title: Late tissue effects following radiotherapy and neoadjuvant hormone therapy of the prostate measured with quantitative magnetic resonance imaging.
abstract: OBJECTIVE
  To use quantitative MRI to detect changes in the vascular and MR relaxation characteristics of the prostate gland 1 year after external beam radiotherapy.
  
  
  METHODS
  Twenty-one patients underwent MRI before and after external beam radiotherapy for prostatic adenocarcinoma. Tracer kinetics analysis was applied to data from regions of interest in prostate tumour, normal prostate peripheral zone and muscle to obtain estimates of blood flow, extravascular-extracellular volume, blood volume and capillary permeability surface area product. T(1) and T(2) were also measured in these regions.
  
  
  RESULTS
  Significant changes (p<0.05) after radiotherapy were found in all three tissues examined. Tumour blood flow was 0.34 and 0.14 ml (ml tissue)(-1) min(-1) before and after treatment, respectively, and T(1) increased from 922 to 1,070 ms. In normal peripheral zone, extravascular-extracellular volume increased from 0.21 to 0.52 ml (ml tissue)(-1), and T(2) decreased from 126 to 106 ms. In muscle, both permeability surface area product and T(2) rose, from 0.02 to 0.06 ml (ml tissue)(-1) min(-1) and from 50 to 56 ms, respectively.
  
  
  CONCLUSIONS
  Quantitative MRI can be used to measure significant changes in both vascular and MR relaxation properties of the prostate and nearby muscle following treatment for prostate cancer using external beam radiotherapy.
authors.affiliation: Imaging Science and Biomedical Engineering, University of Manchester, UK.
authors.forename: Lucy E
authors.initials: LE
authors.lastname: Kershaw
authors.forename: John P
authors.initials: JP
authors.lastname: Logue
authors.forename: Charles E
authors.initials: CE
authors.lastname: Hutchinson
authors.forename: Noel W
authors.initials: NW
authors.lastname: Clarke
authors.forename: David L
authors.initials: DL
authors.lastname: Buckley
mesh_terms: D000230:Adenocarcinoma / Q000188:drug therapy* / Q000532:radiotherapy*; D000368:Aged; D018931:Antineoplastic Agents, Hormonal / Q000008:administration & dosage*; D017024:Chemotherapy, Adjuvant; D003131:Combined Modality Therapy; D003287:Contrast Media; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008833:Microcirculation; D008875:Middle Aged; D011446:Prospective Studies; D011467:Prostate / Q000098:blood supply* / Q000187:drug effects / Q000528:radiation effects; D011471:Prostatic Neoplasms / Q000188:drug therapy* / Q000532:radiotherapy*; D016896:Treatment Outcome
chemical_list: D018931:Antineoplastic Agents, Hormonal; D003287:Contrast Media