title: The performance of PI-RADSv2 and quantitative apparent diffusion coefficient for predicting confirmatory prostate biopsy findings in patients considered for active surveillance of prostate cancer.
abstract: To assess the performance of the updated Prostate Imaging Reporting and Data System (PI-RADSv2) and the apparent diffusion coefficient (ADC) for predicting confirmatory biopsy results in patients considered for active surveillance of prostate cancer (PCA).
  
  
  
  IRB-approved, retrospective study of 371 consecutive men with clinically low-risk PCA (initial biopsy Gleason score ≤6, prostate-specific antigen <10 ng/ml, clinical stage ≤T2a) who underwent 3T-prostate MRI before confirmatory biopsy. Two independent radiologists recorded the PI-RADSv2 scores and measured the corresponding ADC values in each patient. A composite score was generated to assess the performance of combining PI-RADSv2 + ADC.
  
  
  
  PCA was upgraded on confirmatory biopsy in 107/371 (29%) patients. Inter-reader agreement was substantial (PI-RADSv2: k = 0.73; 95% CI [0.66-0.80]; ADC: r = 0.74; 95% CI [0.69-0.79]). Accuracies, sensitivities, specificities, positive predicted value and negative predicted value of PI-RADSv2 were 85, 89, 83, 68, 95 and 78, 82, 76, 58, 91% for ADC. PI-RADSv2 accuracy was significantly higher than that of ADC for predicting biopsy upgrade (p = 0.014). The combined PI-RADSv2 + ADC composite score did not perform better than PI-RADSv2 alone. Obviating biopsy in patients with PI-RADSv2 score ≤3 would have missed Gleason Score upgrade in 12/232 (5%) of patients.
  
  
  
  PI-RADSv2 was superior to ADC measurements for predicting PCA upgrading on confirmatory biopsy.
authors.affiliation: INSERM, U1194, Institut de Recherche en Cancérologie de Montpellier (IRCM), Montpellier, France. stephanienougaret@free.fr.|Department of Radiology, Institut Régional du Cancer de Montpellier, Montpellier, France. stephanienougaret@free.fr.
authors.forename: Stephanie
authors.initials: S
authors.lastname: Nougaret
authors.affiliation: Department of Radiology, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, Room C278, New York, NY, 10065, USA.
authors.forename: Nicola
authors.initials: N
authors.lastname: Robertson
authors.affiliation: Department of Radiology, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, Room C278, New York, NY, 10065, USA.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Golia Pernicka
authors.affiliation: Department of Statistics, UMR 5149 IMAG, CHU Montpellier, Montpellier, France.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Molinari
authors.affiliation: Department of Radiology, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, Room C278, New York, NY, 10065, USA.
authors.forename: Andreas M
authors.initials: AM
authors.lastname: Hötker
authors.affiliation: Department of Urology, Memorial Sloan Kettering Cancer Center, New York, NY, USA.
authors.forename: Behfar
authors.initials: B
authors.lastname: Ehdaie
authors.affiliation: Department of Radiology, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, Room C278, New York, NY, 10065, USA.
authors.forename: Evis
authors.initials: E
authors.lastname: Sala
authors.affiliation: Department of Radiology, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, Room C278, New York, NY, 10065, USA.
authors.forename: Hedvig
authors.initials: H
authors.lastname: Hricak
authors.affiliation: Department of Radiology, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, Room C278, New York, NY, 10065, USA.
authors.forename: Hebert Alberto
authors.initials: HA
authors.lastname: Vargas
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001706:Biopsy; D003287:Contrast Media; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D006801:Humans; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D011237:Predictive Value of Tests; D011471:Prostatic Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D012189:Retrospective Studies; D012680:Sensitivity and Specificity
chemical_list: D003287:Contrast Media
keywords: Biopsy; Cancer; Confirmatory; PI-RADSv2; Prostate