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DeBay DR, Brewer KD. Combined PET/MR: Where Anatomical Imaging Meets Cellular Function. Methods Mol Biol 2024; 2729:391-408. [PMID: 38006508 DOI: 10.1007/978-1-0716-3499-8_22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2023]
Abstract
Recent technological advances in medical imaging have allowed for both sequential and simultaneous acquisition of magnetic resonance imaging (MRI) and positron emission tomography (PET) data. Simultaneous PET/MRI offers distinct advantages by efficiently capturing functional and metabolic processes with co-localized, high-resolution anatomical images while minimizing time and movement. We will describe some of the technical and logistic requirements for optimizing sequential and simultaneous PET/MRI in the preclinical research setting.
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Affiliation(s)
- Drew R DeBay
- Biomedical Translational Imaging Centre (BIOTIC), Halifax, Canada
- Department of Physics and Atmospheric Science, Dalhousie University, Halifax, Canada
| | - Kimberly D Brewer
- School of Biomedical Engineering, Dalhousie University, Halifax, NS, Canada.
- Department of Physics and Atmospheric Science, Dalhousie University, Halifax, Canada.
- Diagnostic Radiology, Dalhousie University, Halifax, Canada.
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2
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Boswinkel M, Franssen GM, Heskamp S. Radiolabeled Antibodies for Immune Checkpoint PET in Preclinical Research. Methods Mol Biol 2024; 2729:143-158. [PMID: 38006495 DOI: 10.1007/978-1-0716-3499-8_9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2023]
Abstract
Antibodies that block immune checkpoints, also called immune checkpoint inhibitors (ICI), have demonstrated impressive anti-tumor efficacy. The success of ICIs results from a complex interplay between cancer cells and their immune microenvironment. One of the predictors for ICI efficacy is the expression of the targeted immune checkpoint, such as programmed death ligand 1 (PD-L1). Immune checkpoints can be expressed on tumor cells and/or subsets of immune cells. PET imaging offers unique possibilities to study the dynamics of immune checkpoint expression in tumor and normal tissues in a longitudinal manner. In this chapter, we describe the methodology to use zirconium-89-labeled antibodies to assess the expression of immune checkpoint molecules in syngeneic murine tumor models by PET imaging.
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Affiliation(s)
- Milou Boswinkel
- Department of Medical Imaging, Nuclear Medicine, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Gerben M Franssen
- Department of Medical Imaging, Nuclear Medicine, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Sandra Heskamp
- Department of Medical Imaging, Nuclear Medicine, Radboud University Medical Center, Nijmegen, The Netherlands.
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3
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van Vliet EA, Immonen R, Prager O, Friedman A, Bankstahl JP, Wright DK, O'Brien TJ, Potschka H, Gröhn O, Harris NG. A companion to the preclinical common data elements and case report forms for in vivo rodent neuroimaging: A report of the TASK3-WG3 Neuroimaging Working Group of the ILAE/AES Joint Translational Task Force. Epilepsia Open 2022. [PMID: 35962745 DOI: 10.1002/epi4.12643] [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: 12/12/2021] [Accepted: 02/01/2022] [Indexed: 11/10/2022] Open
Abstract
The International League Against Epilepsy/American Epilepsy Society (ILAE/AES) Joint Translational Task Force established the TASK3 working groups to create common data elements (CDEs) for various aspects of preclinical epilepsy research studies, which could help improve the standardization of experimental designs. In this article, we discuss CDEs for neuroimaging data that are collected in rodent models of epilepsy, with a focus on adult rats and mice. We provide detailed CDE tables and case report forms (CRFs), and with this companion manuscript, we discuss the methodologies for several imaging modalities and the parameters that can be collected.
