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Motaleb MA, Attalah KM, Shweeta HA, Ibrahim IT. Synthesis and biological evaluation of [ 131I]iodocarvedilol as a potential radiopharmaceutical for heart imaging. BMC Chem 2023; 17:21. [PMID: 36922888 PMCID: PMC10018969 DOI: 10.1186/s13065-023-00935-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Accepted: 03/03/2023] [Indexed: 03/17/2023] Open
Abstract
The optimization of the radiolabeling yield of carvedilol with iodine-131 was described. Dependence of the labeling yield of [131I]iodocarvedilol on the concentration of carvedilol, chloramine-T content, pH of the reaction mixture and reaction time was studied in details. Carvedilol was labeled with iodine-131 at pH 6 with a labeling yield of 92.6 ± 2.77% by using 100 µg carvedilol, 200 µg chloramin-T (CAT) and 30 min reaction time. The formed [131I]iodocarvedilol was nearly stable for a time up to one day. Biodistribution of [131I]iodocarvedilol was investigated in experimental animals. [131/123I]iodocarvedilol was located in the heart with a concentration of 19.6 ± 0.41% of the injected dose at 60 min post injection. It has a high heart uptake and heart to liver ratio, both of which are beneficial for high-quality SPECT (single-photon emission computerized tomography) myocardial imaging. [131/123I]iodocarvedilol solve most the drawbacks of the FDA (Food and Drug Administration) approved 99mTc-sestamibi.
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Affiliation(s)
- M A Motaleb
- Labeled Compounds Department, Hot Laboratories Centre, Egyptian Atomic Energy Authority (EAEA), 13759, Cairo, Egypt.
| | - K M Attalah
- Labeled Compounds Department, Hot Laboratories Centre, Egyptian Atomic Energy Authority (EAEA), 13759, Cairo, Egypt
| | - H A Shweeta
- Labeled Compounds Department, Hot Laboratories Centre, Egyptian Atomic Energy Authority (EAEA), 13759, Cairo, Egypt
| | - I T Ibrahim
- Labeled Compounds Department, Hot Laboratories Centre, Egyptian Atomic Energy Authority (EAEA), 13759, Cairo, Egypt
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2
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Zheng L, Wang Z, Zhang X, Zhou Y, Ji A, Lou H, Liu X, Chen H, Cheng Z. Development of Mitochondria-Targeted Small-Molecule Dyes for Myocardial PET and Fluorescence Bimodal Imaging. J Med Chem 2021; 65:497-506. [PMID: 34937337 DOI: 10.1021/acs.jmedchem.1c01660] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Mitochondria-targeting positron emission tomography (PET) and fluorescent dual-modal probes are rarely reported. As one of the most promising lipophilic cations, F16 and its derivatives (F16s) have never been used for myocardial imaging. In this work, 14 F16s are synthesized and evaluated for cardiac imaging. In vitro cell fluorescence imaging revealed that the lead probe 5MEF is precisely localized in the mitochondria of cardiomyocytes. In addition, it shows excellent ex vivo fluorescence imaging quality with the heart-to-muscle and heart-to-liver ratios up to ∼2. Furthermore, the radiofluorinated probe 18F-5MEF is successfully prepared and shows a high initial heart uptake of 8.66 ± 0.34 % ID/g at 5 min post injection. It displays a high heart imaging performance, a long retention time in the heart, and a low background in the most normal tissues as revealed by PET. To our knowledge, this is the first time novel F16 analogues are designed and developed for myocardial dual-modal imaging.
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Affiliation(s)
- Lingling Zheng
- Department of Nuclear Medicine, Huashan Hospital, Fudan University, No.12 Urumchi Middle Road, Jing'an District, Shanghai 200040, China.,Molecular Imaging Center, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
| | - Zhiming Wang
- Molecular Imaging Center, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
| | - Xiaoqing Zhang
- Department of Nuclear Medicine, Huashan Hospital, Fudan University, No.12 Urumchi Middle Road, Jing'an District, Shanghai 200040, China.,Molecular Imaging Center, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
| | - Yujing Zhou
- Department of Nuclear Medicine, Huashan Hospital, Fudan University, No.12 Urumchi Middle Road, Jing'an District, Shanghai 200040, China.,Molecular Imaging Center, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
| | - Aiyan Ji
- Molecular Imaging Center, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
| | - Hongyue Lou
- Molecular Imaging Center, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
| | - Xingdang Liu
- Department of Nuclear Medicine, Huashan Hospital, Fudan University, No.12 Urumchi Middle Road, Jing'an District, Shanghai 200040, China
| | - Hao Chen
- Molecular Imaging Center, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
| | - Zhen Cheng
- Department of Nuclear Medicine, Huashan Hospital, Fudan University, No.12 Urumchi Middle Road, Jing'an District, Shanghai 200040, China.,Molecular Imaging Center, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China.,Bohai rim Advanced Research Institute for Drug Discovery, Yantai 264000, China
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Ermert J, Benešová M, Hugenberg V, Gupta V, Spahn I, Pietzsch HJ, Liolios C, Kopka K. Radiopharmaceutical Sciences. Clin Nucl Med 2020. [DOI: 10.1007/978-3-030-39457-8_2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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4
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Soares AD, Paixão L, Facure A. Determination of the dose rate constant through Monte Carlo simulations with voxel phantoms. Med Phys 2018; 45:5283-5292. [DOI: 10.1002/mp.13181] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Revised: 08/23/2018] [Accepted: 08/31/2018] [Indexed: 11/09/2022] Open
Affiliation(s)
- Abner D. Soares
- Instituto de Radioproteção e Dosimetria Avenida Salvador Allende, 9 22780‐160 Rio de Janeiro RJ Brazil
| | - Lucas Paixão
- Dep. de Anatomia e Imagem/Faculdade de Medicina Universidade Federal de Minas Gerais 30130‐100 Belo Horizonte MG Brazil
| | - Alessandro Facure
- Comissão Nacional de Energia Nuclear Rua General Severiano 90, sala 402 22294‐900 Rio de Janeiro RJ Brazil
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Molecular modeling and preclinical evaluation of radioiodinated tenoxicam for inflammatory disease diagnosis. J Radioanal Nucl Chem 2018. [DOI: 10.1007/s10967-018-5770-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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Boschi A, Martini P, Pasquali M, Uccelli L. Recent achievements in Tc-99m radiopharmaceutical direct production by medical cyclotrons. Drug Dev Ind Pharm 2017; 43:1402-1412. [PMID: 28443689 DOI: 10.1080/03639045.2017.1323911] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
99mTc is the most commonly used radionuclide in the field of diagnostic imaging, a noninvasive method intended to diagnose a disease, assess the disease state and monitor the effects of treatments. Annually, the use of 99mTc, covers about 85% of nuclear medicine applications. This isotope releases gamma rays at about the same wavelength as conventional X-ray diagnostic equipment, and owing to its short half-life (t½ = 6 h) is ideal for diagnostic nuclear imaging. A patient can be injected with a small amount of 99mTc and within 24 h almost 94% of the injected radionuclide would have decayed and left the body, limiting the patient's radiation exposure. 99mTc is usually supplied to hospitals through a 99Mo/99mTc radionuclide generator system where it is produced from the β decay of the parent nuclide 99Mo (t½ = 66 h), which is produced in nuclear reactors via neutron fission. Recently, the interruption of the global supply chain of reactor-produced 99Mo, has forced the scientific community to investigate alternative production routes for 99mTc. One solution was to consider cyclotron-based methods as potential replacement of reactor-based technology and the nuclear reaction 100Mo(p,2n)99mTc emerged as the most worthwhile approach. This review reports some achievements about 99mTc produced by medical cyclotrons. In particular, the available technologies for target design, the most efficient extraction and separation procedure developed for the purification of 99mTc from the irradiated targets, the preparation of high purity 99mTc radiopharmaceuticals and the first clinical studies carried out with cyclotron produced 99mTc are described.
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Affiliation(s)
- Alessandra Boschi
- a Department of Morphology, Surgery and Experimental Medicine , University of Ferrara , Italy
| | - Petra Martini
- b Department of Physics and Heart Science , University of Ferrara , Ferrara , Italy.,c Legnaro National Laboratories, Italian National Institute for Nuclear Physics (LNL-INFN) , Legnaro , Italy
| | - Micol Pasquali
- b Department of Physics and Heart Science , University of Ferrara , Ferrara , Italy.,c Legnaro National Laboratories, Italian National Institute for Nuclear Physics (LNL-INFN) , Legnaro , Italy
| | - Licia Uccelli
- a Department of Morphology, Surgery and Experimental Medicine , University of Ferrara , Italy
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Radiolabeled Phosphonium Salts as Mitochondrial Voltage Sensors for Positron Emission Tomography Myocardial Imaging Agents. Nucl Med Mol Imaging 2016; 50:185-95. [PMID: 27540422 DOI: 10.1007/s13139-016-0397-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2015] [Revised: 01/07/2016] [Accepted: 01/11/2016] [Indexed: 02/02/2023] Open
Abstract
Despite substantial advances in the diagnosis of cardiovascular disease, (18)F-labeled positron emission tomography (PET) radiopharmaceuticals remain necessary to diagnose heart disease because clinical use of current PET tracers is limited by their short half-life. Lipophilic cations such as phosphonium salts penetrate the mitochondrial membranes and accumulate in mitochondria of cardiomyocytes in response to negative inner-transmembrane potentials. Radiolabeled tetraphenylphosphonium cation derivatives have been developed as myocardial imaging agents for PET. In this review, a general overview of these radiotracers, including their radiosynthesis, in vivo characterization, and evaluation is provided and clinical perspectives are discussed.
