title: Usefulness of pre-biopsy multiparametric magnetic resonance imaging and clinical variables to reduce initial prostate biopsy in men with suspected clinically localized prostate cancer.
abstract: OBJECTIVE
  We evaluated the usefulness of pre-biopsy multiparametric magnetic resonance imaging and clinical variables to decrease initial prostate biopsies.
  
  
  METHODS
  We prospectively evaluated 351 consecutive men with prostate specific antigen between 2.5 and 20 ng/ml, and/or digital rectal examination suspicious for clinically localized disease. All men underwent pre-biopsy multiparametric magnetic resonance imaging and initial 14 to 29-core biopsy, including anterior sampling. Three definitions of significant cancer were defined based on Gleason score and cancer volume (percent positive core and/or maximum cancer length). The overall cohort was divided into men at low risk-prostate specific antigen less than 10 ng/ml and normal digital rectal examination, and high risk-prostate specific antigen 10 ng/ml or greater and/or abnormal digital rectal examination. We evaluated the frequency of significant cancer according to magnetic resonance imaging and risk categories. Clinical variables as significant cancer predictors were analyzed using logistic regression. The sensitivity, specificity, and positive and negative predictive values of magnetic resonance imaging were calculated with or without clinical variables for significant cancer.
  
  
  RESULTS
  The frequency of significant cancer in men with negative vs positive magnetic resonance imaging was 9% to 13% vs 43% to 50% in the low risk group and 47% to 51% vs 68% to 71% in the high risk group. In men at low risk with negative magnetic resonance imaging prostate volume was the only significant predictor of significant cancer. In the low risk group the negative predictive value for significant cancer of a combination of positive magnetic resonance imaging and lower prostate volume (less than 33 ml) was 93.7% to 97.5%.
  
  
  CONCLUSIONS
  Pre-biopsy multiparametric magnetic resonance imaging along with prostate volume decreases the number of initial prostate biopsies by discriminating between significant cancer and other cancer in men with prostate specific antigen less than 10 ng/ml and normal digital rectal examination.
authors.affiliation: Department of Urology, Tokyo Medical and Dental University Graduate School, Tokyo, Japan. noboru.uro@tmd.ac.jp
authors.forename: Noboru
authors.initials: N
authors.lastname: Numao
authors.forename: Soichiro
authors.initials: S
authors.lastname: Yoshida
authors.forename: Yoshinobu
authors.initials: Y
authors.lastname: Komai
authors.forename: Chikako
authors.initials: C
authors.lastname: Ishii
authors.forename: Makoto
authors.initials: M
authors.lastname: Kagawa
authors.forename: Toshiki
authors.initials: T
authors.lastname: Kijima
authors.forename: Minato
authors.initials: M
authors.lastname: Yokoyama
authors.forename: Junichiro
authors.initials: J
authors.lastname: Ishioka
authors.forename: Yoh
authors.initials: Y
authors.lastname: Matsuoka
authors.forename: Fumitaka
authors.initials: F
authors.lastname: Koga
authors.forename: Kazutaka
authors.initials: K
authors.lastname: Saito
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Masuda
authors.forename: Yasuhisa
authors.initials: Y
authors.lastname: Fujii
authors.forename: Satoru
authors.initials: S
authors.lastname: Kawakami
authors.forename: Kazunori
authors.initials: K
authors.lastname: Kihara
mesh_terms: D000368:Aged; D001706:Biopsy / Q000706:statistics & numerical data*; D016009:Chi-Square Distribution; D006801:Humans; D016015:Logistic Models; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011471:Prostatic Neoplasms / Q000175:diagnosis* / Q000473:pathology; D018570:Risk Assessment; D018709:Statistics, Nonparametric
keywords: DRE; GS; Gleason score; MRI; NPV; PPV; PSA; biopsy; diagnosis; digital rectal examination; fPSA; free-to-total PSA; magnetic resonance imaging; negative predictive value; positive predictive value; prostate; prostate specific antigen; prostatic neoplasms