title: A prospective comparison of MRI-US fused targeted biopsy versus systematic ultrasound-guided biopsy for detecting clinically significant prostate cancer in patients on active surveillance.
abstract: BACKGROUND
  In active surveillance (AS) patients: (i) To compare the ability of a multiparametric MRI (mpMRI)-ultrasound biopsy system to detect clinically significant (CS) prostate cancer with systematic 12-core biopsy (R-TRUSBx), and (ii) To assess the predictive value of mpMRI with biopsy as the reference standard.
  
  
  METHODS
  Seventy-two men on AS prospectively underwent 3T mpMRI . MRI-ultrasound fusion biopsy (UroNavBx) and R-TRUSBx was performed. CS cancer was defined using two thresholds: 1) GS ≥ 7 (CS7) and 2) GS = 6 with >50% involvement (GS6). CS cancer detection rates and predictive values were determined.
  
  
  RESULTS
  CS7 cancers were found in 19/72 (26%), 7 (37%) identified by UroNavBx alone, 2 (11%) by R-TRUSBx alone (P = 0.182). UroNav targeted biopsy was 6.3× more likely to yield a core positive for CS7 cancer compared with R-TRUSBx (25% of 141 versus 4% of 874, P < 0.001). Upgrading of GS occurred in 15/72 patients (21%), 13 (87%) detected by UroNavBx and 10 (67%) by R-TRUSBx. The NPV of mpMRI for CS7 cancer was 100%. MRI suspicion level significantly predicted CS cancer on multivariate analysis (OR 3.6, P < 0.001).
  
  
  CONCLUSIONS
  UroNavBx detected CS cancer with far fewer cores compared with R-TRUSBx, and mpMRI had a perfect negative predictive value in this population.
authors.affiliation: Department of Medical Imaging, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, ON, Canada.
authors.forename: Michael R
authors.initials: MR
authors.lastname: Da Rosa
authors.forename: Laurent
authors.initials: L
authors.lastname: Milot
authors.forename: Linda
authors.initials: L
authors.lastname: Sugar
authors.forename: Danny
authors.initials: D
authors.lastname: Vesprini
authors.forename: Hans
authors.initials: H
authors.lastname: Chung
authors.forename: Andrew
authors.initials: A
authors.lastname: Loblaw
authors.forename: Gregory R
authors.initials: GR
authors.lastname: Pond
authors.forename: Laurence
authors.initials: L
authors.lastname: Klotz
authors.forename: Masoom A
authors.initials: MA
authors.lastname: Haider
mesh_terms: D000328:Adult; D000368:Aged; D006801:Humans; D061705:Image-Guided Biopsy / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging / Q000379:methods*; D011237:Predictive Value of Tests; D011446:Prospective Studies; D011467:Prostate / Q000000981:diagnostic imaging / Q000473:pathology; D011471:Prostatic Neoplasms / Q000175:diagnosis*; D015203:Reproducibility of Results; D018084:Ultrasonography, Interventional / Q000379:methods*
keywords: MRI-ultrasound fusion biopsy; active surveillance; multiparametric MRI; prostate