Development and Optimization of a Multifunctional Embolic Platform

Martowirogo, Aditya 1, 2 ;  Liu, Chuan 1 ;  Hoang, Bryan 2 ;  Murphy, Kieran 3 ;  Zheng, Jinzi 1, 2

1. Institute of Biomaterials and Biomedical Engineering, University of Toronto; 2. TECHNA Institute, University Health Network; 3. Department of Interventional Radiology, Toronto Western Hospital

Tumor embolization, the occlusion of tumor vasculature, is performed prior to radiation therapy (RT) if a patient is deemed unfit for surgery due to excessive bleeding. The use of imaging modalities such as magnetic resonance (MR) and computed tomography (CT) determine the location and tumor margins for the delivery of highly-targeted RT. Following embolization using currently available microparticles, which do not provide contrast enhancement in CT or MR, the occluded vasculature prevents the delivery of conventional contrast agents to tumors and hinders post-treatment imaging and image-guided planning. Thus, a novel solution for post-embolization imaging is needed to enable target localization and delineation for RT planning and treatment delivery. We investigated the possibility of engineering an embolic system that can be imaged using multiple modalities in order to address hurdles that currently exist with embolics and post-embolization RT. This study focuses on the development of an embolic microparticle platform with multimodality imaging capabilities, with the potential to enable post-embolization tumor imaging. A proof-of-concept rodent renal embolization protocol was developed in order to ultimately assess in vivo embolization performance of the micron-sized embolic platform. Their multimodal imaging capabilities were assessed using CT and MRI and compared to a clinically used embolic system. Our preliminary findings suggest that these microparticles are imageable using previously mentioned imaging systems, and based on their current sizes of roughly 20 microns, have the potential to induce embolization in smaller structures. Ongoing studies are focused on fabricating clinically relevant sizes in order to evaluate their embolization and imaging performance. If successful, this research has the potential to enable target visualization and delineation during RT planning and treatment delivery to embolized tumors.