Analysis of efficiency of different antennas for microwave ablation using simulation and experimental methods

The objective of this study is to analyze the efficiency of different antennas proposed for microwave ablation therapy using numerical simulation and experimental approach. The simulation was done with COMSOL MULTIPHYSICS® software to design antenna prototypes and evaluate its reflection coefficient, power dissipation distribution, power dissipation density, specific absorption rate and temperature distribution in tissue. Antennas were fabricated from a 50 Ω RG405/U semi-rigid coaxial cable to match the geometric prototypes generated during simulation. Ex vivo bovine livers were ablated with the fabricated antennas using 50 W for 5 and 10 min. Ablation diameters, ablation lengths and aspect ratios were determined. Sleeved antenna produced lowest reflection coefficient, high power dissipation, low power dissipation density, high SAR and high temperature in the simulation. Sleeved antenna provides excellent localization, large ablative diameter, low backward heating and high aspect ratio than single slot, dual slot and monopole antennas.