Brief Correspondence The Incremental Role of Magnetic Resonance Imaging for Prostate Cancer Staging before Radical Prostatectomy Alessandro Morlacco a , Vidit Sharma a , Boyd R. Viers a , Laureano J. Rangel b , Rachel E. Carlson b , Adam T. Froemming c , R. Jeffrey Karnes a, * a Department of Urology, Mayo Clinic in Rochester, MN, USA; b Department of Health Science Research, Mayo Clinic in Rochester, MN, USA; c Department of Radiology, Mayo Clinic in Rochester, MN, USA Prediction of adverse pathological features at surgery, in terms of extracapsular extension (ECE), seminal vesicle invasion (SVI), and node positivity (N+), is of particular interest when defining the surgical approach and the role of magnetic resonance imaging (MRI) in this setting is still a matter of debate. The European Association of Urology [1] and National Comprehensive Cancer Network guidelines [2] do not provide definitive indications for MRI use, simply hypothesizing a role for this technique, especially in high-risk disease. A recent meta-analysis [3] concluded that MRI has a good specificity for T staging, while sensitivity is highly variable. As such, there remains a high-level of clinical uncertainty regarding the potential role of MRI, particularly when compared with conventional, clinically-based risk classification models. In the present study, we compared MRI with existing models (the Cancer of the Prostate Risk Assessment [CAPRA] score and the E U R O P E A N U R O L O G Y X X X ( 2 0 1 6 ) X X X – X X X ava ilable at www.sciencedirect.com journa l homepage: www.europea nurology.com Article info Article history: Accepted August 5, 2016 Associate Editor: Giacomo Novara Keywords: MRI Staging Risk assessment Prostate cancer Prostatectomy Predictive models CAPRA score Partin Table Abstract In the present report we aimed to analyze the incremental value of preoperative magnetic resonance imaging (MRI), in addition to clinical variables and clinically- derived nomograms, in predicting outcomes radical prostatectomy (RP). All Mayo Clinic RP patients who underwent preoperative 1.5-Tesla MRI with endo-rectal coil from 2003 to 2013 were identified. Clinical and histopathological variables were used to calculate Partin estimates and Cancer of the Prostate Risk Assessment (CAPRA) score. MRI results in terms of extracapsular extension (ECE), seminal vesicle invasion (SVI), and lymph-node invasion (N+) were recorded. Using RP pathology as gold standard, we developed multivariate logistic regression models based on clinical variables, Partin Tables, and CAPRA score, and assessed their predictive accuracy before and after the addition of MRI results. Five hundred and one patients were included. MRI + clinical models outperformed clinical-based models alone for all outcomes. Comparing Partin and Partin + MRI predictive models, the areas under the curve were 0.61 versus 0.73 for ECE, 0.75 versus 0.82 for SVI, and 0.82 versus 0.85 for N+. Comparing CAPRA and CAPRA + MRI models, the areas under the curve were 0.69 versus 0.77 for ECE, 0.75 versus 0.83 for SVI, and 0.82 versus 0.85 for N+. Our data show that MRI can improve clinical-based models in prediction of nonorgan confined disease, particularly for ECE and SVI. Patient summary: Magnetic resonance imaging, together with clinical information, can be useful in preoperative assessment before radical prostatectomy. # 2016 European Association of Urology. Published by Elsevier B.V. All rights reserved. * Corresponding author. Mayo Clinic, Gonda Building 7-130, 200 First Street South West Rochester, MN 55905, USA. Tel. +1-507-266-9968; Fax: +1-507-284-4951. E-mail address: Karnes.R@mayo.edu (R.J. Karnes). EURURO-6970; No. of Pages 4 Please cite this article in press as: Morlacco A, et al. The Incremental Role of Magnetic Resonance Imaging for Prostate Cancer Staging before Radical Prostatectomy. Eur Urol (2016), http://dx.doi.org/10.1016/j.eururo.2016.08.015 http://dx.doi.org/10.1016/j.eururo.2016.08.015 0302-2838/# 2016 European Association of Urology. Published by Elsevier B.V. All rights reserved.