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Zan Y, Long Y, Chen K, Li B, Huang Q, Gullberg GT. Design of a short nonuniform acquisition protocol for quantitative analysis in dynamic cardiac SPECT imaging - a retrospective123I-MIBG animal study. Med Phys 2017; 44:3639-3649. [DOI: 10.1002/mp.12288] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2016] [Revised: 03/29/2017] [Accepted: 03/30/2017] [Indexed: 12/25/2022] Open
Affiliation(s)
- Yunlong Zan
- School of Biomedical Engineering; Shanghai Jiao Tong University; Shanghai China
- School of Medicine; Department of Nuclear Medicine; Rui Jin Hospital; Shanghai Jiao Tong University; Shanghai China
- University of Michigan - Shanghai Jiao Tong University Joint Institute; Shanghai Jiao Tong University; Shanghai China
| | - Yong Long
- University of Michigan - Shanghai Jiao Tong University Joint Institute; Shanghai Jiao Tong University; Shanghai China
| | - Kewei Chen
- Image Analysis and Research Lab.; Banner Good Samaritan Medical Center; Phoenix AZ USA
| | - Biao Li
- School of Medicine; Department of Nuclear Medicine; Rui Jin Hospital; Shanghai Jiao Tong University; Shanghai China
| | - Qiu Huang
- School of Biomedical Engineering; Shanghai Jiao Tong University; Shanghai China
- School of Medicine; Department of Nuclear Medicine; Rui Jin Hospital; Shanghai Jiao Tong University; Shanghai China
| | - Grant T. Gullberg
- Life Science Division; Lawrence Berkeley National Laboratory; Berkeley CA USA
- Radiology and Biomedical Imaging; University of California; San Francisco CA USA
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2
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Barkus E, Morrison PD, Vuletic D, Dickson JC, Ell PJ, Pilowsky LS, Brenneisen R, Holt DW, Powell J, Kapur S, Murray RM. Does intravenous Δ9-tetrahydrocannabinol increase dopamine release? A SPET study. J Psychopharmacol 2011; 25:1462-8. [PMID: 20851843 DOI: 10.1177/0269881110382465] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Intravenous (IV) Δ9-tetrahydrocannabinol (THC) induces transient psychotic symptoms in healthy subjects and in schizophrenic patients, but the psychotomimetic mechanism is unknown. One possibility is that THC stimulates dopamine (DA) release in the striatum. In this study we tested whether IV THC led to an increase in striatal DA release compared to placebo. We also investigated whether DA release and positive psychotic symptoms were related. Eleven healthy male volunteers completed two 123I-iodobenzamide ([123I]IBZM) single photon emission tomography (SPET) sessions and received IV THC (2.5 mg) or placebo in a randomized counterbalanced order, under double-blind conditions. Analysable data were obtained from nine participants. The Positive and Negative Syndrome Scale (PANSS) was used to rate psychotomimetic effects. Striatal binding index values were calculated using the occipital cortex as a reference region. Both the PANSS positive and general symptoms increased significantly at 30 min following IV THC. There were no significant differences in binding index in the caudate or putamen under THC compared to placebo conditions. Positive psychotic symptoms and DA release were unrelated. THC did not lead to a significant increase in DA release even though the dose was sufficient for participants to have psychotic symptoms. These findings do not support a central role for striatal DA in THC-elicited psychosis.
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Affiliation(s)
- Emma Barkus
- Institute of Psychiatry, Kings College London, London, UK.
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3
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Bullich S, Cot A, Gallego J, Gunn R, Suárez M, Pavía J, Ros D, Laruelle M, Catafau A. Impact of scatter correction on D2 receptor occupancy measurements using 123I-IBZM SPECT: Comparison to 11C-Raclopride PET. Neuroimage 2010; 50:1511-8. [DOI: 10.1016/j.neuroimage.2010.01.013] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2009] [Revised: 12/28/2009] [Accepted: 01/07/2010] [Indexed: 10/20/2022] Open
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4
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Meyer PT, Sattler B, Winz OH, Fundke R, Oehlwein C, Kendziorra K, Hesse S, Schaefer WM, Sabri O. Kinetic analyses of [123I]IBZM SPECT for quantification of striatal dopamine D2 receptor binding: A critical evaluation of the single-scan approach. Neuroimage 2008; 42:548-58. [PMID: 18595739 DOI: 10.1016/j.neuroimage.2008.05.023] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2008] [Revised: 05/06/2008] [Accepted: 05/15/2008] [Indexed: 11/17/2022] Open
Affiliation(s)
- Philipp T Meyer
- Department of Nuclear Medicine, University Hospital Aachen, Aachen, Germany.
