fluori18

fluori18 is a term used to describe fluorine-18–labeled radiotracers utilized in positron emission tomography (PET) imaging. It does not denote a single chemical but rather a class of compounds in which the fluorine-18 isotope is incorporated into biologically active molecules. The most widely used fluorine-18 radiotracer is 2-deoxy-2-[18F]fluoro-D-glucose (18F-FDG), which tracks glucose metabolism and is employed across oncology, neurology, and cardiology.

Production and properties of fluorine-18 radiotracers rely on cyclotron facilities that bombard enriched 18O water with protons to produce 18F via the 18O(p,n)18F reaction. The isotope has a half-life of about 109.8 minutes and decays by positron emission, enabling high-resolution PET imaging while allowing same-day imaging workflows. After production, 18F is incorporated into radiolabeled molecules through nucleophilic substitution or other radiochemical methods, typically using automated synthesis modules in accredited radiopharmacies. Radiotracers are then purified and subjected to quality control to ensure radiochemical purity and sterility before clinical use.

Common fluorine-18 tracers beyond 18F-FDG include compounds used for brain and tumor characterization, such as 18F-FDOPA, 18F-FET, and 18F-FLT, as well as bone imaging agents like 18F-NaF. The choice of tracer depends on the clinical question, availability, and regulatory approvals. Limitations of fluorine-18 PET imaging include the need for on-site or regional radiopharmacy support due to the tracer’s short half-life and the requirement for appropriate radiation safety and regulatory compliance.

See also: PET imaging, radiopharmaceuticals, cyclotron production.