Transurethral microwave thermotherapy for management of benign prostatic hyperplasia: Durability of response

Objectives. The durability of clinical efficacy of transurethral microwave thermotherapy (TUMT) by Prostatron using a low-energy protocol (maximum power, 50 W) was evaluated on an outpatient basis in patients with symptomatic benign prostatic hyperplasia (BPH). Methods. One hundred Eighteen patients were followed up for longer than 3 months (13.4 +/- 9.5 months; mean +/- SD). Ail evaluations were made at baseline and then 3, 6, 12, 24, and 36 months after therapy. Results. International Prostate Symptom Score (IPSS) significantly decreased from 18.2 to 10.6 at 6 months (P < 0.01), representing a mean improvement of 41% under the baseline. Peak flow rate increased from the baseline of 8.3 mL/s to 10.3 mL/s at 6 months (P < 0.01). The improvement in terms of mean values of both parameters was sustained up to 24 months. Six of 44 patients (14%) who were followed up for 31 months on average required transurethral resection of tile prostate for recurring obstructive symptoms and 10 additional patients (23%) had to be treated with various drug regimens. When the clinical outcome was evaluated in terms of improvement from tile baseline according to a response criteria, disease-free rates for IPSS (more than 25% improvement from the baseline) were 76% at 12 months, 77% at 24 months, and 61% at 36 months. Disease-free rate for peak flow rate (more than 2.5 mL/s from the baseline) was sustained in 44% by 12 months and in 48% by 24 months. The overall outcome of the treatment was assessed by adding scores based on both subjective and objective Efficacy criteria, At 6 months, 67% of the patients were responders, and 15 of 21 (71%) remained as responders at 24 months. Patients who had estimated prostate volume smaller than 50 cc showed more marked improvement in peak flow rate (P < 0.02), and those with baseline IPSS of 20 or more showed greater reduction of IPSS (P < 0.05) at 24 months compared with each counterpart. Conclusions. After TUMT with a low-energy protocol, satisfactory results were obtained and the improvement seems to last at least for 24 months. This low-energy protocol may be most beneficial in patients with relatively small size of tile prostate.