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 [177Lu]-Tetra phenyl porphyrin complexes as
possible imaging agents
Hassan Yousefnia 1 , Amir Reza Jalilian 1 , Samaneh Zolghadri 1 , Yousef
Fazaeli 2 , Ali Bahrami Samani 1 , Mohammad Ghannadi-Maragheh 1
1 Nuclear Science and Technology Research Institute
2 Agriculture, Medicine and Industry Research School
Due to interesting therapeutic properties of 177Lu and tumor avidity
of tetraphenyl porphyrins (TPPs), 177Lu-tetraphenyl porphyrin
(177Lu-TPP) was developed as a possible therapeutic compound. Lu-
177 of 2.6-3 GBq/mg specific activity was obtained by irradiation of
natural Lu2O3 sample with thermal neutron flux of 4—1013 n.cm-
2.s-1. [17Lu]labeled tetraphenyl porphyrin ([177Lu]-TPP) was
prepared using freshly prepared [177Lu]-LuCl3 and tetraphenyl
porphyrin (TPPH2) for 30-60 min at 25°C (radiochemical purity:
>97±1% ITLC, >98±0.5 % HPLC, specific activity: 13-14
GBq/mmol). Stability of the complex was checked in final formulation
and human serum for 24 h. The partition coefficient was calculated
for the compound (log P. 1.89). The biodistribution of the labeled
compound in vital organs of wild-type rats was studied using
scarification studies and SPECT imaging up to 24 h. A detailed
comparative pharmacokinetic study performed for 177Lu cation and
[177Lu]-TPP. The complex is mostly washed out from the circulation
through kidneys and can be an interesting tumor imaging/targeting
agent due to low liver uptake and rapid excretion through the urinary
tract.
Keywords: 177Lu, tetra phenyl prophyrin, biodistribution
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