EM field simulation of minimal invasive MW antennas for thermal therapy

The electromagnetic field of microwave antennas for local thermal therapy and interstitial hyperthermia was investigated using the field evaluation program MAFIA (MAxwell's Equations Using the Finite Integration Algorithm). The numerical method was applied mainly to clinically used applicators. The method was also used for improvement and optimization of more sophisticated applicators, e.g. those in a triaxial technique. Simulations of the frequency dependent impedance match, the E-field and the specific absorption rate (SAR) distribution of applicators immersed in a muscle phantom are presented. The field simulation allows studying realistic effects at all discontinuities of the applicator-catheter-tissue system and gives a better understanding of heating phenomena occurring during interstitial hyperthermia treatment.