SPL Set ID: 08044d8f-036c-4809-997f-dd5180feebe6

11.1 Chemical Characteristics Fludeoxyglucose F-18 Injection is a positron emitting radiopharmaceutical that is used for diagnostic purposes in conjunction with positron emission tomography (PET) imaging. The active ingredient 2-deoxy-2-[ 18 F]fluoro-D-glucose has the molecular formula of C 6 H 11 18 FO 5 with a molecular weight of 181.26, and has the following chemical structure: Fludeoxyglucose F-18 Injection is provided as a ready to use sterile, pyrogen free, clear, colorless citrate buffered solution. Each mL contains between 0.74 - 18.5 GBq (20 - 500 mCi/mL) of 2-deoxy-2-[ 18 F]fluoro-D-glucose at the EOS, 4.5 mg of sodium chloride in citrate buffer. The pH of the solution is between 4.5 and 7.5. The solution is packaged in a multiple-dose glass vial and does not contain any preservative. Chemical Structure 11.2 Physical Characteristics Fluorine F-18 has a physical half-life of 109.7 minutes and decays to Oxygen O-18 (stable) by positron decay. The principal photons useful for imaging are the dual 511 keV “annihilation” gamma photons that are produced and emitted simultaneously in opposite directions when the positron interacts with an electron (Table 2). Table 2. Principal Radiation Emission Data for Fluorine F-18 Radiation/Emission % Per Disintegration Mean Energy * Produced by positron annihilation From: Kocher, D.C. Radioactive Decay Tables DOE/TIC-I 1026, 89 (1981) Positron(β+) 96.73 249.8 keV Gamma(±)* 193.46 511.0 keV The specific gamma ray constant (point source air kerma coefficient) for fluorine F-18 is 5.7 R/hr/mCi (1.35 x 10 -6 Gy/hr/kBq) at 1 cm. The half-value layer (HVL) for the 511 keV photons is 4 mm lead (Pb) or 2.9 mm tungsten (W) alloy. The range of attenuation coefficients for this radionuclide as a function of shield thickness is shown in Table 3. For example, the interposition of an 8 mm thickness of Pb or 5.8 mm thickness of W alloy, with a coefficient of attenuation of 0.25, will decrease the external radiation by 75%. Table 3. Radiation Attenuation of 511 keV Photons by Lead (Pb) and Tungsten (W) Alloy Shielding Shield Thickness (Pb) mm Shield Thickness (W) Alloy mm Coefficient of Attenuation 0 0 0.00 4 2.9 0.50 8 5.8 0.25 13 9.4 0.10 26 18.7 0.01 39 27.6 0.001 52 37.4 0.0001 For use in correcting for physical decay of this radionuclide, the fractions remaining at selected intervals after calibration are shown in Table 4. Table 4. Physical Decay Chart for Fluorine F-18 Minutes Fraction Remaining * calibration time 0* 1.000 15 0.909 30 0.826 60 0.683 110 0.500 220 0.250 440 0.060