High-energy transurethral microwave thermotherapy: a thermoablative treatment for benign prostatic obstruction

High-energy transurethral microwave thermotherapy (TUMT) was developed to increase treatment efficacy over former low-energy treatment protocols as an outpatient-based, anesthesia-free procedure for patients with benign prostatic obstruction. A Phase II study was conducted to evaluate treatment outcome and to enlighten possible prognostic factors.

Eighty-five patients with lower urinary tract symptoms were included in the study. A Madsen symptom score of 8 or more, a maximum flow less than 15 mL/s, and a postvoid residual urine volume (PVR) of under 350 mL were the main requirements for entry.

Eleven patients were lost to follow-up, making 74 patients evaluable at 1-year follow-up. Significant improvement was noticed in all indices: the Madsen symptom score improved 58% from baseline; the maximum flow rate improved from 9.4 to 14.9 mL/s, with a decrease in PVR of 80 mL to 25 mL; bladder outlet obstruction could be relieved in 78% of patients; and prostate volume decreased by 20%, with cavity formation in 42% of patients. Patients with bigger prostates (greater than 40 cm3) and patients with more severe bladder-outlet obstruction appeared to be the best responders. Post-treatment morbidity consisted of a prolonged need for transurethral catheter drainage (mean 16 days), with correlated irritative voiding complaints for an average of 2 to 3 weeks.

Overall improvement of high-energy thermotherapy now shows comparable results to surgical resection of the prostate.