Specific spectral CT in evaluating antiangiogenic efficacy of Axitinib in rabbit VX2 liver tumors / 中国医学影像技术

ABSTRACT

Objective: To explore the value of specific spectral CT in evaluating antiangiogenic efficacy of Axitinib in rabbit VX2 liver tumors. Methods: Forty VX2 liver tumor-bearing rabbits were randomly assigned into study group (n=25, given Axitinib through intragastric administration for 14 days) and control group (n=15, given equal volume of normal saline through intragastric administration for 14 days). Rabbits in study group were scanned with one-stop perfusion and spectral CT mode, while in control group underwent arterial-phase spectral CT scan and perfusion CT scan, sequentially. The optimal scan time for control group was the maximum tumor contrast time based on the time-intensity curve of perfusion CT data of study group. The correlation coefficients of tumor perfusion parameters and the normalized iodine concentration (NIC) at different phases in study group were compared. Correlations between imaging features and vascular endothelial growth factor receptor-2 (VEGFR-2), and the differences among correlation coefficients were analyzed. Results: In control group, 73.33% (11/15) tumors achieved maximum contrast by using the optimal arterial scan time ([18±4]s) acquired from study group. The tumor blood flow (BF), blood volume (BV) and hepatic arterial fraction (HAF) had positive correlations with NIC. No statistical difference of correlation coefficients acquired in the optimal scan time and in the maximum correlation was found except for tumor BV. The tumor BF (r=0.828, P=0.008) and NIC (r=0.820, P=0.010) were positively correlated with VEGFR-2,while PS was negatively correlated with VEGFR-2 (r=-0.782, P=0.010), no statistical difference was found among the above three correlation coefficients (P>0.05). Conclusion: Single-phase contrast-enhanced spectral CT scan at tumor-specific and individual-specific acquisition time might be able to replace perfusion CT in evaluating antiangiogenic efficacy of Axitinib in rabbit VX2 liver tumors.