Production of 177Lu and formulation of Ethylene diamine tetramethylene phosphonate (EDTMP) kits as a bone-seeking radiopharmaceutical

Background: owing to its favourable decay characteristics 177lu [t1/2= 6.71 d, ebeta(max)= 497 kev] is an attractive radionuclide for various therapeutic applications. ethylene diamine tatrame- thylene phosphonate (edtmp) is one of the most widely used ligands which form stable complexes with various radionuclides and all the complexes. materials and methods: enriched 176lu2o3 was dissolved in 0.1 n hcl and evaporated several times and 176lucl3 target was irradiated at 2.6~1013 n.cm- 2.s-1 thermal neutron flux for 14 days.177lucl3 was dissolved in 1n hcl. edtmp was dissolved in double distilled water at ph=7.5-8.5 and freeze-dried kits was radiolabeled with 177lucl3. distribution studies were done in healthy mice. results: the yield of 177lu was (~220 tbq/g; 6000 ci/g), the radionuclidic purity was ~99%.the radiolabeling yield of edtmp kits at 37degreec after 30 min and 4 hours was 98+-0.5% and after 72 hours was 90+-2.1%, the in vitro stability in human serum at 37degreec up to 72 hours post radio- labeling was 85+-1.8%.the biodistribution studies of 177lu-edtmp and 177lucl3 in normal mice showed skeleton uptake and low soft-tissue concentration. conclusion: in this study, we produce ~220 tbq/g (6000 ci/g) of 177lu by neutron activation of 176lu in the tehran research reactor. our results showed 177lu-edtmp as a bone-seeking radiopharmaceutical. due to its suitable nuclear characteristics 177lu appears to be worthwhile for palliative therapy of bone metastasis.