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Affiliation(s)
- Erwin A van Vliet
- Center for Neuroscience, Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, The Netherlands
- Amsterdam UMC Location University of Amsterdam, Department of (Neuro)Pathology, Amsterdam Neuroscience, Amsterdam, The Netherlands
| | - Riikka Immonen
- A.I. Virtanen Institute, University of Eastern Finland, Kuopio, Finland
| | - Ofer Prager
- Departments of Physiology and Cell Biology, Cognitive and Brain Sciences, Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Alon Friedman
- Departments of Physiology and Cell Biology, Cognitive and Brain Sciences, Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev, Beer-Sheva, Israel
- Department of Medical Neuroscience and Brain Repair Center, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Jens P Bankstahl
- Department of Nuclear Medicine, Hannover Medical School, Hannover, Germany
| | - David K Wright
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, Victoria, Australia
| | - Terence J O'Brien
- The Royal Melbourne Hospital, The University of Melbourne, The Alfred Hospital, Monash University, Melbourne, Victoria, Australia
| | - Heidrun Potschka
- Institute of Pharmacology, Toxicology, and Pharmacy, Ludwig-Maximilians-University, Munich, Germany
| | - Olli Gröhn
- A.I. Virtanen Institute, University of Eastern Finland, Kuopio, Finland
| | - Neil G Harris
- Department of Neurosurgery UCLA, UCLA Brain Injury Research Center, Los Angeles, California, USA
- Intellectual and Developmental Disabilities Research Center, UCLA, Los Angeles, California, USA
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4
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Sannajust K, Spriet M, Anishchenko S, Beylin D. Standardized uptake values and attenuation correction in
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F‐sodium fluoride PET of the equine foot and fetlock. Vet Radiol Ultrasound 2022; 63:771-778. [DOI: 10.1111/vru.13127] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Revised: 04/13/2022] [Accepted: 04/14/2022] [Indexed: 11/29/2022] Open
Affiliation(s)
- Kimberley Sannajust
- School of Veterinary Medicine University of California Davis Davis California USA
| | - Mathieu Spriet
- School of Veterinary Medicine University of California Davis Davis California USA
| | - Sergey Anishchenko
- LONGMILE Veterinary Imaging Brain Biosciences Inc. Rockville Maryland USA
| | - David Beylin
- LONGMILE Veterinary Imaging Brain Biosciences Inc. Rockville Maryland USA
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5
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van den Wyngaert T, de Schepper S, Elvas F, Seyedinia SS, Beheshti M. Positron emission tomography-magnetic resonance imaging as a research tool in musculoskeletal conditions. THE QUARTERLY JOURNAL OF NUCLEAR MEDICINE AND MOLECULAR IMAGING : OFFICIAL PUBLICATION OF THE ITALIAN ASSOCIATION OF NUCLEAR MEDICINE (AIMN) [AND] THE INTERNATIONAL ASSOCIATION OF RADIOPHARMACOLOGY (IAR), [AND] SECTION OF THE SOCIETY OF... 2022; 66:15-30. [PMID: 35005878 DOI: 10.23736/s1824-4785.22.03434-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Compared to positron emission tomography/computed tomography (PET/CT), the uptake of PET- magnetic resonance imaging (MRI) has been slow, even more so in clinical practice compared to the (pre-)clinical research setting. However, for applications in musculoskeletal (MSK) research, the combination of PET and MRI into a single modality offers attractive advantages over other imaging modalities. Most importantly, MRI has exquisite soft-tissue detail without the use of contrast agents or ionizing radiation, superior bone marrow visualization, and an extensive spectrum of distinct multiparametric assessment methods. In the preclinical setting, the introduction of PET inserts for small-animal MRI machines has proven to be a successful concept in bringing this technology to the lab. Initial hurdles in quantification have been mainly overcome in this setting. In parallel, a promising range of radiochemistry techniques has been developed to create multimodality probes that offer the possibility of simultaneously querying different metabolic pathways. Not only will these applications help in elucidating disease mechanisms, but they can also facilitate drug development. The clinical applications of PET/MRI in MSK are still limited, but encouraging initial results with novel radiotracers suggest a high potential for use in various MSK conditions, including osteoarthritis, rheumatoid arthritis, ankylosing spondylitis and inflammation and infection. Further innovations will be required to bring down the cost of PET/MRI to justify a broader clinical implementation, and remaining issues with quality control and standardization also need to be addressed. Nevertheless, PET/MRI is a powerful platform for MSK research with distinct qualities that are not offered by other techniques.
