title: Dynamic contrast enhanced magnetic resonance imaging as a biological marker to noninvasively assess the effect of finasteride on prostatic suburethral microcirculation.
abstract: OBJECTIVE
  We assessed dynamic contrast enhanced magnetic resonance imaging as a biological marker of in vivo changes in microcirculation in the prostatic suburethral region.
  
  
  METHODS
  A total of 12 male beagle dogs with spontaneous benign prostatic hyperplasia were randomly allocated to 1 control group and 1 finasteride (Merck and Co., Whitehouse Station, New Jersey) treated group. Two baseline dynamic contrast enhanced magnetic resonance imaging examinations and 3 followups were performed to assess prostate microcirculation. Treatment duration was 3 months. The pharmacokinetic parameters evaluated in prostatic suburethral areas were the maximum enhancement ratio in AU, time to maximum signal enhancement in minutes, amplitude in AU and the exchange rate constant in minutes(-1).
  
  
  RESULTS
  After completion of the therapeutic regimen time to maximum signal enhancement was significantly longer in the finasteride group than in controls (p < 0.01). Amplitude and the exchange rate constant decreased 39% and 34%, respectively, in the finasteride group at the end of treatment, which significantly differed from results in the control group (p < 0.05).
  
  
  CONCLUSIONS
  Dynamic contrast enhanced magnetic resonance imaging is capable of noninvasively assessing the prostatic microcirculation changes induced by finasteride. Pharmacokinetic parameters show considerable promise to be biomarkers for the development of benign prostatic hyperplasia drugs such as 5alpha-reductase inhibitors by the in vivo monitoring of microvascular changes. A relevant clinical application could be the pretreatment assessment of finasteride effectiveness to decrease perioperative bleeding at transurethral prostate resection and in treatment for hematuria.
authors.affiliation: Department of Radiology, Ohio State University, Columbus, Ohio, USA.
authors.forename: Guang
authors.initials: G
authors.lastname: Jia
authors.forename: Johannes T
authors.initials: JT
authors.lastname: Heverhagen
authors.forename: Hans
authors.initials: H
authors.lastname: Polzer
authors.forename: Richard V
authors.initials: RV
authors.lastname: Jacko
authors.forename: Jiachao
authors.initials: J
authors.lastname: Liang
authors.forename: Jun
authors.initials: J
authors.lastname: Zhang
authors.forename: Andrea L
authors.initials: AL
authors.lastname: Levine
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Rosol
authors.forename: Michael V
authors.initials: MV
authors.lastname: Knopp
mesh_terms: D000818:Animals; D003287:Contrast Media; D004285:Dogs; D018120:Finasteride / Q000494:pharmacology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008833:Microcirculation / Q000187:drug effects; D011467:Prostate / Q000098:blood supply* / Q000187:drug effects*; D014521:Urethra
chemical_list: D003287:Contrast Media; D018120:Finasteride