A COMPARISON BETWEEN DIFFERENT SCHEMES OF MICROWAVE CANCER HYPERTHERMIA TREATMENT BY MEANS OF LEFT-HANDED METAMATERIAL LENSES

Abstract

In the hyperthermia therapy, multiple microwave sources can be arranged with appropriate spacing around the tissue containing tumor by using left-handed material (LHM) lenses. We employ some low loss LHM lenses schemes for an effective non-invasive microwave hyperthermia treatment of large tumors up to several centimeters of depth inside the biological tissues. Different configurations of LHM lenses are proposed and compared in order to assess the efficiency of hyperthermia treatment. High-resolution focusing of microwave radiation can be achieved by joint heating of several microwave antennas behind a conformal flat LHM lens. We show that a microwave radiation can be effectively focused in a 1.2 cm diameter tumor located within a lossy breast tissue. The results show that hyperthermia (temperature over 42 ◦ ) is reached and then maintained for one hour without involving the surrounding healthy tissues. Lastly, the heating area is adjusted in both lateral and longitudinal directions changing the position of the microwave sources or selecting LHM lenses with different thickness. This approach confirms that the conformal four-lens system is more efficient to achieve microwave tumor hyperthermia than single- and double-lens schemes.