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5
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Test–retest variability and reliability of123I-IBZM SPECT measurement of striatal dopamine D2 receptor availability in healthy volunteers and influence of iterative reconstruction algorithms. Synapse 2007; 62:62-9. [DOI: 10.1002/syn.20465] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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6
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Buchert R, Berding G, Wilke F, Martin B, von Borczyskowski D, Mester J, Brenner W, Clausen M. IBZM tool: a fully automated expert system for the evaluation of IBZM SPECT studies. Eur J Nucl Med Mol Imaging 2006; 33:1073-83. [PMID: 16614812 DOI: 10.1007/s00259-006-0067-9] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2005] [Accepted: 12/12/2005] [Indexed: 10/24/2022]
Abstract
PURPOSE Visual reading of [(123)I]IBZM SPECT scans depends on the experience of the interpreter. Therefore, semi-quantification of striatal IBZM uptake is commonly considered mandatory. However, semi-quantification is time consuming and prone to error, particularly if the volumes of interest (VOIs) are positioned manually. Therefore, the present paper proposes a new software tool ("IBZM tool") for fully automated and standardised processing, evaluation and documentation of [(123)I]IBZM SPECT scans. METHODS The IBZM tool is an easy-to-use SPM toolbox. It includes automated procedures for realignment and summation of multiple frames (motion correction), stereotactic normalisation, scaling, VOI analysis of striatum-to-reference ratio R, classification of R and standardised display. In order to evaluate the tool, which was developed at the University of Hamburg, the tool was transferred to the University of Hannover. There it was applied to 27 well-documented subjects: eight patients with multi-system atrophy (MSA), 12 patients with Parkinson's disease (PD) and seven controls. The IBZM tool was compared with manual VOI analysis. RESULTS The sensitivity and specificity of the IBZM tool for the differentiation of the MSA subjects from the controls were 100% and 86%, respectively. The IBZM tool provided improved statistical power compared with manual VOI analysis. CONCLUSION The IBZM tool is an expert system for the detection of reduced striatal D(2) availability on [(123)I]IBZM SPECT scans. The standardised documentation supports visual and semi-quantitative evaluation, and it is useful for presenting the findings to the referring physician. The IBZM tool has the potential for widespread use, since it appears to be fairly independent of the performance characteristics of the particular SPECT system used. The tool is available free of charge.
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Affiliation(s)
- Ralph Buchert
- Department of Nuclear Medicine, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246 Hamburg, Germany.
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7
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Poblete García V, García Vicente A, Ruíz Solís S, Martínez Delgado C, Vaamonde J, Rodado Marina S, Cortés Romera M, Talavera Rubio M, Ibáñez R, Soriano Castrejón A. [SPECT with 123I-IBZM: utility in differential diagnosis of degenerative Parkinsonisms and establishment of quantification method]. ACTA ACUST UNITED AC 2005; 24:234-43. [PMID: 16122407 DOI: 10.1157/13076641] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
OBJECTIVES To assess utility of SPECT with 123I-Iolopride ( 123I-IBZM) in the differential diagnosis of patients with Parkinsonian symptoms and try to establish an adequate quantification method. MATERIAL AND METHOD We analyzed a total of 34 patients who underwent a study with 123I-IBZM SPECT. Studies were analyzed qualitatively (visually) and quantitatively, using different quantification methods. We used different sums of slices (2, 3, 4, and 7 slices) with different cortical regions as a reference (frontal and occipital regions). Results were analyzed statistically. The final diagnosis of patients was established by two neurologists, specialized in movement disorders. RESULTS Studies were visually assessed as normal in 24 cases and as pathologic in the other 10 cases. Scintigraphic studies had an adequate diagnostic correlation in 33 of the 34 patients. Four of the 8 methods used in the quantification were statistically significant in the differentation between normal and pathological. The use of different cortical brain regions as reference did not improve differentation between normal and pathologic studies. Global quantitative assessment of the studies showed that normal studies had higher values than pathological ones, with important overlapping between both categories. CONCLUSIONS 123I-IBZM SPECT is an effective diagnostic tool in the establishment of the differential diagnosis in patients with Parkinson's disease and Parkinson-Plus. Quantification of these studies had limited utility since the overlapping of index values between normal and pathological restricts their use in individual cases.
