title: Relationship between Gleason score and apparent diffusion coefficients of diffusion-weighted magnetic resonance imaging in prostate cancer patients.
abstract: BACKGROUND
  We assessed the correlation between the apparent diffusion coefficient (ADC) and pathological Gleason score (GS) of prostate cancer patients.
  
  
  METHODS
  A total of 125 patients who underwent multiparametric magnetic resonance imaging before radical prostatectomy for prostate cancer were included in this study. ADC values were compared with different GS. We used receiver operating characteristic analysis and determined the ADC cutoff value to differentiate tumours with a GS of 6 from those with a GS ≥7.
  
  
  RESULTS
  We identified 34 patients (27.2%) with a GS of 6; 33 patients (26.4%) with a GS of 7; 22 patients (17.6%) with a GS of 8; and 36 patients (28.8%) with a GS of ≥9. The mean ADC value for disease with a GS of 6 was 0.914 ± 0.161 ×10-3mm2/s; GS of 7: 0.741 ± 0.164 ×10-3mm2/s; GS of 8: 0.679 ± 0.130 ×10-3mm2/s; and GS of ≥9: 0.593 ± 0.089 ×10-3mm2/s. An ADC value of 0.830 ×10-3mm2/s was the best cutoff value to identify prostate cancer with a GS of 6.
  
  
  CONCLUSIONS
  We observed an inverse relationship between GS and ADC value. Moreover, a cutoff ADC value may help differentiate disease with a GS of 6 from disease with a GS ≥7.
authors.affiliation: Department of Urology, Samsung Changwon Hospital, Sungkyunkwan University School of Medicine, Changwon, Korea.
authors.forename: Tae Heon
authors.initials: TH
authors.lastname: Kim
authors.affiliation: Department of Radiology, Samsung Medical Centre, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Chan Kyo
authors.initials: CK
authors.lastname: Kim
authors.affiliation: Department of Radiology, Samsung Medical Centre, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Byung Kwan
authors.initials: BK
authors.lastname: Park
authors.affiliation: Department of Urology, Samsung Medical Centre, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Hwang Gyun
authors.initials: HG
authors.lastname: Jeon
authors.affiliation: Department of Urology, Samsung Medical Centre, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Byung Chang
authors.initials: BC
authors.lastname: Jeong
authors.affiliation: Department of Urology, Samsung Medical Centre, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Seong Il
authors.initials: SI
authors.lastname: Seo
authors.affiliation: Department of Urology, Samsung Medical Centre, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Hyun Moo
authors.initials: HM
authors.lastname: Lee
authors.affiliation: Department of Urology, Samsung Medical Centre, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Han Yong
authors.initials: HY
authors.lastname: Choi
authors.affiliation: Department of Urology, Samsung Medical Centre, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Seong Soo
authors.initials: SS
authors.lastname: Jeon