A randomized clinical trial conducted by Oslo University Hospital between 2010 and 2012 included 438 patients with prostate cancer to the non-MRI group (216) or the MRI group (222) before robot-assisted radical prostatectomy (RALP). The primary endpoint was to compare the nerve-sparing surgery types and the proportion of positive surgical margins (PSM) in each group. The MRI group underwent more non-nerve sparing surgery, whereas the proportion of PSM was similar in both groups (p=0.4) [1]. Since the long-term effects of preoperative MRI are unknown, we aimed to assess the variations in the long-term functional and oncological outcomes between the groups.

The aim of this study was to evaluate the oncological and functional outcomes in a 12-year follow-up after RALP in patients preoperatively randomized to no-MRI or MRI.

Material: a total of 438 consecutive patients were referred to RALP. Of these, 222 were randomized to preoperative MRI (intervention group), and 216 were randomized to no MRI (control group). All underwent radical prostatectomy between 2010 and 2012.

Study design: An experimental interventional study with 12-years follow-up

Endpoints: PSA recurrence (PSA ≥0.2ng/ml) Predictors for PSA recurrence (PSM, DÁmico risk group, Gleason score, T-stage) Overall survival (OS) Predictors for OS (PSM, DÁmico risk group, Gleason score, T-stage) MRI predictors for PSM, PSA recurrence and OS

Erectile function (IEEF-5) and urinary continence (IPSS-10) Urinary incontinence rates (≥1daily pads)

Statistics: Before RALP, included patients were randomized to the i) non-MRI group and ii) MRI-group. Kaplan Meier curves express the RFS and OS in the two groups, and the Log-rank test assesses any difference. Cox regression analyses is used to calculate the effect of MRI (Hazard ratios with 95% CIs). Chi-square test is used to assess the difference in incontinence rates, and the Mann-Whitney U test for assessing the difference in median IIEF-5 and IPSS-10 scores. Binary and Cox regression analysis is used to assess the predictive value of a positive surgical margin on PSA recurrence, and the effect of MRI variables in predicting RFS and OS (ADC, tumor volume, and radiological T-classification).

Data collection and handling of data: All patients were included in the study "Clinical impact of MRI in patients with prostate cancer." The urological and/or oncological clinic have followed these patients as part of routine clinical practice. Relevant clinical data are recorded in the "Radical prostatectomy registry ." All patients have already answered appropriate questionnaires during their regular follow-up.

PhD project: The study is a PhD project for radiologist Daniyal Noor at Oslo University Hospital

Inclusion Criteria:

Prostate cancer scheduled for prostatectomy. All participated in the previous RCT

Exclusion Criteria:

Patients who did not sign the consent paper for any reason or did not accept the study premises.

Patients who underwent MRI prior to randomization. Patents who withdrew their consent for any reason during the study.