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Chan C, Dey J, Grobshtein Y, Wu J, Liu YH, Lampert R, Sinusas AJ, Liu C. The impact of system matrix dimension on small FOV SPECT reconstruction with truncated projections. Med Phys 2016; 43:213. [PMID: 26745914 PMCID: PMC4691252 DOI: 10.1118/1.4938098] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2015] [Revised: 10/02/2015] [Accepted: 11/25/2015] [Indexed: 11/07/2022] Open
Abstract
PURPOSE A dedicated cardiac hybrid single photon emission computed tomography (SPECT)/CT scanner that uses cadmium zinc telluride detectors and multiple pinhole collimators for stationary acquisition offers many advantages. However, the impact of the reconstruction system matrix (SM) dimension on the reconstructed image quality from truncated projections and 19 angular samples acquired on this scanner has not been extensively investigated. In this study, the authors aimed to investigate the impact of the dimensions of SM and the use of body contour derived from adjunctive CT imaging as an object support in reconstruction on this scanner, in relation to background extracardiac activity. METHODS The authors first simulated a generic SPECT/CT system to image four NCAT phantoms with various levels of extracardiac activity and compared the reconstructions using SM in different dimensions and with/without body contour as a support for quantitative evaluations. The authors then compared the reconstructions of 18 patient studies, which were acquired on a GE Discovery NM570c scanner following injection of different radiotracers, including (99m)Tc-Tetrofosmin and (123)I-mIBG, comparing the scanner's default SM that incompletely covers the body with a large SM that incorporates a patient specific full body contour. RESULTS The simulation studies showed that the reconstructions using a SM that only partially covers the body yielded artifacts on the edge of the field of view (FOV), overestimation of activity and increased nonuniformity in the blood pool for the phantoms with higher relative levels of extracardiac activity. However, the impact on the quantitative accuracy in the high activity region, such as the myocardium, was subtle. On the other hand, an excessively large SM that enclosed the entire body alleviated the artifacts and reduced overestimation in the blood pool, but yielded slight underestimation in myocardium and defect regions. The reconstruction using the larger SM with body contour yielded the most quantitatively accurate results in all the regions of interest for a range of uptake levels in the extracardiac regions. In patient studies, the SM incorporating patient specific body contour minimized extracardiac artifacts, yielded similar myocardial activity, lower blood pool activity, and subsequently improved myocardium-to-blood pool contrast (p < 0.0001) by an average of 7% (range 0%-18%) across all the patients, compared to the reconstructions using the scanner's default SM. CONCLUSIONS Their results demonstrate that using a large SM that incorporates a CT derived body contour in the reconstruction could improve quantitative accuracy within the FOV for clinical studies with high extracardiac activity.
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Affiliation(s)
- Chung Chan
- Department of Diagnostic Radiology, Yale University, New Haven, Connecticut 06520
| | - Joyoni Dey
- Department of Physics and Astronomy, Medical Physics Program, Louisiana State University, Baton Rouge, Louisiana 70803
| | | | - Jing Wu
- Department of Diagnostic Radiology, Yale University, New Haven, Connecticut 06520
| | - Yi-Hwa Liu
- Department of Internal Medicine, Yale University, New Haven, Connecticut 06520
| | - Rachel Lampert
- Department of Internal Medicine, Yale University, New Haven, Connecticut 06520
| | - Albert J Sinusas
- Department of Diagnostic Radiology, Yale University, New Haven, Connecticut 06520 and Department of Internal Medicine, Yale University, New Haven, Connecticut 06520
| | - Chi Liu
- Department of Diagnostic Radiology, Yale University, New Haven, Connecticut 06520
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10
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Kim DY, Kim HS, Reder S, Zheng JH, Herz M, Higuchi T, Pyo AY, Bom HS, Schwaiger M, Min JJ. Comparison of 18F-Labeled Fluoroalkylphosphonium Cations with 13N-NH3 for PET Myocardial Perfusion Imaging. J Nucl Med 2015; 56:1581-6. [PMID: 26069304 DOI: 10.2967/jnumed.115.156794] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2015] [Accepted: 05/29/2015] [Indexed: 01/16/2023] Open
Abstract
UNLABELLED Despite substantial advances in the diagnosis of cardiovascular disease, there is a need for 18F-labeled myocardial perfusion agents for the diagnosis of ischemic heart disease because current PET tracers for myocardial perfusion imaging have a short half-life that limits their widespread clinical use in PET. Thus, 18F-labeled fluoroalkylphosphonium derivatives (18F-FATPs), including (5-18F-fluoropentyl)triphenylphosphonium cation (18F-FPTP), (6-18F-fluorohexyl)triphenylphosphonium cation (18F-FHTP), and (2-(2-18F-fluoroethoxy)ethyl)triphenylphosphonium cation (18F-FETP), were synthesized. The myocardial extraction and image quality of the 18F-FATPs were compared with those of 13N-NH3 in rat models. METHODS The first-pass extraction fraction (EF) values of the 18F-FATPs (18F-FPTP, 18F-FHTP, 18F-FETP) and 13N-NH3 were measured in isolated rat hearts perfused with the Langendorff method (flow velocities, 0.5, 4.0, 8.0, and 16.0 mL/min). Normal and myocardial infarction rats were imaged with small-animal PET after intravenous injection of 37 MBq of 18F-FATPs and 13N-NH3. To determine pharmacokinetics, a region of interest was drawn around the heart, and time-activity curves of the 18F-FATPs and 13N-NH3 were generated to obtain the counts per pixel per second. Defect size was analyzed on the basis of polar map images of 18F-FATPs and 13N-NH3. RESULTS The EF values of 18F-FATPs and 13N-NH3 were comparable at low flow velocity (0.5 mL/min), whereas at higher flows EF values of 18F-FATPs were significantly higher than those of 13N-NH3 (4.0, 8.0, and 16.0 mL/min, P<0.05). Myocardium-to-liver ratios of 18F-FPTP, 18F-FHTP, 18F-FETP, and 13N-NH3 were 2.10±0.30, 4.36±0.20, 3.88±1.03, and 0.70±0.09, respectively, 10 min after injection, whereas myocardium-to-lung ratios were 5.00±0.25, 4.33±0.20, 7.98±1.23, and 2.26±0.14, respectively. Although 18F-FATPs and 13N-NH3 sharply delineated myocardial perfusion defects, defect size on the 13N-NH3 images was significantly smaller than on the 18F-FATP images soon after tracer injection (0-10 min, P=0.027). CONCLUSION 18F-FATPs exhibit higher EF values and more rapid clearance from the liver and lung than 13N-NH3 in normal rats, which led to excellent image quality in a rat model of coronary occlusion. Therefore, 18F-FATPs are promising new PET radiopharmaceuticals for myocardial perfusion imaging.
