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

摘要

The aim of this study was to compare intratumoural heterogeneity and longitudinal changes assessed by dynamic contrasta??enhanced ultrasound (DCEa??US) and dynamic contrasta??enhanced magnetic resonance imaging (DCEa??MRI) in prostate tumour xenografts. In vivo DCEa??US and DCEa??MRI were obtained 24a??h prea?? (day 0) and posta?? (day 2) radiation treatment with a single dose of 7.5a??Gy. Characterization of the tumour vasculature was determined by Brix pharmacokinetic analysis of the timea??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 DCEa??US were significantly higher than those derived from DCEa??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 intermediatea??enhancement regions. Regarding kep median values, longitudinal changes were not found for any modality. However, at day 2, kep linked to DCEa??US was correlated to MVD in higha??enhancement areas for the treated group (p = 0.05). In contrast, correlation to necrosis was detected for the control group in intermediatea??enhancement areas (p 0.1). Intratumoural heterogeneity and longitudinal changes in tumour vasculature were assessed for both modalities. Microvascular parameters derived from DCEa??US seem to provide reliable biomarkers during radiotherapy as validated by histology. Furthermore, DCEa??US could be a standa??alone or a complementary technique. Copyright ?? 2015 John Wiley & Sons, Ltd.