Functional computed tomographic quantification of angiogenesis in rabbit VX2 soft-tissue tumor before and after interventional therapy

Abstract

Objective: Our purpose was to investigate the applicative value of multislice spiral computed tomography (CT) perfusion imaging on quantitative assessment of tumor angiogenesis before and after transcatheter arterial embolization and monitoring the early interventional therapeutic effect in malignant solid tumors.

Methods: Sixteen New Zealand white rabbits successfully implanted VX2 tumor in the unilateral proximal thigh were divided into 2 groups (8 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 volume (BV), mean transit time (MTT), and permeability surface area product (PS) in VX2 tumors and normal muscles were computed after intravenous bolus administration of iodinated contrast medium, and the differences among them were analyzed. Meanwhile, correlative analysis between perfusion parameters and microvessel density (MVD) counts and average optical density (AOD) of vascular endothelial growth factor (VEGF) was done.

Results: Before interventional therapy, the values of BF, BV, MTT, and PS of the VX2 tumors in interventional group were 303.28 +/- 69.91 mL 100 g min, 7.02 +/- 3.10 mL 100 g, 1.99 +/- 0.28 seconds, and 65.88 +/- 9.38 mL 100 g min, respectively. Compared with the parametric values of normal muscular tissues, there were significant differences among them (F values were 4285.82, 1867.46, 413.04, and 698.42, respectively; P < 0.01). There were no significant differences of the above parametric values between the interventional group and the control group. Three days after interventional therapy, the values of BF, BV, MTT, and PS of the VX2 tumors in the interventional group were 7.53 +/- 2.37 mL 100 g min, 1.20 +/- 0.23 mL 100 g, 3.29 +/- 0.57 seconds, 4.01 +/- 1.51 mL 100 g min, respectively. Compared with the parametric values of preinterventional therapy and the control group, there were significant differences among them (P < 0.01). In addition, there was a good positive correlation between BF, BV, PS, and MVD, and AOD of VEGF (r > 0.7, P < 0.05) in VX2 tumors; however, there was no significant correlation between MTT and MVD (P > 0.05), and there was significant negative correlation between MTT and AOD of VEGF (r = -0.78, P < 0.05).

Conclusions: Multislice spiral CT perfusion imaging is a functional imaging technique that provides useful, quantitative assessment to tumor angiogenesis, blood perfusion, and vascular permeability, which can evaluate the early interventional therapeutic effect in malignant solid tumors invasively and accurately.