Theoretical modeling of a dielectric-loaded box-horn applicator for hyperthermia treatment of tumors in thorax region

Abstract

This paper presents theoretical analysis of the specific absorption rate (SAR) distribution in three-layered tissue (fat, muscle and lung layers as in thorax region) in direct contact with a box-horn applicator for hyperthermia treatment of cancerous tumor. The box-horn is assumed to be filled with dielectric (ceramic NPOT-96) to provide a better impedance match to bio-media. The present analysis is based on plane wave spectral technique. The spatial distribution of SAR in fat, muscle and lung layers are computed and reported at 433 and 2450 MHz. Wider SAR-distribution in each of the bio-layers in cross-sectional area and higher penetration depth in lung are observed at 433 MHz in comparison to those at 2450 MHz for dielectric-loaded box-horn. The normalized SAR distributions are also reported for various tissues (fat/muscle/lung layers) at the same depth in order to make a comparative study in these tissues. A modified box-horn, in which the horn is flared in both E- and H-planes is also considered. The effect of substituting pyramidal horn in place of H-plane sectoral horn in the design of box-horn on the SAR distribution is also examined. The results have been validated against available published results in the literature.