CT Spectral Imaging For Evaluating The Early Effects Of Antiangiogenic Therapy In Colon Cancer

ObjectiveTo explore the feasibility of Using CT(computed tomography, CT) spectral imaging to evaluate the response of anti—angiogenesis treatment of colon cancer.MethodsTo establish an experiment animal model of colon cancer on 20 nude mice.20 nude mice were randomly divided into 2 groups(10 in each group), experimental group and control group. To select 5 tumor—burdened nude mice in each group randomly for performing nonehanced and multi—phase(10s,20 s and 1min)CT scans with GSI mode 8 days after tumors grow. To inject bevacizumab to tumor—burdened nude mice of experimental group(5) in 7th days after planting tumor and give equal dose of normal saline injection to tumor—burdened nude mice of control group(5) at the same time for treatment.To select 5 tumor—burdened nude mice in each group for performing nonehanced and multi—phase(10s, 20 s and 1min) CT scans with GSI mode in 7th days after treatment. To execut tumor—burdened nude mice after each scan and obtain tumors specimens for doing immunohistochemical analysis of microvascular density(MVD) and vascular endothelial growth factor(VEGF)expression. Data statistics used spss17.0 statistical software. The statistical results were analyzed by independent sample t—test, paired t— test and spearman correlation analysis.ResultsEvery phases of enhanced CT spectral imaging in 7th days after treatment.,iodine concentrations in the edge of tumors were higher than in the center of tumors in each group. Iodine concentrations in experimental group, no matter edge or center of tumors, were lower than the control group in every phase. The difference had statistical significance(p < 0.05). Experimental MVD expression values are lower than the control group. The difference was statistically significant(p < 0.05). Therewas no statistically significant difference of VEGF values between two groups. The standardized Iodine concentrations in the edge of the tumors and MVD values had positive correlations(r were 0.994、0.91 and 0.850,p < 0.05),no correlation was found with VEGF values.ConclusionCT spectral imaging can monitoring early treatment response of anti—angiogenesis of bevacizumab in live colon cancer—burdened nude mice, can be more sensitive to monitor the change of iodine concentrations in tumors and had good correlations with pathologic histology results. CT spectral imaging can reflect the microcirculation perfusion of tumors to some extent and provide efficacy index and value for clinical monitoring the response of tumor treatment.