TABLE II.
Activity measured in gold-coated zinc (Zn@Au) NP irradiated with 14.15 and 8-MeV incident protons.
| Variable | First measurement (14.15 MeV) | Second measurement (8.00 MeV) |
|---|---|---|
| Initial measured target activity (Specific activity) | 168 ± 1 μCi @ 32 min EOBa (5.52 mCi/g) | 173 ± 1 μCi @ 17 min EOB (7.52 mCi/g) |
| Initial target activity calculated using Eq. (1) | 50 μCi @ 32 min EOB (66Ga: 17%, 68Ga: 83%) | 33 μCi @ 17 min EOB (66Ga: 10%, 68Ga: 90%) |
| Final measured target activity (Specific activity) | 2 ± 1 μCi @ 24 h 32 min EOB (0.07 mCi/g) | 0.5 ± 0.5 μCi @ 5 h 17 min EOB (0.04 mCi/g) |
| Final target activity calculated using Eq. (1) | 1 μCi @ 24 h 32 min EOB (66Ga: 100%, 68Ga: 0%) | 3 μCi @ 5 h 17 min EOB (66Ga: 99%, 68Ga: 1%) |
| Calculated TTYb of 66Ga for 1-h proton bombardment of natural zinc (mCi/μA) | 4.9 | 0.5 |
| Calculated TTY of 66Ga for 1-h proton bombardment of Zn@Au NPs (mCi/μA) | 0.10 | 0.01 |
| Calculated activity of Zn@Au NPs bombarded using a 50-μA proton current for 2 h (typical FDG production setting), 24 h after EOB (mCi) | 2.37 | 0.24 |
| Calculated specific activityc, 24 h after EOB (mCi/g) | 9.84 | 4.00 |