Input functions for 6-[fluorine-18]Fluorodopa quantitation in parkinsonism: Comparative studies and clinical correlations
- North Shore Univ. Hospital/Cornell Univ., Medical College, Manhasset, NY (United States)
PET has been used to quantify striatal 6-[{sup 18}F]fluro-L-dopa (FDOPA) uptake as a measure of presynaptic dopaminergic function. Striatal FDOPA uptake rate constants (K{sub 1}) can be calculated using dynamic PET imaging with measurements of the plasma FDOPA input function determined either directly or by several estimation procedures. The authors assessed the comparative clinical utility of these methods by calculating the striato-occipital ratio (SOR) and striatal K{sub 1} values in 12 patients with mild to moderate PD and 12 age-matched normal volunteers. The plasma FDOPA time-activity curve (K{sub 1}{sup FD}); the plasma {sup 18}F time-activity curve (K{sub i}{sup P}); the occipital time-activity curve (K{sub i}{sup OCC}); and a simplified population-derived FDOPA input function (K{sub i}{sup EFD}) were used to calculate striatal K{sub i}. Mean values for all striatal K{sub i} estimates and SOR were significantly lower in the PD group. Although all measured parameters discriminated PD patients with normals, K{sub i}{sup FD} and K{sub i}{sup EFD} provided the best between-group separation. K{sub i}{sup FD}, K{sub i}{sup EFD}, and K{sub i}{sup OCC} measures correlated significantly with quantitative disease severity ratings, although K{sub i}{sup FD} predicted quantitative clinical disability most accurately. These results suggest that K{sub i}{sup FD} may be an optimal marker of the parkinsonian disease process. K{sub i}{sup EFD} may be a useful alternative to K{sub i}{sup FD} for most clinical research applications. 40 refs., 4 figs., 7 tabs.
- OSTI ID:
- 96082
- Journal Information:
- Journal of Nuclear Medicine, Vol. 35, Issue 6; Other Information: PBD: Jun 1994
- Country of Publication:
- United States
- Language:
- English
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