Transurethral Microwave Hyperthermia for Benign Prostatic Hyperplasia: Preliminary Clinical and Pathological Results

Abstract

Transurethral microwave hyperthermia is a new conservative treatment modality for benign prostatic hyperplasia. We treated 15 patients with 915 MHz. microwaves delivered transurethrally by a helical applicator. Of the patients 12 showed substantial objective and subjective improvement of obstructive outflow parameters. Significant improvement in objective study parameters included increased mean flow rate (p less than 0.00021), decreased mean residual volume (p less than 0.00001) and decreased mean prostatic volume (p less than 0.0077). Analysis of patterns of failure showed chronic bladder atony, prostate asymmetry and middle lobe configuration as important factors that could explain the failure of hyperthermia in 3 patients. Toxicity was mild, consisting of bladder spasms, perineal pain, dysuria and hematuria. Hyperthermia-induced pathological changes in prostatic tissues, causing periurethral shrinking and secondary dilatation of the prostatic urethra, are described. The reported clinical results of this phase I study are preliminary due to the short followup. A phase II study to optimize transurethral hyperthermia currently is underway. A phase III study is to be phased in comparing hyperthermia with transurethral resection of the prostate.

Transurethral Microwave Therapy: Patient Selection and Outcome

“…Baert et al [16], in a study of 15 patients who under went transurethral microwave therapy, demonstrated a successful outcome in 12 (80%) patients. The 3 patients who failed to improve after treatment had either a large residual urine volume or significant middle lobe hyperTablel.…”

“…The minimally invasive ther apies available include prostatic stenting [12], balloon dilatation [13], laser treatment (TULIP, ELAP) [14] and transrectal or transurethral microwave therapy [15][16][17][18][19].…”

“…It is well tolerated and has few side-effects. Early trials of multiple transrectal [15] and transurethral [16] treatments reported good symptomatic improvement. Transurethral treatment is more effective at relieving symptoms compared with transrectal treatment [17], This study examines the first 41 patients treated using the Leo Microthermer transurethral microwave transmit ter.…”

Balloon Dilation of the Prostate

“…Clear objective and subjective improvement was observed. A conclusion was made that transurethral hy perthermia is a safe and well-tolerated treatment [9], Patients who are at poor risk for surgery could benefit from this therapy.…”

Hyperthermia and Thermotherapy of Benign Prostatic Hyperplasia: A Critical Review

“…Multiple sessions are used. The dura tion of each treatment is 1 h, and 5-10 sessions separated by 72-96 h are recommended [17,18], Subjective im provement was observed in about 70% of the patients with a mean increase in peak flow (3-4 ml) [17,18] (ta ble 2). One may question the role played by repeated cath eterization in the interpretation of these results.…”