Radiolabeled glucocorticoids as molecular probes for imaging brain glucocorticoid receptors by means of positron-emission-tomography (PET)

Over the last two decades, numerous attempts have been made to develop
¹¹C- and ¹⁸F-labeled radiotracers in order to study glucocorticoid receptor (GR)-mediated abnormalities of the hypothalamus-pituitary-adrenocortical (HPA) axis function and regulation in vivo by means of positron emission tomography (PET). The present review wants to address the research efforts dealing with the design, radio-synthesis and radiopharmacological evaluation of PET radiotracers for brain GR im-aging. The underlying problems such as metabolic instability, insufficient blood-brain-barrier penetration and/or high non-specific binding will be discussed.