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Affiliation(s)
- Tim van den Wyngaert
- Department of Nuclear Medicine, Antwerp University Hospital, Edegem, Belgium -
- Faculty of Medicine and Health Sciences (MICA), University of Antwerp, Wilrijk, Belgium -
- Integrated Personalized and Precision Oncology Network (IPPON), University of Antwerp, Wilrijk, Belgium -
| | - Stijn de Schepper
- Department of Nuclear Medicine, Antwerp University Hospital, Edegem, Belgium
- Faculty of Medicine and Health Sciences (MICA), University of Antwerp, Wilrijk, Belgium
| | - Filipe Elvas
- Department of Nuclear Medicine, Antwerp University Hospital, Edegem, Belgium
- Faculty of Medicine and Health Sciences (MICA), University of Antwerp, Wilrijk, Belgium
| | - Seyedeh S Seyedinia
- Division of Molecular Imaging and Theranostics, Department of Nuclear Medicine and Endocrinology, University Hospital Salzburg, Paracelsus Medical University, Salzburg, Austria
| | - Mohsen Beheshti
- Division of Molecular Imaging and Theranostics, Department of Nuclear Medicine and Endocrinology, University Hospital Salzburg, Paracelsus Medical University, Salzburg, Austria
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Renner A, Rausch I, Cal Gonzalez J, Laistler E, Moser E, Jochimsen T, Sattler T, Sabri O, Beyer T, Figl M, Birkfellner W, Sattler B. Technical Note: A PET/MR coil with an integrated, orbiting 511 keV transmission source for PET/MR imaging validated in an animal study. Med Phys 2022; 49:2366-2372. [PMID: 35224747 PMCID: PMC9310742 DOI: 10.1002/mp.15586] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Revised: 02/04/2022] [Accepted: 02/04/2022] [Indexed: 11/11/2022] Open
Abstract
Background Purpose Methods Results Conclusion
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Affiliation(s)
- Andreas Renner
- Center for Medical Physics and Biomedical Engineering Medical University Vienna Austria
- Department of Radiation Oncology Medical University Vienna Austria
| | - Ivo Rausch
- Center for Medical Physics and Biomedical Engineering Medical University Vienna Austria
| | - Jacobo Cal Gonzalez
- Center for Medical Physics and Biomedical Engineering Medical University Vienna Austria
| | - Elmar Laistler
- Center for Medical Physics and Biomedical Engineering Medical University Vienna Austria
| | - Ewald Moser
- Center for Medical Physics and Biomedical Engineering Medical University Vienna Austria
| | - Thies Jochimsen
- Department of Nuclear Medicine University Hospital Leipzig Germany
| | - Tatjana Sattler
- Clinic for Ruminants and Swine University of Leipzig Germany
| | - Osama Sabri
- Department of Nuclear Medicine University Hospital Leipzig Germany
| | - Thomas Beyer
- Center for Medical Physics and Biomedical Engineering Medical University Vienna Austria
| | - Michael Figl
- Center for Medical Physics and Biomedical Engineering Medical University Vienna Austria
| | - Wolfgang Birkfellner
- Center for Medical Physics and Biomedical Engineering Medical University Vienna Austria
| | - Bernhard Sattler
- Department of Nuclear Medicine University Hospital Leipzig Germany
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Nautiyal A, Mondal T, Mitra D, Goel A, Dey SK, Kaushik A. A SIMPLE AND NOVEL APPROACH TO STUDY KINETICS AND ESTIMATE RADIATION DOSES FROM INTERNALLY ADMINISTERED RADIOPHARMACEUTICALS USING AN EXTERNAL DOSE MEASUREMENT SYSTEM. RADIATION PROTECTION DOSIMETRY 2021; 196:141-152. [PMID: 34585244 DOI: 10.1093/rpd/ncab141] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Revised: 08/28/2021] [Accepted: 09/03/2021] [Indexed: 06/13/2023]
Abstract
Various methods have been reported to study radiotracer kinetics and make internal dosimetry feasible in the routine clinical nuclear medicine practice. The aim of the present study was to quantify cumulative activity and organ doses using an indigenously designed and fabricated external dose measurement system. The measurement was demonstrated on patients undergoing whole-body (WB) 18F-FDG (Fluorine-18-fluorodeoxyglucose) direct positron emission tomography/computed tomography investigations. An external dose measurement system comprising of an ionisation chamber-survey meter and the movable focussing collimator was used to quantify the uptake of 18F-FDG in liver and brain. Cumulative activity and normalised cumulative activity in these organs were calculated. The results were validated by performing measurements on a phantom uniformly filled with known activity of 18F-FDG.The difference in the absorbed dose estimated with and without collimator was statistically significant (p < 0.05). The external dose measurement technique is relatively novel, convenient and reliable for the assessment of internal absorbed dose of organs.
