Choline

Choline labeled with Carbon-11 is a promising biomarker for tumor imaging using PET. It has been shown that there is an increased synthesis of membranal phosphatidylcholinein tumor cells that is correlated with high uptake of this radiopharmaceutical in malignant tissues.

It is particularly effective in imaging tumors localized in the brain, lung, esophagus, rectum, prostate and urinary bladder.

In contrast to [F-18]fluorodeoxyglucose(FDG), the uptake of [C11] choline in benign structures such as the normal brain, heart and urinary tract is negligible, resulting in a higher target to background signal ratio for tumors located near those benign structures.

[C-11]Choline is prepared by a [C-11]methylation reaction of dimethylaminoethanol (DMAE) using labeled methyl iodide (MeI), and a simple sep-pak purification step. It is therefore very important to determine accurately the quantity of DMAE in the final product.