Targeting colony‐stimulating factor 1 receptor: From therapeutic drugs to diagnostic radiotracers

Abstract Colony‐stimulating factor 1 receptor (CSF1R) is highly expressed in mononuclear phagocytes and in the central nervous system. It has emerged as a promising target for tumor therapy and neuroinflammation imaging. Although therapeutic agents targeting CSF1R have shown great success, the development of diagnostic radiotracers for CSF1R has faced numerous challenges. Consequently, there is an urgent need to overcome these obstacles for the development of CSF1R radiotracers, particularly positron emission tomography tracers, not only for diagnostic purposes but also to aid the development of more effective therapeutic drugs. Here, we provide a comprehensive overview of the development of CSF1R radiotracers, presenting detailed profiles of each tracer's ability to image CSF1R. Additionally, we discuss reported CSF1R small‐molecule inhibitors and antibodies, highlighting their relevance to the further development of CSF1R radiotracers. We aim to shed light on the current state of CSF1R radiotracer research and development, provide an insight into the challenges in this field, and offer guidance for future exploration.