title: Quantification of angiogenesis in breast cancer by automated vessel identification in CD34 immunohistochemical sections.
abstract: OBJECTIVE
  Tumor growth is dependent upon angiogenesis. Tumor vascularity, as measured by microvessel density or Chalkley counts, has been shown to predict treatment outcome. However, many issues related to reproducibility and methodology have prevented its clinical application. We present a method of automatic vessel identification applied to CD34 immunohistochemical sections which facilitates increased reproducibility.
  
  
  METHODS
  Pixel colour information was used to identify CD34 stain. In order to reduce the effects of noise and background, stained areas smaller than 3.5 μm were ignored.
  
  
  RESULTS
  Comparing automatic and manual vessel counts in 50 randomly selected breast cancer cases, the method achieved an intraclass correlation coefficient of r(a)(2)=0.96 and a 95% confidence interval for the percentage difference between the counts from -26.1% to 10.8%. The method was also found to have a sensitivity approaching 100%.
  
  
  CONCLUSIONS
  The method can reliably be used on colour photographs of staining for CD34 to quantify angiogenesis.
authors.affiliation: Department of Physics, University of Oslo, Postboks 1048 Blindern, N-0316, Oslo, Norway. l.t.g.mikalsen@fys.uio.no
authors.forename: Lars Tore Gyland
authors.initials: LT
authors.lastname: Mikalsen
authors.forename: Hari Prasad
authors.initials: HP
authors.lastname: Dhakal
authors.forename: Oyvind S
authors.initials: OS
authors.lastname: Bruland
authors.forename: Jahn M
authors.initials: JM
authors.lastname: Nesland
authors.forename: Dag Rune
authors.initials: DR
authors.lastname: Olsen
mesh_terms: D018952:Antigens, CD34 / Q000096:biosynthesis*; D001331:Automation; D001943:Breast Neoplasms / Q000378:metabolism*; D002277:Carcinoma / Q000378:metabolism*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007150:Immunohistochemistry / Q000379:methods*; D009361:Neoplasm Invasiveness; D009389:Neovascularization, Pathologic; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D018952:Antigens, CD34