Abstract #4172

Application of a Biodegradable Macromolecular Contrast Agent in Dynamic Contrast Enhanced MRI to Assess the Efficacy of Indocyanine Green Enhanced Photothermal Cancer Therapy

Yi Feng^1,2, Eun-Kee Jeong³, Lyska Emerson⁴, Zheng-Rong Lu⁵

¹Drug Developement, Nevada Cancer Institute, Las Vegas, NV, USA; ²University of Utah, Salt Lake City, UT, USA; ³Radiology, University of Utah; ⁴Pathology, University of Utah; ⁵Pharmaceutics and Pharmaceutical Chemistry, University of Utah

Biodegradable macromolecular contrast agents (BMCA) alleviate the high Gd(III) retention problem of macromolecular contrast agents by in vivo degradation while retaining their advantages over small molecular weight contrast agent in tumor imaging. Tumor bearing mice were treated by photothermal therapy enhanced by intratumoral injection of indocyanine green and subjected to DCE-MRI scan using (Gd-DTPA)-cystamine copolymers (GDCC, a BMCA) and Gd-(DTPA-BMA). Tumor vasculature parameters (two-compartment model) using GDCC significantly dropped 4 hr after treatment and returned to normal 7 days later. Parameters using Gd-(DTPA-BMA) were too high. GDCC is promising in timely and accurately evaluation of anti-cancer treatment using DCE-MRI.