Development of an automatic Copper-62 ATSM preparation module in aseptic condition

Objectives Copper-62 labeled diacetyl-bis(N4-methylthiosemicarbazone), ⁶²Cu-ATSM, is one of promising PET radiopharmaceuticals for hypoxia imaging in clinical trial. The ⁶²Cu can obtained from ⁶²Zn/⁶²Cu generator with a glycine solution and it is possible to try PET studies without a cyclotron. We have designed and developed the flexible module system using miniature humanoid robot kits which are commercially available as hobby. The system was designed a three-way valve unit, a syringe unit and I/O units for controlling external devises. These units were adjusted a sterilized disposable three-way valve and syringe, to realize sterility as well as disposability. In addition, this concept allowed us to prevent cross-contamination of the reagents. In this study, we assembled an automatic module for ⁶²Cu-ATSM preparation in aseptic condition.

Methods The ⁶²Zn/⁶²Cu generator was obtained from National Institute of Radiological Sciences. The automatic module was consisted 2 syringe units and 6 valve units. A glycine solution (200 mM, 5 mL) was used for ⁶²Cu elution from the ⁶²Zn/⁶²Cu generator and then added 5 mL of saline solution including 50 mg of sodium ascorbate to prevent decomposition before injection.

Results We assessed 10 generators for the ⁶²Cu-ATSM preparations. The preparation time was accomplished at sufficient reproducibility under pyrogen-free condition in less than 1 min. The quality control such as radiochemical purity, pH, and sterility were passed. The results were similar to that of manual operations.

Conclusions The automation of the ⁶²Cu-ATSM preparation was produced high quality radiopharmaceutical. In addition, it reduced a human error and an exposure module. Thus, the convenient system may help the research of the PET probe development