Numerical analysis of thin coaxial antennas for microwave coagulation therapy

Microwave coagulation therapy (MCT) has been used for the treatment of small hepatocellular carcinoma (Seki et al. 1994). In the treatment a thin microwave antenna is inserted into the tumor, and the microwave energy heats up the tumor to produce a coagulated region including the cancer cells. We have to heat the cancer cells up to at least 60 /spl deg/C above which the cells are coagulated. Previously, the antenna for MCT has been developed only by experiment and numerical analysis has not been conducted. In this paper, we describe the numerical analysis of the antenna for MCT. During the MCT treatment, the medium properties of the tissue change because the characteristics of the tissue change as the temperature rises. Therefore we should consider this point when analyzing the heating performance of the antenna.