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Affiliation(s)
- Dong-Yeon Kim
- Department of Nuclear Medicine, Chonnam National University Hwasun Hospital, Hwasun, Korea; and
| | - Hyeon Sik Kim
- Department of Nuclear Medicine, Chonnam National University Hwasun Hospital, Hwasun, Korea; and
| | - Sybille Reder
- Department of Nuclear Medicine, Klinikum Rechts der Isar, Technische Universität München, Munich, Germany
| | - Jin Hai Zheng
- Department of Nuclear Medicine, Chonnam National University Hwasun Hospital, Hwasun, Korea; and
| | - Michael Herz
- Department of Nuclear Medicine, Klinikum Rechts der Isar, Technische Universität München, Munich, Germany
| | - Takahiro Higuchi
- Department of Nuclear Medicine, Klinikum Rechts der Isar, Technische Universität München, Munich, Germany
| | - A Young Pyo
- Department of Nuclear Medicine, Chonnam National University Hwasun Hospital, Hwasun, Korea; and
| | - Hee-Seung Bom
- Department of Nuclear Medicine, Chonnam National University Hwasun Hospital, Hwasun, Korea; and
| | - Markus Schwaiger
- Department of Nuclear Medicine, Klinikum Rechts der Isar, Technische Universität München, Munich, Germany
| | - Jung-Joon Min
- Department of Nuclear Medicine, Chonnam National University Hwasun Hospital, Hwasun, Korea; and
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Yang Y, Zheng Y, Tomaselli E, Fang W, Liu S. Impact of Boronate Capping Groups on Biological Characteristics of Novel99mTc(III) Complexes [99mTcCl(CDO)(CDOH)2B-R] (CDOH2= Cyclohexanedione Dioxime). Bioconjug Chem 2015; 26:316-28. [PMID: 25585053 DOI: 10.1021/bc500583k] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Yong Yang
- Department of Nuclear Medicine, Cardiovascular Institute & Fu Wai Hospital, Chinese Academy of Medical Science & Peking Union Medical College, Beijing 100037, China
- School of Health Sciences, Purdue University, West Lafayette, Indiana 47907, United States
| | - Yumin Zheng
- Department of Nuclear Medicine, China-Japan Friendship Hospital, Beijing 100029, China
| | - Elena Tomaselli
- School of Health Sciences, Purdue University, West Lafayette, Indiana 47907, United States
| | - Wei Fang
- Department of Nuclear Medicine, Cardiovascular Institute & Fu Wai Hospital, Chinese Academy of Medical Science & Peking Union Medical College, Beijing 100037, China
| | - Shuang Liu
- School of Health Sciences, Purdue University, West Lafayette, Indiana 47907, United States
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Zheng Y, Ji S, Tomaselli E, Ernest C, Freiji T, Liu S. Effect of co-ligands on chemical and biological properties of (99m)Tc(III) complexes [(99m)Tc(L)(CDO)(CDOH)2BMe] (L=Cl, F, SCN and N3; CDOH2=cyclohexanedione dioxime). Nucl Med Biol 2014; 41:813-24. [PMID: 25169135 PMCID: PMC4381195 DOI: 10.1016/j.nucmedbio.2014.07.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2014] [Accepted: 07/19/2014] [Indexed: 11/17/2022]
Abstract
INTRODUCTION (99m)Tc-Teboroxime ([(99m)TcCl(CDO)(CDOH)2BMe]) is a member of the BATO (boronic acid adducts of technetium dioximes) class of (99m)Tc(III) complexes. This study sought to explore the impact of co-ligands on solution stability, heart uptake and myocardial retention of [(99m)Tc(L)(CDO)(CDOH)2BMe] ((99m)Tc-Teboroxime: L=Cl; (99m)Tc-Teboroxime(F): L=F; (99m)Tc-Teboroxime(SCN): L=SCN; and (99m)Tc-Teboroxime(N3): L=N3). METHODS Radiotracers (99m)Tc-Teboroxime(L) (L=F, SCN and N3) were prepared by reacting (99m)Tc-Teboroxime with NaF, NaSCN and NaN3, respectively. Biodistribution and imaging studies were carried out in Sprague-Dawley rats. Image quantification was performed to compare their heart retention and liver clearance kinetics. RESULTS Complexes (99m)Tc-Teboroxime(L) (L=F, SCN and N3) were prepared in high yield with high radiochemical purity. All new radiotracers were stable for >6h in the kit matrix. In its HPLC chromatogram, (99m)Tc-Teboroxime showed one peak at ~15.5 min, which was shorter than that of (99m)Tc-Teboroxime(F) (~16.4 min). There were two peaks for (99m)Tc-Teboroxime(SCN) at 16.5 and 18.3 min. (99m)Tc-Teboroxime(N3) appeared as a single peak at 18.4 min. Their heart retention and liver clearance curves were best fitted to the bi-exponential decay function. The half-times of fast/slow components were 1.6±0.4/60.7±8.9 min for (99m)Tc-Teboroxime, 0.8±0.2/101.7±20.7 min for (99m)Tc-Teboroxime(F), 1.2±0.3/84.8±16.6 min for (99m)Tc-Teboroxime(SCN), and 2.9±0.9/51.6±5.0 min for (99m)Tc-Teboroxime(N3). The 2-min heart uptake followed the order of (99m)Tc-Teboroxime (3.00±0.37%ID/g)>(99m)Tc-Teboroxime(N3) (2.66±0.01 %ID/g)≈(99m)Tc-Sestamibi (2.55±0.46 %ID/g)>(99m)TcN-MPO (2.38±0.15 %ID/g). (99m)Tc-Teboroxime remains the best in first-pass extraction. The best image acquisition window is 0-5 min for (99m)Tc-Teboroximine and 0-15 min for (99m)Tc-Teboroximine(N3). CONCLUSION Co-ligands had significant impact on the heart uptake and myocardial retention of complexes [(99m)Tc(L)(CDO)(CDOH)2BMe] (L=Cl, F, SCN and N3). Future studies should be directed towards minimizing the liver uptake and radioactivity accumulation in the blood vessels while maintaining their high heart uptake.
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Affiliation(s)
- Yumin Zheng
- School of Health Sciences, Purdue University, IN 47907, USA; Department of Nuclear Medicine, China-Japan Friendship Hospital, Beijing, 100029, China
| | - Shundong Ji
- School of Health Sciences, Purdue University, IN 47907, USA
| | | | - Carley Ernest
- School of Health Sciences, Purdue University, IN 47907, USA
| | - Tom Freiji
- School of Health Sciences, Purdue University, IN 47907, USA
| | - Shuang Liu
- School of Health Sciences, Purdue University, IN 47907, USA.
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Swidan MM, Sakr TM, Motaleb MA, El-Bary AA, El-Kolaly MT. Radioiodinated acebutolol as a new highly selective radiotracer for myocardial perfusion imaging. J Labelled Comp Radiopharm 2014; 57:593-9. [DOI: 10.1002/jlcr.3223] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2014] [Revised: 06/17/2014] [Accepted: 07/03/2014] [Indexed: 11/12/2022]
Affiliation(s)
- M. M. Swidan
- Labeled Compound Department; Hot Labs Center, Atomic Energy Authority; PO13759 Cairo Egypt
| | - T. M. Sakr
- Radioactive Isotopes and Generator Department; Hot Labs Center, Atomic Energy Authority; PO13759 Cairo Egypt
| | - M. A. Motaleb
- Labeled Compound Department; Hot Labs Center, Atomic Energy Authority; PO13759 Cairo Egypt
| | - A. Abd El-Bary
- Pharmaceutics and Industrial Pharmacy Department; Faculty of Pharmacy, Cairo University; PO11562 Cairo Egypt
| | - M. T. El-Kolaly
- Labeled Compound Department; Hot Labs Center, Atomic Energy Authority; PO13759 Cairo Egypt
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Zheng Y, Ji S, Tomaselli E, Liu S. Development of kit formulations for (99m) TcN-MPO: a cationic radiotracer for myocardial perfusion imaging. J Labelled Comp Radiopharm 2014; 57:584-92. [PMID: 25070025 DOI: 10.1002/jlcr.3221] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2014] [Revised: 06/30/2014] [Accepted: 07/03/2014] [Indexed: 11/11/2022]
Abstract
The objective of this study was to develop a kit formulation for [(99m) TcN(mpo)(PNP5)](+) (MPO = 2-mercaptopyridine oxide), ((99m) TcN-MPO) to support its clinical evaluations as a SPECT radiotracer. Radiolabeling studies were performed using three different formulations (two-vial formulation and single-vial formulations with/without SnCl2 ) to explore the factors influencing radiochemical purity (RCP) of (99m) TcN-MPO. We found that the most important factor affecting the RCP of (99m) TcN-MPO was the purity of PNP5. (99m) TcN-MPO was prepared >98% RCP (n = 20) using the two-vial formulation. For single-vial formulations with/without SnCl2 , β-cyclodextrin (β-CD) is particularly useful as a stabilizer for PNP5. The RCP of (99m) TcN-MPO was 95-98% using β-CD, but its RCP was only 90-93% with γ-cyclodextrin (γ-CD). It seems that PNP5 fits better into the inner cavity of β-CD, which forms more stable inclusion complex than γ-CD in the single-vial formulations. The results from biodistribution and imaging studies in Sprague-Dawley rats clearly demonstrated biological equivalence of three different formulations. Single photon-emission computed tomography data suggested that high quality images could be obtained at 0-30-min post-injection without significant interference from the liver radioactivity. Considering the ease for (99m) Tc-labeling and high RCP of (99m) TcN-MPO, the non-SnCl2 single-vial formulation is an attractive choice for future clinical studies.
