Improvement of the resonant cavity applicator for brain tumor hyperthermia

A re-entrant type resonant cavity applicator for deep tumor hyperthermia treatment was presented. In this method, a human body is placed between the gap of the inner re-entrant cylinders, and is heated with electromagnetic fields stimulated in the cavity without contact between the surface of the human body and the applicator. First, a comparison of the heating characteristics of our heating method and RF capacitive heating method was discussed experimentally. At the position of half-length of phantom radius, the normalized temperature values using our heating method and RF capacitive heating method on the r-direction are 0.75 and 1.0, respectively. At the center of the phantom, the normalized values on the z-direction are 1.0 and 0.45, respectively. Second, the clinical heating results of the dog brain using our heating method were presented. In the experiment, the deep region of the dog brain is heated to 42.5C From these results, it is confirmed experimentally that deep regional heating can be done noninvasively without generating hot spots under the surface area of the brain.