Evaluation of dopamine transporter density in healthy Brazilians using Tc-99m TRODAT-1 SPECT (original) (raw)
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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 : 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...
Sex correction improves the accuracy of clinical dopamine transporter imaging
EJNMMI Research, 2021
Background In clinical diagnostic imaging, dopamine transporter (DAT) SPECT scans are commonly evaluated using automated semiquantitative analysis software. Age correction is routinely implemented, but usually no sex correction of DAT binding is performed. Since there are sex differences in presynaptic dopaminergic function, we investigated the effect of DAT sex correction in a sample of healthy volunteers who underwent brain [ 123 I]-FP-CIT SPECT. Methods Forty healthy elderly individuals (21 men and 19 women) underwent brain [ 123 I]-FP-CIT SPECT, and each subject was examined clinically for motor and non-motor parkinsonian symptoms and signs. Regional specific DAT binding ratios (SBR = [ROI-occ]/occ) were calculated using age correction, and the results were compared to those in normal databases with and without sex correction. The level of regional abnormality was set at 2 standard deviations below the mean values of the reference databases. Results In the analysis without sex c...
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.
Dopamine transporter imaging using 99mTc-TRODAT-1 SPECT in Parkinson's disease
Medical science monitor : international medical journal of experimental and clinical research, 2014
Although the decrease in striatal dopamine transporter (DAT) density has been described in North American, European, and Asian Parkinson's disease (PD) patients, studies on this issue are required in the rest of the world. This study examined the diagnostic utility of DAT imaging in Brazilian PD patients. Twenty PD patients (13 males, 7 females, median age: 62 years, median age at disease onset: 56 years, median disease duration: 5 years, and median UPDRS-III score: 29) and 9 age- and sex-matched healthy subjects underwent single-photon emission computerized tomography (SPECT) using 99mTc-TRODAT-1. PD patients showed a significant decrease in the striatum, caudate nucleus, and putamen DAT densities compared with data from healthy subjects. Striatal 99mTc-TRODAT-1 bindings had the highest diagnostic accuracy compared to those estimates from caudate nucleus and putamen. For the diagnosis of PD, a striatal 99mTc-TRODAT-1 binding cut-off value of 0.90 was associated with a sensitivi...
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...
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.
Nuclear Medicine and Biology, 2009
Introduction: Parkinson's disease (PD) affects both dopaminergic and serotonergic systems. In this study, we simultaneously evaluated dopamine and serotonin transporters in primates using dual-isotope single-photon emission computed tomography (SPECT) imaging and compared the results with traditional single-isotope imaging. Methods: Four healthy and one 6-OHDA-induced PD monkeys were used for this study. SPECT was performed over 4 h after individual or simultaneous injection of [ 99m Tc]TRODAT-1 (a dopamine transporter imaging agent) and [ 123 I]ADAM (a serotonin transporter imaging agent). Results: The results showed that the image quality and uptake ratios in different brain regions were comparable between single-and dualisotope studies. The striatal [ 99m Tc]TRODAT-1 uptake in the PD monkey was markedly lower than that in normal monkeys. The uptake of [ 123 I]ADAM in the midbrain of the PD monkey was comparable to that in the normal monkeys, but there were decreased uptakes in the thalamus and striatum of the PD monkey. Conclusions: Our results suggest that dual-isotope SPECT using [ 99m Tc]TRODAT-1 and [ 123 I]ADAM can simultaneously evaluate changes in dopaminergic and serotonergic systems in a PD model.
Annals of Nuclear Medicine, 2019
Purpose "Chemobrain" is a medical secondary effect of cancer chemotherapy treatment characterized by a general decline in cognition affecting visual and verbal memory, attention, complex problem-solving skills, and motor function. Dopamine (DA) central nervous system neurotransmitters serve an important role in cognition, and changes in DA could potentially explain impaired cognition associated with chemotherapy. Therefore, our objective was to assess in vivo dopaminergic dysfunction in the central nervous system (CNS) of a group of female breast cancer survivors with cognitive impairment following chemotherapy. Methods Twenty-eight women reporting chemobrain were recruited for this study and compared to 22 healthy reference women. Striatal dopamine transporter (DAT) binding ratio was determined by 99m Tc-TRODAT-1 (a highly selective radiotracer for DAT in the dorsal striatum) single-photon emission computed tomography and a quantitative evaluation was obtained by DatQUANT™ software (GE Healthcare). The DAT binding ratio (BR DAT) in the patient and control groups was compared using the Student's t test, a multivariate analysis of variance (MANOVA) was used to compare age, years of schooling and BR DAT. The relationship between continuous variables, such as cognitive impairment and BR DAT was assessed using Pearson correlation test. Results There was a difference in BR DAT between the chemobrain patients and control group. Patients had statistically significant (p < 0.05) lower concentrations of the radiopharmaceutical in the striatum. Conclusions We identified a significant dopaminergic decrease in all regions of the dorsal striatum within the patients reporting cognitive dysfunction after chemotherapy. Therefore, our results indicate a possible role of dopamine transporter in the physiopathology of chemobrain, even out of the acute phase of symptoms.