Using optimally focused electromagnetic power for hyperthermia treatment of deep tumors in biological tissue

Favorable responses to heating tumors to 42-45°C has lead to development of electromagnetic antenna applicators which noninvasively couple power to cancerous tumors. This modality avoids surgery trauma, healthy tissue destruction from ionizing radiation, and toxic effects of chemotherapy. By adjusting the antenna radiation characteristics, it is possible to focus power on abnormal tissue while sparing healthy tissue. The current analysis uses simple geometric models of tissue: (planar slab, circular cylinder, and sphere) to determine the best antenna electric field distributors for heating deep, localized tumor volumes. The best distributions deliver as much power as possible to the tumor. It is shown that the best standard frequency for focusing electromagnetic power is 915 MHz, and that the optimal distribution is better than the expected conjugate phase distribution