Labelling of aminomethylenephosphonate derivatives with generator-produced 188Re, and a study of their stability

The labelling of aminomethylenephosphonate (amp) derivatives (EDTMP; ethylenediamine-N,N,N′,N′-tetrakis(methylenephosphonic acid), EDBMP; ethylenediamine-N,N′-bis(methylenephosphonic acid) and NTMP; nitrilotris(methylenephosphonic acid)) with carrier-free 188Re from the 188W/188Re generator was investigated in detail. The stability of the 188Re–amp complex against pH change and dilution with 0.9% NaCl was also studied. It was found that the stability of 188Re–amp was influenced by its formation conditions such as the temperature, pH value and the addition of a carrier.