fludeoksiglukosia

Fludeoxyglucose, commonly abbreviated as FDG, is a radioactive tracer used in Positron Emission Tomography (PET) imaging. It is a glucose analog where the hydroxyl group at the 2-position of deoxyglucose is replaced by a fluorine-18 atom. This structural modification allows FDG to be detected by PET scanners.

Once injected into the bloodstream, FDG is taken up by cells in a manner similar to glucose. Cells with high metabolic activity, particularly those consuming a lot of glucose, will accumulate more FDG. In the body, FDG is phosphorylated by hexokinase to FDG-6-phosphate. However, unlike glucose-6-phosphate, FDG-6-phosphate cannot be further metabolized or transported out of the cell, effectively trapping it within metabolically active tissues.

The fluorine-18 isotope has a half-life of approximately 110 minutes, making it suitable for PET imaging. The decay of fluorine-18 emits positrons, which annihilate with electrons in surrounding tissue, producing two gamma rays that travel in opposite directions. PET scanners detect these gamma rays and reconstruct an image that reflects the distribution of FDG in the body.

FDG-PET is widely used in oncology to detect, stage, and monitor treatment response for various cancers. Cancer cells often exhibit increased glucose metabolism, leading to higher FDG uptake in tumors compared to surrounding healthy tissues. It is also utilized in neurology to assess brain metabolism in conditions like Alzheimer's disease and epilepsy, and in cardiology to evaluate myocardial viability.