title: MRI-guided biopsy of the prostate: correlation between the cancer detection rate and the number of previous negative TRUS biopsies.
abstract: OBJECTIVE
  We aimed to investigate prostate cancer detection rate of magnetic resonance imaging (MRI)-guided biopsy and to elucidate possible relations to the number of prior negative transrectal ultrasonography (TRUS)-guided biopsies.
  
  
  METHODS
  Eighty-seven consecutive patients (mean age, 65.0 years; mean prostate-specific antigen, 13.3 ng/mL) with at least one prior negative TRUS-guided biopsy and persistent suspicion of prostate cancer were included in this study. All patients underwent MRI-guided biopsy after a diagnostic multiparametric MRI examination at 1.5 Tesla. Specimens were immediately fixated and subsequently evaluated by an experienced uropathologist. Prostate cancer detection rates were calculated. Prostate cancer-positive and -negative cores were compared. Correlation between number of prior biopsies and presence of prostate cancer was evaluated.
  
  
  RESULTS
  Cancer detection rates for patients with one (n=24), two (n=25), three (n=18), and four or more (n=20) negative TRUS-guided biopsies were 29.2%, 40.0%, 66.7%, and 35.0%, respectively (P = 0.087). The median number of removed cores per patient was 3 (range, 1-8) without a significant difference between patients with and without cancer (P = 0.48).  Thirty of 36 cancer patients were at intermediate or high risk according to the D´Amico clinical risk score. Eleven of 15 high risk cancers were localized in the transition zone (P = 0.002).
  
  
  CONCLUSIONS
  This study demonstrates high cancer detection rates of MRI-guided biopsy independent of the number of previous TRUS-guided biopsies and the number of taken prostate cores. MRI-guided biopsy therefore represents a less invasive and effective diagnostic tool for patients with prostate cancer suspicion and previous negative TRUS-guided biopsies.
authors.affiliation: Institute of Radiology, Charite Universitaetsmedizin, Berlin, Germany. tahir.durmus@charite.de
authors.forename: Tahir
authors.initials: T
authors.lastname: Durmuş
authors.forename: Uta
authors.initials: U
authors.lastname: Reichelt
authors.forename: Alexander
authors.initials: A
authors.lastname: Huppertz
authors.forename: Bernd
authors.initials: B
authors.lastname: Hamm
authors.forename: Dirk
authors.initials: D
authors.lastname: Beyersdorff
authors.forename: Tobias
authors.initials: T
authors.lastname: Franiel
mesh_terms: D000368:Aged; D001706:Biopsy; D003937:Diagnosis, Differential; D006801:Humans; D061705:Image-Guided Biopsy / Q000379:methods; D053783:Magnetic Resonance Imaging, Interventional / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011467:Prostate / Q000000981:diagnostic imaging / Q000473:pathology*; D011471:Prostatic Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology*; D012007:Rectum / Q000000981:diagnostic imaging / Q000473:pathology; D015203:Reproducibility of Results; D018084:Ultrasonography, Interventional