Casey J McCarthy, Peter J H Scott
The identification of efficient radiochemical methods has been a long-standing challenge in the development and production of positron emission tomography (PET) tracers. Carbon-11, being a short-lived (t1/2 = 20.4 min) isotope, offers a unique set of challenges for regulatory-compliant radiochemistry with exceptional time constraints. Simultaneously, the diversity of radiochemical scaffolds available from carbon-11 maintains its importance in clinical PET radiosynthesis. [11C]Hydrogen cyanide ([11C]HCN) represents a unique example of a versatile 11C-synthon that can deliver broad chemical diversity for the synthesis of 11C-labeled PET radiopharmaceuticals. This review article describes recent investigations with [11C]HCN including its production, radiochemistry, and use in developing new PET radiopharmaceuticals.