title: Spatial relationship between hypoxia and the (perfused) vascular network in a human glioma xenograft: a quantitative multi-parameter analysis.
abstract: OBJECTIVE
  To quantitatively study the spatial distribution of tumor hypoxia in relation to the perfused vasculature.
  
  
  METHODS
  Using a human glioma xenograft model, nude mice were administered two different hypoxia markers (NITP or pimonidazole) and the perfusion marker Hoechst 33342. Frozen tumor sections were sequentially scanned for perfusion, hypoxia, and vasculature, respectively, to quantitate perfusion, vasculature, and hypoxia parameters in the same section.
  
  
  RESULTS
  All tumors showed incomplete perfusion. Both NITP and pimonidazole stained the same hypoxic tumor areas. No statistically significant differences between the two markers were observed. The density of the perfused vessels was inversely related to the hypoxic fraction. At critical distances from perfused vessels, hypoxia occurred. These data suggest that predominantly diffusion-limited hypoxia was detected, based on the spatial distribution of nearby vessels. Also, the proportion of hypoxia distributed over arbitrary zones of 50 microm around perfused vessels was calculated. The largest proportion of hypoxia was found at distances beyond 100 microm from perfused vessels.
  
  
  CONCLUSIONS
  With the multiple staining and functional microscopic imaging technique described here, the spatial relationship between perfused vessels and hypoxia was quantified in whole tumor cross-sections. The usefulness of this histologically-based method to quantitate morphological and physiological aspects of the tumor microenvironment was evaluated.
authors.affiliation: Department of Radiotherapy, University of Nijmegen, Nijmegen, The Netherlands. p.rijken@rther.azn.nl
authors.forename: P F
authors.initials: PF
authors.lastname: Rijken
authors.forename: H J
authors.initials: HJ
authors.lastname: Bernsen
authors.forename: J P
authors.initials: JP
authors.lastname: Peters
authors.forename: R J
authors.initials: RJ
authors.lastname: Hodgkiss
authors.forename: J A
authors.initials: JA
authors.lastname: Raleigh
authors.forename: A J
authors.initials: AJ
authors.lastname: van der Kogel
mesh_terms: D000818:Animals; D001562:Benzimidazoles; D015687:Cell Hypoxia; D005456:Fluorescent Dyes; D005910:Glioma / Q000098:blood supply* / Q000503:physiopathology*; D006801:Humans; D007150:Immunohistochemistry; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D009593:Nitroimidazoles; D011838:Radiation-Sensitizing Agents; D012039:Regional Blood Flow; D013806:Theophylline / Q000031:analogs & derivatives*; D014183:Transplantation, Heterologous
chemical_list: D001562:Benzimidazoles; D005456:Fluorescent Dyes; D009593:Nitroimidazoles; D011838:Radiation-Sensitizing Agents; C075173:7-(4'-(2-nitroimidazole-1-yl)butyl)theophylline; C033815:pimonidazole; D013806:Theophylline; C017807:bisbenzimide ethoxide trihydrochloride