Correlations Between CT Perfusion Parameters and Vascular Endothelial Growth Factor Expression and Microvessel Density in Implanted VX2 Lung Tumors

To evaluate the correlation between CT perfusion parameters and tumor angiogenesis, expression of VEGF is implanted in VX2 lung tumor. VX2 tumor cells were injected in 15 healthy New Zealand rabbits. After 20 days, tumors with diameter over 7 mm were scanned with 16 row spiral CT. Using Software Perfusion 3, blood flow (BF), blood volume (BV), permeability surface area product (PS), and the maximum attenuation value (MAV) were obtained. After CT examination, rabbit was sacrificed, and slices from tumor tissue were prepared and checked with immunohistochemical staining with anti-CD34 and anti-VEGF monoclonal antibodies. Correlation of CT perfusion parameters with MVD and VEGF expression was determined by using Pearson correlation analysis. Blood supply of tumor and regions around tumor was higher than that of normal lung tissue. PS value increased sharply in tumor tissue. PS value in regions around tumor was also higher than that of normal lung tissue but lower than that of tumor tissue. Significant positive correlation was observed between CT perfusion parameters (BF, BV, PS, and MAV) and expression of VEGF and MVD in tumor tissue. CT perfusion parameters provide reliable information of the microcirculation in tumor tissue; therefore, it can be used as indexes to characterize angiogenesis of tumor.