A novel 188W/188Re electrochemical generator with potential for medical applications

Rhenium-188 is a well recognized therapeutic radionuclide and its use in a variety of applications has been reported. The current methods of obtaining no-carrier added 188 Re from conventional alumina based generators require 188 W of very high specific activity for obtaining reasonable quantities of 188 Re in an adequately concentrated form. We have developed a simple electrochemical separation technique adaptable for using low specific activity 188 W, for the separation of 188 Re from 188 W, and obtain 188 Re amenable for radiolabeling biomolecules. The overall decay corrected yield of 188 Re was > 70%. The recovered 188 Re had high radiochemical (> 97%) and radionuclidic purity (> 99.99%). The suitability of the 188 Re for radiolabeling was demonstrated by its use for the complexation of DMSA and HEDP with labeling yields > 98%. Repeated separation of 188 Re from a stock solution of 188 W could be demonstrated for a period of 70 d. The preliminary results suggest that the process can be scaled up to higher activity levels and suggest that this strategy can be further explored for the development of electrolytic type 188 W/ 188 Re generator suitable for clinical applications.