Table 3.
Main findings from [18F]PM-PBB3 and [18F]PI-2620 tau PET studies.
| Paper | Tracer | Clinical population | Findings |
|---|---|---|---|
| Ishizuchi (2021) | [18F]PM-PBB3 | 1 PSP | Increased tracer retention in PSP tau sites |
| Li (2021) | [18F]PM-PBB3 | 20 PSP, 7 MSA, 10 PD, 13 HC | Increased tracer binding in typical PSP regions; binding did not increase with age in any group, indicating unlikely off-target activity |
| Mashima (2021) | [18F]PM-PBB3 | 1 CBD | Increased tracer accumulation in subcortical regions and asymmetrical neocortex led to CBD diagnosis |
| Zhou (2021) | [18F]PM-PBB3 | 7 MAPT carriers, 15 HC | Tracer binding increased over time as FTD developed in MAPT carriers |
| Jantarato (2021) | [18F]PI-2620 | 26 HC, 7 AD, 36 MCI | Tracer binding consistent with Braak staging in AD |
| Palleis (2021) | [18F]PI-2620 | 45 CBS, 14 HC | Tracer binding contralateral to clinically more affected side in CBS |
| Song (2021) | [18F]PI-2620 | 37 PSP, 10 HC | Globus pallidus internus uptake differentiated PSP from controls |
| Song (2021) | [18F]PI-2620 | 10 AD, 15 PSP, 14 CBS | Tracer uptake differentiates 3R/4R tauopathies from PSP and CBD; binding less stable in 4R tauopathies |
| Tezuka (2021) | [18F]PI-2620 | 3 PSP, 2 CBS, 1CBD, 8 AD, 7 HC | Increased tracer binding in globus pallidus in APs compared to AD but not HC; late-acquisition PET may not be appropriate for imaging 4R-tauopathies |
| Brendel (2020) | [18F]PI-2620 | 40 PSP-RS, 20 PSP-non-RS, 10 alpha-synucleinopathies, 10 AD, 10 HC | Increased binding in PSP target regions compared to control groups; region with best discriminatory ability was globus pallidus internus |
| Oh (2020) | [18F]PI-2620 | 3 HC, 9 MCI-AD, 6 FTD, 3 CBS/CBD, 2 PD (with dementia), 3 PSP | Tracer binding distinguished Parkinsonism from other tauopathies; asymmetrical binding in CBD consistent with literature; new off-target binding regions identified |