RFA (OR, 0.79; 95 % CI, 0.53 – 1.20; p = 0.2689). In the subgroup analysis, which included only RCTs, significantly reduced rates of LTP were demonstrated in the MWA group compared to RFA (OR, 0.40; 95 % CI, 0.18 – 0.92; p = 0.03). Meta-analysis showed no significant differences in IDR between MWA and RFA (OR, 0.73; 95 % CI, 0.45 – 1.16; p = 0.1826). The risk of major complications was not different between the two approaches (OR, 0.80; 95 % CI, 0.46 – 1.37; p= 0.4129). No significant differences were found between the two modalities in patients with tumors less or larger than 3 cm. A further subgroup meta-analysis was conducted to evaluate the effectiveness of ablation methods in patients with hepatocellular cancer and colorectal liver metastases separately. Although the majority of outcomes were similar between the two approaches, subgroup analysis of included RCTs showed statistically decreased rates of LTP in patients with HCC following MWA compared to RFA. Conclusions MWA showed promising results and demonstrated better outcomes in terms of LTP compared to RFA. Further randomized trials are required to evaluate the superiority of MWA over RFA. Publication History Article published online: 04 January 2021 © 2020. Thieme. All rights reserved. Georg Thieme Verlag KG Rüdigerstraße 14, 70469 Stuttgart, Germany