Fludeoxyglucose F 18 Injection (fdg) is a positron emitting radiopharmaceutical containing
no-carrier added radioactive 2-deoxy-2-[18F]fluoro-D-g1ucose, which
is used for diagnostic purposes in conjunction with Positron Emission Tomography
(PET). It is administered by intravenous injection.
The active ingredient 2-deoxy-2-[18F]fluoro-D-g1ucose (Fludeoxyglucose
F 18), abbreviated [18F] FDG, has a molecular formula of C6H1118FO5
with a molecular weight of 181.26 daltons, and has the following chemical structure:
Fludeoxyglucose F 18 Injection (fdg) is provided as a ready to use isotonic, sterile,
pyrogen free, clear, colorless citrate buffered solution. Each mL contains between
0.37 to 3.7 GBq (10.0 - 100 mCi) of 2-deoxy-2-[18F]fluoro-D glucose
at the end of synthesis (EOS), 4.5 mg of sodium chloride and 7.2 mg of citrate
ions. The pH of the solution is between 5.0 to 7.5. The solution is packaged
in a multiple-dose glass vial and does not contain any preservative.
Fluorine F 18 decays by positron (β+) emission and has a half-life
of 109.7 minutes. The principal photons useful for diagnostic imaging are the
511 keV gamma photons, resulting from the interaction of the emitted positron
with an electron (Table 1).
Table 1. Principal Emission Data for Fluorine F 18
||% per Disintegration
| *Produced by positron annihilation
From: Kocher, D.C. "Radioactive Decay Tables" DOE/TIC-11026, 89 (1981).
The specific gamma ray constant for fluorine F 18 is 6.0 R/hr/mCi (0.3 Gy/hr/kB) at 1cm. The half-value layer (HVL) for the 511 keV photons is 4.1 mm lead (Pb). A range of values for the attenuation of radiation results from the interposition of various thickness of Pb. The range of attenuation coefficients for this radionuclide is shown in Table 2. For example, the interposition of an 8.3 mm thickness of Pb, with a coefficient of attenuation of 0.25, will decrease the external radiation by 75%.
Table 2. Radiation Attenuation of 511 keV Photons by Lead
|Shield Thickness (Pb) mm
||Coefficient of Attenuation
For use in correcting for physical decay of this radionuclide, the fractions remaining at selected intervals after calibration are shown in Table 3.
Table 3. Physical Decay Chart for Fluorine F 18
|* Calibration time
Last reviewed on RxList: 9/15/2008
This monograph has been modified to include the generic and brand name in many instances.