Transurethral hyperthermia for benign prostatic hyperplasia: preliminary clinical results.

A total of 21 patients with biopsy proved benign prostatic hyperplasia underwent treatment on a pilot protocol involving intracavitary transurethral radiating microwave (630 or 915 MHz.) antenna hyperthermia. Acute and subacute toxicity was mild and consisted primarily of bladder spasm (26% of the patients), hematuria (23%) and dysuria (9%), none of which significantly limited the achievement of desired temperatures during the treatment sessions. No chronic treatment-related morbidity or mortality was observed. Detailed thermal mapping, performed along the course of the prostatic urethra, recorded temperatures of 43C or more at greater than 75% of the loci. Highly significant increases in urine flow rate, decrease in post-void residual urine capacity and decrease in frequency of nocturia were observed. A marginally significant decrease in prostate volume was noted and, with a median followup of 12.5 months, only 3 patients have required subsequent prostatic resection. Transurethral hyperthermia represents a safe and promising outpatient approach to treatment of benign prostatic hyperplasia, particularly for patients who are not candidates for conventional surgical approaches because of medical or personal reasons. Further studies with the goal of optimizing the technique appear to be warranted, although long-term results would be best evaluated with prospective phase 3 trials.