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Affiliation(s)
- Amit Nautiyal
- Institute of Nuclear Medicine & Molecular Imaging, AMRI Hospitals, Dhakuria, Kolkata, India
- Amity Institute of Nuclear Science & Technology, Amity University Uttar Pradesh, Noida, India
| | - Tanmoy Mondal
- Department of Biotechnology, Maulana Abul Kalam Azad University of Technology, Salt Lake, Kolkata, India
| | - Deepanjan Mitra
- Institute of Nuclear Medicine & Molecular Imaging, AMRI Hospitals, Dhakuria, Kolkata, India
| | - Alpana Goel
- Amity Institute of Nuclear Science & Technology, Amity University Uttar Pradesh, Noida, India
| | - Subrata Kumar Dey
- Department of Biotechnology, Maulana Abul Kalam Azad University of Technology, Salt Lake, Kolkata, India
| | - Aruna Kaushik
- Institute of Nuclear Medicine & Allied Sciences, Brig. S.K. Mazumdar Marg, Timarpur, Delhi, India
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McLarty E, Spriet M, Beylin D, Chou PY, Filliquist B, Marcellin-Little DJ, Kapatkin AS. Comparison of 18F-sodium fluoride positron emission tomography and CT: An exploratory study in 12 dogs with elbow pain. Vet Radiol Ultrasound 2021; 62:498-506. [PMID: 33855752 DOI: 10.1111/vru.12967] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Revised: 12/29/2020] [Accepted: 01/29/2021] [Indexed: 01/06/2023] Open
Abstract
18F-Sodium Fluoride (18F-NaF) positron emission tomography (PET) provides high resolution functional information about bone activity and can be fused with CT images to improve three-dimensional localization and characterization of lesions. This prospective, observational study assessed 18F-NaF PET-CT for imaging of canine elbows, compared PET with CT findings, and assessed correlation with lameness. Twelve patients with elbow pain were included. Cases included primarily young, large breed dogs. A three-level clinical lameness score was assigned to each forelimb. All dogs had bilateral elbow joints imaged with CT and PET under general anesthesia, approximately 1.5 h after intravenous injection of 3 MBq/kg of 18F-NaF. Imaging findings were independently reviewed by two radiologists using a three-level scoring scheme over nine anatomical regions in the elbow. PET imaging identified areas of bone activity where minimal change was identified on CT. PET imaging also demonstrated absence of uptake in areas where modeling was present on CT. A stronger correlation was observed between clinical grades and PET scores (r2 = 0.38, P = .001) than between clinical grades and CT scores (r2 = 0.17, P = .048). The total PET scores were significantly different for each clinical grade (P = .013) but total CT scores did not differ (P = .139). This exploratory study suggests that PET improves the ability to detect lesions and to determine the clinical significance of CT findings in dogs with elbow pain.
