Copper Complexes for Theranostics: From PET Imaging to Therapy

Various radio copper (Cu) labeled radiopharmaceuticals have been reported. Among them, Cu-diacetyl-bis(N4-methyl-thiosemicarbazone) (Cu-ATSM) labeled with Cu-62/64 was originally designed as a PET radiopharmaceutical for imaging of hypoxic metabolism. Basic as well as clinical studies have demonstrated the usefulness and limitations of Cu-ATSM as a diagnostic imaging agent. From the recent therapeutic application of Cu-64, the potential of Cu-64-ATSM for the targeted radionuclide therapy of hypoxic tumor has been clarified. Oxidative stress in neurodegenerative diseases has also been a target of Cu-ATSM, not only as a diagnostic imaging agent, but as a therapeutic drug with a selective Cu delivery system to the Cu depleted region in ALS as well as Parkinson’s disease animal models. Cu-ATSM is a simple metal compound, but may have wide-ranging possibilities not only in oncology but also neurology applications.