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Affiliation(s)
- Vm Poblete García
- Servicio de Medicina Nuclear, Hospital Ntra, Sra. de Alarcos, Ciudad Real, Spain
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8
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Seppi K, Schocke MFH, Donnemiller E, Esterhammer R, Kremser C, Scherfler C, Diem A, Jaschke W, Wenning GK, Poewe W. Comparison of diffusion-weighted imaging and [123I]IBZM-SPECT for the differentiation of patients with the Parkinson variant of multiple system atrophy from those with Parkinson's disease. Mov Disord 2005; 19:1438-45. [PMID: 15390073 DOI: 10.1002/mds.20229] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Both dopamine D2 receptor (D2R) binding single-photon emission computed tomography (SPECT) with [123I]iodobenzamide (IBZM) and diffusion-weighted imaging (DWI) have been shown to contribute to the differential diagnosis of patients with the Parkinson variant of multiple system atrophy (MSA-P) and Parkinson's disease (PD). We aimed to compare these two routinely available functional imaging modalities in differentiating patients with MSA-P from PD. For this purpose, results obtained by DWI and IBZM-SPECT were intraindividually compared in a cross-sectional study of 15 MSA-P and 17 PD patients matched for age and disease duration. The activity ratios of striatal to frontal cortex uptake (S/FC ratio) were used as a semiquantitative measure of the relative density of basal ganglia dopamine receptors labeled by IBZM. Regional apparent diffusion coefficients (rADC) were determined in the striatum. MSA-P patients had significantly lower S/FC ratios and significantly higher striatal rADCs than both PD patients and healthy volunteers. There were no significant differences in S/FC ratios and striatal rADC between PD patients and healthy volunteers. Sensitivity of IBZM-SPECT versus DWI for the differentiation of MSA-P from PD was 80% versus 93%, specificity 71% versus 100%, the predictive accuracy 75% versus 97%, the positive predictive value 71% versus 100%, and the negative predictive value 80% versus 94%. Striatal rADCs had a significant higher overall predictive accuracy than D2R binding with IBZM. In summary, our data suggest that DWI may be more accurate compared to IBZM-SPECT in the differential diagnosis of MSA-P versus PD.
