title: Updated prostate imaging reporting and data system (PIRADS v2) recommendations for the detection of clinically significant prostate cancer using multiparametric MRI: critical evaluation using whole-mount pathology as standard of reference.
abstract: OBJECTIVE
  To evaluate the recommendations for multiparametric prostate MRI (mp-MRI) interpretation introduced in the recently updated Prostate Imaging Reporting and Data System version 2 (PI-RADSv2), and investigate the impact of pathologic tumour volume on prostate cancer (PCa) detectability on mpMRI.
  
  
  METHODS
  This was an institutional review board (IRB)-approved, retrospective study of 150 PCa patients who underwent mp-MRI before prostatectomy; 169 tumours ≥0.5-mL (any Gleason Score [GS]) and 37 tumours <0.5-mL (GS ≥4+3) identified on whole-mount pathology maps were located on mp-MRI consisting of T2-weighted imaging (T2WI), diffusion-weighted (DW)-MRI, and dynamic contrast-enhanced (DCE)-MRI. Corresponding PI-RADSv2 scores were assigned on each sequence and combined as recommended by PI-RADSv2. We calculated the proportion of PCa foci on whole-mount pathology correctly identified with PI-RADSv2 (dichotomized scores 1-3 vs. 4-5), stratified by pathologic tumour volume.
  
  
  RESULTS
  PI-RADSv2 allowed correct identification of 118/125 (94 %; 95 %CI: 90-99 %) peripheral zone (PZ) and 42/44 (95 %; 95 %CI: 89-100 %) transition zone (TZ) tumours ≥0.5 mL, but only 7/27 (26 %; 95 %CI: 10-42 %) PZ and 2/10 (20 %; 95 %CI: 0-52 %) TZ tumours with a GS ≥4+3, but <0.5 mL. DCE-MRI aided detection of 4/125 PZ tumours ≥0.5 mL and 0/27 PZ tumours <0.5 mL.
  
  
  CONCLUSIONS
  PI-RADSv2 correctly identified 94-95 % of PCa foci ≥0.5 mL, but was limited for the assessment of GS ≥4+3 tumours ≤0.5 mL. DCE-MRI offered limited added value to T2WI+DW-MRI.
  
  
  CONCLUSIONS
  • PI-RADSv2 correctly identified 95 % of PCa foci ≥0.5 mL • PI-RADSv2 was limited for the assessment of GS ≥4+3 tumours ≤0.5 mL • DCE-MRI offered limited added value to T2WI+DW-MRI.
authors.affiliation: Department of Radiology, Memorial Sloan Kettering Cancer Center, 1275 York Av, room C278, New York, NY, 10065, USA. vargasah@mskcc.org.
authors.forename: H A
authors.initials: HA
authors.lastname: Vargas
authors.affiliation: Department of Radiology, Memorial Sloan Kettering Cancer Center, 1275 York Av, room C278, New York, NY, 10065, USA.
authors.forename: A M
authors.initials: AM
authors.lastname: Hötker
authors.affiliation: Department of Epidemiology and Biostatistics, Memorial Sloan Kettering Cancer Center, 1275 York Av., New York, NY, 10065, USA.
authors.forename: D A
authors.initials: DA
authors.lastname: Goldman
authors.affiliation: Department of Epidemiology and Biostatistics, Memorial Sloan Kettering Cancer Center, 1275 York Av., New York, NY, 10065, USA.
authors.forename: C S
authors.initials: CS
authors.lastname: Moskowitz
authors.affiliation: Department of Surgery, Memorial Sloan Kettering Cancer Center, 1275 York Av., New York, NY, 10065, USA.
authors.forename: T
authors.initials: T
authors.lastname: Gondo
authors.affiliation: Department of Surgery, Memorial Sloan Kettering Cancer Center, 1275 York Av., New York, NY, 10065, USA.
authors.forename: K
authors.initials: K
authors.lastname: Matsumoto
authors.affiliation: Department of Surgery, Memorial Sloan Kettering Cancer Center, 1275 York Av., New York, NY, 10065, USA.
authors.forename: B
authors.initials: B
authors.lastname: Ehdaie
authors.affiliation: Department of Radiology, Memorial Sloan Kettering Cancer Center, 1275 York Av, room C278, New York, NY, 10065, USA.
authors.forename: S
authors.initials: S
authors.lastname: Woo
authors.affiliation: Department of Pathology, Memorial Sloan Kettering Cancer Center, 1275 York Av., New York, NY, 10065, USA.
authors.forename: S W
authors.initials: SW
authors.lastname: Fine
authors.affiliation: Department of Pathology, Memorial Sloan Kettering Cancer Center, 1275 York Av., New York, NY, 10065, USA.
authors.forename: V E
authors.initials: VE
authors.lastname: Reuter
authors.affiliation: Department of Radiology, Memorial Sloan Kettering Cancer Center, 1275 York Av, room C278, New York, NY, 10065, USA.
authors.forename: E
authors.initials: E
authors.lastname: Sala
authors.affiliation: Department of Radiology, Memorial Sloan Kettering Cancer Center, 1275 York Av, room C278, New York, NY, 10065, USA.
authors.forename: H
authors.initials: H
authors.lastname: Hricak
mesh_terms: D000368:Aged; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D017410:Practice Guidelines as Topic; D011467:Prostate / Q000000981:diagnostic imaging / Q000473:pathology; D011471:Prostatic Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology*; D011873:Radiology Information Systems; D012189:Retrospective Studies
keywords: DCE; Diffusion; MRI; PI-RADS; Prostate cancer