Local microwave hyperthermia of benign prostatic hyperplasia.

Recently, hyperthermia has been used for treatment of benign prostatic hyperplasia. The preliminary results reported were promising. However, apart from patients with total urinary retention, objective voiding parameters have not been reported in detail for patients with prostatism. In a phase II study we treated 30 patients with benign prostatic hyperplasia by local microwave hyperthermia (915 MHz.). The prostate was heated transrectally to 42 to 43C, with the treatment consisting of 8 sessions of 60 minutes each given twice a week. To assess the results of treatment several parameters were determined before and 4 weeks after hyperthermia therapy, including transrectal ultrasound of the prostate with volumetry, urinary flow rate and residual volume. Of the patients 28 could be evaluated and only 2 showed a relevant improvement. Neither the voiding parameters nor the size of the prostate could be changed significantly by hyperthermia. The success rate of 7.1% is even lower than the spontaneous temporary regression rate of benign prostatic hyperplasia. Thus, we believe that hyperthermia cannot be regarded as an effective treatment for benign prostatic hyperplasia comparable to transurethral resection.