Introduction: Particle-emitting, bone-seeking radiopharmaceuticals have attracted the attention of the nuclear medicine community over the last three decades for the treatment of the pain of osteoblastic metastases. The objectives of this research were to produce quality-controlled 159Gd-EDTMP in order to provide a new therapeutic radiopharmaceutical for use in clinical applications. 

Methods: The investigation was an experimental study in which 159Gd (T1/2=18.479 h, Eβ (max)=970.60 keV, Eγ=363.55 (11.4%) keV] was produced by thermal neutron bombardment of natural Gd2O3 at the Tehran Research Reactor (TRR) for a period  of 7 d at a flux of 3–4×1013 neutrons/cm2.s. It was then quality-controlled and used to radio-label the in-house prepared ethylene diamine tetra acetic acid (EDTM).

Results: Complexation parameters were optimized to achieve maximum yields (>99%). The radiochemical purity of 159Gd-EDTMP was checked by radio thin layer chromatography RTLC. It was found to retain its stability at room temperature (>95%). Bio-distribution studies of the complexes conducted in wild rats showed significant bone uptake with rapid clearance from blood.

Conclusion: The properties of the 159Gd-EDTMP that was produced suggest then use of a new, efficient, palliative therapeutic agent for metastatic bone pain instead of some other current radiopharmaceuticals.


Key words: EDTMP, gadolinium, radiotherapy, bone