Production and tumour uptake of [ 64 Cu]Pyruvaldehyde- bis (N 4 -methylthiosemicarbazone) for PET and/or therapeutic purposes

Abstract

BACKGROUND: Copper-64 (T_1/2=12.7ºh) is an important radionuclide used both in PET imaging and therapy. [⁶⁴Cu]-pyruvaldehyde- bis(N⁴-methylthiosemicarbazone) ([64Cu]-PTSM) has already been used in the detection of cerebral and myocardial blood flow. In this study, a simple production method and tumour accumulation of [⁶⁴Cu]-PTSM in fibrosarcoma-bearing mice were reported.
MATERIAL AND METHODS: Cu-64 was produced via the 68Zn(p, αn)⁶⁴Cu nuclear reaction. [⁶⁴Cu]-PTSM was prepared using in-house made PTSM ligand and [⁶⁴Cu]cuprous acetate and injected to fibrosarcoma-bearing mice.
RESULTS: Copper-64 was prepared in chloride form (≈ 200 mCi, > 95% chemical yield at 180º 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. A significant tumour uptake was observed 2 hours post injection in tumour-bearing mice (tu- mour/muscle: 9, tumour/blood: 6).
CONCLUSION: [⁶⁴Cu]-PTSM was prepared on a radiopharmaceutical scale using readily available zinc-68, with high quality and was shown to possess application in the therapy and/or imaging of fibrosarcoma.