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Affiliation(s)
- Yumin Zheng
- School of Health Sciences, Purdue University, West Lafayette, IN, 47907, USA; Department of Nuclear Medicine, China-Japan Friendship Hospital, Beijing, 100029, China
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Verger A, Imbert L, Yagdigul Y, Fay R, Djaballah W, Rouzet F, Fourquet N, Poussier S, Roch V, Le Guludec D, Karcher G, Marie PY. Factors affecting the myocardial activity acquired during exercise SPECT with a high-sensitivity cardiac CZT camera as compared with conventional Anger camera. Eur J Nucl Med Mol Imaging 2013; 41:522-8. [PMID: 24202049 DOI: 10.1007/s00259-013-2617-2] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2013] [Accepted: 10/14/2013] [Indexed: 10/26/2022]
Abstract
PURPOSE Injected doses are difficult to optimize for exercise SPECT since they depend on the myocardial fraction of injected activity (MFI) that is detected by the camera. The aim of this study was to analyse the factors affecting MFI determined using a cardiac CZT camera as compared with those determined using conventional Anger cameras. METHODS Factors affecting MFI were determined and compared in patients who had consecutive exercise SPECT acquisitions with (201)Tl (84 patients) or (99m)Tc-sestamibi (87 patients) with an Anger or a CZT camera. A predictive model was validated in a group of patients routinely referred for (201)Tl (78 patients) or (99m)Tc-sestamibi (80 patients) exercise CZT SPECT. RESULTS The predictive model involved: (1) camera type, adjusted mean MFI being ninefold higher for CZT than for Anger SPECT, (2) tracer type, adjusted mean MFI being twofold higher for (201)Tl than for (99m)Tc-sestamibi, and (3) logarithm of body weight. The CZT SPECT model led to a +1 ± 26% error in the prediction of the actual MFI from the validation group. The mean MFI values estimated for CZT SPECT were more than twofold higher in patients with a body weight of 60 kg than in patients with a body weight of 120 kg (15.9 and 6.8 ppm for (99m)Tc-sestamibi and 30.5 and 13.1ppm for (201)Tl, respectively), and for a 14-min acquisition of up to one million myocardial counts, the corresponding injected activities were only 80 and 186 MBq for (99m)Tc-sestamibi and 39 and 91 MBq for (201)Tl, respectively. CONCLUSION Myocardial activities acquired during exercise CZT SPECT are strongly influenced by body weight and tracer type, and are dramatically higher than those obtained using an Anger camera, allowing very low-dose protocols to be planned, especially for (99m)Tc-sestamibi and in non-obese subjects.
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Affiliation(s)
- Antoine Verger
- Department of Nuclear Medicine, CHU-Nancy, Nancy, 54000, France
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Gao S, Zhao G, Wen Q, Bai L, Chen B, Ji T, Ji B, Ma Q. Pharmacokinetics and biodistribution of 99mTc N-MPO in healthy human volunteers. Clin Nucl Med 2013; 39:e14-9. [PMID: 23917788 DOI: 10.1097/rlu.0b013e3182872a8c] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
PURPOSE Tc N-MPO ([Tc N(MPO)(PNP5)]: HMPO = 2-mercaptopyridine N-oxide, and PNP5 = N-ethoxyethyl-N,N-bis[2-(bis(3-methoxypropyl)phosphino)ethyl]amine) is a new Tc radiotracer useful for myocardial perfusion imaging. This study was designed to determine its pharmacokinetics and biodistribution in healthy volunteers. PATIENTS AND METHODS Ten healthy volunteers were involved in this study. Each subject was administered approximately 925 MBq of Tc N-MPO under rest or stress conditions (n = 5 per group). Whole-body planar images were obtained at 10, 30, 60, 240, and 1440 minutes after injection. Organ uptake was quantified by region-of-interest analysis. The blood clearance and urine excretion kinetics were determined by collecting blood and urine samples at different time points. RESULTS Tc N-MPO showed significant accumulation in myocardium with prolonged retention. At rest, its percentage of injected dose (%ID) uptake in the heart, lungs, and liver at 10 minutes after injection was 2.47% (0.64%), 1.84% (0.64%), and 20.88% (5.23%), respectively. The liver uptake decreased to 6.79%ID (1.60%ID) at 60 minutes after injection and 4.50%ID (1.86%ID) at 240 minutes after injection. Under stress conditions, the heart uptake was slightly increased (2.57%ID [0.21%ID]). The rapid liver clearance led to favorable heart-to-liver ratios, reaching values of 0.27%ID (0.07%ID) under rest condition and 0.28%ID (0.05%ID) under stress condition at 60 minutes after injection. CONCLUSIONS Tc N-MPO demonstrates a highly favorable biodistribution in humans. The high heart uptake and the fast liver washout of Tc N-MPO will allow SPECT images of the left ventricle to be acquired as early as 10 minutes after injection.
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Affiliation(s)
- Shi Gao
- From the Department of Nuclear Medicine, China-Japan Union Hospital, Jilin University, Changchun, China
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Kim DY, Kim HS, Le UN, Jiang SN, Kim HJ, Lee KC, Woo SK, Chung J, Kim HS, Bom HS, Yu KH, Min JJ. Evaluation of a Mitochondrial Voltage Sensor, (18F-Fluoropentyl)Triphenylphosphonium Cation, in a Rat Myocardial Infarction Model. J Nucl Med 2012; 53:1779-85. [DOI: 10.2967/jnumed.111.102657] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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Evaluation of (99) (m)TcN-MPO as a new myocardial perfusion imaging agent in normal dogs and in an acute myocardial infarction canine model: comparison with (99) (m)Tc-sestamibi. Mol Imaging Biol 2011; 13:121-7. [PMID: 20458635 DOI: 10.1007/s11307-010-0304-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
PURPOSE (99) (m)TcN-MPO ([(99) (m)TcN(mpo)(PNP5)](+): mpo = 2-mercaptopyridine oxide and PNP5 = N-ethoxyethyl-N,N-bis[2-(bis(3-methoxypropyl)phosphino)ethyl]amine) is a cationic (99) (m)Tc-nitrido complex, which has favorable biodistribution and myocardial uptake with rapid liver clearance in Sprague Dawley rats. The objective of this study was to compare the biodistribution and pharmacokinetics of (99) (m)TcN-MPO and (99) (m)Tc-Sestamibi in normal dogs, and to evaluate the potential of (99) (m)TcN-MPO as a myocardial perfusion agent in canines with acute myocardial infarction. METHODS Five normal mongrel dogs were injected intravenously with (99) (m)TcN-MPO. Venous blood samples were collected via a femoral vein catheter at 0.5, 1, 2, 3, 4, 5, 10, 20, 30, 40, 60, and 90 min post-injection (p.i.). Anterior-posterior planar images were acquired by γ-camera at 10, 20, 30, 60, 90, and 120 min p.i. Regions of interest (ROIs) were drawn around the heart, liver, and lungs. The heart/liver and heart/lung ratios were calculated by dividing the mean counts in heart ROI by the mean counts in the liver and lung ROI, respectively. For comparison, (99) (m)Tc-sestamibi was also evaluated in the same five dogs. The interval period between the two examinations was 1 week to eliminate possible interference between these two radiotracers. In addition, single positron emission computed tomography (SPECT) images in the canine infarct model were collected 24 h after myocardial infarction at 30 and 60 min after the administration of (99) (m)TcN-MPO (n = 4) or (99) (m)Tc-Sestamibi (n = 4). RESULTS It was found that (99) (m)TcN-MPO and (99) (m)Tc-Sestamibi displayed very similar blood clearance characteristics during the first 90 min p.i. Both (99) (m)TcN-MPO and (99) (m)Tc-Sestamibi had a rapid blood clearance with less than 50% of initial radioactivity remaining at 1 min and less than 5% at 30 min p.i. (99) (m)TcN-MPO and (99) (m)Tc-Sestamibi both showed good heart/lung contrast. The heart/liver ratio of (99) (m)TcN-MPO increased with time (0.53 ± 0.06 at 10 min, 0.90 ± 0.062 at 30 min, and 1.22 ± 0.06 at 60 min p.i.), whereas the heart/liver ratio of (99) (m)Tc-Sestamibi remained low at all time points (0.50 ± 0.03 at 10 min, 0.64 ± 0.03 at 30 min, and 0.60 ± 0.02 at 60 min p.i.). SPECT imaging studies in canines with acute myocardial infarction indicated that good visualization of the left ventricular wall and perfusion defects could be achieved at 30 min after administration of (99) (m)TcN-MPO but not after (99) (m)Tc-Sestamibi. CONCLUSION The combination of reasonable heart uptake with rapid hepatobiliary excretion makes (99) (m)TcN-MPO a promising new radiotracer for myocardial perfusion imaging.
