Reproducibility of Iodine123-f3CIT SPECT Brain Measurement of Dopamine Transporters (original) (raw)
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Evaluation of dopamine transporter density in healthy Brazilians using Tc-99m TRODAT-1 SPECT
Medicine, 2021
Purpose: The presynaptic dopamine transporter (DAT) modulates the uptake of dopamine by regulating its concentration in the central nervous system. We aimed to evaluate the DAT binding potential (DAT-BP) in a sample of healthy Brazilians through [ 99m Tc] TRODAT-1 single-photon emission computed tomography imaging. Methods: We selected 126 healthy individuals comprising 72 men and 54 women, aged 18-80 years. We conducted semi-quantitative evaluation in transaxial slices, following which we identi ed the regions of interest in the striatal region using the occipital lobe as a region of non-speci c DAT-BP. We found a decrease in DAT-BP in healthy individuals aged over 30 years, culminating in a 42% mean reduction after 80 years. Results: There was no difference in the decrease by age group between the right (R 2 linear=0.466) and left striatum (R 2 linear=0.510). Women presented a higher DAT-BP than men (women: R 2 linear=0.431; men: R 2 linear=0.457); nonetheless, their decrease by age group was equal to that in men. Conclusion: Our study sheds light on important DAT-BP ndings in healthy Brazilian subjects. Our results will facilitate understanding of brain illnesses that involve the dopamine system, such as neuropsychiatric disorders.
Evaluation of Dopamine Transporter Density in Healthy Brazilians Using [99mTc] TRODAT-1 SPECT
2020
Purpose: The presynaptic dopamine transporter (DAT) modulates the uptake of dopamine by regulating its concentration in the central nervous system. We aimed to evaluate the DAT binding potential (DAT-BP) in a sample of healthy Brazilians through [ 99m Tc] TRODAT-1 single-photon emission computed tomography imaging. Methods: We selected 126 healthy individuals comprising 72 men and 54 women, aged 18-80 years. We conducted semi-quantitative evaluation in transaxial slices, following which we identi ed the regions of interest in the striatal region using the occipital lobe as a region of non-speci c DAT-BP. We found a decrease in DAT-BP in healthy individuals aged over 30 years, culminating in a 42% mean reduction after 80 years. Results: There was no difference in the decrease by age group between the right (R 2 linear=0.466) and left striatum (R 2 linear=0.510). Women presented a higher DAT-BP than men (women: R 2 linear=0.431; men: R 2 linear=0.457); nonetheless, their decrease by age group was equal to that in men. Conclusion: Our study sheds light on important DAT-BP ndings in healthy Brazilian subjects. Our results will facilitate understanding of brain illnesses that involve the dopamine system, such as neuropsychiatric disorders.
Journal of Nuclear Medicine
were2.06 ±0.27and 1.50± 0.15,respectively. ThemeanR@, and RAfor Parkinson'sdiseasepatientswere0.78 ±0.31and 0.65 ± 0.24, respectively. Both R, and RA for normal controls were signtl icantly higher than those for Parkinson's disease patients (p values for R@, andRA were1.91x 1O_8 @ 3•4@ x 10_lU, respectively). TheR.,haslinearrelationships with bothRAand(BGâ€" OCC@/OCC ratioat 115 mm.TheR@,, hasa highercorrelation(r = 0.99)with RA than it does with (BG-OCC)/OCC(r = 0.93).Conclusion: The R@,, RAand (BG-OCC@/OCC for Parldnson'sdiseasepatientswere clearly separated from those of normal controls, and they may be useful outcome measuresfor clinical diagnosis.The simplest (BG â€" OCC)/OCC ratio, requiring a single late time point, could be useful in clinical situations, whereas R, or RA is preferred when the dynamic data are available. The findingssuggestthat 1@I-IPT is a useful tracer for diagnosing Parkinson's disease and studying dopamine reuptake sites.
