title: Role of PI-RADSv2 with multiparametric MRI in determining who needs active surveillance or definitive treatment according to PRIAS.
abstract: To evaluate the role of Prostate Imaging Reporting and Data System v. 2 (PI-RADSv2) in triaging patients with prostate cancer according to Prostate Cancer Research International: Active Surveillance (PRIAS).
  
  
  
  Between January 2012 and December 2014, 456 patients with biopsy-proven cancer underwent multiparametric 3T magnetic resonance imaging (MRI) using T2-weighted, diffusion-weighted, and dynamic contrast-enhanced MRI sequences, and then radical prostatectomy. Two radiologists independently reviewed MR images using PI-RADSv2. For AS, PRIAS required clinical stage <T3, prostate-specific antigen (PSA) ≤10 ng/mL, PSA density <0.2 ng/mL2, Gleason score (GS) ≤6, and the number of positive cores ≤2. For AS, PI-RADSv2 required an index lesion scored <4. Standard reference was prostatectomy, in which insignificant cancer was defined as a small (<0.5 cm3) organ-confined lesion with GS ≤6. Sensitivity and specificity for insignificant cancer were obtained with PRIAS, PI-RADSv2, and both.
  
  
  
  The sensitivity and specificity with PRIAS were 82.9% (68/82) and 70.9% (265/374), respectively. PI-RADSv2 decreased the sensitivity to 61% (50/82) to 80.5% (66/82), but increased the specificity to 77.8% (291/374) to 90.8% (340/374). The combination of PRIAS and PI-RDASv2 increased significantly the specificity to 89.6% (335/374) to 92.8% (347/374) (P < 0.001).
  
  
  
  PRIAS using multiparametric MRI can identify a greater number of insignificant cancers than PI-RADSv2. However, PI-RADSv2 helps detect many significant cancers that are misdiagnosed as insignificant cancer with PRIAS.
  
  
  
  3 Technical Efficacy: Stage 2 J. MAGN. RESON. IMAGING 2017;45:1753-1759.
authors: Department of Radiology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.|Kangwon National University School of Medicine, Chuncheon, Korea.
authors: Jung Jae
authors: JJ
authors: Park
authors: Department of Radiology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
authors: Byung Kwan
authors: BK
authors: Park
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000066491:Clinical Decision-Making / Q000379:methods*; D005060:Europe; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods* / Q000592:standards*; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging / Q000592:standards; D015588:Observer Variation; D011379:Prognosis; D011471:Prostatic Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology* / Q000601:surgery*; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D057832:Watchful Waiting
keywords: Gleason score; classification; multiparametric magnetic resonance imaging; prostate cancer; prostate specific antigen