The value of the dopamine D2/3 receptor ligand 18F-desmethoxyfallypride for the differentiation of idiopathic and nonidiopathic parkinsonian syndromes.

Abstract

UNLABELLED:

We evaluated the utility of the selective dopamine D(2/3) receptor ligand (18)F-desmethoxyfallypride ((18)F-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 (18)F-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 (18)F-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 < 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:

(18)F-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 D(2/3) 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 (123)I-iodobenzamide SPECT.

• Authors: Christian la Fougère, Gabriele Pöpperl, Johannes Levin, Björn Wängler, Guido Böning, Christopher Uebleis, Paul Cumming, Peter Bartenstein, Kai Bötzel, Klaus Tatsch
• Journal: Journal of nuclear medicine : official publication, Society of Nuclear Medicine (J Nucl Med) Vol. 51 Issue 4 Pg. 581-7 (Apr 2010) ISSN: 1535-5667 [Electronic] United States
• PMID: 20237026 (Publication Type: Journal Article)

Chemical References

• Ligands
• Receptors, Dopamine D2
• Receptors, Dopamine D3
• Salicylamides
• desmethoxyfallypride

Topics

• Adult
• Aged
• Aged, 80 and over
• Diagnosis, Differential
• Female
• Follow-Up Studies
• Humans
• Ligands
• Male
• Middle Aged
• Neostriatum (metabolism)
• Parkinson Disease (diagnosis, diagnostic imaging, metabolism)
• Positron-Emission Tomography
• ROC Curve
• Receptors, Dopamine D2 (metabolism)
• Receptors, Dopamine D3 (metabolism)
• Retrospective Studies
• Salicylamides (metabolism)
• Sensitivity and Specificity