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Affiliation(s)
- Klaus Seppi
- Department of Neurology, University of Innsbruck, Innsbruck, Austria
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9
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Scherfler C, Scholz SW, Donnemiller E, Decristoforo C, Oberladstätter M, Stefanova N, Diederen E, Virgolini I, Poewe W, Wenning GK. Evaluation of [123I]IBZM pinhole SPECT for the detection of striatal dopamine D2 receptor availability in rats. Neuroimage 2005; 24:822-31. [PMID: 15652317 DOI: 10.1016/j.neuroimage.2004.10.005] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2004] [Revised: 09/28/2004] [Accepted: 10/06/2004] [Indexed: 10/26/2022] Open
Abstract
Single photon emission computed tomography (SPECT) and MRI coregistration have been assessed to characterize striatal dopamine D2/D3 receptor (D2/D3R) availability in rats following injection of the D2 and D3R radioligand [123I] iodobenzamide ([123I]IBZM). High-resolution SPECT data were obtained with a pinhole collimator. In order to precisely estimate brain regions of low radioligand uptake, SPECT images were coregistered onto a MRI template with high accuracy (maximum mismatch 1.1 mm). To evaluate an adequate dose of radioligand to be administered without exceeding the radioligand-to-receptor occupancy >5% and to define an appropriate time period for image acquisition, three untreated groups of animals received 29.6, 37, and 44.4 MBq of [123I]IBZM and underwent five consecutive SPECT acquisitions lasting 64 min each. Ratio calculations between specific striatal radioligand uptake and nondisplaceable cerebellar uptake revealed a secular equilibrium between 75 and 355 min post-tracer application in all three animal groups. Consequently, since the highest regional uptake values were obtained in the animal group receiving 44.4 MBq [123I]IBZM, this injection dose was considered to be appropriate. Finally, the capacity of the imaging method to detect distinct severity levels of striatal dopamine D2/D3 receptor loss was tested in a low, medium, and high dose quinolinic acid (QA) animal model of Huntington's disease. Motor impairment indicative of striatal dysfunction was monitored using amphetamine-induced rotational behavior and locomotor activity. Loss of striatal D2/D3R bearing medium-sized spiny neurons was assessed by DARPP-32 immunohistochemistry and compared to [123I]IBZM binding. Optical density measures of DARPP-32 immunohistochemistry demonstrated QA dose-dependent mild to subtotal unilateral striatal lesions ranging from 29.4% to 96.9% when compared to the nonlesioned side. Linear regression analysis showed that measurements of striatal DARPP-32 optical density and striatal [123I]IBZM uptake of the lesioned side were highly correlated (r2=0.83; P<0.001) whereas correlation with locomotor activity was less tight (r2=0.23; P<0.05; amphetamine-induced rotational behavior was not significantly correlated). This is the first study to demonstrate that in vivo [123I]IBZM SPECT and MRI coregistration are highly sensitive and, in contrast to behavioral measures, accurately detect mild to subtotal striatal lesions by measuring loss of D2/D3R availability. SPECT-MRI-based estimation of regional [123I]IBZM uptake provides a cost effective and widely available in vivo imaging technique for assessing striatal integrity in animal studies.
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Affiliation(s)
- Christoph Scherfler
- Clinical Department of Neurology, Innsbruck Medical University, 6020 Innsbruck, Austria.
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10
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Lavalaye J, Linszen DH, Booij J, Reneman L, Gersons BP, van Royen EA. Dopamine D2 receptor occupancy by olanzapine or risperidone in young patients with schizophrenia. Psychiatry Res 1999; 92:33-44. [PMID: 10688158 DOI: 10.1016/s0925-4927(99)00032-3] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
A crucial characteristic of antipsychotic medication is the occupancy of the dopamine (DA) D2 receptor. We assessed striatal DA D2 receptor occupancy by olanzapine and risperidone in 36 young patients [31 males, 5 females; mean age 21.1 years (16-28)] with first episode schizophrenia, using [123I]iodobenzamide (IBZM) SPECT. The occupancy of DA D2 receptors was not significantly different between olanzapine and risperidone. However, in subgroups of most prescribed doses, DA D2 occupancy was higher in the risperidone 4-mg group (79%) compared to the olanzapine 15-mg group (62%). [123I]IBZM binding ratios decreased with olanzapine dose (r = -0.551; P < 0.01), indicating higher DA D2 receptor occupancy with higher olanzapine dose. Akathisia and positive symptoms were correlated with [123I]IBZM binding ratio (r = -0.442; P < 0.01; and r = -0.360; P < 0.05, respectively). Prolactin (PRL) levels were elevated in the risperidone, but not in the olanzapine group, at comparable D2 receptor occupancy levels. In the olanzapine group, PRL levels were correlated with [123I]IBZM binding ratio (r = -0.551; P < 0.01). In conclusion, both olanzapine and risperidone induce a high striatal D2 receptor occupancy, dependent on dose and group formation. The lower incidence of prolactin elevation with olanzapine, compared to risperidone, may not be attributed to a lower D2 receptor occupancy.
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Affiliation(s)
- J Lavalaye
- Department of Psychiatry, Academic Medical Centre, Amsterdam, The Netherlands.
