CLINICAL-RESULTS OF THERMORADIOTHERAPY FOR SOFT-TISSUE TUMORS

Thirty-one unresectable and/or recurrent soft tissue tumours in 27 pat ients underwent hyperthermia in combination with radiation therapy. Lo coregional hyperthermia was administered once or twice a week for 40-6 0 min to a total of 2-14 sessions using RF capacitive or microwave hea ting equipment. Radiation therapy was given 10-20 min before hyperther mia at doses of 20.8 to 70 Gy. The mean +/- SD of the maximum, average , and minimum intratumour temperatures was 44.0 +/- 2.9 degrees C, 42. 3 +/- 1.6 degrees C, 40.1 +/- 1.1 degrees C respectively, and that of the percentage of the intratumour points that exceeded 41 and 43 degre es C was 66.0 +/- 33.6, and 31.0 +/- 26.1 respectively. Of the 31 tumo urs treated, 13 (42%) showed CR (complete regression), 10 (32%) PR(> 5 0 and < 100% regression) and 8 (26%) NC (<50% regression). Since intra tumour low density areas on post-treatment CT scans have been demonstr ated to be a useful parameter for assessing tumour response to thermor adiotherapy, the presence of low density areas was also assessed. Low density areas were classified into the following three categories acco rding to the percent area occupied in the maximal cross-section of the tumour: type I, < 50%, type II, 50-80%; type III, > 80%. Of 20 tumour s evaluable, 6 (30%) exhibited type III change, 11 (55%) type II and 3 (15%) type I. All of the type III tumours demonstrated a marked respo nse on follow-up or histopathological examination. The major complicat ion associated with treatment was skin ulcer in two patients. The five -year survival of the total 27 patients and 18 patients who had no dis tant metastases at the start of treatment was 32 and 48% respectively. These results indicate the clinical benefit of thermoradiotherapy usi ng RF capacitive or microwave equipment for locally advanced and/or re current soft tissue tumours.