Development of a SnO-based Ti/Sc generator for medical applications.

Towards application of Sc for diagnostic nuclear medicine, a Ti/Sc generator based on an inorganic resin has been evaluated. Unlike other radionuclide generators used for medical applications, the long-term retention of the parent Ti is vital due to its long half life. Herein, tin dioxide (SnO), a robust inorganic-based resin, has been synthesized and used as the stationary phase for a Ti/Sc generator. The sorption behavior of Ti/Sc was tested on SnO with varying acids, concentrations, and times. Preliminary batch study results showed >88 % Ti retention to the resin at lower acid concentrations (0.05 M HNO and 0.05 M HCl). A pilot generator was evaluated for a year, demonstrating 85.3 ± 2.8 % Sc elution yields and 0.71 ± 0.14 % Ti breakthrough in 5 M HNO. Based on capacity studies, a 7.4 MBq (200 µCi) upscaled generator system was constructed for further evaluation of the SnO resin stability and the efficacy of the eluted Sc for radiolabeling. Sc could be regularly eluted from this generator in 5 M HNO with an overall average radiochemical yield 84.7 ± 9.5 %. Post-elution processing of the Sc with DGA-normal resin removed all Ti present and allowed for high Sc-DOTA labeling yields of 94.2 ± 0.5 %. Overall, SnO has been shown to be a viable material for a Ti/Sc generator.