Comparison of Brain Exposures for 11C-PBR28, 18F-GE180, and 5 Other Radioligands
| Parameter | 11C-PBR28 | 18F-GE180 | 11C-LY2428703 (28) | 18F-FMPEP-d2 (30) | 18F-SP203 (50) | 11C-(R)-rolipram (31) | 11C-NOP-1A (32) |
| Target | TSPO | TSPO | mGluR1 | CB1 | mGluR5 | PDE4 | NOP |
| Brain SUVpeak | ∼2 | ∼0.7 | ∼0.5 | 3–4 | ∼6 | 2–2.5 | 5–7 |
| Exposure SUV (0–20 min) | 41.1 | 169.8 | 202.2 | 47.8 | 37.0 | 124.9 | 36.7 |
| fp (%) | 4.1 | 3.5 | 0.094 | 0.63 | 5.2 | 6.4 | 10.1 |
| Effective exposure* | 1.7 | 5.9 | 0.19 | 0.30 | 1.9 | 8.0 | 3.7 |
↵* Area under curve of input function during first 20 min multiplied by free fraction.
mGluR1 = metabotropic glutamate receptor 1; CB1 = cannabinoid receptors type 1; mGluR5 = metabotropic glutamate receptor 5; PDE4 = phosphodiesterase 4; NOP = nociceptin/orphanin FQ peptide.
Brain exposure for 11C-PBR28 and 18F-GE180, compared with that of the 5 other radioligands analyzed in Zanotti-Fregonara (28).