Innovative PET and SPECT tracers

Abstract

Although suitable radiotracers are available for many clinical applications in emission tomography such as SPECT and PET, improved tracers are required for advanced nuclear medical imaging. But their development remains a challenge. The demand for new tracers arises from recent progress in the development of imaging techniques and innovations in isotope production. Particularly the latter has triggered an interest in hitherto less favored radionuclides for routine applications of nuclear medical imaging. Since most new tracers are radioactive metals, the coordination chemistry of some of the elements of interest needs to be extended to meet the specific requirements that apply to the preparation of radioactive pharmaceuticals. New tracers for SPECT and PET are typically developed for one or more of the following reasons: (a) to optimize (frequently multidentate) ligand structures for specific radiometal ions, (b) to develop multiuse ligands for the complexation of multiple metal ions, (c) to search for convenient coupling strategies for bioconjugates, and (d) to provide agents for theranostic solutions. This chapter gives an overview of strategies in radiochemistry and tracer development for nuclear medical imaging applications.