title: Quantitative Multiparametric MRI Features and PTEN Expression of Peripheral Zone Prostate Cancer: A Pilot Study.
abstract: OBJECTIVE
  The objective of our study was to investigate associations between quantitative image features of multiparametric MRI of the prostate and PTEN expression of peripheral zone prostate cancer.
  
  
  METHODS
  A total of 45 peripheral zone cancer foci from 30 patients who had undergone multiparametric prostate MRI before prostatectomy were identified by a genitourinary pathologist and a radiologist who reviewed histologic findings and MR images. Histologic sections of cancer foci underwent immunohistochemical analysis and were scored according to the percentage of tumor-positive cells expressing PTEN as negative (0-20%), mixed (20-80%), or positive (80-100%). Average and 10th percentile apparent diffusion coefficient (ADC) values, skewness of T2-weighted signal intensity histogram, and quantitative perfusion parameters (i.e., forward volume transfer constant [K(trans)], extravascular extracellular volume fraction [ve], and reverse reflux rate constant between the extracellular space and plasma [k(ep)]) from the Tofts model were calculated for each cancer focus. Associations between the quantitative image features and PTEN expression were analyzed with the Spearman rank correlation coefficient (r).
  
  
  RESULTS
  Analysis of the 45 cancer foci revealed that 21 (47%) were PTEN-positive, 12 (27%) were PTEN-negative, and 12 (27%) were mixed. There was a weak but significant negative correlation between Gleason score and PTEN expression (r = -0.30, p = 0.04) and between k(ep) and PTEN expression (r = -0.35, p = 0.02). There was no significant correlation between other multiparametric MRI features and PTEN expression.
  
  
  CONCLUSIONS
  This preliminary study of radiogenomics of peripheral zone prostate cancer revealed weak-but significant-associations between the quantitative dynamic contrast-enhanced MRI feature k(ep) and Gleason score with PTEN expression. These findings warrant further investigation and validation with the aim of using multiparametric MRI to improve risk assessment of patients with prostate cancer.
authors.affiliation: 1 Department of Radiology, University of Chicago, 5841 S Maryland Ave, MC 2026, Chicago, IL 60637.
authors.forename: Stephanie M
authors.initials: SM
authors.lastname: McCann
authors.affiliation: 1 Department of Radiology, University of Chicago, 5841 S Maryland Ave, MC 2026, Chicago, IL 60637.
authors.forename: Yulei
authors.initials: Y
authors.lastname: Jiang
authors.affiliation: 1 Department of Radiology, University of Chicago, 5841 S Maryland Ave, MC 2026, Chicago, IL 60637.
authors.forename: Xiaobing
authors.initials: X
authors.lastname: Fan
authors.affiliation: 1 Department of Radiology, University of Chicago, 5841 S Maryland Ave, MC 2026, Chicago, IL 60637.
authors.forename: Jianing
authors.initials: J
authors.lastname: Wang
authors.affiliation: 2 Department of Pathology, University of Chicago, Chicago, IL.
authors.forename: Tatjana
authors.initials: T
authors.lastname: Antic
authors.affiliation: 3 Washington University School of Medicine, Mallinckrodt Institute of Radiology, St. Louis, MO.
authors.forename: Fred
authors.initials: F
authors.lastname: Prior
authors.affiliation: 4 Department of Medicine, University of Chicago, Chicago, IL.
authors.forename: David
authors.initials: D
authors.lastname: VanderWeele
authors.affiliation: 1 Department of Radiology, University of Chicago, 5841 S Maryland Ave, MC 2026, Chicago, IL 60637.
authors.forename: Aytekin
authors.initials: A
authors.lastname: Oto
mesh_terms: D000368:Aged; D003287:Contrast Media; D038524:Diffusion Magnetic Resonance Imaging; D006801:Humans; D007150:Immunohistochemistry; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D051059:PTEN Phosphohydrolase / Q000096:biosynthesis / Q000235:genetics*; D010865:Pilot Projects; D011467:Prostate / Q000378:metabolism* / Q000473:pathology* / Q000601:surgery; D011468:Prostatectomy; D011471:Prostatic Neoplasms / Q000175:diagnosis* / Q000235:genetics* / Q000378:metabolism / Q000601:surgery; D012189:Retrospective Studies
chemical_list: D003287:Contrast Media; D051059:PTEN Phosphohydrolase; C494929:PTEN protein, human
keywords: Gleason score; dynamic contrast-enhanced MRI; phosphatase and tensin homolog (PTEN); prostate cancer