Objectives To evaluate the safety and efficacy of magnetic resonance imaging (MRI)-guided transurethral ultrasound ablation (TULSA) as a minimally invasive alternative for benign prostatic obstruction (BPO).

Patients and Methods This prospective, single-centre, early phase II study (NCT03350529) included 30 men with BPO scheduled for primary transurethral resection of the prostate. Assessments over 12 months included uroflowmetry, prostate-specific antigen (PSA) levels, and validated questionnaires at baseline and 3-month intervals. MRI was performed at baseline and at 3 and 12 months. Medication use and adverse events (AEs) were recorded and graded using the Clavien-Dindo classification.

Results The median patient age at treatment was 67 years. During the 12-month post-TULSA follow-up, prostate volume decreased from a median of 52 to 32 mL, and PSA levels from 3.1 to 1.5 mu g/L. The maximum flow rate increased from 11.1 to 18.3 mL/s (P < 0.001), and the average flow rate from 4.2 to 9.1 mL/s (P < 0.001). Residual volume decreased from 71 to 40 mL, and voided volume increased from 211 to 301 mL. The International Prostate Symptom Score (IPSS) decreased from 17 to 4 (P < 0.001), and IPSS quality of life score improved from 4 to 1 (P < 0.001). The 26-item Expanded Prostate Cancer Index Composite urinary irritative/obstructive scores improved from 66 to 94 (P < 0.001), and urinary incontinence scores improved from 86 to 100 (P = 0.008). Sexual function remained stable or improved. A total of 13 AEs were recorded, including 11 Grade II events (urinary tract infections/retentions) and one Grade IIIb event (epididymitis requiring drainage under general anaesthesia). All AEs resolved during follow-up.

Conclusions Transurethral ultrasound ablation appears to be a safe and effective experimental treatment for BPO, demonstrating clinically marked improvements in urinary function and quality of life at 12 months while preserving continence and sexual functions. However, it is not yet recommended by guidelines, and long-term outcomes and validation in larger cohorts remain essential.