INTRASPINAL TEMPERATURES DURING REGIONAL DEEP HYPERTHERMIA-INDUCED BYELECTROMAGNETIC-RADIATION IN THE MACACA-MULATTA

A capacitive ring system operating at 27 MHz was tested for temperatur e distribution in the abdominal cavity of the living Rhesus monkey. Ca theters were introduced through the abdomen and their location checked after the experiment. During two of these experiments a catheter was also introduced into the intraspinal canal. Temperature distribution w as rather homogeneous within the abdominal cavity. Core temperature re mained 3-5 degrees C below intraabdominal temperatures. The intraspina l temperature increase was of the same magnitude compared with intra-a bdominal temperature increase. Similar findings in other species have been reported by others. It is concluded that during noninvasive induc tion of regional hyperthermia by electromagnetic radiation, where a hi gh level of energy is directed close to the spine, the intraspinal tem peratures may be increased as high as the temperatures within the surr ounding tissues. The central nervous system may be relatively sensitiv e to hyperthermia and hyperthermia may sensitize the spinal cord to ra diation. Therefore, when hyperthermia is targeted at areas near the sp ine, either alone or in combination with radiotherapy applied to the t olerance limit of the spinal cord, these findings will have to be take n into consideration.