Study of multi-slice CT perfusion imaging on angiogenesis of VX 2 tumor in rabbits: before and after interventional therapy

Abstract

Objective To investigate the applicative value of multi-slice CT (MSCT)perfusion imaging on quantitative assessment of tumor angiogenesis before and after interventional therapy and monitoring the early interventional therapeutic effect in malignant soft-tissue tumor.Methods Twenty-four New Zealand white rabbits successfully implanted VX_2 tumor in the unilateral proximal thigh were divided into two groups (twelve per group)at random and performed conventional CT plain scan and perfusion scan 14 days after implantation and 3 days after interventional therapy respectively.The values of blood flow (BF),blood valume(BV),mean transit time (MTT)and premeability surface(PS)of VX_2 tumors and normal muscular tissues were computed and the differences among them were analyzed.Meanwhile, correlative analysis between perfusion parameters and micro-vessel density(MVD)counts,average A value of vascular endothelial growth factor(VEGF)was done.Results Before interventional therapy,the values of BF,BV,MTT and PS of VX_2 tumors in interventional group were(303.3±69.9)ml·100g~(-1)·min~(-1), (7.02±3.10)ml/100 g,(1.99±0.28)s and (65.9±9.4)ml·100g~(-1)·min~(-1)respectively. Compared with the parametric values of normal muscular tissues,there were significant differences between them (F value was 4285.82,1867.46,413.04 and 698.42 respectively,P0.01 ). There were no significant differences of the above parametric values between interventional group and the control group (F value was 2.47,2.03,0.02 and 0.53 respectively,P0.05).The values of MVD counts,average A value of VEGF of VX_2 tumors in interventional group were 50.1±4.1/HP and 0.352±0.011 respectively.There were no significant differences between interventional group and the control group (F value was 0.02 and 0.19 respectively,P0.05).Three days after interventional therapy,the values of BF,BV,MTT,PS,MVD and VEGF of VX_2 tumors in interventional group were (7.5±2.4)ml· 100g~(-1)·min~(-1),(1.20±0.23)ml/100g,(3.29±0.57)s,(4.0±1.5)ml·100g~(-1)·min~(-1), 16.0±2.4/HP and 0.215±0.008 respectively.Compared with the values of pre-interventional therapy and the control group,there were significant differences among them(P0.01).Additionally,the values of BF,BV,PS in VX_2 tumors had a significant positive correlation with MVD counts,average A value of VEGF (r0.7,P0.05),however,the value of MTT had no significant correlation with MVD (P0.05)but had a significant negative correlation with average A value of VEGF(r=-0.78,P0.05).Conclusion MSCT perfusion imaging is a functional imaging technique that is capable of quantitative assessment to tumor angiogenesis,blood perfusion and vascular permeability,which can evaluate the early interventional therapeutic effect in malignant soft-tissue tumor invasively and accurately.