(728) Preoperative mpMRI Vascular Metrics Predict Erectile Function in Men Undergoing Nerve-Sparing Prostatectomy

Introduction Robot-assisted radical prostatectomy (RARP): gold standard as a surgical radical option for localised prostate cancer. Despitenerve-sparing, erectile dysfunction (ED) remains common. mpMRI is established for diagnosis and surgical planning. Membranous urethral length predicts continence recovery, but imagingpredictors of ED are unknown. Accessory pudendal arteries are present in up to a third of patients; however there has not beenestablished relationship with their presence and erectile function outcomes. Objective Assess whether mpMRI-derived vascular parameters predict baseline and postoperative erectile function. Methods We conducted a prospective study including consequitive men undergoing bilateral nerve-sparing RARP at a tertiary center.Inclusion criteria were preoperative dynamic contrast-enhanced mpMRI and available International Index of Erectile Function-6(IIEF-6) scores at baseline and 6 months. Patients with poor-quality or biparametric MRI or prior prostate cancer therapy wereexcluded. mpMRI studies were independently reviewed by two expert uro-radiologists, who were blinded to surgical details, erectilefunction outcomes, and each other's assessments. Imaging markers assessed included accessory pudendal artery (APA) presence,origin, and contribution, as well as prostate (PER) and corporal enhancement ratios (CER). Any discrepancies between readerswere discussed and resolved by consensus; in cases where consensus could not be reached, a senior radiology arbitratoradjudicated. Correlation tests, t-tests, and multivariable regression analyses evaluated associations between imaging metrics anderectile function. Results Seventy-one patients were included (median age 62). APA were present in 32.8%, most commonly originating from the obturatorartery. APA presence was associated with higher baseline IIEF-6 scores (24.3 vs 19.7, p = 0.025). PER was negatively associatedwith baseline erectile function (β = –0.048, p = 0.021), whereas CER showed a borderline positive association (β = 0.039, p =0.051). At 6 months post-RARP, erectile function did not differ between APA and non-APA groups (10.1 vs 9.2, p = 0.645), and nompMRI parameter predicted erectile recovery. In multivariable analysis, APA presence predicted higher baseline erectile function,while higher PER and older age predicted lower function. Conclusions mpMRI can detect APA and quantify perfusion dynamics. APA presence and vascular enhancement ratios are associated withbaseline erectile function. The surgeons coud be alerted to its presence. Further prospective research is needed to evaluate therelationship of image-detected APA and post radical prostatectomy erectile dysfunction. Disclosure No