Labeling of diethylenetriamine-N,N,N′,N″,N″-pentakis(methylenephosphonic) acid (DTPMP) with rhenium-188 using stannous chloride
as a reducing agent has been investigated. Dependence of the yield of the 188Re–DTPMP complex on the concentration of the reducing agent, pH, reaction time, temperature, ascorbic acid and amount of carrier
added has been studied. Under optimum conditions, the labeling yield of 188Re–DTPMP complex is 95% for the carrier-free 188Re but with the carrier-added 188Re the labeling yield is more than 97%. Furthermore, the stability of the 188Re–DTPMP complex against pH change and dilution with saline has been also studied. It is found that the addition of carrier
stabilizes the 188Re–DTPMP complex against pH change and dilution.