Panel Disdussion

3rd International Congress 3rd International of Nuclear Congress Medicine of Nuclear & 15th Medicine Iranian Annual & 15th Iranian Congress Annual of
Nuclear Congress Medicine of Nuclear Medicine
Shahid Beheshti Shahid Beheshti University University of Medical Sciences of Medical 19-21 Sciences May 201119-21 May 2011
Production of colloidal radiopharmaceutical 90Y
Hydroxyapatite for radiosynovectomy uses
Sima Attar Nosrati, Mohamad Reza Davarpanah, Hoseinali
Khoshhosn, Mohsen Harati
NSTRI
Introduction: Radiosynovectomy is a well-accepted therapeutic
procedure in inflammatory joint diseases. There are several
radionuclides available for this treatment, However, Yttrium-90 (90Y)
is often believed to be among the most useful of the radionuclides
that have been considered for therapeutic applications in large joints.
90Y has a half-life of 64.1 h and emits beta rays of high energy
(Eβmax=2.3 MeV), with no accompanying gamma-rays.
Hydroxyapatite (HA) [Ca10(PO4)6(OH)2] is the natural mineral
constituent of bone matrix and can be synthesized in the desired
particle size range. HA particles get converted to Ca2+ and PO43-
ions by natural metabolic process and eliminated over a period of 6
weeks.
Purpose: The present study describes the production of 90Y-HA
colloidal radiopharmaceutical and its characterization including the
size distribution profile of the particles, radiochemical purity,
radionuclidic purity, stability and biodistribution studies.
Method: For the preparation of 90Y labeled HA particles, 40 mg of
HA particles added to a 2ml conical vial, 0.8 ml of saline solution, the
suspension was stirred for 5 minutes at room temperature. 100 μL of
90YCl3 solution (~370 MBq of 90Y) was added and the mixture was
shaken for 1 h at room temperature and the radiolabeled particles
were then separated from free 90Y activity by centrifugation. The
radiolabeled particles were resuspended in 2 ml saline, shaken for
few minutes and centrifuged to determine the labeling efficiency.
Results: The radiolabelling yield was 98% and the radiochemical
purity of the labelled product was 97%. Particle size distribution of
the product was 2-10 μm. Stability studies in vitro showed that 90Y-
HA particles were stable in saline as well as at least 3 days).
Biodistribution experiments in rats showed good localization of the
particles in the synovium of the knee joint.
Conclusion: HA particles labeled with 90Y can be prepared with high
labeling efficiency for radiosynovectomy applications. The 90Y-HA
particles prepared are stable and the method is convenient for
routine production of this radiopharmaceutical.
Keywords: Colloide, Radiopharmaceutical, Radiosynovectomy, 90Y-
HA, Hydroxyapatite
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