AUA 2017: Development and Validation of a Nomogram for Predicting PIRADS 4-5 Lesions on Multiparametric Prostate MRI

Boston, MA ( Dr. Truong and colleagues from the University of Rochester presented their experience with developing a nomogram for predicting PIRADS 4-5 lesions on multiparametric MRI (mpMRI) today at the Uroradiology poster session at the 2017 AUA Annual Meeting. As we have seen with other presentations at this session, there is increasing utilization of mpMRI particularly in the setting of a negative biopsy with rising PSA, and for patients enrolled in active surveillance (AS) protocols.

For this study, the authors queried their database of 1023 patients who underwent a mpMRI of the prostate, among which 883 patients met the inclusion criteria of aiding in detection of prostate cancer detection or while on AS. Clinical variables assessed for nomogram development included age, PSA, prostate volume, and PSA density (PSAD). Using multivariable logistic regression to generate the nomogram, significant predictors of PIRADS 4-5 lesions included age, PSA, prostate volume, and PSAD (all p < 0.001), with an AUC of 0.746 (p < 0.001). The authors then constructed a separate nomogram using PSAD alone, which had an AUC of 0.729 (p < 0.001). Importantly, the two nomograms performed similarly regardless of indication for mpMRI. The strength of this study is that performing this nomogram in the clinic incurs no additional cost as the components of the nomogram are readily available to the clinician. A minor limitation is that these nomograms still require external validation prior to becoming widely adopted.

Since PIRADS 4-5 lesions have the highest likelihood of harboring clinically significant prostate cancer, nomograms predicting these lesions have the potential to be very helpful in the clinical setting when deciding which patients to proceed with mpMRI. Furthermore, because there are no established guidelines as to when to order a mpMRI for a patient on AS, these nomograms may have the ability to further clarify timing and appropriate utilization of imaging.



Presented By: Matthew Truong, University of Rochester, Rochester, NY, USA

Co-Authors: Thomas Frye, Dang Lam, Ji Hae Park, Bokai Wang, Changyong Feng, Gary Hollenberg, Eric Weinberg, Edward Messing

Written By: Zachary Klaassen, MD, Urologic Oncology Fellow, University of Toronto, Princess Margaret Cancer Centre
Twitter: @zklaassen_md

at the 2017 AUA Annual Meeting - May 12 - 16, 2017 – Boston, Massachusetts, USA