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
Development of 165Dy-chitosan for radio-synovectomy
Simindokht Shirvani-Arani, Ali Bahrami-Samani, Amir Reza Jalilian,
Mohammad Ghannadi-Maragheh
Radiopharmaceutical Research and Development Laboratory (RRDL)
Introduction: Radioactive chitosan complexes are new internal
radiation therapeutic agents; they exist in solution state in acidic pH
and in gel state in pH of the human body. Therefore they do not leak
from the lesion. In addition radioactive chitosan complex is a natural
biocompatible and biodegradable product which can be excreted after
decay. In this research the 165Dy-chitosan complex (165Dy-Chit)
was prepared successfully with high radiochemical purity (>99%) in
diluted acetic acid solution.
Methods: 165Dy was produced by thermal neutron bombardment on
natural Dy (NO3)3 at the Tehran Research Reactor (TRR) for a period
of 6 hours at a flux of 3-4—1013 neutrons/cm2.s. The preparation of
165Dy-Chit was performed with regard to the optimized situation
reported by shin et al in which complexation gradually increased with
increase in ligand concentration and reached to almost 100% at a
value of 35mg of chitosan in 4 ml acetic acid (pH. 3). Radiochemical
purity was determined using ITLC.
Results: The 165Dy-Chit complex was prepared with high
radiochemical yield (>99 %) in the optimized condition; 35mg/3ml of
chitosan concentration in diluted acetic acid solution (pH=3). The
prepared complex was stable in the final solution at room
temperature, 37ºC and presence of human serum, and can be used
even 24 hours after preparation. The retention in the injected rabbit
knee joint was observed after passing three half lives of radionuclide.
Conclusion: The short half-life of 165Dy (2.3 h) suggests minimal
exposure of non-target organs by reduction of leakage. Numerous
reports have shown the efficacy and safety of 165Dy for the
treatment of chronic synovitis. These studies indicate that 165Dy-Chit
shows promising features and warrants further investigation for
development as a cost-effective agent for radiosynovectomy. It is
ready to be used for therapeutic applications in the country.
Keywords: 165Dy Chitosan, radiosynovectomy
188