11Cphosphocholine

11Cphosphocholine is a radiopharmaceutical used in positron emission tomography (PET) imaging. It is a carbon-11 labeled analogue of phosphocholine that enables visualization of choline metabolism and membrane phospholipid turnover in vivo. The tracer provides information about cellular membrane synthesis and the activity of choline kinase, processes often upregulated in cancer cells.

Production and properties

11Cphosphocholine is produced in a cyclotron by incorporating the carbon-11 isotope into the phosphocholine molecule. Because carbon-11 has a half-life of about 20.4 minutes, synthesis, quality control, and imaging must be performed rapidly, and facilities typically require on-site radiochemistry capabilities to use the tracer clinically.

Mechanism of uptake

Following intravenous administration, 11Cphosphocholine is transported into cells via choline transporters and is phosphorylated by choline kinase to 11C-labeled phosphocholine, which becomes trapped inside the cell. The PET signal largely reflects the rate of choline uptake and phosphorylation, providing a surrogate measure of membrane turnover and tumor metabolic activity.

Clinical use and limitations

11Cphosphocholine has been investigated in several cancer types, including prostate cancer, gliomas, breast cancer, and hepatocellular carcinoma, with the aim of distinguishing malignant from benign lesions and monitoring therapy response. Uptake can also occur in inflammatory or benign conditions, reducing specificity. Its use is generally confined to centers with on-site cyclotron facilities and appropriate radiochemistry expertise; in many settings, other tracers such as 11C-choline or longer-lived alternatives are more commonly used. It is primarily employed in research contexts and is not universally approved as a standard diagnostic agent.

See also

11C-choline, PET radiopharmaceuticals, radiotracer imaging.