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Affiliation(s)
- Ehren McLarty
- University of California Davis, School of Veterinary Medicine, Department of Surgical and Radiological Sciences, Davis, California, USA
| | - Mathieu Spriet
- University of California Davis, School of Veterinary Medicine, Department of Surgical and Radiological Sciences, Davis, California, USA
| | - David Beylin
- Brain Biosciences, Inc., Rockville, Maryland, USA
| | - Po-Yen Chou
- University of California Davis, School of Veterinary Medicine, Department of Surgical and Radiological Sciences, Davis, California, USA
| | - Barbro Filliquist
- University of California Davis, School of Veterinary Medicine, Department of Surgical and Radiological Sciences, Davis, California, USA
| | - Denis J Marcellin-Little
- University of California Davis, School of Veterinary Medicine, Department of Surgical and Radiological Sciences, Davis, California, USA
| | - Amy S Kapatkin
- University of California Davis, School of Veterinary Medicine, Department of Surgical and Radiological Sciences, Davis, California, USA
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Abstract
Positron emission tomography (PET) is a non-invasive imaging technology employed to describe metabolic, physiological, and biochemical processes in vivo. These include receptor availability, metabolic changes, neurotransmitter release, and alterations of gene expression in the brain. Since the introduction of dedicated small-animal PET systems along with the development of many novel PET imaging probes, the number of PET studies using rats and mice in basic biomedical research tremendously increased over the last decade. This article reviews challenges and advances of quantitative rodent brain imaging to make the readers aware of its physical limitations, as well as to inspire them for its potential applications in preclinical research. In the first section, we briefly discuss the limitations of small-animal PET systems in terms of spatial resolution and sensitivity and point to possible improvements in detector development. In addition, different acquisition and post-processing methods used in rodent PET studies are summarized. We further discuss factors influencing the test-retest variability in small-animal PET studies, e.g., different receptor quantification methodologies which have been mainly translated from human to rodent receptor studies to determine the binding potential and changes of receptor availability and radioligand affinity. We further review different kinetic modeling approaches to obtain quantitative binding data in rodents and PET studies focusing on the quantification of endogenous neurotransmitter release using pharmacological interventions. While several studies have focused on the dopamine system due to the availability of several PET tracers which are sensitive to dopamine release, other neurotransmitter systems have become more and more into focus and are described in this review, as well. We further provide an overview of latest genome engineering technologies, including the CRISPR/Cas9 and DREADD systems that may advance our understanding of brain disorders and function and how imaging has been successfully applied to animal models of human brain disorders. Finally, we review the strengths and opportunities of simultaneous PET/magnetic resonance imaging systems to study drug-receptor interactions and challenges for the translation of PET results from bench to bedside.
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Rodríguez-Villafuerte M, Hernández EM, Alva-Sánchez H, Martínez-Dávalos A, Ávila-Rodríguez MA. Positron range effects of 66Ga in small-animal PET imaging. Phys Med 2019; 67:50-57. [PMID: 31669670 DOI: 10.1016/j.ejmp.2019.10.024] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Revised: 09/25/2019] [Accepted: 10/09/2019] [Indexed: 11/18/2022] Open
Abstract
PURPOSE Gallium-66 is a non-conventional positron emitter that stands out not only for its high potential to label peptides, proteins and antibodies, but also because it can provide spatio-temporal information of relatively slow physiological processes in the body due to its conveniently long half-life of 9.5 h. However, 66Ga emits the most energetic positrons for PET imaging. The lack of information of the positron range effect on spatial resolution for this positron emitter is an issue, particularly in preclinical imaging. METHODS The line spread function (LSF) in tissue-equivalent materials with densities between 0.2 and 1.93 g/cm3 was obtained with 66Ga and 18F. A complementary study with the NEMA NU 4-2008 image quality phantom is also included. RESULTS High-energy positrons moving in lower density materials produce far-reaching activity distributions. The LSFs were characterized with Lorentzian-Gaussian fits, with spatial resolution (FWHM) in the 2.14-3.2 mm range, and long tails extending a few tens of mm depending on the material type and density. A narrowing of the LSF was observed for lung-equivalent materials, indicating the lack of enough material for the positron annihilation to take place. The NEMA NU 4-2008 image quality phantom produced blurred images, notoriously observed in the hot and cold cylinders used for evaluation of recovery coefficients (RC) and spill-over ratios (SOR), producing very low RC and very large SOR. CONCLUSIONS Quantitative PET imaging with the non-conventional 66Ga is hampered due to the large range of its high-energy positrons affecting both spatial resolution and activity concentration quantification.
