Abstract :
The synthesis of an Re-HEDP complex using carrier-free 188Re from the 188W/188Re generator was investigated. Stannous chloride was used as the reducing agent for the reduction of rhenium and l-ascorbic acid was used as an antioxidant in the reaction medium. Dependence of the yield of the 188Re-HEDP on the concentration of the reducing agent, pH, reaction time, temperature, ionic strength and amount of carrier added was examined. Under optimum conditions, the labeling yields of 188Re-HEDP was more than 95% for the carrier-free as well as the carrier-added 188Re. Differences of reaction conditions between 188Re-HEDP and 188Re-MDP were clearly observed. Furthermore, the stability of the 188Re complex against pH change and dilution with saline was also studied. It was found that the formation conditions of 188Re-HEDP, such as addition of a carrier, the temperature and pH, influenced its stability.
