Nucl Med Mol Imaging.  2021 Apr;55(2):79-85. 10.1007/s13139-021-00687-6.

High-Efficiency Cationic Labeling Algorithm of Macroaggregated Albumin with ⁶⁸ Gallium

• Ayşe U
• Aziz G
• Doğangün Y

• KMID: 2515026
• DOI: http://doi.org/10.1007/s13139-021-00687-6

Abstract

Purpose
The generator product radionuclide gallium-68( ⁶⁸ Ga) is widely used for PET/CT imaging agents and the ⁶⁸ Ga-labeled MAA is an attractive alternative to ^99m Tc-labeled MAA. Using a commercially available MAA labeling kit for 99m Tc, we presented a reliable synthesis protocol with a highly efficient, organic solvent-free cationic method in GMP conditions in the Scintomics automated synthesis unit.
Methods
The labeling process was performed by incubating for 7 min at 90 ° C in the borax vial containing the generator product ⁶⁸ GaCl 3 MAA-HEPES eluted from the PSH + cartridge with 1.5 mL 5 molar NaCl. Quality control of the final product content was examined, and radiopharmaceutical production was carried out in accordance with GMP guidelines.
Results
⁶⁸ Ga eluted from the generator was obtained in more than 99% radiochemical purity and efficiency. In this case, the labeling efficiency was found to be >99%. When the results of SEM-EDX analysis in the final product were examined, it was determined that most of toxic metals were no appreciable in the product content.
Conclusions
The radiochemical and chemical purity of the final product allows direct use without purification steps to remove “free ⁶⁸ Ga” or other toxic compounds.

Keyword

Gallium-68; MAA; Macroaggregated albumin; Positron emission tomography; Radiopharmaceutical; Lung perfusion scintigraphy