PT - JOURNAL ARTICLE AU - la Fougère, Christian AU - Pöpperl, Gabriele AU - Levin, Johannes AU - Wängler, Björn AU - Böning, Guido AU - Uebleis, Christopher AU - Cumming, Paul AU - Bartenstein, Peter AU - Bötzel, Kai AU - Tatsch, Klaus TI - The Value of the Dopamine D<sub>2/3</sub> Receptor Ligand <sup>18</sup>F-Desmethoxyfallypride for the Differentiation of Idiopathic and Nonidiopathic Parkinsonian Syndromes AID - 10.2967/jnumed.109.071811 DP - 2010 Apr 01 TA - Journal of Nuclear Medicine PG - 581--587 VI - 51 IP - 4 4099 - http://jnm.snmjournals.org/content/51/4/581.short 4100 - http://jnm.snmjournals.org/content/51/4/581.full SO - J Nucl Med2010 Apr 01; 51 AB - We evaluated the utility of the selective dopamine D2/3 receptor ligand 18F-desmethoxyfallypride (18F-DMFP) for the differential diagnosis of patients with idiopathic parkinsonian syndrome (IPS) and nonidiopathic parkinsonian syndrome (non-IPS). On the basis of the superior sensitivity of PET, we hypothesized that 18F-DMFP should have properties for the differential diagnosis of these syndromes superior to what has been reported for the more conventional SPECT procedures. Methods: A series of 81 patients with parkinsonism (26 women, 55 men; mean age ± SD, 68 ± 11 y) were included in this retrospective analysis. A 30-min 18F-DMFP PET recording was acquired starting 1 h after injection of the tracer (180–200 MBq, intravenously). The specific binding (SB) in divisions of the striatum was calculated relative to the occipital cortex using an observer-independent semiautomatic volume-of-interest–based technique. The optimal SB threshold was defined by means of receiver-operating-characteristic analysis, which was also used for the evaluation of the diagnostic performance of SB, ratios between striatal subregions, and absolute asymmetries in SB. Results: Significant differences (P &lt; 0.001) were found in striatal SB between IPS and non-IPS, most notably in the posterior putamen, for which the diagnostic power for discrimination of IPS and non-IPS was the highest (sensitivity, 87%; specificity, 96%; and accuracy, 91%). A further gain of diagnostic power (sensitivity, 92%; specificity, 96%; and accuracy, 94%) was obtained through discriminant analysis combining 3 parameters: SB of the posterior putamen, the posterior–to–anterior putamen ratio, and the posterior putamen–to–caudate ratio. Conclusion: 18F-DMFP PET is useful for the differential diagnosis of IPS and non-IPS in patients with parkinsonism. The findings are consistent with relative sparing of D2/3 receptors in the dopamine-denervated putamen of IPS patients, in contrast to a more substantial loss of striatal dopamine receptors in non-IPS patients. The PET procedure for this differential diagnosis was superior to the reported experience with 123I-iodobenzamide SPECT.