Radio-hyperthermia in post-surgical recurrence of melanoma

Malignant melanoma is one of the most radioresistant tumors. It can be treated with combinated hyperthermia and radiation therapy.

From January 1991 through June 1992, 7 patients, 1 male and 6 female, aged 40-88 years (mean 75), with skin and nodal post-surgical recurrences of melanoma, were treated with a combination of radiation therapy and hyperthermia. Two patients presented systemic disease when they reached our observation, but all of them were without symptoms. None of them underwent surgical excision of the recurrence before or during thermoradiotherapy. None received chemotherapy for these recurrences or had received radiotherapy in the past. They were irradiated with electron beams, with electron energies selected according to the depth of the lesions. The total dose was 40 Gy in 10 fractions in 5 weeks. Hyperthermia was administered for 10 minutes to 1 hour after irradiation. An inductive method of radiofrequency heating at 434 of 915 MHz was used depending on the depth of the lesions. In all of these treatments a ionized water bolus was used. The prescribed hyperthermic dose was 42 degrees C for half a hour. The treatments were carried out twice a week for 5 weeks. A fiberoptic multichannel thermometer was used for thermometry.

Four patients (57%) achieved a complete response, 2 patients (29%) a partial response, and 1 patient (14%) stabilization. We found no correlation between tumor volume and response rate. Site effects and complications of the treatment were minimal (moderate erythema).

Our results are in the wide range of values reported in the literature.