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Goethals LR, Santos I, Caveliers V, Paulo A, De Geeter F, Lurdes PG, Fernandes C, Lahoutte T. Rapid hepatic clearance of 99mTc-TMEOP: a new candidate for myocardial perfusion imaging. CONTRAST MEDIA & MOLECULAR IMAGING 2010; 6:178-88. [DOI: 10.1002/cmmi.413] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2010] [Revised: 06/29/2010] [Accepted: 07/29/2010] [Indexed: 11/06/2022]
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Miller TD, Gibbons RJ. Measuring myocardium at risk in acute myocardial infarction--a continuing challenge. J Nucl Cardiol 2010; 17:778-80. [PMID: 20717762 DOI: 10.1007/s12350-010-9278-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Vallabhajosula S, Killeen RP, Osborne JR. Altered Biodistribution of Radiopharmaceuticals: Role of Radiochemical/Pharmaceutical Purity, Physiological, and Pharmacologic Factors. Semin Nucl Med 2010; 40:220-41. [DOI: 10.1053/j.semnuclmed.2010.02.004] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Bolzati C, Cavazza-Ceccato M, Agostini S, Refosco F, Yamamichi Y, Tokunaga S, Carta D, Salvarese N, Bernardini D, Bandoli G. Biological in Vitro and in Vivo Studies of a Series of New Asymmetrical Cationic [99mTc(N)(DTC-Ln)(PNP)]+ Complex (DTC-Ln = Alicyclic Dithiocarbamate and PNP = Diphosphinoamine). Bioconjug Chem 2010; 21:928-39. [DOI: 10.1021/bc900493e] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Affiliation(s)
- Cristina Bolzati
- ICIS-CNR, Corso Stati Uniti, 4, 35127 Padova, Italy, Department of Pharmaceutical Sciences, University of Padua, Via Marzolo, 5, 35131 Padova, Italy, Research Center, Nihon Medi-Physics Co., Ltd., 3-1 Kitasode, Sodegaura, Chiba 299-0266, Japan, and Department of Veterinary Clinical Science, University of Padua, Viale dell’Università 16, 35020 Legnaro, Padua, Italy
| | - Mario Cavazza-Ceccato
- ICIS-CNR, Corso Stati Uniti, 4, 35127 Padova, Italy, Department of Pharmaceutical Sciences, University of Padua, Via Marzolo, 5, 35131 Padova, Italy, Research Center, Nihon Medi-Physics Co., Ltd., 3-1 Kitasode, Sodegaura, Chiba 299-0266, Japan, and Department of Veterinary Clinical Science, University of Padua, Viale dell’Università 16, 35020 Legnaro, Padua, Italy
| | - Stefania Agostini
- ICIS-CNR, Corso Stati Uniti, 4, 35127 Padova, Italy, Department of Pharmaceutical Sciences, University of Padua, Via Marzolo, 5, 35131 Padova, Italy, Research Center, Nihon Medi-Physics Co., Ltd., 3-1 Kitasode, Sodegaura, Chiba 299-0266, Japan, and Department of Veterinary Clinical Science, University of Padua, Viale dell’Università 16, 35020 Legnaro, Padua, Italy
| | - Fiorenzo Refosco
- ICIS-CNR, Corso Stati Uniti, 4, 35127 Padova, Italy, Department of Pharmaceutical Sciences, University of Padua, Via Marzolo, 5, 35131 Padova, Italy, Research Center, Nihon Medi-Physics Co., Ltd., 3-1 Kitasode, Sodegaura, Chiba 299-0266, Japan, and Department of Veterinary Clinical Science, University of Padua, Viale dell’Università 16, 35020 Legnaro, Padua, Italy
| | - Yoshihiro Yamamichi
- ICIS-CNR, Corso Stati Uniti, 4, 35127 Padova, Italy, Department of Pharmaceutical Sciences, University of Padua, Via Marzolo, 5, 35131 Padova, Italy, Research Center, Nihon Medi-Physics Co., Ltd., 3-1 Kitasode, Sodegaura, Chiba 299-0266, Japan, and Department of Veterinary Clinical Science, University of Padua, Viale dell’Università 16, 35020 Legnaro, Padua, Italy
| | - Shinji Tokunaga
- ICIS-CNR, Corso Stati Uniti, 4, 35127 Padova, Italy, Department of Pharmaceutical Sciences, University of Padua, Via Marzolo, 5, 35131 Padova, Italy, Research Center, Nihon Medi-Physics Co., Ltd., 3-1 Kitasode, Sodegaura, Chiba 299-0266, Japan, and Department of Veterinary Clinical Science, University of Padua, Viale dell’Università 16, 35020 Legnaro, Padua, Italy
| | - Davide Carta
- ICIS-CNR, Corso Stati Uniti, 4, 35127 Padova, Italy, Department of Pharmaceutical Sciences, University of Padua, Via Marzolo, 5, 35131 Padova, Italy, Research Center, Nihon Medi-Physics Co., Ltd., 3-1 Kitasode, Sodegaura, Chiba 299-0266, Japan, and Department of Veterinary Clinical Science, University of Padua, Viale dell’Università 16, 35020 Legnaro, Padua, Italy
| | - Nicola Salvarese
- ICIS-CNR, Corso Stati Uniti, 4, 35127 Padova, Italy, Department of Pharmaceutical Sciences, University of Padua, Via Marzolo, 5, 35131 Padova, Italy, Research Center, Nihon Medi-Physics Co., Ltd., 3-1 Kitasode, Sodegaura, Chiba 299-0266, Japan, and Department of Veterinary Clinical Science, University of Padua, Viale dell’Università 16, 35020 Legnaro, Padua, Italy
| | - Daniele Bernardini
- ICIS-CNR, Corso Stati Uniti, 4, 35127 Padova, Italy, Department of Pharmaceutical Sciences, University of Padua, Via Marzolo, 5, 35131 Padova, Italy, Research Center, Nihon Medi-Physics Co., Ltd., 3-1 Kitasode, Sodegaura, Chiba 299-0266, Japan, and Department of Veterinary Clinical Science, University of Padua, Viale dell’Università 16, 35020 Legnaro, Padua, Italy
| | - Giuliano Bandoli
- ICIS-CNR, Corso Stati Uniti, 4, 35127 Padova, Italy, Department of Pharmaceutical Sciences, University of Padua, Via Marzolo, 5, 35131 Padova, Italy, Research Center, Nihon Medi-Physics Co., Ltd., 3-1 Kitasode, Sodegaura, Chiba 299-0266, Japan, and Department of Veterinary Clinical Science, University of Padua, Viale dell’Università 16, 35020 Legnaro, Padua, Italy
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Kim YS, Wang F, Liu S. Minimizing liver uptake of cationic Tc radiotracers with ether and crown ether functional groups. World J Hepatol 2010; 2:21-31. [PMID: 21160953 PMCID: PMC2999265 DOI: 10.4254/wjh.v2.i1.21] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/01/2009] [Revised: 01/11/2010] [Accepted: 01/18/2010] [Indexed: 02/06/2023] Open
Abstract
Ischemia-related diseases, particularly coronary artery disease (CAD), account for the majority of deaths worldwide. Myocardial ischemia is a serious condition and the delay in reperfusion of ischemic tissues can be life-threatening. This is particular true in the aged population. Rapid and accurate early detection of myocardial ischemia is highly desirable so that various therapeutic regiments can be given before irreversible myocardial damage occurs. Myocardial perfusion imaging with radiotracers is an integral component in evaluations of patients with known or suspected CAD. (99m)Tc-Sestamibi and (99m)Tc-Tetrofosmin are commercial radiopharmaceuticals currently available for myocardial perfusion imaging. Despite their widespread clinical applications, both (99m)Tc-Sestamibi and (99m)Tc-Tetrofosmin do not meet the requirements of an ideal perfusion imaging agent, largely due to their high liver uptake. The intense liver uptake makes it difficult to interpret the heart activity in the inferior and left ventricular wall. Photon scattering from the high liver radioactivity accumulation remains a significant challenge for diagnosis of heart diseases. This review will summarize the most recent research efforts to minimize the liver uptake of cationic (99m)Tc radiotracers by using ether and crown ether-containing chelators. Fast liver clearance will shorten the duration of imaging protocols (< 30 min post-injection), and allow for early acquisition of heart images with high quality. Improvement of heart/liver ratio may permit better detection of the presence and extent of coronary artery disease. Identification of such a new radiotracer that allows for the improved noninvasive assessment of myocardial perfusion would be of considerable benefit in treatment of patients with suspected CAD.
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Affiliation(s)
- Young-Seung Kim
- Young-Seung Kim, Shuang Liu, School of Health Sciences, Purdue University, 550 Stadium Mall Drive, West Lafayette, IN 47907, United States
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Kim YS, Shi J, Zhai S, Hou G, Liu S. Mechanism for myocardial localization and rapid liver clearance of Tc-99m-N-MPO: a new perfusion radiotracer for heart imaging. J Nucl Cardiol 2009; 16:571-9. [PMID: 19288164 DOI: 10.1007/s12350-009-9068-y] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2008] [Revised: 01/14/2009] [Accepted: 01/25/2009] [Indexed: 10/21/2022]
Abstract
BACKGROUND [Tc-99m-N(mpo)(PNP5)](+) (Tc-99m-N-MPO: Hmpo = 2-mercaptopyridine N-oxide and PNP5 = N-ethoxyethyl-N,N-bis[2-(bis(3-methoxypropyl)phosphino)ethyl]amine) is a new Tc-99m radiotracer useful for myocardial perfusion imaging. The main objective of this study is to elucidate the mechanism for myocardial localization and fast liver clearance of Tc-99m-N-MPO in comparison with Tc-99m-sestamibi ([Tc-99m-(MIBI)(6)](+): MIBI = 2-methoxy-2-methylpropylisonitrile). METHODS AND RESULTS Subcellular distribution of Tc-99m-N-MPO and Tc-99m-sestamibi was examined in the excised Sprague-Dawley (SD) rat myocardium. Biodistribution and planar imaging studies were performed using SD rats in the absence/presence of Cyclosporin-A. Due to negative plasma and mitochondrial potentials, 84.5% +/- 3.2% of Tc-99m-N-MPO was found in the mitochondrial fraction as compared to 88.0% +/- 1.5% of Tc-99m-sestamibi. There was no significant difference in their mitochondrial accumulation. Tc-99m-N-MPO was also able to retain its chemical integrity in rat myocardium. Pre-treatment of SD rats with Cys-A result in significant increase in the kidney and liver uptake of Tc-99m-N-MPO. CONCLUSION Tc-99m-N-MPO and Tc-99m-sestamibi share almost identical subcellular distribution and localization mechanism. The MDR transport function of hepatocytes and renal cells is responsible for the fast clearance kinetics of Tc-99m-N-MPO from liver and kidneys, respectively. Tc-99m-N-MPO is a very promising myocardial perfusion radiotracer with favorable biodistribution properties and rapid liver clearance.
