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DRUG ELUTING MICROSPHERES
CHARACTERISTICS OF AVAILABLE AGENTS
RAJ NARAYANAN M.D.
PROFESSOR OF CLINICAL RADIOLOGY
CHIEF – VASCULAR & INTERVENTIONAL RADIOLOGY
UNIVERSITY OF MIAMI – MILLER SCHOOL OF MEDICINE
DEB vs. conventional TACE Pharmacokinetics: serum concentration over time
* From Varela et al. Chemoembolization of hepatocellular carcinoma with drug eluting beads: Efficacy and doxorubicin pharmacokinetics. J
Hepatology 46 (2007) 474-481
BEAD SIZES LC Beads
500-700 & 300-500
300-500 & 100-300
100-300
M1
Tandem
40, 75, 100µm
Quadrasphere
30-60
50-100
100-150
150-200
TANDEM
POLYZENE F SHELL
Biocompatible
HYDROGEL CORE
Felxible
Hydrophilic
Crosslinked Methacrylate polymer
Copolymer of vinyl acetate and
methyl acrylate
Non degradable, hydrophilic material
Dry size 50-100µ expands to 200-400µ;
30-60µ expands to 120-240µ in
saline/non-ionic contrast
QuadraSphere Microspheres (US name)
HepaSphere Microspheres (ROW)
Microspheres are not PVA
based
Unique formulation results in
a highly compressible sphere
that moulds to the vessel
lumen and architecture
Achieves complete occlusion
and increased intimal contact,
even in bifurcated vessels
QuadraSphere / HepaSphere Microspheres
Courtesy of Dr. K. Osuga
Doxorubicin is loaded by
two processes:
1. Mechanical absorption
2. Ionic interaction
Negatively charged polymer bonds with positively
charged doxorubicin*
-O O
OH
O O-
OH
n
O
OH
C
O
NH3+
OH
H3C
OCH3 O
O OH
OH
O
CH2OH
HepaSphere Microspheres:
Doxorubicin loading and delivery
Doxorubicin loads throughout spheres for
controlled release
TREATMENT WITH QUADRASPHERE
50 YEAR OLD MALE
HISTORY OF HCC HCC
SINGLE TREATMENT WITH 2 VIALS OF QUADRASHERE
2 VIALS 30-60 MICRON SIZE LOADED WITH 50 MG OF DOXORUBICIN
DELIVERY SIZE 120-240 MICRONS
LC BEAD
Soft deformable microspheres
Reduce blood flow to tumor
Slow release of Drug enhances the
anti-tumor effect and decreases
systemic exposure
The LC Bead has a negative charge and
doxorubicin has a positive charge
The doxorubicin is loaded and eluted by an
‘reversible ionic exchange mechanism’.
Hydrated Beads Loaded Beads
Interaction of doxorubicin with
SO3 groups displaces water from
the hydration shells
Hydration shell
associated with
PVA and ionic groups
Bulk (non-
bound)
water
Provide intraprocedural feedback with visualization under fluoroscopy (2D) and
CBCT (3D) to aid in targeted embolization
Discover regions at risk for under- treatment; may improve outcomes
Radiopaque LC Bead®: LUMI
Kindly provided by Drs. Duran, Lin, and Geschwind.
Data on file, Biocompatibles UK Ltd, a BTG International group company.
CBCTWithout Soluble Contrast
THANK