SPL Set ID: 2bbd8f48-fdf9-45cb-8305-124a03f7a52c

11.1 Chemical Characteristics Sodium Fluoride F 18 Injection is a positron emitting radiopharmaceutical, containing no-carrier-added, radioactive fluoride F18 that is used for diagnostic purposes in conjunction with PET imaging. It is administered by intravenous injection. The active ingredient, sodium fluoride F18, has the molecular formula Na[ 18 F] with a molecular weight of 40.99, and has the following chemical structure: Sodium Fluoride F 18 Injection is provided as a ready-to-use, isotonic, sterile, pyrogen-free, preservative-free, clear and colorless solution. Each mL of the solution contains between 370 MBq and 7,400 MBq (10 mCi to 200 mCi) sodium fluoride F18, at the EOS reference time, in 0.9% aqueous sodium chloride. The pH of the solution is between 4.5 and 8. The solution is presented in XX mL multiple- dose glass vials with variable total volume and total radioactivity in each vial. image of chemical structure 11.2 Physical Characteristics Fluoride F18 decays by positron (β+) emission and has a half-life of 109.7 minutes. Ninety-seven percent of the decay results in emission of a positron with a maximum energy of 633 keV and 3% of the decay results in electron capture with subsequent emission of characteristic X-rays of oxygen. 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 2). Fluorine F18 atom decays to stable 18 O-oxygen. Table 2: Principal Emission Data for Fluoride F18 Radiation/Emission % per Disintegration Mean Energy Positron (β+) 96.73 249.8 keV Gamma (±) Produced by positron annihilation [3] Kocher, D.C. Radioactive Decay Data Tables DOE/TIC-11026, 69, 1981. 193.46 511.0 keV The specific gamma ray constant for fluoride F18 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 4.1 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 3. 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 3:Radiation Attenuation of 511 keV Photons by Lead (Pb) Shielding Shield Thickness (Pb) mm Coefficient of Attenuation 0 0.00 4 0.50 8 0.25 13 0.10 26 0.01 39 0.001 52 0.0001 Table 4 lists the fraction of radioactivity remaining at selected time intervals from the calibration time. This information may be used to correct for physical decay of the radionuclide. Table 4: Physical Decay Chart for Fluoride F18 Time Since Calibration Fraction Remaining 0 Calibration time 1.00 15 minutes 0.909 30 minutes 0.826 60 minutes 0.683 110 minutes 0.500 220 minutes 0.250 440 minutes 0.060 12 hours 0.011 24 hours 0.0001