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

Abstract

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.

Clinical Management of Liver Cancer in India and Other Developing Nations: A Focus on Radiation Based Strategies

“…The sole stumbling block to greater adoption of 188 Re-lipiodol in India is the sparse local availability of 188 W/ 188 Re generators, still imported at a significant cost and subject to international market vagaries. An earlier report by Bal and Kumar strongly advocated the need for affordable 188 Re generator technology [108], and the know-how for making various types of 188 W/ 188 Re generators in India using 188 W raw material already exists [109,110], but it would be a significant advantage for any future planned reactors to possess the requisite characteristics for indigenous 188 W production for use in clinical-grade generators in India.…”

Continued Availability of the Tungsten-188/Rhenium-188 Generator to Enhance Therapeutic Utility of 188Re

“…Although a variety of 188 W/ 188 Re generator prototypes have been described in the literature , the alumina-based generator system has been demonstrated as the most simple, reliable and is widely used to obtain 188 Re for clinical use [12,[22][23][24][25][26][30][31][32]. Other variations which have been described and include 188 W/ 188 Re generators based on zirconium oxide/zirconia [27,[37][38][41][42], gel-type technology [44][45][46], electrochemistry [43], extraction centrifuge techniques [40], thermo-chromatography, use of high capacity adsorbent-based, nanomaterial-based and solvent extraction, but apparently none of these systems have been further evaluated for routine use of 188 Re in a clinical setting. The first evaluation of the generator separation of no-carrier-added 188 Re from the 188 W parent using a generator-based system was explored in 1966 [9][10].…”

Pivotal role of separation chemistry in the development of radionuclide generators to meet clinical demands

“…153 The rst use of the electrochemical separation approach for the preparation of radionuclide generators was reported by Chakravarty et al 154 The authors reported the development of the 90 Sr/ 90 Y generator for the separation of clinical grade 90 Y from long lived 90 Sr. 154 The technology was further extended to other parent/daughter systems, such as 188 W/ 188 Re, 99 Mo/ 99m Tc, etc., by the same group of authors. [155][156][157] The exquisite sensitivity and specicity of the electrochemical technique not only provides daughter radionuclides of the requisite purity, but also offer the scope of using low specic activity parent radionuclides (neutron activated 99 Mo or 188 W) for the preparation of clinical-scale generators, and also eliminates the need for a post-elution concentration procedure prior to radiopharmaceutical preparation.…”