title: Prostate Imaging Reporting and Data System, Version 2, Assessment Categories and Pathologic Outcomes in Patients With Gleason Score 3 + 4 = 7 Prostate Cancer Diagnosed at Biopsy.
abstract: OBJECTIVE
  The purpose of this study is to assess associations between Prostate Imaging Reporting and Data System, version 2 (PI-RADSv2), categories and the presence of a tumor with a Gleason score (GS) of 4 + 3 = 7 or greater or the presence of extraprostatic extension (EPE) at radical prostatectomy (RP) in patients with a GS 3 + 4 = 7 tumor at biopsy.
  
  
  METHODS
  A total of 81 men with GS 3 + 4 = 7 prostate cancer diagnosed by transrectal ultrasound-guided biopsy underwent multiparametric MRI and RP between 2012 and 2015. Two blinded radiologists assessed multiparametric MR images and assigned PI-RADSv2 assessment categories (categories 1-5) with the use of sector maps, which were compared with regard to the location of the tumor, the GS, and the presence of EPE at RP. Comparisons were performed between groups with the use of chi-square and multivariate analysis. Diagnostic accuracy was assessed using ROC curve analysis, and localization was compared using the Fisher exact test.
  
  
  RESULTS
  A total of 53.1% of men (43/81) had EPE, and 21.0% (17/81) had GS 4 + 3 = 7 prostate cancer after RP, whereas 2.5% of men (2/81) had their tumors downgraded to GS 3 + 3 = 6. No statistically significant difference in patient age, prostate specific antigen level, or clinical stage existed between groups (p > 0.05). PI-RADSv2 assessment categories were significantly higher for GS 4 + 3 = 7 tumors (p = 0.03). PI-RADSv2 showed moderate accuracy for the diagnosis of GS 4 + 3 = 7 tumors (AUC, 0.65; 95% CI, 0.54-0.77), with a category of 4 or higher having a sensitivity and specificity for diagnosis of 94.1% and 23.4%, respectively. No patient with a PI-RADSv2 category lower than 3 had a GS 4 + 3 = 7 tumor. Accuracy of tumor localization ranged from 86.4% to 92.6%, with 88.2% of errors (15/17) occurring in GS 3 + 3 = 6 or GS 3 + 4 = 7 tumors (p = 0.30). PI-RADSv2 categories were noted to be higher when EPE was present (p < 0.001). Interobserver agreement was moderate (κ = 0.43).
  
  
  CONCLUSIONS
  For GS 3 + 4 = 7 cancers detected at transrectal ultrasound-guided biopsy, higher PI-RADSv2 assessment categories are associated with upgrading to GS 4 + 3 = 7 cancer and with the presence of EPE after RP. A PI-RADSv2 score of 3 or higher was 100% sensitive for diagnosing GS 4 + 3 = 7 tumors.
authors.affiliation: 1 Department of Medical Imaging, The Ottawa Hospital, The University of Ottawa, 1053 Carling Ave, Ottawa, ON K1Y 4E9, Canada.
authors.forename: Christopher S
authors.initials: CS
authors.lastname: Lim
authors.affiliation: 1 Department of Medical Imaging, The Ottawa Hospital, The University of Ottawa, 1053 Carling Ave, Ottawa, ON K1Y 4E9, Canada.
authors.forename: Matthew D F
authors.initials: MDF
authors.lastname: McInnes
authors.affiliation: 2 Department of Anatomical Pathology, The Ottawa Hospital, The University of Ottawa, Ottawa, ON, Canada.
authors.forename: Trevor A
authors.initials: TA
authors.lastname: Flood
authors.affiliation: 3 Department of Urology, The Ottawa Hospital, The University of Ottawa, Ottawa, ON, Canada.
authors.forename: Rodney H
authors.initials: RH
authors.lastname: Breau
authors.affiliation: 3 Department of Urology, The Ottawa Hospital, The University of Ottawa, Ottawa, ON, Canada.
authors.forename: Christopher
authors.initials: C
authors.lastname: Morash
authors.affiliation: 1 Department of Medical Imaging, The Ottawa Hospital, The University of Ottawa, 1053 Carling Ave, Ottawa, ON K1Y 4E9, Canada.
authors.forename: Rebecca E
authors.initials: RE
authors.lastname: Thornhill
authors.affiliation: 1 Department of Medical Imaging, The Ottawa Hospital, The University of Ottawa, 1053 Carling Ave, Ottawa, ON K1Y 4E9, Canada.
authors.forename: Nicola
authors.initials: N
authors.lastname: Schieda
mesh_terms: D000368:Aged; D001707:Biopsy, Needle; D003287:Contrast Media; D006801:Humans; D061705:Image-Guided Biopsy; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D011159:Population Surveillance; D011468:Prostatectomy; D011471:Prostatic Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology* / Q000601:surgery; D012189:Retrospective Studies; D018084:Ultrasonography, Interventional
chemical_list: D003287:Contrast Media
keywords: Gleason score; active surveillance; multiparametric MRI; prostate cancer; stage