ucla biomedical cyclotron - Medication Listings

11.1 Chemical Characteristics Gallium Ga 68 Gozetotide Injection is a radioactive diagnostic agent for intravenous administration. It contains 5 mcg gozetotide, 18.5 MBq/mL to 185 MBq/mL (0.5 mCi/mL to 5 mCi/mL) of gallium Ga 68 gozetotide at calibration time, 1 mL ethanol, 1 mL water for injection, and 10 mL of 0.9% sodium chloride solution (approximately 12 mL total volume). Gallium Ga 68 Gozetotide Injection is provided as a sterile, pyrogen free, clear, colorless solution for intravenous use, with a pH between 4.0 and 7.0. Gozetotide is also known as PSMA-11. Gallium Ga 68 gozetotide is a urea based peptidomimetic that has a covalently bound chelator (HBED-CC). The peptide has the amino acid sequence Glu-NH-CO-NH-Lys(Ahx)-HBED-CC. Gallium Ga 68 gozetotide has a molecular weight of 1011.91 g/mol and its chemical structure is shown in Figure 1. Figure 1: Chemical Structure of Gallium Ga 68 Gozetotide Chemical Structure 11.2 Physical Characteristics Gallium-68 (Ga 68) decays with a half-life of 68 minutes to stable zinc-68. Table 2 and Table 3 display the principal radiation emission data and physical decay of Ga 68. Table 2: Principal Radiation Emission Data (>1%) for Gallium Ga 68 Radiation/ Emission % Disintegration Mean Energy (MeV) beta+ 88% 0.8360 beta+ 1.1% 0.3526 gamma 178% 0.5110 gamma 3.0% 1.0770 X-ray 2.8% 0.0086 X-ray 1.4% 0.0086 Table 3: Physical Decay Chart for Gallium Ga 68 Minutes Fraction Remaining 0 1 15 0.858 30 0.736 60 0.541 90 0.398 120 0.293 180 0.158 240 0.086 360 0.025 11.3 External Radiation Table 4 displays the radiation attenuation by lead shielding of Ga 68. Table 4: Radiation Attenuation of 511 keV Photons by Lead (Pb) Shielding Shield Thickness (Pb) mm Coefficient of Attenuation 6 0.5 12 0.25 17 0.1 34 0.01 51 0.001