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Affiliation(s)
| | - E M Hernández
- Instituto de Física, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - H Alva-Sánchez
- Instituto de Física, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - A Martínez-Dávalos
- Instituto de Física, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - M A Ávila-Rodríguez
- Unidad Radiofarmacia-Ciclotrón, Facultad de Medicina, Universidad Nacional Autónoma de México, Mexico City, Mexico
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137Cs transmission imaging and segmented attenuation corrections in a small animal PET scanner. Radiol Phys Technol 2017; 10:321-330. [DOI: 10.1007/s12194-017-0407-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2017] [Revised: 07/01/2017] [Accepted: 07/03/2017] [Indexed: 10/19/2022]
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Romero E, Martínez A, Oteo M, García A, Morcillo MA. Preparation of ⁶⁸Ga-labelled DOTA-peptides using a manual labelling approach for small-animal PET imaging. Appl Radiat Isot 2015; 107:113-120. [PMID: 26492321 DOI: 10.1016/j.apradiso.2015.10.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2015] [Revised: 09/21/2015] [Accepted: 10/04/2015] [Indexed: 01/30/2023]
Abstract
(68)Ga-DOTA-peptides are a promising PET radiotracers used in the detection of different tumours types due to their ability for binding specifically receptors overexpressed in these. Furthermore, (68)Ga can be produced by a (68)Ge/(68)Ga generator on site which is a very good alternative to cyclotron-based PET isotopes. Here, we describe a manual labelling approach for the synthesis of (68)Ga-labelled DOTA-peptides based on concentration and purification of the commercial (68)Ga/(68)Ga generator eluate using an anion exchange-cartridge. (68)Ga-DOTA-TATE was used to image a pheochromocytoma xenograft mouse model by a microPET/CT scanner. The method described provides satisfactory results, allowing the subsequent (68)Ga use to label DOTA-peptides. The simplicity of the method along with its implementation reduced cost, makes it useful in preclinical PET studies.
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Affiliation(s)
- Eduardo Romero
- CIEMAT - Research Centre for Energy, Environment and Technology, Biomedical Applications and Pharmacokinetics Unit, Avenida Complutense 40, 28040 Madrid, Spain.
| | - Alfonso Martínez
- CIEMAT - Research Centre for Energy, Environment and Technology, Biomedical Applications and Pharmacokinetics Unit, Avenida Complutense 40, 28040 Madrid, Spain
| | - Marta Oteo
- CIEMAT - Research Centre for Energy, Environment and Technology, Biomedical Applications and Pharmacokinetics Unit, Avenida Complutense 40, 28040 Madrid, Spain
| | - Angel García
- CIEMAT - Research Centre for Energy, Environment and Technology, Biomedical Applications and Pharmacokinetics Unit, Avenida Complutense 40, 28040 Madrid, Spain
| | - Miguel Angel Morcillo
- CIEMAT - Research Centre for Energy, Environment and Technology, Biomedical Applications and Pharmacokinetics Unit, Avenida Complutense 40, 28040 Madrid, Spain
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Nedergaard MK, Kristoffersen K, Michaelsen SR, Madsen J, Poulsen HS, Stockhausen MT, Lassen U, Kjaer A. The use of longitudinal 18F-FET MicroPET imaging to evaluate response to irinotecan in orthotopic human glioblastoma multiforme xenografts. PLoS One 2014; 9:e100009. [PMID: 24918622 PMCID: PMC4053391 DOI: 10.1371/journal.pone.0100009] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2014] [Accepted: 05/21/2014] [Indexed: 11/26/2022] Open
Abstract
Objectives Brain tumor imaging is challenging. Although 18F-FET PET is widely used in the clinic, the value of 18F-FET MicroPET to evaluate brain tumors in xenograft has not been assessed to date. The aim of this study therefore was to evaluate the performance of in vivo18F-FET MicroPET in detecting a treatment response in xenografts. In addition, the correlations between the 18F-FET tumor accumulation and the gene expression of Ki67 and the amino acid transporters LAT1 and LAT2 were investigated. Furthermore, Ki67, LAT1 and LAT2 gene expression in xenograft and archival patient tumors was compared. Methods Human GBM cells were injected orthotopically in nude mice and 18F-FET uptake was followed by weekly MicroPET/CT. When tumor take was observed, mice were treated with CPT-11 or saline weekly. After two weeks of treatment the brain tumors were isolated and quantitative polymerase chain