Development and long-term evaluation of a new ⁶⁸Ge/⁶⁸Ga generator based on nano-SnO₂ for PET imaging

Radionuclide generator systems can routinely provide radionuclides on demand such as ⁶⁸Ga produced by a ⁶⁸Ge/⁶⁸Ga generator without the availability of an on-site accelerator or a research reactor. Thus, in this work nano-SnO₂ was used to develop a new ⁶⁸Ge/⁶⁸Ga generator which was evaluated over a period of 17 months and 305 elution cycles. The elution yield was 91.1 ± 1.8% in the first 7 mL (1 M HCl as eluent) when the generator was new and then it decreased with time and use to 73.8 ± 1.9%. Around 80% of the elutable ⁶⁸Ga activity was obtained in 1 mL and the ⁶⁸Ge content in the eluate did not exceed 1 × 10^-4% over the investigation period when it was eluted regularly. The described generator provided adequate results for radiolabelling of DOTA-TOC with direct use of eluate. In addition, [⁶⁸Ga]Ga-DOTA-TOC was tested satisfactorily for in vivo tumor detection by microPET/CT imaging in a lung cancer mouse model.