(R)-[18F]NEBIFQUINIDE: A promising new PET tracer for TSPO imaging

Abstract Positron emission tomography (PET) imaging of the 18 kDa translocator protein (TSPO), has a high diagnostic potential in neurodegenerative disorders and cancer. However, TSPO is considered a challenge for molecular imaging due to the poor availability of suitable radiotracers with adequate pharmacokinetic properties. Here, we describe the development of a radiofluorinated pyridinyl isoquinoline analogue of the established TSPO PET tracer ( R )-[ 11 C]PK11195 with improved binding properties in all known human TSPO phenotypes. We conducted a complete preclinical evaluation using in vitro , in vivo and ex vivo methods to assess the performance of this novel radiotracer and observed high specific binding of the radiotracer to TSPO, as well as high metabolic stability. Therefore, we propose this radiolabeled compound for further evaluation in animal models as well as in clinical trials.