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Affiliation(s)
- Young-Seung Kim
- School of Health Sciences, Purdue University, West Lafayette, IN 47907, USA
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Monzen H, Hara M, Nakanishi A, Hirata M, Suzuki T, Ogasawara M, Higuchi H, Kobayashi H, Yuki R, Hirose K. New protocol of myocardial SPECT imaging with technetium-99m sestamibi for reducing the time interval between rest and adenosine stress phases. Radiol Phys Technol 2009; 2:70-6. [PMID: 20821132 DOI: 10.1007/s12194-008-0047-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2008] [Revised: 11/11/2008] [Accepted: 11/11/2008] [Indexed: 11/25/2022]
Abstract
We have developed a new protocol of myocardial perfusion-gated single-photon emission computed tomography (SPECT), by use of technetium-99m sestamibi (MIBI), in which SPECT imaging at rest followed by SPECT imaging after adenosine with low level ergometer stress can be conducted by use of the Monzen position within a shortened total testing time of 1 h or less. The study group consisted of 137 patients who underwent this new imaging protocol. The diagnostic quality of the images was as good as that of images obtained with the conventional method (30-60 min after the injection of MIBI). The SPECT image quality for the 137 patients was evaluated, and the percentages of images rated as excellent, good, fair, and poor were 65.3, 27.4, 5.8, and 1.5% for the rest image, and 68.2, 21.9, 8.4, and 1.5% for the stress image, respectively. The shortened total testing time reduced the physical and mental burden on the patient compared with that of conventional myocardial perfusion imaging. Because this technique allows us to perform rest and stress myocardial imaging within a short period, it is expected to be very useful in the clinical setting.
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Affiliation(s)
- Hajime Monzen
- Department of Radiology, Otsu Red Cross Hospital, Otsu-shi, Shiga, Japan.
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Zhang WC, Fang W, Li B, Wang XB, He ZX. Experimental Study of [ 99mTc(PNP5) (DBODC)] + as a New Myocardial Perfusion Imaging Agent. Cardiology 2009; 112:89-97. [DOI: 10.1159/000141013] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/15/2007] [Accepted: 02/08/2008] [Indexed: 11/19/2022]
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Evaluation of 99mTcN-15C5 as a new myocardial perfusion imaging agent in normal dogs and canines with coronary stenosis. Nucl Med Commun 2008; 29:775-81. [PMID: 18677204 DOI: 10.1097/mnm.0b013e328302ca4a] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVES This study was designed to evaluate the biodistribution and blood clearance characteristics of 99mTcN-15C5 and its potential as a myocardial perfusion radiotracer. METHODS Five normal mongrel dogs were injected with 99mTcN-15C5 intravenously. Blood samples were collected at 0.5, 1, 2, 3, 4, 5, 10, 15, and 30 min postinjection (p.i.). Anterior planar images were acquired at 5, 15, 30, 60, 90, and 120 min p.i. Regions of interest (ROIs) were drawn around heart, liver, and lungs. The raw activity in each ROI was expressed as counts/pixel/min. Heart/liver and heart/lung ratios were calculated by dividing the mean counts in heart ROI by the mean counts in liver and lung ROI, respectively. For comparison, 99mTc-sestamibi was also evaluated in the same five dogs. In dogs with coronary stenoses, single photon emission computed tomography images were acquired at 30, 60, and 120 min after administration of 99mTcN-15C5 with/without adenosine. RESULTS 99mTcN-15C5 and 99mTc-sestamibi had very similar blood clearance characteristics during the first 30 min p.i. The heart/liver ratio of 99mTcN-15C5 increased from 0.48+/-0.05 at 5 min p.i. to 1.85+/-0.11 at 120 min p.i., whereas the heart/liver ratio of 99mTc-sestamibi was improved only slightly from 0.45+/-0.04 at 5 min p.i. to 0.74+/-0.15 at 120 min p.i. SPECT imaging studies in canines with coronary stenoses indicated that good visualization of the perfusion defect could be achieved at 30 min after administration of 99mTcN-15C5 with the adenosine stress. CONCLUSION The combination of high heart uptake and rapid liver clearance makes 99mTcN-15C5 a promising new radiotracer for myocardial perfusion imaging.
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Misra P, Lebeche D, Ly H, Schwarzkopf M, Diaz G, Hajjar RJ, Schecter AD, Frangioni JV. Quantitation of CXCR4 expression in myocardial infarction using 99mTc-labeled SDF-1alpha. J Nucl Med 2008; 49:963-9. [PMID: 18483105 DOI: 10.2967/jnumed.107.050054] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
UNLABELLED The chemokine stromal-derived factor-1alpha (SDF-1alpha, CXCL12) and its receptor CXCR4 are implicated as key mediators of hematopoietic stem cell retention, cancer metastasis, and HIV infection. Their role in myocardial infarction (MI) is not as well defined. The noninvasive in vivo quantitation of CXCR4 expression is central to understanding its importance in these diverse processes as well in the cardiac response to injury. METHODS Recombinant SDF-1alpha was radiolabeled under aprotic conditions and purified by gel-filtration chromatography (GFC) using high-specific-activity 99mTc-S-acetylmercaptoacetyltriserine-N-hydroxysuccinimide ([99mTc-MAS3]-NHS) prepared by solid-phase preloading. Radiotracer stability and transmetallation under harsh conditions were quantified by GFC. Affinity, specificity, and maximum number of binding sites (Bmax) were quantified, with adenoviral-expressed CXCR4 on nonexpressing cells and endogenous receptor on rat neonatal cardiomyocytes, using a high-throughput live-cell-binding assay. Blood half-life, biodistribution, and clearance of intravenously injected [99mTc-MAS3]-SDF-1alpha were quantified in Sprague-Dawley rats before and after experimentally induced MI. RESULTS [99mTc-MAS3]-SDF-1alpha could be prepared in 2 h total with a specific activity of 8.0 x 10(7) MBq/mmol (2,166 Ci/mmol) and a radiochemical purity greater than 98%. Degradation of the radiotracer after boiling for 5 min, with and without 1 mM dithiothreitol, and transmetallation in 100% serum at 37 degrees C for 4 h were negligible. [99mTc-MAS3]-SDF-1alpha exhibits high specificity for CXCR4 on the surface of living rat neonatal cardiomyocytes, with an affinity of 2.7 +/- 0.9 nM and a Bmax of 4.8 x 10(4) binding sites per cell. After intravenous injection, 99mTc-labeled SDF-1alpha displays a blood half-life of 25.8 +/- 4.6 min, rapid renal clearance with only 26.2 +/- 6.1 percentage injected dose remaining in the carcass at 2 h, consistently low uptake in most organs (<0.1 percentage injected dose per gram), and no evidence of blood-brain barrier penetration. After MI was induced, CXCR4 expression levels in the myocardium increased more than 5-fold, as quantified using [99mTc-MAS3]-SDF-1alpha and confirmed using confocal immunofluorescence. CONCLUSION We describe a 99mTc-labeled SDF-1alpha radiotracer that can be used as a sensitive and specific probe for CXCR4 expression in vivo and demonstrate that this radiotracer is able to quantify changes in CXCR4 expression under different physiologic and pathologic states. Taken together, CXCR4 levels should now be quantifiable in vivo in a variety of animal model systems of human diseases.
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Affiliation(s)
- Preeti Misra
- Division of Hematology/Oncology, Beth Israel Deaconess Medical Center, Boston, Massachusetts 02215, USA
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Tc-99m-N-MPO: novel cationic Tc-99m radiotracer for myocardial perfusion imaging. J Nucl Cardiol 2008; 15:535-46. [PMID: 18674722 DOI: 10.1016/j.nuclcard.2008.02.022] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2007] [Accepted: 02/21/2008] [Indexed: 11/21/2022]
Abstract
BACKGROUND Technetium 99m-N-MPO ([Tc-99m-N(mpo)(PNP5)](+)) is a cationic Tc-99m nitrido complex. The objective of this study is to evaluate its potential as a new radiotracer for myocardial perfusion imaging. METHODS AND RESULTS Biodistribution studies were performed in Sprague-Dawley rats and guinea pigs to compare the myocardial uptake and excretion kinetics of Tc-99m-N-MPO from noncardiac organs, such as the liver and lungs, with those of the known cationic Tc-99m radiotracers: Tc-99m-N-DBODC5 and Tc-99m-sestamibi. Planar imaging was performed in Sprague-Dawley rats to evaluate the utility of Tc-99m-N-MPO as a myocardial perfusion imaging agent. Metabolism studies were carried out by use of both Sprague-Dawley rats and guinea pigs. In general, the heart uptake of Tc-99m-N-MPO was between that of Tc-99m-sestamibi and Tc-99m-N-DBODC5 over the 2-hour study period. However, the heart-liver ratio of Tc-99m-N-MPO (12.75 +/- 3.34) at 30 minutes after injection was more than twice that of Tc-99m-N-DBODC5 (6.01 +/- 1.45) and approximately 4 times higher than that of Tc-99m-sestamibi (2.90 +/- 0.22). The heart uptake and heart-liver ratio of Tc-99m-N-MPO and Tc-99m-sestamibi in guinea pigs were significantly lower than those obtained in Sprague-Dawley rats. The metabolism studies demonstrated no detectable Tc-99m-N-MPO metabolites in the urine and feces samples of the Sprague-Dawley rats at 120 minutes after injection. In guinea pigs no Tc-99m-N-MPO metabolites were detected in the urine at 120 minutes, but only approximately 60% of Tc-99m-N-MPO remained intact in the feces samples. In contrast, there was no intact Tc-99m-sestamibi detected in urine samples, and less than 15% of Tc-99m-sestamibi remained intact in the feces samples. Planar imaging studies indicated that clinically useful images of the heart may be obtained as early as 15 minutes after injection of Tc-99m-N-MPO. CONCLUSION The combination of favorable organ biodistribution and myocardial uptake with rapid liver clearance makes Tc-99m-N-MPO a very promising myocardial perfusion radiotracer worthy of further evaluation in various preclinical animal models.
