title: Diffusion-weighted magnetic resonance imaging detects significant prostate cancer with high probability.
abstract: OBJECTIVE
  We prospectively assessed the diagnostic accuracy of diffusion-weighted magnetic resonance imaging for detecting significant prostate cancer.
  
  
  METHODS
  We performed a prospective study of 111 consecutive men with prostate and/or bladder cancer who underwent 3 Tesla diffusion-weighted magnetic resonance imaging of the pelvis without an endorectal coil before radical prostatectomy (78) or cystoprostatectomy (33). Three independent readers blinded to clinical and pathological data assigned a prostate cancer suspicion grade based on qualitative imaging analysis. Final pathology results of prostates with and without cancer served as the reference standard. Primary outcomes were the sensitivity and specificity of diffusion-weighted magnetic resonance imaging for detecting significant prostate cancer with significance defined as a largest diameter of the index lesion of 1 cm or greater, extraprostatic extension, or Gleason score 7 or greater on final pathology assessment. Secondary outcomes were interreader agreement assessed by the Fleiss κ coefficient and image reading time.
  
  
  RESULTS
  Of the 111 patients 93 had prostate cancer, which was significant in 80 and insignificant in 13, and 18 had no prostate cancer on final pathology results. The sensitivity and specificity of diffusion-weighted magnetic resonance imaging for detecting significant PCa was 89% to 91% and 77% to 81%, respectively, for the 3 readers. Interreader agreement was good (Fleiss κ 0.65 to 0.74). Median reading time was between 13 and 18 minutes.
  
  
  CONCLUSIONS
  Diffusion-weighted magnetic resonance imaging (3 Tesla) is a noninvasive technique that allows for the detection of significant prostate cancer with high probability without contrast medium or an endorectal coil, and with good interreader agreement and a short reading time. This technique should be further evaluated as a tool to stratify patients with prostate cancer for individualized treatment options.
authors.affiliation: Department of Radiology, Neuroradiology and Nuclear Medicine, Institute of Diagnostic, Interventional and Pediatric Radiology, University of Bern, Bern, Switzerland.
authors.forename: Lauren J
authors.initials: LJ
authors.lastname: Bains
authors.affiliation: Department of Urology, University of Bern, Bern, Switzerland.
authors.forename: Urs E
authors.initials: UE
authors.lastname: Studer
authors.affiliation: Department of Radiology, Neuroradiology and Nuclear Medicine, Institute of Diagnostic, Interventional and Pediatric Radiology, University of Bern, Bern, Switzerland.
authors.forename: Johannes M
authors.initials: JM
authors.lastname: Froehlich
authors.affiliation: Department of Urology, University of Bern, Bern, Switzerland.
authors.forename: Gianluca
authors.initials: G
authors.lastname: Giannarini
authors.affiliation: Department of Radiology, Neuroradiology and Nuclear Medicine, Institute of Diagnostic, Interventional and Pediatric Radiology, University of Bern, Bern, Switzerland.
authors.forename: Maria
authors.initials: M
authors.lastname: Triantafyllou
authors.affiliation: Institute of Pathology, University of Bern, Bern, Switzerland.
authors.forename: Achim
authors.initials: A
authors.lastname: Fleischmann
authors.affiliation: Department of Radiology, Neuroradiology and Nuclear Medicine, Institute of Diagnostic, Interventional and Pediatric Radiology, University of Bern, Bern, Switzerland. Electronic address: harriet.thoeny@insel.ch.
authors.forename: Harriet C
authors.initials: HC
authors.lastname: Thoeny
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D038524:Diffusion Magnetic Resonance Imaging / Q000706:statistics & numerical data*; D006801:Humans; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D011446:Prospective Studies; D011471:Prostatic Neoplasms / Q000175:diagnosis*; D015203:Reproducibility of Results
keywords: diagnosis; differential; magnetic resonance imaging; observer variation; prostate; prostatic neoplasms