Preparation of Radiopaque Drug-Eluting Beads for Transcatheter Chemoembolization

Abstract

PurposeTo develop a simple method to produce radiopaque drug-eluting microspheres (drug-eluting beads [DEBs]) that could be incorporated into the current clinical transcatheter arterial chemoembolization workflow and evaluate their performance in vitro and in vivo. Materials and MethodsAn ethiodized oil (Lipiodol; Guerbet, Villepinte, France) and ethanol solution was added to a lyophilized 100–300 µm bead before loading with doxorubicin. These radiopaque drug-eluting beads (DEBs; Biocompatibles UK Ltd, Farnham, United Kingdom) were evaluated in vitro for x-ray attenuation, composition, size, drug loading and elution, and correlation between attenuation and doxorubicin concentration. In vivo conspicuity was evaluated in a VX2 tumor model. ResultsLipiodol was loaded into lyophilized beads using two glass syringes and a three-way stopcock. Maximum bead attenuation was achieved within 30 minutes. X-ray attenuation of radiopaque beads increased linearly (21–867 HU) with the amount of beads (0.4–12.5 vol%; R2 = 0.9989). Doxorubicin loading efficiency and total amount eluted were similar to DC Bead (Biocompatibles UK Ltd); however, the elution rate was slower for radiopaque DEBs (P < .05). Doxorubicin concentration linearly correlated with x-ray attenuation of radiopaque DEBs (R2 = 0. 99). Radiopaque DEBs were seen in tumor feeding arteries after administration by fluoroscopy, computed tomography, and micro-computed tomography, and their location was confirmed by histology. ConclusionsA simple, rapid method to produce radiopaque DEBs was developed. These radiopaque DEBs provided sufficient conspicuity to be visualized with x-ray imaging techniques.