Abstract #1685

Extravasation of a New High Molecular Weight Contrast Agent in Tumour Vasculature, Probed by MRI & Histology

Kelly Catherine McPhee¹, Jennifer E. H. Baker^1,2, Katayoun Saatchi³, Urs O. Hfeli³, Stefan a Reinsberg¹

¹Physics & Astronomy, University of British Columbia, Vancouver, British Columbia, Canada; ²Radiation Biology Unit, BC Cancer Research Centre, Vancouver, British Columbia, Canada; ³Pharmaceutical Sciences, University of British Columbia, Vancouver, British Columbia, Canada

In this pilot study, we investigate a novel, high-molecular weight (HMW) contrast agent, hyperbranched polyglycerol (HPG), doubly labeled with Gd and a fluorescent marker. Longitudinal measures of T1 were made in vivo. We observed accumulation of HPG over several days, followed by a drop after about a week both in MRI (via changes in T1 baseline), and in histology (via the fluorescent tag). Histology shows HPG remains within or proximal to vasculature at early time points, but extravasates and accumulates at greater distances from vessels over time.