特异性能谱CT评估阿西替尼抗兔VX2肝肿瘤血管生成效果

Specific spectral CT in evaluating antiangiogenic efficacy of Axitinib in rabbit VX2 liver tumors

目的观察特异性能谱CT增强扫描评估阿西替尼抗兔VX2肝肿瘤血管生成疗效的价值。方法将40只VX2瘤兔随机分为实验组(25只,灌胃给予阿西替尼)和对照组(15只,灌胃给予等量生理盐水),干预时间均为14天。对实验组行一站式灌注联合能谱CT扫描,对照组依次行能谱动脉期增强扫描和灌注CT扫描。重建基于实验组灌注CT时间-强度曲线所获肝肿瘤对比度最大时的能谱图像,以之作为对照组增强扫描时间;比较实验组不同时相肝肿瘤灌注参数与均一化碘浓度(NIC)相关系数之间的差异。采用Spearman相关性分析观察实验组血管内皮生长因子受体2(VEGFR-2)表达与灌注参数及NIC间的相关性及相关系数间差异。结果实验组肝肿瘤对比度最大时间为(18±4)s,可使对照组73.33%(11/15)肝肿瘤达到最大对比度。该时间点实验组血流量(BF)、血容量(BV)及肝动脉分数(HAF)与NIC均呈正相关,除BV外,各相关系数与各时相相应最大相关系数差异无统计学意义(P均>0.05)。实验组BF(r=0.828、P=0.008)及NIC(r=0.820、P=0.010)与VEGFR-2呈正相关,PS与VEGFR-2呈负相关(r=-0.782、P=0.010),且差异无统计学意义(P>0.05)。结论肿瘤特异性和个体特异性能谱CT动脉期增强可评估阿西替尼抗兔VX2肝肿瘤血管生成效果,能力与灌注CT相当。

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.