Post-elution processing of 44Ti/44Sc generator-derived 44Sc for clinical application

The 44Ti/44Sc (T1/244Ti=60 a) generator provides cyclotron-independent access to positron-emitting 44Sc (T1/2=3.97 d) for PET imaging. This work aims to post-elution processing of initial 44Sc generator eluates in order to reduce its volume, HCl concentration and remove the oxalate anions. The on-line adsorption of 44Sc on cationic resin AG 50W-X8 (200–400 mesh, H+-form) is achieved with >98% efficacy. Subsequently, the purified 44Sc is desorbed by using 3 ml of 0.25 M ammonium acetate (pH=4.0).The post-processing takes 10 min. The overall yield of the post-processing reached 90%, which is referred to the 44Sc obtained from the 44Ti/44Sc generator. In addition to the chemical purification, the content of 44Ti breakthrough was further reduced by one order of magnitude. The 185 MBq generator finally provides 150 MBq of 44Sc containing <10 Bq of 44Ti ready for labeling.