[ 11 C]Choline

Choline is an important component of phospholipids in the cell membranes. Tissues with increased metabolism will lead to an increased uptake of choline. Choline is phosphorylated by choline kinases (CHK) to phosphorylcholine within cells, and, after several biosynthetic processes, finally is integrated into phospholipids (1). Because tumor cells have a high metabolic rate, choline uptake is high in order to keep up with the demands with the synthesis of phospholipids in their cellular membranes (2). Positron emission tomography (PET) with [11C]Choline has been reported to be useful for the detection and differential diagnosis of brain tumors, prostate cancer, lung cancer, and esophageal cancer (3, 4), whereas [18F]2-fluoro-2-deoxyglucose (FDG) lacks of specificity or sensitivity (3).