reaction were performed on the xenograft tumors and in parallel on archival patient tumor specimens. Results The relative tumor-to-brain (T/B) ratio of SUVmax was significantly lower after one week (123±6%, n = 7 vs. 147±6%, n = 7; p = 0.018) and after two weeks (142±8%, n = 5 vs. 204±27%, n = 4; p = 0.047) in the CPT-11 group compared with the control group. Strong negative correlations between SUVmax T/B ratio and LAT1 (r = −0.62, p = 0.04) and LAT2 (r = −0.67, p = 0.02) were observed. In addition, a strong positive correlation between LAT1 and Ki67 was detected in xenografts. Furthermore, a 1.6 fold higher expression of LAT1 and a 23 fold higher expression of LAT2 were observed in patient specimens compared to xenografts. Conclusions 18F-FET MicroPET can be used to detect a treatment response to CPT-11 in GBM xenografts. The strong negative correlation between SUVmax T/B ratio and LAT1/LAT2 indicates an export transport function. We suggest that 18F-FET PET may be used for detection of early treatment response in patients.
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Affiliation(s)
- Mette K. Nedergaard
- Department of Clinical Physiology, Nuclear Medicine & PET and Cluster for Molecular Imaging, Rigshospitalet and University of Copenhagen, Copenhagen, Denmark
- * E-mail:
| | - Karina Kristoffersen
- Department of Radiation Biology, The Finsen Center, Rigshospitalet, Copenhagen, Denmark
| | - Signe R. Michaelsen
- Department of Radiation Biology, The Finsen Center, Rigshospitalet, Copenhagen, Denmark
| | - Jacob Madsen
- Department of Clinical Physiology, Nuclear Medicine & PET and Cluster for Molecular Imaging, Rigshospitalet and University of Copenhagen, Copenhagen, Denmark
| | - Hans S. Poulsen
- Department of Radiation Biology, The Finsen Center, Rigshospitalet, Copenhagen, Denmark
| | | | - Ulrik Lassen
- Phase 1 Unit, Department of Oncology, The Finsen Center, Rigshospitalet, Copenhagen, Denmark
| | - Andreas Kjaer
- Department of Clinical Physiology, Nuclear Medicine & PET and Cluster for Molecular Imaging, Rigshospitalet and University of Copenhagen, Copenhagen, Denmark
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15
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Bardram Johnbeck C, Munk Jensen M, Haagen Nielsen C, Fisker Hag AM, Knigge U, Kjaer A. 18F-FDG and 18F-FLT-PET imaging for monitoring everolimus effect on tumor-growth in neuroendocrine tumors: studies in human tumor xenografts in mice. PLoS One 2014; 9:e91387. [PMID: 24626055 PMCID: PMC3953383 DOI: 10.1371/journal.pone.0091387] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2013] [Accepted: 02/08/2014] [Indexed: 12/31/2022] Open
Abstract
Introduction The mTOR inhibitor everolimus has shown promising results in some but not all neuroendocrine tumors. Therefore, early assessment of treatment response would be beneficial. In this study, we investigated the in vivo and in vitro treatment effect of everolimus in neuroendocrine tumors and evaluated the performance of 18F-FDG and the proliferation tracer 18F-FLT for treatment response assessment by PET imaging. Methods The effect of everolimus on the human carcinoid cell line H727 was examined in vitro with the MTT assay and in vivo on H727 xenograft tumors. The mice were scanned at baseline with 18F-FDG or 18F-FLT and then treated with either placebo or everolimus (5 mg/kg daily) for 10 days. PET/CT scans were repeated at day 1,3 and 10. Results Everolimus showed significant inhibition of H727 cell proliferation in vitro at concentrations above 1 nM. In vivo tumor volumes measured relative to baseline were significantly lower in the everolimus group compared to the control group at day 3 (126±6% vs. 152±6%; p = 0.016), day 7 (164±7% vs. 226±13%; p<0.001) and at day 10 (194±10% vs. 281±18%; p<0.001). Uptake of 18F-FDG and 18F-FLT showed little differences between control and treatment groups, but individual mean uptake of 18F-FDG at day 3 correlated with tumor growth day 10 (r2 = 0.45; P = 0.034), 18F-FLT mean uptake at day 1 correlated with tumor growth day 7 (r2 = 0.63; P = 0.019) and at day 3 18F-FLT correlated with tumor growth day 7 (r2 = 0.87; P<0.001) and day 10 (r2 = 0.58; P = 0.027). Conclusion Everolimus was effective in vitro and in vivo in human xenografts lung carcinoid NETs and especially early 18F-FLT uptake predicted subsequent tumor growth. We suggest that 18F-FLT PET can be used for tailoring therapy for neuroendocrine tumor patients through early identification of responders and non-responders.
