Colorectal tumor vascularity: quantitative assessment with multidetector CT--do tumor perfusion measurements reflect angiogenesis?
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.
Goh
Vicky
V
Paul Strickland Scanner Centre, Mount Vernon Hospital, Northwood, Middlesex, England.
Halligan
Steve
S
Daley
Frances
F
Wellsted
David M
DM
Guenther
Thomas
T
Bartram
Clive I
CI
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
D014408:Biomarkers, Tumor; D003287:Contrast Media; D051272:Glucose Transporter Type 1; D042461:Vascular Endothelial Growth Factor A; D007479:Iopamidol