Combined hyperthermia and irradiation in the treatment of superficial tumors: results of a prospective randomized trial of hyperthermia fractionation (1/wk vs 2/wk).

From December 1984 to December 1989, 240 superficially located recurrent/metastatic malignant lesions (173 patients) were enrolled in a prospective randomized study of one versus two hyperthermia fractions per week. In the majority of patients, the dose of radiation therapy was less than 4000 cGy over 4 to 5 weeks. Stratification was by tumor size, site, and histology. The goal of the hyperthermia sessions were 42.5 degrees C for 45-60 min minimum intra-tumor measured temperature. Hyperthermia was given after radiation within 30-60 min. External applicators, both microwave (over 90% of treatments) and ultrasound, were used. Overall, complete response rate in 222 evaluable lesions was 56.3% (125/222) with a minimum follow-up of 6 months and a maximum follow-up of 52 months. The complete response rate for once a week versus twice a week hyperthermia group was 54.7% and 57.8%, respectively. The severe complication rate was 18% (41/222). There was no difference between the two treatment arms. Cox regression analyses were performed to study the prognostic significance of patient characteristics, tumor characteristics, and treatment parameters. Detailed analysis and results are presented.