Microwave ablation at 915 MHz vs. 2.45 GHz: Single and multiple-antenna considerations

This work compares microwave ablation with interstitial antennas operating at 915 MHz vs. 2.45 GHz. Numerical simulations and experiments in ex vivo tissues are used to compare single- and multiple-antenna ablations at both frequencies. When considering multiple-antenna ablations, both synchronous and asynchronous arrays are investigated. Simulation and experimental results indicate that a single antenna operating at 2.45 GHz yields an ablation zone diameter ~25% larger than an antenna operating at 915 MHz when powered with 30 W for 10 min. At both frequencies considered in this study, synchronous equal-phased arrays yield more spherical ablation zones than asynchronous arrays. These results suggest that antennas operating at 2.45 GHz may be better suited for rapid creation of spherical ablation zones in liver tissue.