title: Assessment of Prostate Cancer Aggressiveness by Use of the Combination of Quantitative DWI and Dynamic Contrast-Enhanced MRI.
abstract: OBJECTIVE
  The objective of this study was to investigate whether the apparent diffusion coefficient (ADC) value from DWI and the forward volume transfer constant (K(trans)) value from dynamic contrast-enhanced MRI independently predict prostate cancer aggressiveness, and to determine whether the combination of both parameters performs better than either parameter alone in assessing tumor aggressiveness before treatment.
  
  
  METHODS
  This retrospective study included 158 men with histopathologically confirmed prostate cancer who underwent 3-T MRI before undergoing prostatectomy in 2011. Whole-mount step-section pathologic maps identified 195 prostate cancer foci that were 0.5 mL or larger; these foci were then volumetrically assessed to calculate the per-tumor ADC and K(trans) values. Associations between MRI and histopathologic parameters were assessed using Spearman correlation coefficients, univariate and multivariable logistic regression, and AUCs.
  
  
  RESULTS
  The median ADC and K(trans) values showed moderate correlation only for tumors for which the Gleason score (GS) was 4 + 4 or higher (ρ = 0.547; p = 0.042). The tumor ADC value was statistically significantly associated with all dichotomized GSs (p < 0.005), including a GS of 3 + 3 versus a GS of 3 + 4 or higher (AUC, 0.693; p = 0.001). The tumor K(trans) value differed statistically significantly only between tumors with a GS of 3 + 3 and those with a primary Gleason grade of 4 (p ≤ 0.015), and it made a statistically significant contribution only in differentiating tumors with a GS of 4 + 3 or higher (AUC, 0.711; p < 0.001) and those with a GS of 4 + 4 or higher (AUC, 0.788; p < 0.001) from lower-grade tumors. Combining ADC and K(trans) values improved diagnostic performance in characterizing tumors with a GS of 4 + 3 or higher and those with a GS of 4 + 4 or higher (AUC, 0.739 and 0.856, respectively; p < 0.01).
  
  
  CONCLUSIONS
  Although the ADC value helped to differentiate between all GSs, the K(trans) value was only a benefit in characterizing more aggressive tumors. Combining these parameters improves their performance in identifying patients with aggressive tumors who may require radical treatment.
authors.affiliation: 1 Department of Radiology, Memorial Sloan-Kettering Cancer Center, 1275 York Ave, New York, NY 10065.|2 Department of Diagnostic and Interventional Radiology, Universitätsmedizin Mainz, Mainz, Germany.
authors.forename: Andreas M
authors.initials: AM
authors.lastname: Hötker
authors.affiliation: 3 Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, NY.
authors.forename: Yousef
authors.initials: Y
authors.lastname: Mazaheri
authors.affiliation: 1 Department of Radiology, Memorial Sloan-Kettering Cancer Center, 1275 York Ave, New York, NY 10065.
authors.forename: Ömer
authors.initials: Ö
authors.lastname: Aras
authors.affiliation: 4 Department of Epidemiology and Biostatistics, Memorial Sloan-Kettering Cancer Center, New York, NY.
authors.forename: Junting
authors.initials: J
authors.lastname: Zheng
authors.affiliation: 4 Department of Epidemiology and Biostatistics, Memorial Sloan-Kettering Cancer Center, New York, NY.
authors.forename: Chaya S
authors.initials: CS
authors.lastname: Moskowitz
authors.affiliation: 5 Urology Service, Department of Surgery, Memorial Sloan-Kettering Cancer Center, New York, NY.
authors.forename: Tatsuo
authors.initials: T
authors.lastname: Gondo
authors.affiliation: 6 Department of Pathology, Memorial Sloan-Kettering Cancer Center, New York, NY.
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Matsumoto
authors.affiliation: 1 Department of Radiology, Memorial Sloan-Kettering Cancer Center, 1275 York Ave, New York, NY 10065.
authors.forename: Hedvig
authors.initials: H
authors.lastname: Hricak
authors.affiliation: 1 Department of Radiology, Memorial Sloan-Kettering Cancer Center, 1275 York Ave, New York, NY 10065.
authors.forename: Oguz
authors.initials: O
authors.lastname: Akin
mesh_terms: D000328:Adult; D000368:Aged; D003287:Contrast Media; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D019786:Gadolinium DTPA; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D011471:Prostatic Neoplasms / Q000473:pathology*; D012189:Retrospective Studies
chemical_list: D003287:Contrast Media; D019786:Gadolinium DTPA
keywords: DWI; MRI; prostate cancer