MRI-informed urethral preservation strategy for early continence recovery after robot-assisted radical prostatectomy: a multicenter randomized controlled trial.

To evaluate whether an MRI-informed urethral preservation strategy based on preoperative membranous urethral length (MUL) and prostatic apical morphology improves early continence recovery after robot-assisted radical prostatectomy (RARP). This multicenter, prospective, randomized, assessor-blinded exploratory trial enrolled 100 patients with biopsy-confirmed prostate cancer scheduled for transperitoneal RARP. Patients were randomly assigned in a 1:1 ratio to an MRI-informed urethral preservation group or a conventional RARP group. In the intervention group, a prespecified algorithm combined three MUL strata (< 10, 10-<14, and ≥ 14 mm), apical morphology, and apical oncological risk to determine the planned urethral transection strategy; oncological safety findings overrode maximal preservation. The primary endpoint was social continence recovery at 1 month. The sample size was feasibility-based. A total of 100 patients were randomized, with 50 patients in each group. At 1 month, social continence recovery was observed in 32 patients (64.0%) in the MRI-informed group and 21 patients (42.0%) in the conventional group (unadjusted OR 2.46, 95% CI 1.10-5.49; P = 0.028). The median time to social continence recovery was 28 versus 46 days (HR 1.56, 95% CI 1.04-2.35; P = 0.032). Overall positive surgical margin rates (20.0% vs. 22.0%) and apical positive surgical margin rates (6.0% vs. 8.0%) were numerically similar. An MRI-informed urethral preservation strategy based on preoperative MUL and prostatic apical morphology may improve early continence recovery after RARP. Overall and apical positive surgical margin rates and anastomosis-related complication rates were numerically similar between groups. However, these secondary comparisons were underpowered and do not establish oncological or procedural safety. Larger, adequately powered randomized trials with longer follow-up are required.