SUPERFICIAL TUMOR HYPERTHERMIA WITH FLAT LEFT-HANDED METAMATERIAL LENS

Flat left-handed metamaterial (LHM) lens can generate appropriate focusing spot in biological tissue as required in microwave tumor hyperthermia treatment. By using single ∞at LHM lens to concentrate microwave in a mass of tissue covered by water bolus, microwave hyperthermia scheme is proposed for superflcial tumor hyperthermia. The power distribution in tissue is simulated by flnite- difierence time-domain method, and the thermal pattern is calculated by solving the bio-heat transfer equation. It is demonstrated that, by using a ∞at LHM lens of thickness of 4cm to concentrate microwave of 2.45GHz, a temperature above 42 - C can be achieved and maintained in one hour in a tissue region of about 1.0cm in width and 1.2cm in depth in tissue with the source amplitude of 43.44V/cm, which is suitable for superflcial tumor hyperthermia. By adjusting the position of microwave source, the heating zone in tissue can be adjusted in both the lateral and depth direction in tissue. The in∞uence of fat layer, efiects of water bolus and microwave frequency on hyperthermia, is investigated as well.