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Lu J, Kong D, Yang Z, Yang S, Fan W, Jia H, Wang X. Preparation of 99mTc-nitrido asymmetrical heterocomplex with 4-(cyclohexylpiperazin-1-yl)-dithioformate and its biological evaluation as a potential myocardial imaging agent. Appl Radiat Isot 2007; 65:1134-9. [PMID: 17616466 DOI: 10.1016/j.apradiso.2007.04.021] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2006] [Revised: 04/19/2007] [Accepted: 04/19/2007] [Indexed: 11/17/2022]
Abstract
Potassium 4-(cyclohexylpiperazin-1-yl)-dithioformate (HPDTF) was synthesized from 1-cyclohexylpiperazine. The corresponding (99m)Tc-nitrido asymmetrical heterocomplex [(99m)TcN(PNP5)(HPDTF)](+) [PNP5=bis-(dimethoxypropylphosphinoethyl)ethoxyethylamine] was prepared via the [(99m)TcN](int)(2+) precursor in high yields (>95%) and characterized by HPLC and paper electrophoresis. It was found to be lipophilic and cationic, with high stability in vitro. Studies of its biodistribution in mice showed high heart uptake and good myocardial retention ((11.12+/-1.41)% ID/g at 5 min and (10.88+/-1.45)% ID/g at 120 min), as well as rapid clearance from liver, blood and soft tissues. At 60 min post-injection, the heart-to-liver, heart-to-lung and heart-to-blood ratios were 1.30, 3.89 and 27.56, respectively, which suggested that the complex might be suitable for myocardial imaging.
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Affiliation(s)
- Jie Lu
- Key Laboratory of Radiopharmaceuticals (Beijing Normal University), Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, PR China.
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He Z, Hsieh WY, Kim YS, Liu S. Evaluation of novel cationic 99mTc(I)-tricarbonyl complexes as potential radiotracers for myocardial perfusion imaging. Nucl Med Biol 2007; 33:1045-53. [PMID: 17127179 DOI: 10.1016/j.nucmedbio.2006.08.009] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2006] [Revised: 08/08/2006] [Accepted: 08/29/2006] [Indexed: 11/30/2022]
Abstract
This report describes the evaluation of three cationic (99m)Tc(I)-tricarbonyl complexes--[(99m)Tc(CO)(3)(L)](+) (L=N-methoxyethyl-N,N-bis[2-(bis(3-ethoxypropyl)phosphino)ethyl]amine (ME-PNP), N-[15-crown-5)-2-yl]-N,N-bis[2-(bis(3-ethoxypropyl)phosphino)ethyl]amine (15C5-PNP) and N-[18-crown-6)-2-yl]-N,N-bis[2-(bis(3-ethoxypropyl)phosphino)ethyl]amine (18C6-PNP))--as potential radiotracers for myocardial perfusion imaging. Biodistribution, imaging and metabolism studies were performed using Sprague-Dawley rats. It was found that bisphosphine ligands have a significant impact on the biodistribution characteristics and clearance kinetics of their cationic (99m)Tc(I)-tricarbonyl complexes. Among the three radiotracers evaluated in this study, [(99m)Tc(CO)(3)(15C5-PNP)](+) has a very high initial heart uptake and is retained in the rat myocardium for >2 h. It also shows rapid clearance from the liver and lungs. The heart/liver ratio of [(99m)Tc(CO)(3)(15C5-PNP)](+) is approximately 2.5 times better than that of (99m)Tc-sestamibi at 30 min postinjection. [(99m)Tc(CO)(3)(15C5-PNP)](+) is almost identical to (99m)TcN-DBODC5 with respect to heart uptake, heart/lung ratio and heart/liver ratio. Results from metabolism studies show that there is no significant metabolism for [(99m)Tc(CO)(3)(15C5-PNP)](+) in the urine, but it does show a small metabolite peak (<10%) in the radio high-performance liquid chromatography chromatogram of the feces sample at 120 min postinjection. Results planar imaging studies demonstrate that [(99m)Tc(CO)(3)(15C5-PNP)](+) has a much better liver clearance profile than (99m)Tc-sestamibi and might give clinically useful images of the heart as early as 30 min postinjection. [(99m)Tc(CO)(3)(15C5-PNP)](+) is a very promising candidate for more preclinical evaluations in various animal models.
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Affiliation(s)
- Zhengjie He
- School of Health Sciences, Purdue University, West Lafayette, IN 47907-2051, USA
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Hatada K, Ruiz M, Riou LM, Lima RL, Goode AR, Watson DD, Beller GA, Glover DK. Organ biodistribution and myocardial uptake, washout, and redistribution kinetics of Tc-99m N-DBODC5 when injected during vasodilator stress in canine models of coronary stenoses. J Nucl Cardiol 2007; 13:779-90. [PMID: 17174809 DOI: 10.1016/j.nuclcard.2006.08.016] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2005] [Revised: 08/08/2006] [Accepted: 08/08/2006] [Indexed: 11/28/2022]
Abstract
BACKGROUND Technetium 99m N-DBODC5 is a new myocardial perfusion tracer shown to exhibit high heart uptake and rapid liver clearance in normal rats. The objectives of this canine study were (1) to compare the organ biodistribution and myocardial uptake, washout, and redistribution kinetics of Tc-99m N-DBODC5 with Tc-99m sestamibi over a period of 3 hours in a more clinically relevant large animal species and (2) to compare the myocardial uptake of Tc-99m N-DBODC5 with thallium 201 when co-injected during vasodilator stress in dogs with coronary stenoses. METHODS AND RESULTS At peak adenosine-induced hyperemia, 10 dogs with critical left anterior descending artery stenoses received either Tc-99m N-DBODC5 (n = 6) or Tc-99m sestamibi (n = 4) and microspheres, followed by serial imaging and blood sampling over a period of 3 hours. Another 14 dogs with either critical (n = 7) or mild (n = 7) left anterior descending artery stenoses underwent simultaneous injection of Tc-99m N-DBODC5, Tl-201, and microspheres during peak vasodilator stress. Like sestamibi, Tc-99m N-DBODC5 showed good myocardial uptake with slow washout and minimal redistribution over a period of 3 hours (P = not significant); however, Tc-99m N-DBODC5 cleared more rapidly from the liver (heart-lung ratio at 30 minutes, 0.92+/-0.11 versus 0.51 +/- 0.05; P < .05). When injected during hyperemic flow, the myocardial extraction plateau for Tc-99m N-DBODC5 was lower than that for Tl-201 and was intermediate between Tc-99m sestamibi and Tc-99m tetrofosmin. CONCLUSIONS Excellent organ biodistribution and myocardial uptake and clearance kinetic properties, combined with rapid liver clearance and a favorable flow-extraction relationship, make Tc-99m N-DBODC5 a very promising new myocardial perfusion imaging agent.
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Affiliation(s)
- Kengo Hatada
- Second Department of Internal Medicine, Cardiovascular Division, Kansai Medical University Takii Hospital Moriguchi City, Osaka, Japan
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Liu S. Ether and crown ether-containing cationic 99mTc complexes useful as radiopharmaceuticals for heart imaging. Dalton Trans 2007:1183-93. [PMID: 17353949 DOI: 10.1039/b618406e] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
While radiopharmaceutical research has been focused on the development of target-specific radiotracers for early detection and radiotherapy of cancers in the last decade, there is a limited effort on new cationic 99mTc radiotracers for heart imaging. This review will summarize some of the most recent developments in ether- and crown ether-containing cationic 99mTc radiotracers that have a fast liver clearance with a heart/liver ratio substantially better than that of 99mTc-Sestamibi and 99mTc-Tetrofosmin, the two commercial 99mTc radiopharmaceuticals currently available for myocardial perfusion imaging. Fast liver clearance might shorten the duration of imaging protocols (<30 min post-injection), and allow for early acquisition of heart images of high quality. Improvement of heart/liver ratio may permit better detection of the presence and extent of coronary artery disease. Identification of such a new radiotracer that allows for the improved non-invasive delineation of myocardial perfusion would be of considerable benefit in treatment of patients with suspected coronary artery disease.
