Comparison of Radiochemical and Chemical Impurities in Liquid Wastes of Two Different Ge-68/Ga-68 Generators used in Nuclear Medicine PET Chemistry

Abstract

Objectives: Germanium-68/gallium-68 (Ge-68/Ga-68) generator eluate contains a number of metal cations that can compete with (GaCl3)-Ga-68, reducing specific radioactivity. The first step in peptide labeling with (GaCl3)-Ga-68 is to remove Ge-68 and several other metals with a long half-life. In this purification step, the elution residue that is passed through the cartridge is collected in glass waste bottles. Waste management is included in good production practices, and in particular, the activity of long half-life Ge-68 (270.95 days) and other toxic metal levels need to be examined. Our objective in this study is to determine the Ge-68 activity in liquid waste produced by the generation of Ga-68 and heavy metal concentrations from the generator column materials and to assess whether it can be disposed of as normal waste. Methods: Liquid wastes produced by passing the Ge-68/Ga-68 generator eluate of 2 different identities via PSH+ cartridge have been analyzed with the inductively coupled plasma mass spectrometry device in the advanced technology application and research center of our university. Results: The average of the Ge-68 radioactive pollution was estimated to be 0.142 ppm (mu g.mL(-1)) in the liquid waste analysis after passing through the PSH+ cartridge in the pre-elution in the GalluGEN brand generator. While there was no tin (Sn) impurity, it was determined that the average zinc (Zn) was 1.95 ppm (mu g.mL(-1)) and the average aluminum (Al) impurity was 10.95 ppm (mu g.mL(-1)). While no Ge-68 radioactive pollution was determined in the iThemba LABS brand generator, the average Sn was 0.098 ppm (mu g.mL(-1)), average Zn 48.6 ppm (mu g.mL(-1)), and average Al impurity 4.135 ppm (mu g.mL(-1)). Conclusion: All Ge-68/Ga-68 generators produced have their own certificates. Metallic contamination in the postmarking waste of Ge-68/Ga-68 generators can be different. It would be a safe method to keep these wastes in place until they are dumped into the sewage systems, given their half-lives in terms of long half-life radioactive metallic contamination.