Antenna Applicator for Microwave Hyperthermia Treatment of Pediatric Brain Cancer

A novel antenna applicator for microwave hyperthermia allowing treatment of deep brain tumors is proposed. The applicator consists of up to 16 antennas placed around the head in a helmet-like set-up and operates at a frequency range of 430-1000~MHz. The self-grounded bow-tie antennas are housed in a molded plastic enclosure with the shape of a truncated cone. The inner space of the enclosure is filled with distilled water. The antennas are attached to a perimetric water bolus with a thickness of 2 cm and aligned with the head shape. The focusing ability of the applicator was investigated on a homogeneous SAM model and on a model of a 13-year old patient containing a spherical tumor of 2 cm radius. Two different tumor positions were investigated: the right frontal lobe and the central brain. The obtained SAR distributions are favorable, although a relatively high level of energy is also absorbed on the surface of the body. This heating is however not expected to cause problems as it can be cooled by blood perfusion and water bolus. Our results show that focused microwave heating in the brain is feasible and warrants further verification on phantoms