Relief of Lower Urinary Tract Symptoms After MRI-Guided Transurethral Ultrasound Ablation for Localized Prostate Cancer: Subgroup Analyses in Patients with Concurrent Cancer and Benign Prostatic Hyperplasia

MR-Guided Transurethral Ultrasound Ablation (TULSA)-An Emerging Minimally Invasive Treatment Option for Localised Prostate Cancer

The optimal treatment strategy for men with localised prostatic cancer of low and intermediate risk is an actively evolving field. It is important to strike a balance between maximal oncological control and minimal treatment-related complications, which helps preserve the patients' quality of life. MR-guided transurethral ultrasound ablation (TULSA) has emerged as a minimally invasive treatment option for this group of patients. This article aims to provide of a background on TULSA technology, a step-by-step procedural guide of MR-guided TULSA and to summarise the current evidence of TULSA in management of localised prostatic cancer, as well as other potential indications.

Minimally invasive techniques in quest of Holy Grail of surgical management of enlarged prostates: a narrative review

PURPOSE

Past decade has seen a renewed interest in minimally invasive surgical techniques (MISTs) for management of enlarged prostate. This narrative review aims to explore newer MIST for benign prostatic hyperplasia (BPH) which are not yet integrated into established societal guidelines.

METHODS

We conducted a literature search across PubMed, Google Scholar, and FDA ClinicalTrials.gov databases on June 1st, 2023, to identify studies published within the past decade exploring various MISTs for BPH. Additionally, we gathered insights from abstracts presented in meetings of professional associations and corporate websites. We broadly classified these procedures into three distinct categories: energy-based, balloon dilation, and implant/stent treatments. We collected detail information about the device, procedure details, its inclusion and exclusion criteria, and outcome.

RESULTS

Our review reveals that newer energy-based MISTs include Transperineal Laser Ablation, Transurethral Ultrasound Ablation, and High-Intensity Focused Ultrasound. In the sphere of balloon dilation, Transurethral Columnar Balloon Dilation and the Optilume BPH Catheter System were gaining momentum. The noteworthy implants/stents that are on horizon include Butterfly Prostatic Retraction Device, Urocross Expander System, Zenflow Spring System, and ProVee Urethral Expander System.

CONCLUSION

The exploration of various MISTs reflects ongoing efforts to enhance patient care and address limitations of existing treatments. This review provides a bird-eye view and valuable insights for urologists and researchers seeking to navigate the dynamic landscape of MISTs in the quest for effective and minimally invasive solutions for enlarged prostates.

MRI-guided Minimally Invasive Focal Therapies for Prostate Cancer

Two cases involving patients diagnosed with localized prostate cancer and treated with MRI-guided focal therapies are presented. Patient selection procedures, techniques, outcomes, challenges, and future directions of MRI-guided focal therapies, as well as their role in the treatment of low- to intermediate-risk localized prostate cancer, are summarized.

First experiences using transurethral ultrasound ablation (TULSA) as a promising focal approach to treat localized prostate cancer: a monocentric study

PURPOSE

To share our experience using transurethral ultrasound ablation (TULSA) treatment for focal therapy of localized prostate cancer (PCa).

MATERIALS AND METHODS

Between 10/2019 and 06/2021 TULSA treatment for localized PCa was performed in 22 men (mean age: 67 ± 7 years, mean initial PSA: 6.8 ± 2.1 ng/ml, ISUP 1 in n = 6, ISUP 2 in n = 14 and 2 patients with recurrence after previous radiotherapy). Patients were selected by an interdisciplinary team, taking clinical parameters, histopathology from targeted or systematic biopsies, mpMRI and patients preferences into consideration. Patients were thoroughly informed about alternative treatment options and that TULSA is an individual treatment approach. High-intensity ultrasound was applied using an ablation device placed in the prostatic urethra. Heat-development within the prostatic tissue was monitored using MR-thermometry. Challenges during the ablation procedure and follow-up of oncologic and functional outcome of at least 12 months after TULSA treatment were documented.

