title: Do apparent diffusion coefficient (ADC) values obtained using high b-values with a 3-T MRI correlate better than a transrectal ultrasound (TRUS)-guided biopsy with true Gleason scores obtained from radical prostatectomy specimens for patients with prostate cancer?
abstract: OBJECTIVE
  To investigate the usefulness of apparent diffusion coefficient (ADC) values in predicting true Gleason scores from radical prostatectomy specimen (tGS), compared with systematic transrectal ultrasound (TRUS)-guided biopsy GS (bGS).
  
  
  METHODS
  One hundred and five patients with biopsy-proven prostate cancer underwent preoperative DWI (b-values of 0, 1000, and 2000s/mm(2)) of 3-T MRI. The mean and minimum ADCs of visible tumors were calculated for either of a pair of b-values: 0 and 1000s/mm(2) (ADC1000), or 0 and 2000s/mm(2) (ADC2000), and relationships between the four ADC parameters and tGS evaluated for the peripheral zone (PZ) and transition zone (TZ). For multiple tumors, the dominant tumor's GS and ADCs were estimated for cancer aggressiveness assessment by computing ROC curves.
  
  
  RESULTS
  Significant negative correlations were observed between tGS and mean ADC1000, mean ADC2000, minimum ADC1000, and minimum ADC2000 (r=-0.41, -0.39, -0.39, and -0.37, respectively) of 100 visible PZ tumors and 66 visible TZ tumors (r=-0.40, -0.42, -0.29, and -0.21, respectively). For distinguishing high-grade from low/intermediate-grade PZ lesions, the areas under the curve (AUCs) of mean ADC1000 (0.751), mean ADC2000 (0.710), minimum ADC1000 (0.768), and minimum ADC2000 (0.752) were similar to that of the highest bGS (0.708) (p=0.61, p=0.98, p=0.47, and p=0.60, respectively). For distinguishing high-grade from low/intermediate-grade TZ lesions, AUCs of mean ADC1000 (0.779), and mean ADC2000 (0.811) were similar to that of the highest bGS (0.805) (p=0.83 and p=0.97).
  
  
  CONCLUSIONS
  Tumor ADCs obtained with high b-values could predict prostate cancer aggressiveness as effectively as systematic TRUS-guided biopsy.
authors.affiliation: Department of Radiology, Kobe University Graduate School of Medicine, Kobe, Japan. kitajima@med.kobe-u.ac.jp
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Kitajima
authors.forename: Satoru
authors.initials: S
authors.lastname: Takahashi
authors.forename: Yoshiko
authors.initials: Y
authors.lastname: Ueno
authors.forename: Hideaki
authors.initials: H
authors.lastname: Miyake
authors.forename: Masato
authors.initials: M
authors.lastname: Fujisawa
authors.forename: Fumi
authors.initials: F
authors.lastname: Kawakami
authors.forename: Kazuro
authors.initials: K
authors.lastname: Sugimura
mesh_terms: D000368:Aged; D038524:Diffusion Magnetic Resonance Imaging / Q000706:statistics & numerical data*; D061765:Endoscopic Ultrasound-Guided Fine Needle Aspiration / Q000706:statistics & numerical data*; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007564:Japan / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D011468:Prostatectomy / Q000706:statistics & numerical data; D011471:Prostatic Neoplasms / Q000453:epidemiology* / Q000473:pathology* / Q000601:surgery; D015203:Reproducibility of Results; D012307:Risk Factors; D012680:Sensitivity and Specificity