what is FDG used in Nuclear Medicine? Done by my friends and I

1. 2009
Collected and organized
by:
Haya Al-Thuwaini,
Shatha Al-Mushait,
Nora Al-Ohaly, Khulod Al-
Washmi, Aaliah Alqahtani
, Aalia BaFqeeh
[WHAT IS FDG?]

2. FDG
Fluorodeoxyglucose is a glucose analog. Its full chemical name is
2-fluoro-2-deoxy-D-glucose, commonly abbreviated to FDG.
it is a compound in which a radioactive fluoride atom which was produced in a
cyclotron is attached to a molecule of glucose. Once in the body, the FDG
molecule is absorbed by various tissues just as normal glucose would be, and
the radiation from the fluorine is used to map the distribution of glucose within
the patient.
FDG works well to detect tumors because it can avidly concentrate in
cancerous tissue. it looks like sugar to the tumor, so it tends to gobble it up.
Because it isn’t the sugar the tumor is used to, it really can’t use it; it gets stuck
there, and you have a chance to image it. Basically, you’re fooling the tumor
into thinking that it’s taking up something that it needs.
It has been understood for over 5o years, that cancer cells, in general, have
increased glucose uptake and anaerobic metabolism compared to normal
tissues. Like glucose, FDG is taken up into cells through glucose transport
proteins (GLUT) and then phosphorylated by hexokinase to FDG-6-phosphate.
the FDG-6-phosphate becomes trapped in tissue in proportion to the rate of
glycolysis. This accumulation of 18F-FDG-6-phosphate forms the basis of tumor
metabolic imaging with PET.

3. FDG is most used in the medical imaging modality positron emission
tomography (PET),in which a compound is labeled with a radioisotope tracer
and injected into a patient. In a typical procedure, a patient is injected with
FDG — a dose of 5–10 millicuries — after not eating for four hours. After a 60–
120 minute wait, during which time the patient is asked to remain still and quiet
while the compound travels through the body, he or she lies down under the
camera system and is imaged .The scanner reads the 511-keV gamma photon
resulting from the interaction of the FDG-emitted positrons with electrons in
the body at locations where the FDG has become concentrated. A computer
then converts the data to images for physicians to examine.
Because the half-life of the F-18 radioisotope is short, 109.8 minutes, and
because the compound is also excreted in urine, there is no need for the patient
to take extra precautions due to the radiation—most of the compound is gone
by the time the examination is over and the patient is free to leave.
References
 http://www.ans.org/pubs/magazines/nn/docs/1999-11-2.pdf
 http://www.molecularimagingcenter.org/index.cfm?
PageID=7834&RPID=7165#PET scan, PET scanner
 http://en.wikipedia.org/wiki/FDG
 http://www.rxlist.com/fludeoxyglucose-drug.htm