title: Comparison of prostate MRI-3D transrectal ultrasound fusion biopsy for first-time and repeat biopsy patients with previous atypical small acinar proliferation.
abstract: BACKGROUND
  This study evaluates the clinical benefit of magnetic resonance-transrectal ultrasound (MR-TRUS) fusion biopsy over systematic biopsy between first-time and repeat prostate biopsy patients with prior atypical small acinar proliferation (ASAP).
  
  
  METHODS
  100 patients were enrolled in a single-centre prospective cohort study: 50 for first biopsy, 50 for repeat biopsy with prior ASAP. Multiparameteric magnetic resonance imaging (MP-MRI) and standard 12-core ultrasound biopsy (Std-Bx) were performed on all patients. Targeted biopsy using MRI-TRUS fusion (Fn-Bx) was performed f suspicious lesions were identified on the pre-biopsy MP-MRI. Classification of clinically significant disease was assessed independently for the Std-Bx vs. Fn-Bx cores to compare the two approaches.
  
  
  RESULTS
  Adenocarcinoma was detected in 49/100 patients (26 first biopsy, 23 ASAP biopsy), with 25 having significant disease (17 first, 8 ASAP). Fn-Bx demonstrated significantly higher per-core cancer detection rates, cancer involvement, and Gleason scores for first-time and ASAP patients. However, Fn-Bx was significantly more likely to detect significant cancer missed on Std-Bx for ASAP patients than first-time biopsy patients. The addition of Fn-Bx to Std-Bx for ASAP patients had a 166.7% relative risk reduction for missing Gleason ≥ 3 + 4 disease (number needed to image with MP-MRI=10 patients) compared to 6.3% for first biopsy (number to image=50 patients). Negative predictive value of MP-MRI for negative biopsy was 79% for first-time and 100% for ASAP patients, with median followup of 32.1 ± 15.5 months.
  
  
  CONCLUSIONS
  MR-TRUS Fn-Bx has a greater clinical impact for repeat biopsy patients with prior ASAP than biopsy-naïve patients by detecting more significant cancers that are missed on Std-Bx.
authors: Department of Medical Imaging.
authors: Derek W
authors: DW
authors: Cool
authors: Department of Medical Imaging.
authors: Cesare
authors: C
authors: Romagnoli
authors: Department of Surgery, Division of Urology.
authors: Jonathan I
authors: JI
authors: Izawa
authors: Department of Surgery, Division of Urology.
authors: Joseph
authors: J
authors: Chin
authors: Robarts Research Institute.
authors: Lori
authors: L
authors: Gardi
authors: Robarts Research Institute.
authors: David
authors: D
authors: Tessier
authors: Department of Medical Imaging.
authors: Ashley
authors: A
authors: Mercado
authors: Department of Medical Imaging.
authors: Jonathan
authors: J
authors: Mandel
authors: Department of Biophysics; University of Western Ontario, London, ON, Canada.
authors: Aaron D
authors: AD
authors: Ward
authors: Robarts Research Institute.
authors: Aaron
authors: A
authors: Fenster