Local microwave hyperthermia in the treatment of carcinoma of the prostate.

The clinical electromagnetic hyperthermia system has been in use at the Kaplan Hospital since 1980, for treating patients with hyperthermia combined with radio- or chemotherapy. For prostatic tumors, hyperthermia at 43 degrees C is achieved in the prostatic mass using microwaves of 2.45 GHz, with simultaneous cooling of the rectal mucosa and the rectal wall. Thirty-two patients with carcinoma of the prostate have been treated: 4 with heat alone, 20 with hyperthermia combined with radiotherapy, and 8 with hyperthermia combined with hormonal therapy. Follow-up was carried out up to 34 months. Objective local tumor regression was achieved in 3 out of 4 patients treated by heat alone, but the patients relapsed after 6 months. All the 20 patients treated with combined hyperthermia and radiotherapy responded to treatment. Patients treated with combined hyperthermia and hormone therapy responded locally to treatment but died of their metastatic disease, or of unrelated diseases with a follow-up period up to 31 months. Hyperthermia did not increase morbidity beyond that expected for radiation therapy.