title: Risk stratification of prostate cancer utilizing apparent diffusion coefficient value and lesion volume on multiparametric MRI.
abstract: To evaluate the performance of apparent diffusion coefficient (ADC) and lesion volume in potentially risk-stratifying patients with prostate cancer (PCa).
  
  
  
  Men with elevated prostate-specific antigen or abnormal digital rectal exam underwent a 3T multiparametric magnetic resonance imaging (mpMRI) with endorectal coil. ADC maps were calculated using b values of 0, 500, 1000, and 1500; additional images were obtained with b value of 2000. We prospectively enrolled 312 men with lesions suspicious for cancer (suspicion score 2-5) on mpMRI. MRI/ultrasound fusion-guided prostate biopsies were performed. Mean ADC of suspicious lesions were correlated against lesion volume, Gleason and D'Amico risk.
  
  
  
  The cancer detection rate of fusion biopsy per lesion was 45.6% (206/452). Cancerous lesions were larger (median volume: 0.40 vs. 0.30 cm3; P = 0.016). The median ADC (×10-6mm2/sec) for lesions negative and positive for PCa were 984.5 and 666.5, respectively (P < 0.0001). The AUC of ADC in predicting PCa was 0.79. Larger lesions were associated with higher risk PCa (Gleason and D'Amico) and lower ADC (all P < 0.0001).
  
  
  
  The mean ADC of suspicious lesions on mpMRI was inversely correlated, while lesion volume had a direct correlation with PCa detection. Future follow-up studies are needed to assess longitudinal cancer risks of suspicious mpMRI lesions.
  
  
  
  2 J. Magn. Reson. Imaging 2017;45:610-616.
authors.affiliation: Department of Urology, University of Michigan Medical School, Ann Arbor, Michigan, USA.
authors.forename: Simpa S
authors.identifier: 0000-0001-7461-7079
authors.initials: SS
authors.lastname: Salami
authors.affiliation: Department of Radiology, Hofstra North Shore-LIJ School of Medicine, New Hyde Park, New York, USA.
authors.forename: Eran
authors.initials: E
authors.lastname: Ben-Levi
authors.affiliation: Department of Pathology, Hofstra North Shore-LIJ School of Medicine, New Hyde Park, New York, USA.
authors.forename: Oksana
authors.initials: O
authors.lastname: Yaskiv
authors.affiliation: Molecular Imaging Program, National Institutes of Health, Bethesda, Maryland, USA.
authors.forename: Baris
authors.initials: B
authors.lastname: Turkbey
authors.affiliation: Department of Radiology, Hofstra North Shore-LIJ School of Medicine, New Hyde Park, New York, USA.
authors.forename: Robert
authors.initials: R
authors.lastname: Villani
authors.affiliation: Department of Urology, Icahn School of Medicine at Mount Sinai, New York, New York, USA.
authors.forename: Ardeshir R
authors.initials: AR
authors.lastname: Rastinehad
mesh_terms: D000368:Aged; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods* / Q000706:statistics & numerical data; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D015994:Incidence; D008297:Male; D008824:Michigan / Q000453:epidemiology; D008875:Middle Aged; D064847:Multimodal Imaging / Q000379:methods; D011379:Prognosis; D011471:Prostatic Neoplasms / Q000000981:diagnostic imaging / Q000453:epidemiology* / Q000473:pathology*; D015203:Reproducibility of Results; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D047368:Tumor Burden
keywords: active surveillance; fusion biopsy; prostate cancer screening