SPIO-Labeled 90Y Microspheres Permit Accurate Quantification of Macroscopic Intra-Hepatic Biodistribution

Weiguo Li¹, ², Zhuoli Zhang¹, Yang Guo¹, Jodi Nicolai¹, Reed A. Omary¹, Andrew C. Larson¹

Visualization and quantification of Yttrium-90 (90Y) microsphere biodistribution using conventional radiologic modalities is challenging. Whereas labeling 90Y microspheres with SPIOs offers the potential to use MRI to visualize in vivo biodistribution, optimization of the amount of SPIO included within these microspheres may be critical. In this study, we have demonstrated the potential to optimize SPIO content for future studies intended to quantify microsphere concentrations in vivo; we found that spheres with 2% SPIO contents will be ideal candidates for in vivo studies.