Comparison of Microwave and Radiofrequency Ablation for the Treatment of Small- and Medium-Sized Hepatocellular Carcinomas in a Prospective Randomized Trial

Abstract

Purpose  To compare the therapeutic response and clinical outcome of CT-guided percutaneous microwave (MWA) and radiofrequency ablation (RFA) for the treatment of small- and medium-sized HCC. Materials and Methods  In this prospective trial, 50 patients with HCC were randomly assigned to MWA or RFA treatment. MRI was performed 24h before and after ablation and subsequently in 3-month intervals. Ablation volumes, ablation durations, adverse events (AE), technique efficacy, technical success, local tumor progression (LTP), disease-free survival (DFS), intrahepatic distant recurrence (IDR), and overall survival (OS) rates were evaluated. Results  The mean ablation volume was 66.5cm³ for MWA and 29.2 cm³ for RFA (p <0.01). The mean ablation durations for MWA and RFA were 11.2±4.0min and 16.3±4.7min, respectively (p <0.01). Six mild AEs were documented (p >0.05). All treatments had a technical success rate and a technique efficacy rate of 100% (50/50, p =1.00). LTP within 2 years occurred in 1/25 (4%) in the MWA group and in 4/25 (16%) in the RFA group (p =0.06). IDR within 2 years was 8/25 (32%) for MWA and 14/25 (56%) for RFA (p <0.05). The median DFS was 24.5 months and 13.4 months for MWA and RFA, respectively (p =0.02). The 1-, 2-, 3-year OS rates were 100%, 80%, 72% in the MWA group and 72%, 64%, 60% in the RFA group, respectively (p ≥0.14). Conclusion  The clinical outcome after MWA or RFA for HCC treatment was very similar with no significant differences in LTP or OS.However, MWA shows a trend toward better DFS with fewer IDRs than RFA. Key Points:   MWA allows for larger ablation volumes and a shorter treatment duration compared to RFA in patients with HCC. MWA shows a trend toward better disease-free survival and fewer intrahepatic distant recurrences compared to RFA. The three-year survival rates show no significant difference between the two methods.