Table 5.
Comparison of the number of included longitudinal studies investigating a given biomarker modality with the number reporting a significant association between the biomarker modality and a clinical measure of disease progression
| Biomarker modality | Number of studies investigating biomarker modality | Number of studies reporting a significant association between biomarker modality and a clinical measure of disease progression |
|---|---|---|
| FDOPA brain PET |
5 |
0 |
| DAT brain PET or SPECT |
8 |
3 |
| FDG brain PET |
2 |
2 |
| SPECT to investigate cerebral blood flow |
3 |
2 |
| MRI brain |
1 |
0 |
| Electrophysiological tests |
1 |
0 |
| Other | 1 | 0 |
PET and SPECT brain imaging studies which used ligands to examine dopamine active transporter function are grouped together. SPECT studies which use ligands to investigate cerebral blood flow are also grouped together. (SPECT, single-photon emission computed tomography; PET, positron emission tomography; MRI, magnetic resonance imaging; FDOPA, [18F]6-fluoro-L-3,4-dihydroxyphenylalanine; FDG, [18F]-2-fluoro-2-deoxyglucose; DAT, dopamine active transporter).