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Affiliation(s)
- Camilla Bardram Johnbeck
- Department of Clinical Physiology, Nuclear Medicine & PET and Cluster for Molecular Imaging, Faculty of Health Sciences, Rigshospitalet and University of Copenhagen, Copenhagen, Denmark
- * E-mail:
| | - Mette Munk Jensen
- Department of Clinical Physiology, Nuclear Medicine & PET and Cluster for Molecular Imaging, Faculty of Health Sciences, Rigshospitalet and University of Copenhagen, Copenhagen, Denmark
| | - Carsten Haagen Nielsen
- Department of Clinical Physiology, Nuclear Medicine & PET and Cluster for Molecular Imaging, Faculty of Health Sciences, Rigshospitalet and University of Copenhagen, Copenhagen, Denmark
| | - Anne Mette Fisker Hag
- Department of Clinical Physiology, Nuclear Medicine & PET and Cluster for Molecular Imaging, Faculty of Health Sciences, Rigshospitalet and University of Copenhagen, Copenhagen, Denmark
| | - Ulrich Knigge
- Department of Surgical Gastroenterology C and Department of Endocrinology, Rigshospitalet, Copenhagen, Denmark
| | - Andreas Kjaer
- Department of Clinical Physiology, Nuclear Medicine & PET and Cluster for Molecular Imaging, Faculty of Health Sciences, Rigshospitalet and University of Copenhagen, Copenhagen, Denmark
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Attenuation correction for small animal PET images: a comparison of two methods. COMPUTATIONAL AND MATHEMATICAL METHODS IN MEDICINE 2013; 2013:103476. [PMID: 23690871 PMCID: PMC3652124 DOI: 10.1155/2013/103476] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/18/2012] [Revised: 03/09/2013] [Accepted: 03/10/2013] [Indexed: 11/18/2022]
Abstract
In order to extract quantitative parameters from PET images, several physical effects such as photon attenuation, scatter, and partial volume must be taken into account. The main objectives of this work were the evaluation of photon attenuation in small animals and the implementation of two attenuation correction methods based on X-rays CT and segmentation of emission images. The accuracy of the first method with respect to the beam hardening effect was investigated by using Monte Carlo simulations. Mouse- and rat-sized phantoms were acquired in order to evaluate attenuation correction in terms of counts increment and recovery of uniform activity concentration. Both methods were applied to mice and rat images acquired with several radiotracers such as(18)F-FDG, (11)C-acetate, (68)Ga-chloride, and (18)F-NaF. The accuracy of the proposed methods was evaluated in heart and tumour tissues using (18)F-FDG images and in liver, kidney, and spinal column tissues using (11)C-acetate, (68)Ga-chloride, and (18)F-NaF images, respectively. In vivo results from animal studies show that, except for bone scans, differences between the proposed methods were about 10% in rats and 3% in mice. In conclusion, both methods provide equivalent results; however, the segmentation-based approach has several advantages being less time consuming and simple to implement.
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