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11
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Van der Schyf CJ, Dormehl IC, Oliver DW, Hugo N, Keeve R, Müller-Gärtner HW, Pond SM, Castagnoli N. Long-term treatment with the tetrahydropyridine analog (HPTP) of haloperidol influences dopamine ligand binding in baboon brain. An [123I]iodobenzamide (IBZM) SPECT study. BRAIN RESEARCH. MOLECULAR BRAIN RESEARCH 1996; 43:251-8. [PMID: 9037540 DOI: 10.1016/s0169-328x(96)00201-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Haloperidol (HP) and its tetrahydropyridine dehydration product 4-(4-chlorophenyl)-[4-(fluorophenyl)-4-oxobutyl]-1,2,3,6-tetrahydropyrid ine (HPTP) are both metabolized in vivo to several pyridinium metabolites with potential neurotoxic properties similar to the neurotoxin 1-methyl-4-phenylpyridinium (MPP+), a metabolite of the parkinsonian-inducing agent 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). The effect of long-term HPTP treatment on the central nervous system of baboons (Papio ursinus) was studied using [123I]iodobenzamide (IBZM) and single photon emission computed tomography (SPECT) at 1-14 weeks after termination of HPTP treatment. Striatal dopamine receptor binding was measured semiquantitatively by calculating the IBZM count rate ratios of the basal ganglia to frontal cortex and basal ganglia to cerebellum. Relative striatal perfusion was assessed by similar 99mTc-HMPAO (hexamethylpropylene amine oxime) ratios. Time activity curves of IBZM from the brain structures suggest that HPTP treatment results in a marked reduction in central dopamine ligand binding, and in particular D2-like receptor binding. Increased washout of the ligand from all the brain structures investigated was seen in the HPTP-treated animals, also consistent with reduced binding. Cerebral blood flow in the control and HPTP-treated groups was similar, indicating that this did not account for the reduced dopamine receptor binding of the IBZM ligand. These data suggest that treatment with HPTP induces significant effects on dopamine receptor binding that may contribute to some of the neurological disorders observed in humans undergoing chronic HP treatment.
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Affiliation(s)
- C J Van der Schyf
- Department of Pharmaceutical Chemistry, Potchefstroom University for Christian Higher Education, South Africa.
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12
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Brücke T, Wöber C, Podreka I, Wöber-Bingöl C, Asenbaum S, Aull S, Wenger S, Ilieva D, Harasko-van der Meer C, Wessely P. D2 receptor blockade by flunarizine and cinnarizine explains extrapyramidal side effects. A SPECT study. J Cereb Blood Flow Metab 1995; 15:513-8. [PMID: 7714010 DOI: 10.1038/jcbfm.1995.63] [Citation(s) in RCA: 53] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Twenty-six patients under treatment with the calcium channel blockers flunarizine (Fz) or cinnarizine (Cz) were examined-with single-photon emission computed tomography using [123I]iodobenzamide as a ligand. The striatal dopamine D2 receptor-binding potential was determined and found to be reduced by 14 to 63% (39.5 +/- 15.0%; p < 0.0001) in patients compared with age-matched control values. This reduction was larger in 12 patients with extrapyramidal symptoms and was only slowly reversible after discontinuation of treatment. Patients treated for > 6 months had significantly larger reductions than patients treated for a shorter period. Parkinsonian symptoms were only seen in patients older than 50 years. Our findings prove a neuroleptic-like action of Fz and Cz, which seems to be the major reason for their extrapyramidal side effects. Older age and long-term treatment are predisposing factors for these effects.
