Production, Quality Control and Biological Evaluation of 166Ho-PDTMP as a Possible Bone Palliation Agent

Abstract

<em>Objective(s):</em>In this study, ¹⁶⁶Ho-1,2-propylene di-amino tetra(methy1enephosphonicAcid) (¹⁶⁶Ho-PDTMP) complex was prepared as a bone palliation agent. <br/><em>Materials and Methods:</em>The complex was successfully prepared using an in-house synthesized EDTMP ligand and ¹⁶⁶HoCl₃. Ho-166 chloride was obtained by thermal neutron irradiation (1 × 1013 n.cm-2.s-1) of natural Ho(NO₃)₃ samples followed by radiolabeling and stability studies. Biodistribution in wild type rats was also peformed. <br/><em>Results: </em>The complex was prepared with thespecific activity of 278 GBq/mg and high radiochemical purity (>99%, checked by ITLC). ¹⁶⁶Ho-PDTMP complex was stabilized in the final preparation and in the presence of human serum (>90%) up to 72 hr. The biodistribution of ¹⁶⁶Ho-PDTMP in wild-type rats demonstrated significant bone uptake was up to 48 hr compared to ¹⁶⁶HoCl₃. <br/><em>Conclusion:</em> The produced ¹⁶⁶Ho-PDTMP properties suggest a possible new bone palliative therapeutic to overcome the metastatic bone pains. <br/>