The Value of the Dopamine D2/3 Receptor Ligand 18F-Desmethoxyfallypride for the Differentiation of Idiopathic and Nonidiopathic Parkinsonian Syndromes

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FIGURE 1.
Striatal dopamine D_2/3 receptor binding of ¹⁸F-DMFP in 1 patient with non-IPS (A) and 1 patient with IPS (B). Decreased D_2/3 receptor binding, which was predominant in dorsal part of striatum, is shown in non-IPS (A), whereas increased D_2/3 receptor binding mainly in posterior putamen could be discerned even visually (B) and was interpreted as relative sparing of D_2/3 receptor.
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FIGURE 2.
(A) ROC for SB in caudate nucleus, anterior and posterior putamen, putamen, and striatum. (B) ROC for individual ratios: P to NC, PP to NC, and PP to PA.

TABLE 1

SB in All Striatal Regions, Ratios, and Absolute Lateralization Indices in Patients with IPS and Non-IPS

	IPS		Non-IPS				Sensitivity (%)	Specificity (%)			Accuracy (%)
Binding and region	Mean ± SD	Range	Mean ± SD	Range	P	ROC (AUC ± SE)	Sensitivity (%)	Specificity (%)	NPV (%)	PPV (%)	Accuracy (%)
Dopamine D_2/3–specific binding
Striatum	2.16 ± 0.32	1.52–2.96	1.55 ± 0.28	0.86–2.00	<0.001	0.936 ± 0.027	86.5	90.9	88.9	88.9	88.9
Caudate nucleus	1.91 ± 0.32	1.23–2.66	1.48 ± 0.25	0.84–1.98	<0.001	0.859 ± 0.041	73.0	86.4	79.2	81.8	80.2
Putamen	2.23 ± 0.33	1.60–3.04	1.57 ± 0.31	0.79–2.08	<0.001	0.944 ± 0.024	86.5	93.2	89.1	91.4	90.1
Anterior putamen	2.12 ± 0.31	1.54–2.97	1.62 ± 0.28	1.00–2.12	<0.001	0.894 ± 0.036	83.8	86.4	86.4	83.8	85.2
Posterior putamen	2.42 ± 0.39	1.67–3.31	1.49 ± 0.42	0.46–2.13	<0.001	0.970 ± 0.016	86.5	95.5	89.4	94.1	91.4
P-to-NC ratio	1.18 ± 0.10		1.07 ± 0.20		<0.01	0.690 ± 0.058	81.1	47.7	75.0	56.6	63.0
PP-to-NC ratio	1.27 ± 0.13		1.02 ± 0.28		<0.001	0.830 ± 0.045	81.1	75.0	82.5	73.2	77.8
PP-to-PA ratio	1.14 ± 0.09		0.91 ± 0.18		<0.001	0.907 ± 0.032	83.8	81.8	85.7	79.5	82.7
Combination SB_PP and PP-to-PA ratio	—		—		—	—	97.3	84.1	97.4	83.7	90.1
ALI
Striatum	0.05 ± 0.04		0.10 ± 0.10		<0.01	0.372 ± 0.062	45.9	43.2	48.7	40.5	44.4
Caudate nucleus	0.08 ± 0.07		0.10 ± 0.06		>0.05	0.357 ± 0.063	62.2	20.5	39.1	39.7	39.5
Anterior putamen	0.05 ± 0.03		0.10 ± 0.11		<0.01	0.329 ± 0.059	75.7	11.4	35.7	41.8	40.7
Posterior putamen	0.08 ± 0.06		0.17 ± 0.18		<0.01	0.340 ± 0.060	86.5	11.4	50.0	45.1	45.7
Discriminant analysis (SB_PP, PP-to-PA ratio, and PP-to-NC ratio)	—		—		—	—	91.9	95.5	93.3	94.4	93.8

Level of significance from Student t test (P); AUC with respective SE from ROC analysis; and sensitivity, specificity, NPV, PPV, and accuracy for optimal specific binding threshold are presented.