title: Colorectal tumor vascularity: quantitative assessment with multidetector CT--do tumor perfusion measurements reflect angiogenesis?
abstract: OBJECTIVE
  To establish the relationships between quantitative perfusion computed tomography (CT) parameters-specifically, primary tumor blood flow, blood volume, transit time, and permeability surface-area product-and immunohistologic markers of angiogenesis in colorectal cancer.
  
  
  METHODS
  After institutional review board approval and informed patient consent were obtained for this prospective study, 23 patients (11 men, 12 women; mean age, 68.4 years; age range, 34.8-87.1 years) with colorectal adenocarcinoma underwent a 65-second perfusion CT examination, and tumor blood flow, blood volume, mean transit time, and permeability surface-area product were determined. After surgery, resected specimens were sectioned and stained immunohistochemically to identify CD34 for quantification of microvessel density (MVD), to identify smooth muscle actin for assessment of pericyte coverage index, to identify vascular endothelial growth factor (VEGF), and to identify glucose transporter protein (GLUT-1). Perfusion CT measurements were correlated with MVD, pericyte coverage index, VEGF expression, and GLUT-1 expression by using Pearson or Spearman rank correlation analysis, with significance assigned at the 5% level.
  
  
  RESULTS
  Mean blood flow, blood volume, transit time, and permeability surface-area product values were 72.1 mL/min/100 g of tissue +/- 28.4 (standard deviation), 6.2 mL/100 g of tissue +/- 1.4, 9.3 seconds +/- 3.9, and 13.9 mL/min/100 g of tissue +/- 3.2, respectively. Blood volume (r = 0.59, P = .002) and permeability surface-area product (r = 0.46, P = .03) correlated positively with MVD, but blood flow (r = 0.27, P = .22) and transit time (r = -0.18, P = .44) did not. There were no significant associations between any perfusion CT parameter and pericyte coverage index (r <or= 0.36, P > .05), VEGF score (rho <or= 0.30, P >or= .15), or GLUT-1 score (rho < 0.21, P >or= .33).
  
  
  CONCLUSIONS
  Tumor permeability surface-area product and blood volume correlate positively with MVD and may reflect the microvascularity of colorectal tumors.
authors.affiliation: Paul Strickland Scanner Centre, Mount Vernon Hospital, Northwood, Middlesex, England.
authors.forename: Vicky
authors.initials: V
authors.lastname: Goh
authors.forename: Steve
authors.initials: S
authors.lastname: Halligan
authors.forename: Frances
authors.initials: F
authors.lastname: Daley
authors.forename: David M
authors.initials: DM
authors.lastname: Wellsted
authors.forename: Thomas
authors.initials: T
authors.lastname: Guenther
authors.forename: Clive I
authors.initials: CI
authors.lastname: Bartram
mesh_terms: D000230:Adenocarcinoma / Q000000981:diagnostic imaging*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000032:analysis; D001783:Blood Flow Velocity; D015179:Colorectal Neoplasms / Q000000981:diagnostic imaging*; D003287:Contrast Media; D005260:Female; D051272:Glucose Transporter Type 1 / Q000032:analysis; D006801:Humans; D007150:Immunohistochemistry; D007479:Iopamidol; D008297:Male; D008875:Middle Aged; D009389:Neovascularization, Pathologic / Q000000981:diagnostic imaging*; D011857:Radiographic Image Interpretation, Computer-Assisted; D018709:Statistics, Nonparametric; D014057:Tomography, X-Ray Computed / Q000379:methods*; D042461:Vascular Endothelial Growth Factor A / Q000032:analysis
chemical_list: D014408:Biomarkers, Tumor; D003287:Contrast Media; D051272:Glucose Transporter Type 1; D042461:Vascular Endothelial Growth Factor A; D007479:Iopamidol