Interstitial temperature mapping during Prolieve transurethral microwave treatment: Imaging reveals thermotherapy temperatures resulting in tissue necrosis and patent prostatic urethra

Prolieve® Transurethral Thermodilatation for treatment of Symptomatic Benign Prostatic Hyperplasia: 5-Year Results from a Prospective Multi-Center Trial

Introduction & Objective Prolieve® transurethral thermodilatation (TUTD) is the only third-generation transurethral microwave thermotherapy (TUMT) device that incorporates balloon dilation/compression of the prostatic urethra with cooled TUMT, at ≤50W power. We evaluated its 5-year efficacy in the treatment of symptomatic benign prostatic hyperplasia (BPH) in an open-label prospective multi-center trial. Methods Eligible patients with AUA symptom score (AUASS) ≥ 9, peak urine flow rate (Qmax) <12 ml/s, and prostate size 20-80 g without obstructing median lobe anatomy were enrolled. Prolieve® TUTD was delivered in the office setting under local anesthesia. AUASS, Quality of Life (QOL), BPH impact index (BPHII), Qmax and other measures were assessed at baseline, and at least annually thereafter to year 5. Adverse events (AEs) were recorded. Treatment success over time was analyzed using the Kaplan-Meier method while changes from baseline were evaluated using paired t-tests. Results Intention to treat (ITT) population was 225, of whom 220 with a mean (SD) age of 65 (5.9). completed treatment. 187/220 (85%) did not require urethral catheterization. AUAS, QOL and BPHII scores significantly improved from baseline in ≤ 3 months, with sustained improvements to year 5. Qmax also significantly improved from baseline at each annual follow up evaluation. Cumulative 5-year surgical retreatment rate was 14.2% (95% CI 9.5-20.8%). Transient urinary urgency and dysuria were the most commonly reported AEs. Conclusions Prolieve® TUTD is a safe and effective treatment option for BPH, with durable long-term improvements in voiding subjective symptoms and urinary flow rates. It is deliverable in the office setting and has a low catheterization rate and sexual side effects are rare.

Rezūm System Water Vapor Treatment for Lower Urinary Tract Symptoms/Benign Prostatic Hyperplasia: Validation of Convective Thermal Energy Transfer and Characterization With Magnetic Resonance Imaging and 3-Dimensional Renderings

OBJECTIVE

To evaluate by magnetic resonance imaging the physical effects of convective thermal energy transfer with water vapor as a means of treating lower urinary tract symptoms due to benign prostatic hyperplasia.

METHODS

Sixty-five men with lower urinary tract symptoms were treated with the Rezūm System by transurethral intraprostatic injection of water vapor. A group of 45 of these men consented to undergo a series of gadolinium-enhanced magnetic resonance imagings of the prostate after treatment to monitor the size and location of ablative lesions, their time course of resolution, and the corresponding change in prostate tissue volume. Visualization was conducted at 1 week, 1, 3, and 6 months after treatment.

RESULTS

Outcomes were available for 44 patients. Convective thermal lesions were limited to the transition zone and correlated with targeted treatment locations. At 1 week after treatment, the mean volume of ablative lesions was 8.2 cm(3) (0.5-24.0 cm(3)). At 6 months, whole prostate volume was reduced by a mean of 28.9% and transition zone volume by 38.0% as compared with baseline 1-week images. At 3 and 6 months after treatment, the lesion volumes had reduced by 91.5% and 95.1%, respectively. Lesions remained within the targeted treatment zone without compromising integrity of the bladder, rectum, or striated urinary sphincter.

CONCLUSION

This imaging study confirms the delivery of convective water vapor technology to create thermal lesions in the prostate tissue. Lesions generated underwent near complete resolution by 3 and 6 months after treatment with a concomitant one-third reduction in overall prostate and transition zone volumes.