Abstract
Radiopharmaceutical development usually requires chelators to route radiometals to specific cancer targets. However, there is no universal chelator. To reduce off-target side effects, new chelators are needed as the radiometal toolset grows. DOTA is the most often used chelator for radiometals in radiopharmaceutical development, however DOTA's extreme conditions make it unsuitable for labeling heat sensitive biological vectors. The ideal chelator should be thermodynamically and kinetically stable, allowing labeling under mild conditions (~37 °C). In recent years, new hybrid chelators with enhanced characteristics have emerged, warranting further investigation for medical applications. This paper aims to discuss some of these promising chelators.