MP43-01 A PROSTATE BIOPSY RISK CALCULATOR BASED ON MAGNETIC RESONANCE IMAGING: DEVELOPMENT, VALIDATION, AND COMPARISON TO THE PBCG RISK CALCULATOR

Abstract

You have accessJournal of UrologyProstate Cancer: Detection & Screening IV (MP43)1 Sep 2021MP43-01 A PROSTATE BIOPSY RISK CALCULATOR BASED ON MAGNETIC RESONANCE IMAGING: DEVELOPMENT, VALIDATION, AND COMPARISON TO THE PBCG RISK CALCULATOR Hiten D. Patel, Elizabeth L. Koehne, Steven M. Shea, Andrew Fang, Marielia Gerena, Alex Gorbonos, Marcus L. Quek, Robert C. Flanigan, Ari Goldberg, Soroush Rais-Bahrami, and Gopal N. Gupta Hiten D. PatelHiten D. Patel More articles by this author , Elizabeth L. KoehneElizabeth L. Koehne More articles by this author , Steven M. SheaSteven M. Shea More articles by this author , Andrew FangAndrew Fang More articles by this author , Marielia GerenaMarielia Gerena More articles by this author , Alex GorbonosAlex Gorbonos More articles by this author , Marcus L. QuekMarcus L. Quek More articles by this author , Robert C. FlaniganRobert C. Flanigan More articles by this author , Ari GoldbergAri Goldberg More articles by this author , Soroush Rais-BahramiSoroush Rais-Bahrami More articles by this author , and Gopal N. GuptaGopal N. Gupta More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000002064.01AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Implementation of multiparametric MRI (mpMRI) prior to prostate biopsy has improved detection of clinically significant prostate cancer (csPCa) through use of mpMRI–transrectal ultrasound fusion-guided biopsies, but imaging findings are not considered in traditional prediction tools. Therefore, we aimed to develop, validate, and compare a PCa risk calculator (RC) incorporating mpMRI findings to the Prostate Biopsy Collaborative Group (PBCG) RC. METHODS: Patients without a diagnosis of PCa receiving mpMRI prior to prostate biopsy in the Prospective Loyola University mpMRI (PLUM) Prostate Biopsy Cohort (2015-2020) were included for training and internal validation. Data from a separate institution served as external validation. Clinical variables included age, race, family history, digital rectal examination, prior negative biopsy, PSA, mpMRI prostate volume, and presence of any PI-RADS v2 mpMRI lesion. PSA density (PSAD) was based on mpMRI volume. A multinomial logistic regression model was constructed with outcomes of no cancer, clinically insignificant PCa (Gleason 3+3), and csPCa (Gleason ≥3+4). Receiver operating characteristics and calibration curves were evaluated. Decision curve analysis (DCA) was conducted. RESULTS: A total of 1,010 patients were separated into training (N=674) and validation (N=336) cohorts with a separate population for external validation (N=371). In the training cohort, 322 (47.8%) were diagnosed with PCa and 208 (30.9%) represented csPCa. The PLUM model included standard clinical variables with addition of log-transformed PSAD, mpMRI volume, and PI-RADS score. The multinomial PLUM RC outperformed the PBCG RC in the training (AUC: 0.859 vs. 0.660,p<0.001), internal validation (AUC: 0.882 vs. 0.678,p<0.001), and external validation (AUC: 0.839 vs. 0.694,p<0.001) samples for detection of csPCa. The PBCG RC was prone to overprediction while the PLUM RC was well calibrated. At a cost level of missing 7.5% of csPCa, the PLUM RC could have avoided 41.0% (566/1381) of biopsies compared to 19.1% (264/1381) for PBCG. On DCA at a threshold probability of 15%, PLUM was equivalent to a strategy of avoiding 13.8 biopsies per 100 without missing any csPCa compared to 2.7 biopsies per 100 for PBCG. CONCLUSIONS: Addition of mpMRI findings to standard clinical variables significantly improved the ability of the PLUM RC to detect PCa and csPCa compared to the PBCG RC. A large proportion of biopsies could be avoided using the PLUM RC in shared decision-making to inform the decision for prostate biopsy. Source of Funding: Efforts to support data extraction and maintenance of The Prospective Loyola University mpMRI Prostate Biopsy Cohort database is supported by funding from Siemens Medical Solutions USA, Inc. This work was funded in part by Junior Faculty Development Grant (ACS-IRG 001-53) and by Developmental funds from the UAB Comprehensive Cancer Center Support Grant (NCI P30 CA 013148) granted to Soroush Rais-Bahrami © 2021 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 206Issue Supplement 3September 2021Page: e781-e781 Advertisement Copyright & Permissions© 2021 by American Urological Association Education and Research, Inc.MetricsAuthor Information Hiten D. Patel More articles by this author Elizabeth L. Koehne More articles by this author Steven M. Shea More articles by this author Andrew Fang More articles by this author Marielia Gerena More articles by this author Alex Gorbonos More articles by this author Marcus L. Quek More articles by this author Robert C. Flanigan More articles by this author Ari Goldberg More articles by this author Soroush Rais-Bahrami More articles by this author Gopal N. Gupta More articles by this author Expand All Advertisement Loading ...