Impact of preoperative MRI on surgical outcomes of robot-assisted laparoscopic prostatectomy: a single-center retrospective cohort of 844 patients.

Background: Multiparametric magnetic resonance imaging (mpMRI) refines local staging in prostate cancer, but its effect on hard surgical endpoints after robot-assisted laparoscopic prostatectomy (RALP) remains uncertain. Objectives: To evaluate whether systematic preoperative mpMRI implementation was associated with improved surgical margin status and early biochemical control in a mature robotic RALP program. Design: Single-center retrospective cohort study comparing two calendar periods (pre‑mpMRI era vs mpMRI era). Methods: We included 844 consecutive men who underwent RALP for cT1-cT2 N0 M0 prostate adenocarcinoma between January 2007 and December 2019. Patients were classified into a pre-mpMRI era (2007-2012) and a post-mpMRI era (2014-2019), excluding 2013 as a transition year. From 2014, standardized 3T mpMRI interpreted by a single uroradiologist was systematically integrated into side-specific surgical planning, including nerve-sparing decisions. The primary endpoint was any positive surgical margin (PSM); the secondary endpoint was biochemical recurrence (BCR, prostate-specific antigen (PSA) ⩾ 0.2 ng/mL) within 24 months. Logistic regression (overall and stratified by pT2/pT3) assessed associations between era and PSM, with multivariable adjustment for age, PSA, tumor volume, biopsy Gleason score, D'Amico risk group, and pathological stage. BCR-free survival was analyzed with Kaplan-Meier curves, log-rank tests, and Cox models censored at 24 months. Results: Of 844 men, 393 were operated on in 2007-2012 and 451 in 2014-2019. Compared with the pre-mpMRI era, patients in the mpMRI era were older (median 67 vs 64 years) and had larger tumor volume (3.6 vs 2.2 cc) and less favorable Gleason and D'Amico profiles, while pT distribution was similar. Margin status was available for 802 patients; PSM decreased from 25% (97/381) to 15% (65/421) in the mpMRI era (absolute reduction ~10 percentage points). In the overall cohort, surgery in the mpMRI era was associated with lower odds of PSM (adjusted odds ratio 0.51; 95% CI 0.34-0.74; Conclusion: In a high-volume center with a stable, experienced robotic surgeon, the preoperative mpMRI era has been linked to better surgical outcomes, particularly for patients with more pT3 disease. While this temporal association supports a potential contribution of systematic preoperative mpMRI to surgical precision, residual temporal confounding cannot be excluded. Early BCR-free survival within 24 months did not differ significantly between eras after adjustment for baseline risk. In the future, more precise 3D MRI mapping could further enhance the preservation of neurovascular bundles without compromising the oncological prognosis. Trial registration: Not applicable (retrospective analysis of routinely collected clinical data).