[Clinical research on hyperthermia of cancer using microwave heating equipment of lens applicator type]

Ninety cases with 96 tumors were treated by the 430 MHz microwave heating systems, HTS-100, at Tokyo Metropolitan Komagome Hospital, Kyoto University and Aichi Cancer Center. The results of treatment were analyzed, and the following have been clarified. Three cases are demonstrated showing feature of HTS-100. 1) The results of 383 sessions of heating by HTS-100 were analyzed, and it has been clarified that even the larger tumors, more than 5 cm both in size and depth, can be heated satisfactorily to temperatures higher than 42 degrees C. This system is capable of heating remarkably wider areas compared with the conventional microwave heating systems. 2) Hyperthermia by HTS-100 and radiotherapy were combined for treatment. The success rate (total percentage of CR plus PRa) of 89 cases analyzed was as high as 66.3%. Furthermore, local heating was successful for 60.7% of tumors, larger than 5 cm and deeper than 4 cm. 3) Combination of microwave heating and RF wave heating is a new method which is helpful for expansion of indications. 4) The frequencies of side effects of HTS-100 heating were: pain, 15.6%; sensation of heat, 6.3%; burns, 3.6%. Most of side effects were transient and slight. The higher frequency of pain than the conventional microwave heating is attributable to expansion of heating area.