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Affiliation(s)
- Shuang Liu
- School of Health Sciences, Purdue University, 550 Stadium Mall Drive, West Lafayette, IN 47907, USA.
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Liu S, He Z, Hsieh WY, Kim YS. Evaluation of novel cationic (99m)Tc-nitrido complexes as radiopharmaceuticals for heart imaging: improving liver clearance with crown ether groups. Nucl Med Biol 2006; 33:419-32. [PMID: 16631092 DOI: 10.1016/j.nucmedbio.2006.01.005] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2005] [Revised: 12/19/2005] [Accepted: 01/03/2006] [Indexed: 10/24/2022]
Abstract
This report describes the evaluation of a series of novel cationic (99m)Tc-nitrido complexes, [(99m)TcN(DTC)(PNP)]+ (DTC = crown ether-containing dithiocarbamates; PNP = bisphosphine), as potential radiotracers for myocardial perfusion imaging. Synthesis of cationic (99m)Tc-nitrido complexes was accomplished in two steps according to literature methods. Biodistribution studies were performed in rats. Planar images of Sprague-Dawley rats administered with 15+/-2 MBq of cationic (99m)Tc radiotracer were obtained using a PhoGama large field-of-view Anger camera. Samples from both urine and feces were analyzed by a reversed-phase radio-HPLC method. Results from biodistribution studies showed that most of the cationic (99m)Tc-nitrido complexes have a high initial heart uptake with a long myocardial retention. They also show a rapid clearance from the liver and lungs. Cationic complexes [(99m)TcN(L2)(L6)]+ and [(99m)TcN(L4)(L6)]+ show heart/liver ratios four to five times better than that of (99m)Tc-sestamibi due to their much faster liver clearance. Their heart uptake and heart/liver ratio are comparable to that of (99m)TcN-DBODC5 within the experimental error. These findings have been confirmed by the results from imaging studies. Radio-HPLC analysis of urine and feces samples indicated that there was very little metabolism of cationic (99m)Tc-nitrido complexes in rats under anesthesia. The key finding of this study is that lipophilicity remains the most important factor affecting both heart uptake and target-to-background (T/B) ratios. Crown ethers are very useful functional groups to improve the liver clearance of cationic (99m)Tc-nitrido complexes. It is the combination of the appropriate DTCs and bisphosphines that results in cationic (99m)Tc-nitrido complexes with high heart uptake and fast clearance from the liver at the same time. The fast liver clearance of [(99m)TcN(L2)(L6)]+ and [(99m)TcN(L4)(L6)]+ suggests that they might be used to obtain clinically useful images as early as 30 min postinjection. [(99m)TcN(L2)(L6)]+ and [(99m)TcN(L4)(L6)]+ are very promising candidates for further evaluation in more extensive preclinical animal models.
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Affiliation(s)
- Shuang Liu
- School of Health Sciences, Purdue University, Lafayette, IN 47907, USA.
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Reyes E, Loong CY, Harbinson M, Rahman S, Prvulovich E, Ell PJ, Anagnostopoulos C, Underwood SR. A comparison of Tl-201, Tc-99m sestamibi, and Tc-99m tetrofosmin myocardial perfusion scintigraphy in patients with mild to moderate coronary stenosis. J Nucl Cardiol 2006; 13:488-94. [PMID: 16919572 DOI: 10.1016/j.nuclcard.2006.03.018] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2005] [Accepted: 04/24/2006] [Indexed: 10/24/2022]
Abstract
BACKGROUND Thallium 201, technetium 99m sestamibi (MIBI), and Tc-99m tetrofosmin differ in their myocardial uptake characteristics. This may make the technetium tracers less sensitive for detecting mild to moderate coronary stenosis. METHODS AND RESULTS We identified 163 patients with angiographic mild to moderate stenosis (50%-89%) and coexistent severe disease (88/163 patients) from a previous study of patients who received either thallium, MIBI, or tetrofosmin for myocardial perfusion scintigraphy. Summed segmental uptake scores were used to assess myocardial perfusion of territories supplied by the mildly to moderately stenotic vessels. Mean (+/- SD) summed stress uptake scores in the left anterior descending artery territory were 21.4 +/- 3.8, 21.6 +/- 4.2, and 22.1 +/- 2.3 for thallium, MIBI, and tetrofosmin, respectively (P = .7); mean summed difference uptake scores were 1.2 +/- 1.8, 1.1 +/- 1.9, and 1.0 +/- 1.1, respectively (P = .8). In the non-left anterior descending artery territory, mean summed stress uptake scores were 32.5 +/- 6.3, 34.0 +/- 6.3, and 34.5 +/- 4.7 for thallium, MIBI, and tetrofosmin, respectively (P = .4), whereas mean summed difference scores were 1.9 +/- 2.6, 1.7 +/- 2.2, and 1.7 +/- 2.3, respectively (P = .9). CONCLUSION There were no significant differences between the tracers for the summed uptake scores. This suggests that the 3 tracers are comparable in clinical practice for assessing the extent and severity of perfusion abnormalities arising from mild to moderate coronary artery stenosis, especially in the presence of coexistent severe disease.
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Affiliation(s)
- Eliana Reyes
- National Heart and Lung Institute, Imperial College London, London, United Kingdom.
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Zaret BL. Second Annual Mario S. Verani, MD, Memorial Lecture: Nuclear cardiology, the next 10 years. J Nucl Cardiol 2004; 11:393-407. [PMID: 15295408 DOI: 10.1016/j.nuclcard.2004.05.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The nuclear cardiology of the future will be based on new clinical and biologic targets. It will be driven by modern concepts of molecular and cell biology and molecular genetics. A major effort involves detection of atherosclerosis and vascular vulnerability. Approaches include targeting proliferating smooth muscle cells, angiogenesis, vascular injury, inflammation through a variety of mechanisms, defining cell death and protease activation, and imaging gene expression. Another new clinical target involves imaging stem cells and various progenitor cells. To meet these new objectives, advanced imaging technology is required. This involves the development of micro-single photon emission computed tomography and micro-positron emission tomography systems as well as fusion technology involving radiologic computed tomography imaging together with nuclear imaging. Vascular lesion detection imaging may require intravascular detectors. The future of nuclear cardiology, based on molecular imaging, is extraordinarily exciting. The newly defined biologic targets will allow the answering of many of the key clinical questions that will dominate cardiovascular care in cardiovascular investigation over the next decade.
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Affiliation(s)
- Barry L Zaret
- Department of Internal Medicine, Yale University School of Medicine, New Haven, CT 06520, USA.
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Bolzati C, Benini E, Cazzola E, Jung C, Tisato F, Refosco F, Pietzsch HJ, Spies H, Uccelli L, Duatti A. Synthesis, Characterization, and Biological Evaluation of Neutral Nitrido Technetium(V) Mixed Ligand Complexes Containing Dithiolates and Aminodiphosphines. A Novel System for Linking Technetium to Biomolecules. Bioconjug Chem 2004; 15:628-37. [PMID: 15149191 DOI: 10.1021/bc0499782] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A new biomolecule labeling method that utilizes the [(99m)Tc(N)(PNP)](2+) metal fragment is presented. Thus, a series of nitrido mixed-ligand M(V) complexes (M = (99m)Tc, (99g)Tc, Re), [M(N)(Ln)(PNP)], where Ln is the dianionic form of a dithiolate or substituted-dithiolate ligand and PNP is an aminodiphosphine, is described. (99m)Tc complexes can be prepared using either a two-step or a three-step procedure starting from generator-eluted pertechnetate through a prereduced mixture of [(99m)Tc(N)]-containing species, followed by sequential or contemporary addition of the relevant dithiolate and aminodiphosphine. The reactions of 2,3-dimercaptopropionic acid (H(2)L1) with [Tc(N)(PNP)](2+) were investigated in detail. It was found that this bidentate ligand coordinated the metal fragment through the [S(-),S(-)] donor atom pair, to yield neutral mixed-ligand complexes [(99m)Tc(N)(L1)(PNP)] in high specific activity. The additional carboxylic functional group was not involved in metal coordination, thus remaining available for conjugation to target-specific molecules. Dithiolates incorporating pendant functional group(s) gave rise to a 1:1 diastereoisomeric mixture of syn-[M(N)(Ln)(PNP)] and anti-[M(N)(Ln)(PNP)] derivatives, depending on the relative orientation of the dithiolate substituent(s) with respect to the terminal nitrido group, and no isomeric conversion was detected. (99m)Tc species had been proven to be identical with the (99g)Tc complexes prepared at the macroscopic level by comparison of the corresponding radiometric and UV/vis HPLC profiles. Challenge experiments with cysteine or glutathione indicated that these physiological agents had no effect on the stability of this class of mixed-ligand (99m)Tc-complexes. Biodistribution studies in rats of selected (99m)Tc-complexes showed a rapid clearance from the blood and tissues after 60 min pi.
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