RESULTS

No major adverse events were documented. In the 12 month follow-up period, no significant changes of urinary continence, irritative/obstructive voiding symptoms, bowel irritation or hormonal symptoms were reported according to the Expanded Prostate Cancer Index Composite (EPIC) score. Erectile function was significantly impaired 3-6 months (p < 0.01) and 9-12 months (p < 0.05) after TULSA. PSA values significantly decreased after therapy (2.1 ± 1.8 vs. 6.8 ± 2.1 ng/ml, p < 0.001). PCa recurrence rate was 23% (5/22 patients).

CONCLUSION

Establishment of TULSA in clinical routine was unproblematic, short-term outcome seems to be encouraging. The risk of erectile function impairment requires elaborate information of the patient.

Magnetic resonance imaging-guided ultrasound ablation for prostate cancer - A contemporary review of performance

Prostate cancer (PCa) is one of the most common malignancies in men, but patient outcomes are varied depending on extent of disease. Radical, whole-gland therapies, such as prostatectomy or radiotherapy, are definitive treatments for PCa, but they are associated with significant morbidity, including erectile dysfunction and urinary incontinence. Focal therapies for PCa, whereby the part of gland harboring disease is selectively treated, spares the normal surrounding structures, and minimizes the morbidity associated with whole gland treatment. The use of magnetic resonance imaging (MRI) guidance provides advantages over ultrasound guidance, such as better localization and targeting of clinically significant PCa (csPCa), as well as MRI thermometry which optimizes tissue ablation temperatures. This review will discuss two MRI-guided high-intensity focused ultrasound (HIFU) techniques - transrectal MR-guided focused ultrasound (MRgFUS) and TULSA (transurethral ultrasound ablation) ablation for localized PCa. Overall, recent major trials for MRgFUS and TULSA have shown promising oncological and functional results in the treatment of low- to intermediate-risk PCa. Recent Phase II MRgFUS trials have shown better oncologic outcomes than the published results for focal ultrasound guided HIFU and may justify the additional costs associated with MRI guidance. While initial studies on TULSA have focused on subtotal gland ablation, recent trials assessing oncological outcomes for focal treatment of angular sectors have shown promise.

Magnetic Resonance Imaging-Guided Transurethral Ultrasound Ablation of Prostate Cancer: A Systematic Review

Purpose: MRI-guided transurethral ultrasound ablation (TULSA) uses real-time MR thermometry feedback to target prostate disease. We systematically review the literature to synthesize efficacy, functional, and safety outcomes and assess the influence of planned ablation fraction on outcome. Materials and Methods: PubMed, Embase, and the Cochrane Library were searched from inception to June 2021 following Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. Studies reporting at least one efficacy, functional, or safety outcome after a single TULSA treatment were included. The relationship of freedom from salvage treatment and potency preservation with planned ablation volume was modeled. Results: Two hundred twenty-four patients were treated in 10 studies with up to a 5-year follow-up, mainly for primary localized prostate cancer (PCa) plus smaller cohorts with recurrent PCa, and locally advanced PCa (LAPC). The prostate-specific antigen decline from baseline up to 2 years, including focal to whole-gland ablation plans, was 54% to 97%. The rate of salvage treatment after one TULSA treatment for primary PCa was 7% to 17%. Continence and potency preservation were from 92% to 100% and from 75% to 98%. Urinary symptoms were stable in men with good voiding function at baseline, and 85% of men with concurrent PCa and lower urinary tract symptoms met the criteria for improvement. Symptom relief in a small cohort of men with LAPC was observed. Grade III adverse events were incurred by 13/224 men (6%), with no rectal injury/fistula or Grade IV complication. The planned ablation fraction was linearly related to salvage-free survival. The relationship between potency preservation and planned ablation fraction followed a sigmoid curve. Conclusions: As an alternative to conventional treatments, TULSA is safe and effective for prostate tissue ablation in men with primary PCa. There is also evidence that TULSA delivers effective relief of urinary symptoms while treating PCa in a single, low-morbidity procedure. The likelihood of freedom from additional treatment or potency preservation is associated with the planned ablation fraction.