Journal of nuclear medicine : official publication, Society of Nuclear Medicine, 1996
Iodine-123-labeled IPT (N-(3-iodopropen-2-yl)-2 beta-carbomethoxy-3 beta-(4-chlorophenyl)tropane) is an analog of cocaine that selectively binds the presynaptic dopamine transporter. This study sought to characterize changes in the striatal uptake of IPT with normal aging. The sample included 18 healthy human volunteers. Their ages ranged from 19 to 67 yr. Dynamic SPECT scans of the brain were acquired with about 185 MBq (5 mCi) of IPT on a triple-headed camera. The images were reconstructed with a three-dimensional restorative filter and corrected for attenuation. The mean concentration of radioactivity [microCi/ml] was measured in the head of the caudate and body of the putamen. The remainder of the supratentorial brain was used as a reference. The specific uptake of IPT was higher in the caudate than in the putamen of each subject. It decreased significantly with age in both regions. The mean specific uptake in seven volunteers who were less than 30 yr old was 17.6 +/- 4.9 in the...
Synapse, 1993
Single photon emission computed tomography (SPECT) studies of regional kinetic uptake and pharmacological specificity of [1231]methyl 3P-(4-iodophenyl) tropane-2P-carboxylate ([1231]p-CIT) were performed in nonhuman primates (n = 41). In control experiments, activity was concentrated in striatum and in hypothalamic1 midbrain regions. Striatal uptake increased for 140-180 min and displayed stable levels thereafter. Striatal to cerebellar activity ratios were 7.3 2 0.9 (mean kSEM) a t 300 min. About 75% of striatal uptake was displaceable by injection of nonradioactive P-CIT. Hypothalamic/midbrain activity reached maximal levels at approximately 45 min. A slow washout phase followed this peak activity. Activities in frontal, occipital, and cerebellar regions were characterized by a n early peak (20-30 rnin), followed by rapid washout. Displacement studies demonstrated that striatal uptake was associated with dopamine (DA) transporters, as it was displaced by GBR 12909, a selective DA uptake inhibitor, but not by citalopram, a selective serotonin (5-HT) uptake inhibitor. The inverse was true in the hypothalamic/midbrain area, suggesting that the uptake in this area was associated primarily with 5-HT transporters. Maprotiline, a selective norepinephrine uptake inhibitor, did not affect [1231]p-CIT uptake. In vivo site occupancy ED,, values of cocaine, 2~-carbomethoxy-3~-(4-fluorophenyl)tropane (CFT), and 6-CIT were measured in the striatum with a stepwise displacement paradigm. In vivo ED50 values correlated strongly with in vitro IC,o values for binding to DA transporters. Infusion of high dose of L-DOPA (250 pmolkg) failed to displace striatal [1231]P-CIT binding, suggesting that the binding would not be affected by L-DOPA administration in Parkinsonian patients. However, studies performed with injection of d-amphetamine indirectly suggested that high synaptic levels of DA may compete with [1231]p-CIT binding. These studies suggest that [1231]p-CIT will be a useful SPECT tracer of DA and 5-HT transporters in living human brain.
European Journal of Nuclear Medicine and Molecular Imaging, 2008
Background Dual-head SPECT systems are used by many clinical departments for [123I]FP-CIT SPECT imaging, while triple-head or brain-dedicated systems with better imaging performance are more commonly used by research institutions. There are limited data comparing the capability of the two types of system to measure dopamine transporter (DAT) loss in vivo. Purpose The aim of this study was to compare the ability of a dual-head and a brain-dedicated SPECT system to estimate the degree of DAT loss in different movement disorders with variable nigrostriatal impairment, with [123I]FP-CIT. Materials and methods Four patients with essential tremor, 24 with Parkinson’s disease (PD), six with spinocerebellar ataxia type 2 and six controls were studied with [123I]FP-CIT. SPECT scans were performed on a dual-head (E.CAM—Siemens) and subsequently on a brain-dedicated system (Ceraspect—DSI). Results Striatal DAT outcome measures on the E.CAM and the Ceraspect were strongly correlated and the putamen-to-caudate ratios were almost identical. Although the measured values were lower by 52 ± 25% in caudate and by 51 ± 31% in putamen on the E.CAM (p < 0.0001), the average striatal DAT decrease in each patient group compared with controls was similar for both systems. In PD patients, similar correlations (p < 0.05) were found between motor UPDRS or Hoehn and Yahr stage and striatal DAT density. Conclusions Despite underestimation of striatal DAT outcome measures, the E.CAM showed similar capability as the Ceraspect in measuring the degree of nigrostriatal dopaminergic deficit and assessing the correlation between DAT outcome measures and clinical variables of PD severity and stage.
