title: Periprostatic fat thickness on MRI: correlation with Gleason score in prostate cancer.
abstract: OBJECTIVE
  The purpose of this study was to retrospectively evaluate the relationship between periprostatic fat thickness on MRI and Gleason score of prostate cancer using radical prostatectomy as the reference standard.
  
  
  METHODS
  This study included 190 patients (mean age [± SD], 66.9 ± 7.0 years) who underwent MRI before radical prostatectomy. Two radiologists measured the subcutaneous and periprostatic fat thickness on midsagittal T2-weighted MR images as the shortest perpendicular distance from the pubic symphysis to the skin and prostate, respectively. Subcutaneous and periprostatic fat along with age, height, weight, body mass index, and prostate-specific antigen (PSA) were correlated with Gleason score by using Pearson (r) or Spearman (ρ) correlation coefficients and compared between low- (Gleason score = 6) and high- (≥ 7) grade prostate cancer by using univariate and multivariate logistic regression analyses.
  
  
  RESULTS
  The mean subcutaneous and periprostatic fat thicknesses were 24.0 ± 8.4 mm and 5.0 ± 2.0 mm, respectively. The Gleason score was significantly correlated with age (ρ = 0.181, p = 0.012), PSA (ρ = 0.345, p < 0.001), and periprostatic fat thickness (ρ = 0.228, p = 0.002). Multivariate analysis revealed that age, height, PSA level, and periprostatic fat thickness (odds ratio, 1.331; 95% CI, 1.063-1.666) were independently predictive of high-grade (p ≤ 0.013) disease.
  
  
  CONCLUSIONS
  Periprostatic fat thickness on MRI showed a mild to modest but significant correlation with Gleason score of prostate cancer with radical prostatectomy as the reference standard and was an independent predictive factor for high-grade prostate cancer.
authors.affiliation: 1 Department of Radiology, Seoul National University College of Medicine, 101 Daehak-ro, Jongno-gu, Seoul 110-744, Korea.
authors.forename: Sungmin
authors.initials: S
authors.lastname: Woo
authors.forename: Jeong Yeon
authors.initials: JY
authors.lastname: Cho
authors.forename: Sang Youn
authors.initials: SY
authors.lastname: Kim
authors.forename: Seung Hyup
authors.initials: SH
authors.lastname: Kim
mesh_terms: D000273:Adipose Tissue / Q000473:pathology*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D011467:Prostate / Q000473:pathology*; D011471:Prostatic Neoplasms / Q000473:pathology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013223:Statistics as Topic
keywords: Gleason score; MRI; periprostatic fat; prostate cancer; radical prostatectomy