Microwave hyperthermia as an adjunct to radiation therapy: summary experience of 256 multifraction treatment cases

Results in 256 cases of malignant disease treated by multifraction combination hyperthermia-radiation therapy under the supervision of one physician are presented. The overall response rate was 94% including a 62% complete response. Complications specifically ascribed to hyperthermia were minor, and most side effects of combined treatment were radiation dose related. Tumor response was somewhat better for chest wall recurrence (72% CR) and for adenocarcinoma in general (64% CR), but no significant dependence on tumor site or type was found. Most patients were treated with low dose external radiation with hyperthermia given by air cooled microwave applicators or intracavitary antennae operating at 915 or 300 MHz, and some by interstitial microwave antennae plus 192 Ir. Results appeared to be independent of the microwave source employed. Response did depend on radiation dose: complete response rate with 4000 rad was 65%, and with 2000 rad was 42%.