Multimodal approach to assess tumour vasculature and potential treatment effect with DCE‐US and DCE‐MRI quantification in CWR22 prostate tumour xenografts

The aim of this study was to compare intratumoural heterogeneity and longitudinal changes assessed by dynamic contrast‐enhanced ultrasound (DCE‐US) and dynamic contrast‐enhanced magnetic resonance imaging (DCE‐MRI) in prostate tumour xenografts. In vivo DCE‐US and DCE‐MRI were obtained 24 h pre‐ (day 0) and post‐ (day 2) radiation treatment with a single dose of 7.5 Gy. Characterization of the tumour vasculature was determined by Brix pharmacokinetic analysis of the time–intensity curves. Histogram analysis of voxels showed significant changes (p < 0.001) from day 0 to day 2 in both modalities for kep, the exchange rate constant from the extracellular extravascular space to the plasma, and kel, the elimination rate constant of the contrast. In addition, kep and kel values from DCE‐US were significantly higher than those derived from DCE‐MRI at day 0 (p < 0.0001) for both groups. At day 2, kel followed the same tendency for both groups, whereas kep showed this tendency only for the treated group in intermediate‐enhancement regions. Regarding kep median values, longitudinal changes were not found for any modality. However, at day 2, kep linked to DCE‐US was correlated to MVD in high‐enhancement areas for the treated group (p = 0.05). In contrast, correlation to necrosis was detected for the control group in intermediate‐enhancement areas (p < 0.1). Intratumoural heterogeneity and longitudinal changes in tumour vasculature were assessed...
Source: Contrast Media and Molecular Imaging - Category: Radiology Authors: Tags: Full Paper Source Type: research