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Affiliation(s)
- T Brücke
- Neurological University Clinic Vienna, Austria
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13
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Volk S, Maul FD, Hör G, Schreiner M, Weppner M, Holzmann T, Pflug B. Dopamine D2 receptor occupancy measured by single photon emission computed tomography with 123I-Iodobenzamide in chronic schizophrenia. Psychiatry Res 1994; 55:111-8. [PMID: 10711799 DOI: 10.1016/0925-4927(94)90005-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Single photon emission computed tomography (SPECT) with 123I-iodobenzamide (123I-IBZM) was used to study 22 chronic schizophrenic patients. The patients, who were receiving maintenance therapy with typical neuroleptics, had not shown any significant improvement since their admission to the hospital. Basal ganglia/frontal cortex ratios of the uptake of 123I-IBZM did not show significant differences on the basis of neuroleptic dosage in chlorpromazine equivalents. There were, however, significant differences in 123I-IBZM uptake in the basal ganglia among patients characterized by negative, mixed, and positive symptoms of schizophrenia. Although only a small number of patients had shown a positive response to treatment by the time of discharge, D2 receptor blockade was significantly higher in responders than in nonresponders. In addition, there was an inverse correlation between reduced activation as measured by the Brief Psychiatric Rating Scale and the basal ganglia/frontal cortex ratio. These findings suggest a complex pathogenetic link between the blockade of dopamine D2 receptors and psychopathology in chronic schizophrenic patients. SPECT studies with 123I-IBZM appear to have prognostic value in identifying chronic schizophrenic patients who respond poorly to neuroleptic treatment.
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Affiliation(s)
- S Volk
- Department of Clinical Psychiatry II, Johann Wolfgang Goethe Universität, Frankfurt am Main, Germany
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14
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Abstract
A patient with a macroprolactinoma and extrasellar extension was treated by incomplete transfrontal surgery, external irradiation and additional bromocriptine (Br) treatment. After 4 years, partial bromocriptine resistance developed (a rare occurrence) together with the appearance of intracranial metastases. 123I-Iodobenzamide was helpful in evaluating the dopamine D2 receptor status of the metastatic tumour both in vivo using single-photon emission computed tomography (SPECT) and in vitro. Prolactin release by the cultured metastatic tumour cells was more potently inhibited by CV 205-502 than by bromocriptine. The patient, treated by surgery, irradiation and CV 205-502, developed a ptosis of the left eye and a transient psychiatric delusional state, the latter probably an effect of the dopamine agonist. As the right frontal metastasis was markedly positive on SPECT with 111In-SMS, somatostatin treatment was added to the CV 205-502.
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Affiliation(s)
- J Assies
- Department of Psychiatry, Academic Medical Centre, Amsterdam, The Netherlands
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15
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Toyama H, Ichise M, Ballinger JR, Fornazzari L, Kirsh JC. Dopamine D2 receptor SPECT imaging: basic in vivo characteristics and clinical applications of 123I-IBZM in humans. Ann Nucl Med 1993; 7:29-38. [PMID: 8461237 DOI: 10.1007/bf03164789] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The purposes of this study are to evaluate the utility of kit formulation, the basic in vivo characteristics, and clinical usefulness of dopamine D2 receptor imaging with 123I-(S)-(-)-3-iodo-2-hydroxy-6-methoxy-N-[(1-ethyl-2-pyrrodinyl)m ethyl]- benzamide (123I-IBZM). We studied 22 normal controls, 3 early symptomatic Huntington's disease patients, and 1 patient with visual hallucination on and off neuroleptics. 123I-IBZM could be conveniently prepared with a high degree of purity from a kit, but with relatively low radiochemical yield. We demonstrated 123I-IBZM receptor binding equilibrium by performing serial SPECT scanning in a normal volunteer. The basal ganglia/frontal cortex (BG/FC) ratios plateaued after the specific binding reached equilibrium approximately 60 minutes after injection. The BG/FC ratio declined significantly with age. The ratios for the Huntington's disease patients were significantly lower than those for normal controls. The images of the patient off neuroleptic therapy showed dramatically increased BG activity compared with those obtained while on therapy. The BG/FC ratio provides an estimate of Bmax/Kd and hence the receptor density. It appears important to perform SPECT early in the equilibrium phase and at a fixed time after injection to obtain significantly high signal to noise ratios. 123I-IBZM is an ideal tracer for SPECT including a rotating gamma camera type which can provide estimates of the receptor density objectively by calculating the BG/FC ratio, and is a promising agent for the investigation of dopamine D2 receptors in clinical conditions.
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Affiliation(s)
- H Toyama
- Division of Nuclear Medicine, Mount Sinai Hospital, Toronto, Ontario, Canada
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