Temperature Rise of Resonant Circuits for Hyperthermia Excited by Weak RF Magnetic field

Hyperthermia is a cancer treatment of raising the body temperature. It has an advantage that there are not major side effects as compared with various established treatments of surgical operation, radiotherapy and chemotherapy. When heat is applied to cancer cells, a survival rate of the cells drops sharply at 42.5 deg.C. There are various warming methods in hyperthermia. A weak RF pulse of the magnetic field with a low duty ratio under normal diagnosis sequence of the MRI operation could raise the circuit temperature up to 13 deg.C. A combination of the hyperthermia using heated implants and diagnostic functions of MRI offers significant advantages In order to deliver them through catheter into the human body, their miniaturization down to 1mm order is required. Optimizations of a L/C combination, size and other parameters are discussed in this paper.