title: Diagnosis of relevant prostate cancer using supplementary cores from magnetic resonance imaging-prompted areas following multiple failed biopsies.
abstract: OBJECTIVE
  To establish the value of MRI in targeting re-biopsy for undiagnosed prostate cancer despite multiple negative biopsies and determine clinical relevance of detected tumors.
  
  
  METHODS
  Thirty-eight patients who underwent MRI after 2 or more negative biopsies due to continued clinical suspicion and later underwent TRUS-guided biopsy supplemented by biopsy of suspicious areas depicted by MRI were identified. Diagnostic performance of endorectal 3T MRI in diagnosing missed cancer foci was assessed using biopsy results as the standard of reference. Ratio of positive biopsies using systematic versus MRI-prompted approaches was compared. Gleason scores of detected cancers were used as surrogate for clinical relevance.
  
  
  RESULTS
  Thirty-four percent of patients who underwent MRI before re-biopsy had prostate cancer on subsequent biopsy. The positive biopsy yield with systematic sampling was 23% versus 92% with MRI-prompted biopsies(p<0.0001). Seventy-seven percent of tumors were detected exclusively in the MRI-prompted zones. Sensitivity, specificity, positive predictive value, negative predictive value and accuracy of MRI to provide a positive biopsy were 92%, 60%, 55%, 94% and 71%, respectively. The anterior gland and apical regions contained most tumors; 75% of cancers detected by MRI-prompted biopsy had Gleason score≥7.
  
  
  CONCLUSIONS
  Clinically relevant tumors missed by multiple TRUS-guided biopsies can be detected by a MRI-prompted approach.
authors.affiliation: Department of Radiology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, USA. daniel.costa@utsouthwestern.edu
authors.forename: Daniel N
authors.initials: DN
authors.lastname: Costa
authors.forename: B Nicolas
authors.initials: BN
authors.lastname: Bloch
authors.forename: David F
authors.initials: DF
authors.lastname: Yao
authors.forename: Martin G
authors.initials: MG
authors.lastname: Sanda
authors.forename: Long
authors.initials: L
authors.lastname: Ngo
authors.forename: Elizabeth M
authors.initials: EM
authors.lastname: Genega
authors.forename: Ivan
authors.initials: I
authors.lastname: Pedrosa
authors.forename: William C
authors.initials: WC
authors.lastname: DeWolf
authors.forename: Neil M
authors.initials: NM
authors.lastname: Rofsky
mesh_terms: D000368:Aged; D001707:Biopsy, Needle / Q000706:statistics & numerical data*; D001900:Boston / Q000453:epidemiology; D005188:False Negative Reactions; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods / Q000706:statistics & numerical data*; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D011471:Prostatic Neoplasms / Q000453:epidemiology* / Q000473:pathology*; D015203:Reproducibility of Results; D018570:Risk Assessment; D012680:Sensitivity and Specificity