Preparation of Radiopaque Drug-Eluting Beads for Transcatheter Chemoembolization

PURPOSE: Transarterial chemoembolization (TACE) with drug eluting microspheres improves drug delivery to tumors and reduces systemic exposure compared to conventional TACE (cTACE), but lacks imaging feedback. The objective of this study was to develop a simple method to produce radiopaque drug eluting microspheres that could be incorporated into the current clinical TACE workflow and evaluate their performance in vitro and in vivo. METHODS: A Lipiodol(®) and ethanol solution was added to a lyophilized 100–300 μm bead prior to loading with doxorubicin. These radiopaque drug eluting beads (DEBs, Biocompatibles UK Ltd) were evaluated in vitro for X-ray attenuation, composition, size, drug loading/elution, and correlation between attenuation and doxorubicin concentration. In vivo conspicuity was evaluated in a VX2 tumor model. RESULTS: Lipiodol was loaded into lyophilized beads using two glass syringes and a 3-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%; R(2) = 0.9989). Doxorubicin loading efficiency and total amount eluted was similar to DC Bead(®); however, the elution rate was slower for radiopaque DEBs (P