Preparation of [64 Cu] pyruvaldehyde-bis (N4 -methylthiosemicarbazone) complex as a PET and / or therapeutic radiopharmaceutical

Background: Copper-64 (T1/2 =12.7 h) is an important radionuclide used both in PET imaging and therapy. [64 Cu]- pyruvaldehyde-bis (N4-methylthiosemicarbazone)([64Cu]-PTSM) is one of the most famous copper radiopharmaceuticals with unique specifications (suitable half-life, stability, etc.) The wide range of 64Cu applications arouse great interest for its production. Material and methods: Cu-64 was produced via the 68Zn (p,αn)64Cu nuclear reaction and isolated from the irradiated target by a two-step chemical method. [64Cu]-PTSM was prepared using in house made PTSM ligand and [64Cu] cuprous acetate. The complex formation parameters (time, temperature, concentration and elution methods) were determined carefully. Results: Copper-64 was prepared in chloride form (∼ 200 mCi,>95% chemical yield at 180 μA for 1.1 h irradiation, radionuclidic purity> 96%,copper-67 as impurity). The solution of 64Cu-PTSM was prepared in >80% radiochemical yield and more than 98% radiochemical purity. Quality controls and stability tests were performed for the final solution. Conclusion: [64Cu]-PTSM was prepared at the radiopharmaceutical scales with high quality and potential to be used in therapeutic/imaging centers