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” 188Re from conventional alumina based generators require 188W of very high specific activity for obtaining reasonable quantities of 188Re in an adequately concentrated form. We have developed a simple electrochemical separation technique adaptable for using low specific activity 188W, for the separation of 188Re from 188W, and obtain 188Re amenable for radiolabeling biomolecules. The overall decay corrected yield of 188Re was >70%. The recovered 188Re had high radiochemical (>97%) and radionuclidic purity (>99.99%). The suitability of the 188Re for radiolabeling was demonstrated by its use for the complexation of DMSA and HEDP with labeling yields >98%. Repeated separation of 188Re from a stock solution of 188W 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 188W/ 188Re generator suitable for clinical applications.