Single-Center Evaluation of Treatment Success Using Two Different Protocols for MRI-Guided Transurethral Ultrasound Ablation of Localized Prostate Cancer

Objectives

To assess differences in 24-month oncologic and functional outcomes in men with low to intermediate-risk prostate cancer treated with MRI-guided transurethral ultrasound ablation (TULSA) using intentionally conservative versus intensified treatment parameters.

Patients and Methods

Patients from a single center involved in two multicenter trials were included in this analysis. This included 14 of 30 patients with Gleason 3 + 3 from a Phase I study using intentionally conservative treatment parameters, and 15 of 115 patients with Gleason ≤ 3 + 4 from a pivotal study using intensified parameters. Follow-up data compared across these cohorts included 12-month biopsy and MRI for all patients, and 24-month PSA, micturition and quality of life (IIEF, IPSS, IPSS-QOL). The prognostic value of baseline parameters and PSA kinetics on 12-month histological recurrence was evaluated by logistic regression.

Results

12-month biopsy revealed clinically significant residual disease in 4 (29%) and 2 (14%) patients from the Phase I and pivotal studies, respectively. PSA nadir was 0.7 ng/ml for Phase I and 0.5 ng/ml for pivotal study patients. Patient age at diagnosis, use of MRI fusion/systematic prostate biopsy, number of obtained cores at initial biopsy, PSA course, and PSA nadir were identified as prognostic factors for treatment success. All but one patient from each cohort maintained erection firmness sufficient for penetration. No cases of pad use were reported at 24 months. There were no Grade 4 or higher adverse events, and no late toxicity related to the procedure.

Conclusion

Two-year follow-up demonstrated the efficacy of TULSA for the treatment of localized prostate cancer, and the durability of PSA and functional outcomes. Intensifying treatment parameters in the pivotal trial had no impact on safety or functional outcomes through 24 months, while reducing the recurrence rate for clinically significant disease. Careful patient selection by MRI fusion/systematic prostate biopsy and adequate follow-up through routine 12-month biopsy are recommended.

Magnetic resonance imaging-guided transurethral ultrasound ablation for benign prostatic hyperplasia: 12-month clinical outcomes of a phase I study

OBJECTIVES

To investigate the safety and feasibility of magnetic resonance imaging (MRI)-guided transurethral ultrasound ablation (TULSA) for the treatment of benign prostatic obstruction (BPO).

PATIENTS AND METHODS

An investigator-initiated, prospective, registered (NCT03350529), phase I study enrolled men with lower urinary tract symptoms due to benign prostatic hyperplasia in need of surgical intervention. Patients were followed for 12 months after TULSA. Uroflowmetry, prostate-specific antigen (PSA) level, and a comprehensive set of functional questionnaires including the Expanded Prostate cancer Index Composite-26, International Prostate Symptom Score (IPSS) and five-item version of the International Index of Erectile Function were obtained at baseline and every 3 months afterwards. MRI was obtained at baseline, and at 3 and 12 months after TULSA. Medication use before and after TULSA were recorded. Adverse events (AEs) were reported using the Clavien-Dindo classification.

RESULTS

A total of 10 men underwent TULSA with no severe AEs encountered. The baseline median (interquartile range [IQR]) age and prostate volume were 68 (63-72) years and 53 (45-66) mL, respectively. At baseline, six patients were moderately symptomatic and four patients severely symptomatic. Nine patients at baseline were on BPO medication. The median (IQR) improvement in the IPSS was 82%, from 17.5 (15.3-23.0) at baseline to 4.0 (2.3-6.3) at 12 months. Similarly, the median maximum urinary flow rate improved by 101%, from a median (IQR) of 12.4 (8.8-17.6) mL/s at baseline to 21.8 (17.6-26.5) mL/s at 12 months. Improvements were already seen at 3 months. The median prostate volume and PSA reduction at 12 months were 33% and 48%, respectively. There were no changes in continence, sexual, erectile or bowel functions. At 12 months, five out of six men with normal ejaculatory function before TULSA reported normal antegrade ejaculations. All patients taking BPO medication before TULSA discontinued medication after TULSA.

CONCLUSION

TULSA appears to be a safe and effective treatment for BPO, with promising 12-month follow-up outcomes. Further studies with larger cohorts are needed to confirm the observed results.