Theranostics 2016; 6(1):28-39. doi:10.7150/thno.13137 This issue

Research Paper

A Novel Inherently Radiopaque Bead for Transarterial Embolization to Treat Liver Cancer - A Pre-clinical Study

Rafael Duran1,2, Karun Sharma3, Matthew R. Dreher4, Koorosh Ashrafi5, Sahar Mirpour1, MingDe Lin6, Ruediger E. Schernthaner1,2, Todd R. Schlachter1,2, Vania Tacher1, Andrew L. Lewis5, Sean Willis5, Mark den Hartog7, Alessandro Radaelli7, Ayele H. Negussie8, Bradford J. Wood8, Jean-François H. Geschwind1,2✉

1. Russell H. Morgan Department of Radiology and Radiological Science, Division of Vascular and Interventional Radiology, Johns Hopkins Hospital, Baltimore, MD, USA
2. Department of Diagnostic Radiology and Imaging Science, Yale University School of Medicine, New Haven, CT, USA
3. Department of Diagnostic Imaging and Radiology, Children's National Medical Center, Washington, DC, USA
4. Biocompatibles Inc, Oxford, CT, USA
5. Biocompatibles UK Ltd, a BTG International group company, Farnham, Surrey, United Kingdom
6. U/S Imaging and Interventions (UII), Philips Research North America, Briarcliff Manor, NY, USA
7. iXR, Philips Healthcare, Best, The Netherlands
8. Center for Interventional Oncology, Radiology and Imaging Sciences, Clinical Center, National Institutes of Health, Bethesda, MD, USA

This is an open access article distributed under the terms of the Creative Commons Attribution (CC BY-NC) License. See for full terms and conditions.
Duran R, Sharma K, Dreher MR, Ashrafi K, Mirpour S, Lin M, Schernthaner RE, Schlachter TR, Tacher V, Lewis AL, Willis S, Hartog Md, Radaelli A, Negussie AH, Wood BJ, Geschwind JFH. A Novel Inherently Radiopaque Bead for Transarterial Embolization to Treat Liver Cancer - A Pre-clinical Study. Theranostics 2016; 6(1):28-39. doi:10.7150/thno.13137. Available from

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Graphic abstract

Purpose: Embolotherapy using microshperes is currently performed with soluble contrast to aid in visualization. However, administered payload visibility dimishes soon after delivery due to soluble contrast washout, leaving the radiolucent bead's location unknown. The objective of our study was to characterize inherently radiopaque beads (RO Beads) in terms of physicomechanical properties, deliverability and imaging visibility in a rabbit VX2 liver tumor model.

Materials and Methods: RO Beads, which are based on LC Bead® platform, were compared to LC Bead. Bead size (light microscopy), equilibrium water content (EWC), density, X-ray attenuation and iodine distribution (micro-CT), suspension (settling times), deliverability and in vitro penetration were investigated. Fifteen rabbits were embolized with either LC Bead or RO Beads + soluble contrast (iodixanol-320), or RO Beads+dextrose. Appearance was evaluated with fluoroscopy, X-ray single shot, cone-beam CT (CBCT).

Results: Both bead types had a similar size distribution. RO Beads had lower EWC (60-72%) and higher density (1.21-1.36 g/cc) with a homogeneous iodine distribution within the bead's interior. RO Beads suspension time was shorter than LC Bead, with durable suspension (>5 min) in 100% iodixanol. RO Beads ≤300 µm were deliverable through a 2.3-Fr microcatheter. Both bead types showed similar penetration. Soluble contrast could identify target and non-target embolization on fluoroscopy during administration. However, the imaging appearance vanished quickly for LC Bead as contrast washed-out. RO Beads+contrast significantly increased visibility on X-ray single shot compared to LC Bead+contrast in target and non-target arteries (P=0.0043). Similarly, RO beads demonstrated better visibility on CBCT in target arteries (P=0.0238) with a trend in non-target arteries (P=0.0519). RO Beads+dextrose were not sufficiently visible to monitor embolization using fluoroscopy.

Conclusion: RO Beads provide better conspicuity to determine target and non-target embolization compared to LC Bead which may improve intra-procedural monitoring and post-procedural evaluation of transarterial embolization.

Keywords: VX2, Embolization, Hepatocellular carcinoma, TACE, radiopaque beads