Comparison of microwave ablation and multipolar radiofrequency ablation, both using a pair of internally cooled interstitial applicators: Results in ex vivo porcine livers

摘要

Purpose: To compare the effectiveness of microwave ablation (MWA) and multipolar radiofrequency ablation (RFA) in ex vivo porcine livers, in both cases using a pair of internally cooled interstitial applicators. Materials and methods: MWA was performed on ex vivo porcine livers (n?=?60) using a pair of simultaneously powered, internally cooled shaft interstitial antennae. Four power settings were used: 50?W, 60?W, 70?W and 80?W (n?=?15 per setting). Multipolar RFA was also performed on ex vivo porcine livers (n?=?30), also using a pair of simultaneously powered, internally cooled shaft interstitial bipolar applicators. This was performed for two applicator types T30 (3?cm length) and T40 (4?cm length) at a manufacturer prescribed power of 60?W and 80?W, respectively (n?=?15 per applicator). Spacing between the two probes was 2?cm in all cases. Each power setting was applied for 15 ablations for 10?min each. The long-axis diameter (Dl), short-axis diameter (Ds) and the ratio Ds/Dl for each ablation were measured. Temperature data were recorded at 10 positions. Temperature curves were recorded at 3 locations, as well as the time required for the temperature to rise to 50°C. Results: Dl and Ds for all the power settings of MWA were significantly larger than that of both kinds of multipolar RFA (P??0.05). The rates of temperature to rise to 50°C in all the MW ablations power settings were significantly faster than those in both multipolar RF ablations. Conclusion: MWA by the simultaneous application of double antennae may be more advantageous for treating larger liver tumour than multipolar RFA.