Table 1.
Comparison of microscale [18F]FDOPA synthesis performance using manual and automated approaches. All values are averages ± standard deviations for the indicated number of replicates. All percentages are decay-corrected unless otherwise indicated. N.M. indicates the quantity was not measured.
| Manual synthesis (n=3) | Automated synthesis-low starting activity (n=4) | Automated synthesis-higher starting activity (n=3) | |
|---|---|---|---|
| Starting activity (MBq) | 4.4 ~ 12 | 13 ~ 23 | 350 ~ 380 |
| Synthesis time including purification (min) | ~33 | ~30 | ~31 |
| [18F]FDOPA conversion (%) | 95.6 ± 0.4 | 78 ± 4 | 54.9 ± 1.9 |
| Crude RCY (%) | 20.5 ± 3.5 | 15.2 ± 2.1 | 5.2 ± 0.7 |
| Isolated RCY (%) | 15.1 ± 1.6 | 10.3 ± 1.4 | 4.7 ± 1.0 |
| Isolated RCY (%, non-corrected) | 12.3 ± 1.3 | 8.5 ± 1.2 | 3.9 ± 1.8 |
| Enantiomeric purity (%) | 98.0 ± 0.2 | N.M. | N.M. |
| Total activity loss during synthesis (%) | 50 ± 5 | 78 ± 2 | 85 ± 2 |
| Unrecoverable activity on cover chip (%) | 24.7 ± 0.3 | cover not used | cover not used |
| Unrecoverable activity on bottom chip (%) | 2.1 ± 0.4 | 2.9 ± 0.2 | 5.9 ± 2.9 |
| Radioactivity recovery (%) | 21 ± 4 | 20 ± 2 | 10 ± 2 |