April 28, 2015
Glucose is essential for providing the energy needed to support cellular processes and is in high demand by areas of the body, which are especially active, such as the brain. Similarly, rapidly growing and differentiating cancer cells have an increased metabolic demand and glucose uptake.
A radiolabelled glucose analogue, 18F-fluoro-deoxyglucose (FDG), is taken up by energy-hungry cancer cells as if it were ordinary glucose. However, the hydroxyl group needed for the glucose to be further metabolised within the cell has been replaced with the radiolabel. Furthermore, phosphorylation of the FDG once it enters the cell means it cannot leave. The FDG is thus trapped within the cell until radioactive decay occurs and a new hydroxyl group is formed allowing the glucose to be metabolized.