Speaker
Description
The development of radiopharmaceuticals labeled with positron-emitting radionuclides has significantly expanded the capabilities of molecular imaging in nuclear medicine. Among these radionuclides, gallium-68 (⁶⁸Ga) and copper-64 (⁶⁴Cu) have attracted considerable attention due to their favorable decay properties and compatibility with a wide range of targeting molecules. This abstract summarizes practical experience with the routine preparation, radiolabeling, and quality control of ⁶⁸Ga- and ⁶⁴Cu-labeled radiopharmaceuticals in a radio pharmacy setting.
Gallium-68 is typically obtained from a ⁶⁸Ge / ⁶⁸Ga generator, enabling on-site production without the need for a cyclotron. But in the centrum equipped with cyclotron the ⁶8Zn(p,n)⁶8Ga reaction can be used. For ⁶⁸Ga activity comparable to generator liquid targets are applicable. For higher activity now the solid target are used. Its short half-life (67.7 min) makes it well suited for labeling peptides such as DOTA-conjugated compounds used in PET imaging. In our experience, automated or semi-automated synthesis modules provide reliable and reproducible labeling yields with high radiochemical purity. Critical steps in solid targets production are metal impurity control, optimized buffer systems, and temperature-controlled complexation. Quality control procedures generally involve radio-HPLC or radio-TLC analysis to verify radiochemical purity and ensure compliance with pharmacopeial requirements.
Copper-64 (t½ = 12.7 h), produced mainly in cyclotrons via the ⁶⁴Ni(p,n)⁶⁴Cu reaction, offers complementary advantages due to its longer half-life, enabling delayed imaging and distribution to centers without on-site production facilities. It is commonly used with chelators such as DOTA, NOTA, to label peptides, antibodies, and other biomolecules. Our production workflow includes careful control of reaction conditions, purification when necessary, and comprehensive quality assessment to ensure stability and suitability for clinical application.
Overall, both radionuclides provide versatile platforms for PET imaging agents. Practical experience indicates that standardized production protocols, reliable synthesis modules, and rigorous quality control procedures are essential for achieving consistent radiochemical yields and ensuring patient safety. Continued optimization of labeling chemistry and production workflows will further support the clinical implementation of ⁶⁸Ga- and ⁶⁴Cu-based radiopharmaceuticals.