Treatment response with transurethral microwave hyperthermia in different forms of benign prostatic hyperplasia: a preliminary report.

During a 7-month period, 79 patients with benign prostatic hyperplasia (BPH) were treated with 915 MHz transurethral hyperthermia (TUHT). All patients had obstructive and irritative signs and symptoms which warranted surgical treatment considerations. Of the 79 patients treated, 31 had follow-ups of 12 months or longer and seven additional patients experienced treatment failure requiring surgical management. These 38 patients were studied to evaluate the relationship of treatment response to the pretreatment prostatic morphology assessed during cystoscopy. There was a well-balanced distribution of patients regarding the important pretreatment characteristics in different morphological types of prostatic hypertrophy. These important characteristics included: prostate volume, postvoiding residual volume, mean peak flow rate, and mean symptom score on the FDA scale. The study patients were scheduled to receive five 60-min TUHT sessions with temperature controlled on the urethral surface at 45.5 degrees C. The treatment were well tolerated and administered on an outpatient basis without sedation or anesthesia. There was a significant difference in the incidence of major improvement in patients with lateral lobe hyperplasia and those with median lobe enlargement, 73 vs. 30%, P = 0.018. From this study, it appears that BPH patients who are found at cystoscopy to have a predominance of median lobe hypertrophy should, perhaps, be selected for treatment other than TUHT. A Phase I study utilizing a modified transurethral applicator to accommodate the specific problem of patients with median lobe hyperplasia is currently being planned.