Fully automated multi generator elution for a single synthesis of ⁶⁸ Ga-labelled compounds using the Trasis mini AIO

Ziel/Aim Critical shortage of Ge-68, high demand for Ga-68 and increasing costs for the respective generator systems pose a challenge in clinical practice. There is a need for a cost effective and efficient automated radiosynthesis providing ⁶⁸Ga-labelled radiotracers in large quantities. Multiple generators in a single radiosynthesis may be a promising alternative. The goal of this study was to test the feasibility of two different generator combinations.

Methodik/Methods Fully automated radio-synthesis of [⁶⁸Ga]Ga-DOTATOC or [⁶⁸Ga]Ga-HBED-PSMA-11 was performed on a MiniAO (Trasis®) module. The set-up is GMP compliant with (1) slightly modified single-use cassettes for the cationic pre-purification of the ⁶⁸Ge/⁶⁸Ga generator eluate and (2) dedicated ready-to-use chemical kits. We investigated two different combinations of two ⁶⁸Ge/⁶⁸Ga generators Galli Eo (IRE) as well as Galliapharm (EZAG). Each combination provided cumulated activities of 1400 ± 200 MBq per elution.

Ergebnisse/Results Combination of two generators within the MiniAO module was possible by modification of the single-use cassettes together with the standard labelling sequence to obtain a second connection port. Both generator setups (Galli Eo/Galli Eo) and Galli Eo/Galliapharm) were comparably effective. The respectively modified systems allowed the production of [⁶⁸Ga]Ga-DOTATOC or [⁶⁸Ga]Ga-HBED-PSMA-11 with non-decay corrected labelling yields of 71 ± 8 % and radiochemical purities > 98 %. The average synthesis time was 25 minutes. Assuming a patient dose of 150 MBq (for Ga-68 radiopharmaceutical), both generator combinations using the modified cassettes provided up to two additional patient doses per production implying substantial cost savings per dose.

Schlussfolgerungen/Conclusions The standard labelling sequence as well as the cassettes for the cationic purification could be successfully modified to allow an efficient automated Ga-68 multi generator elution for the radiosynthesis of [⁶⁸ Ga]GaDOTATOC or [⁶⁸ Ga]Ga-HBED-PSMA-11. Based on the use of dedicated ready-to-use chemical kits, the multi generator elution has proven to be a very reliable modification for the routine clinical production providing more radiolabelled product with lower costs.