Journal of nuclear medicine : official publication, Society of Nuclear Medicine, 1997
UNLABELLED Iodine-123-N-(3-iodopropene-2-yl)-2beta-carbomethoxy-3beta-( 4-chlorophenyl) tropane (123I-IPT) is a new dopamine transporter ligand that selectively binds the dopamine reuptake sites. Transporter concentrations have been known to decrease in Parkinson's disease patients. The purpose of this study was to evaluate the usefulness of IPT as an imaging agent for measuring changes in transporter concentrations in Parkinson's disease. METHODS IPT labeled with 6.78 +/- 0.67 mCi 123I was injected intravenously as a bolus into eight normal controls (mean age 41 +/- 12 yr) and 17 Parkinson's disease patients (mean age 55 +/- 9 yr). Dynamic SPECT scans of the brain were then performed for 5 min each over 120 min on a triple-headed gamma camera equipped with medium-energy collimators. Regions of interest were drawn on the middle set of the image at the level of the basal ganglia (BG) for each subject. Time-activity curves were generated for the left BG, right BG and occip...
EJNMMI Research
Purpose Our aim was to compare a widely distributed commercial tool with an older free software (i) one another, (ii) with a clinical motor score, (iii) versus reading by experts. Procedures We analyzed consecutive scans from one-hundred and fifty-one outpatients submitted to brain DAT SPECT for a suspected parkinsonism. Images were post-processed using a commercial (Datquant®) and a free (BasGanV2) software. Reading by expert was the gold standard. A subset of patients with pathological or borderline scan was evaluated with the clinical Unified Parkinson’s Disease Rating Scale, motor part (MDS-UPDRS-III). Results SBR, putamen-to-caudate (P/C) ratio, and both P and C asymmetries were highly correlated between the two software with Pearson’s ‘r’ correlation coefficients ranging from .706 to .887. Correlation coefficients with the MDS-UPDRS III score were higher with caudate than with putamen SBR values with both software, and in general higher with BasGanV2 than with Datquant®. Datqu...
Nuclear Medicine and Biology, 1995
IPCIT [2/I-carboisopropoxy-3p-(4-iodophenyl)tropane; also designated RTI-1211 is the isopropyl ester of p-CIT [2/I-carbomethoxy-3/?-(4-iodophenyl) tropane]. Although /I-CIT binds to dopamine (DA), serotonin (5-HT) and norepinephrine (NE) transporters, IPCIT has been reported to be selective for the DA transporter. IPCIT was labeled with '151 and its receptor binding to membranes prepared from baboon striatum was compared with that of [iZ51]/I-CIT. These studies confirmed the relative selectivity of IPCIT for the DA transporter in comparison to 5-HT and NE transporters. The nonspecific binding of ['251]IPCIT was almost four times greater than that of ['2SI]P-CIT. The biodistribution of IPCIT was examined in two baboons with whole body imaging for 24-30 h after administration of 3mCi of "?I-labeled tracer. The brain uptake peaked within the first hour at 9.2% of the injected dose and the majority of activity in the body cleared through the hepatobiliary system. The distribution of activity within the brain was examined with ex viro autoradiography in one monkey injected with ['231]IPCIT. Activity was concentrated in the caudate and putamen and had values of 5 and 7nCi/cms per PCiig, respectively. The distribution in brain regions receiving moderately dense serotonergic innervation (e.g. superior colliculus and thalamus) had levels of activity equivalent to that in cerebellum. This study confirmed the in vitro and in uitw selectivity of IPCIT for the DA transporter but also showed that ['251]IPCIT had higher in rim nonspecific binding than ['ZSI]/I-CIT.