Quantitative Molecular MR Imaging of U87 Brain Tumor Angiogenesis using a Novel RGD Gd-Based Emulsion

Benjamin Marty¹, Franoise Geffroy¹, Boucif Djemai¹, Benoit Theze², Aline Perrin¹, Caroline Robic³, Marc Port³, Philippe Robert³, Denis Le Bihan¹, Franck Lethimonnier¹, Sbastien Mriaux¹

Molecular magnetic resonance imaging is an increasingly used tool to investigate tumors angiogenic activity. Here we used a high relaxivity Gadolinium based (Gd-based) emulsion grafted with RGD peptides to target αvβ3 protein over-expressed during tumor angiogenesis induced in mice brain. This study proposes to quantify the Gd-based emulsion concentration by acquiring dynamic T1 maps. Thanks to this methodology we are able to detect and quantify the accumulation of contrast agent in the tumor after its intravenous injection. A proof of concept of its binding was obtained in vivo with brain tumors induced in nude mice, and was confirmed by histology.