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Development of a new advanced animal cradle for small animal multiple imaging modalities: acquisition and evaluation of high-throughput multiple-mouse imaging. Phys Eng Sci Med 2021; 44:1367-1376. [PMID: 34724162 DOI: 10.1007/s13246-021-01065-4] [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: 07/02/2020] [Accepted: 10/12/2021] [Indexed: 10/20/2022]
Abstract
The physiological conditions of small animals are an essential component to be considered when acquiring images for pre-clinical studies, and they play a vital role in the overall results of a study. However, several previous studies did not consider these conditions. In this study, a new animal cradle that can be modified and adjusted to suit multiple imaging modalities such as positron emission tomography (PET)/computed tomography (CT) and magnetic resonance imaging (MRI) was developed. Unlike previous cradles where only one mouse can be imaged at a time, a total of four mice can be imaged simultaneously using this new cradle. Additionally, fusion images with high-throughput multiple-mouse imaging (MMI) of PET/MRI and PET/CT images can be acquired using this newly developed cradle. The dynamic brain images were also acquired simultaneously by applying PET dynamic imaging technology to high-throughput MMI methods. The results of this study suggest that the newly developed small animal cradle can be widely used in pre-clinical studies.
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Kim SY, Jung JH, Lee HJ, Soh H, Lee SJ, Oh SJ, Chae SY, Lee JH, Lee SJ, Hong YS, Kim TW, Moon DH. [ 18F]fluorothymidine PET Informs the Synergistic Efficacy of Capecitabine and Trifluridine/Tipiracil in Colon Cancer. Cancer Res 2017; 77:7120-7130. [PMID: 29055019 DOI: 10.1158/0008-5472.can-17-1406] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2017] [Revised: 08/09/2017] [Accepted: 10/13/2017] [Indexed: 11/16/2022]
Abstract
In cancer therapy, enhanced thymidine uptake by the salvage pathway can bypass dTMP depletion, thereby conferring resistance to thymidylate synthase inhibition. We investigated whether sequential combination therapy of capecitabine and trifluridine/tipiracil (TAS-102) could synergistically enhance antitumor efficacy in colon cancer xenograft models. We also examined 3'-deoxy-3'-[18F]fluorothymidine ([18F]FLT) PET as a means to predict therapeutic response to a sequential combination of capecitabine and trifluridine/tipiracil. [3H]FLT uptake after 5-fluorouracil treatment in vitro and [18F]FLT uptake after capecitabine (360 mg/kg/day) in athymic nude mice (Balb/c-nu) with xenografts (n = 10-12 per group) were measured using eight human colon cancer cell lines. We determined the synergistic effects of sequential combinations of 5-fluorouracil and trifluridine in vitro as well as the sequential combination of oral capecitabine (30-360 mg/kg) and trifluridine/tipiracil (trifluridine 75 or 150 mg/kg with tipiracil) in six xenograft models (n = 6-10 per group). We observed significant increases in [3H]FLT uptake in all cell lines and [18F]FLT uptake in five xenograft models after 5-fluorouracil and capecitabine treatment, respectively. Increased [18F]FLT uptake after capecitabine followed by extinction of uptake correlated strongly with tumor growth inhibition (ρ = -0.81, P = 0.02). The effects of these combinations were synergistic in vitro A synergy for sequential capecitabine and trifluridine/tipiracil was found only in mouse xenograft models showing increased [18F]FLT uptake after capecitabine. Our results suggest that the sequential combination of capecitabine and trifluridine/tipiracil is synergistic in tumors with an activated salvage pathway after capecitabine treatment in mice, and [18F]FLT PET imaging may predict the response to capecitabine and the synergistic antitumor efficacy of a sequential combination of capecitabine and trifluridine/tipiracil. Cancer Res; 77(24); 7120-30. ©2017 AACR.
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Affiliation(s)
- Seog-Young Kim
- Convergence Medicine Research Center, Asan Institute for Life Sciences, Asan Medical Center, Seoul, Republic of Korea.,Department of Convergence Medicine, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Jin Hwa Jung
- Convergence Medicine Research Center, Asan Institute for Life Sciences, Asan Medical Center, Seoul, Republic of Korea
| | - Haeng Jung Lee
- Convergence Medicine Research Center, Asan Institute for Life Sciences, Asan Medical Center, Seoul, Republic of Korea
| | - Hyunsu Soh
- Convergence Medicine Research Center, Asan Institute for Life Sciences, Asan Medical Center, Seoul, Republic of Korea
| | - Sang Ju Lee
- Department of Nuclear Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Seung Jun Oh
- Department of Nuclear Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Sun Young Chae
- Department of Nuclear Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Jai Hyuen Lee
- Department of Nuclear Medicine, Dankook University College of Medicine, Cheonan, Chungcheongnam-do, Republic of Korea
| | - Seung Jin Lee
- Department of Pharmacology, Chungnam National University College of Pharmacy, Daejeon, Republic of Korea
| | - Yong Sang Hong
- Department of Oncology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Tae Won Kim
- Department of Oncology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Dae Hyuk Moon
- Department of Nuclear Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea.
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Vanhove C, Bankstahl JP, Krämer SD, Visser E, Belcari N, Vandenberghe S. Accurate molecular imaging of small animals taking into account animal models, handling, anaesthesia, quality control and imaging system performance. EJNMMI Phys 2015; 2:31. [PMID: 26560138 PMCID: PMC4642455 DOI: 10.1186/s40658-015-0135-y] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2015] [Accepted: 11/05/2015] [Indexed: 11/22/2022] Open
Abstract
Small-animal imaging has become an important technique for the development of new radiotracers, drugs and therapies. Many laboratories have now a combination of different small-animal imaging systems, which are being used by biologists, pharmacists, medical doctors and physicists. The aim of this paper is to give an overview of the important factors in the design of a small animal, nuclear medicine and imaging experiment. Different experts summarize one specific aspect important for a good design of a small-animal experiment.
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Affiliation(s)
- Christian Vanhove
- Department of Electronics and Information Systems, MEDISIP, Ghent University-iMinds Medical IT-IBiTech, De Pintelaan 185 block B, B-9000, Ghent, Belgium.
| | - Jens P Bankstahl
- Department of Nuclear Medicine, Preclinical Molecular Imaging, Hannover Medical School, Carl-Neuberg-Str. 1, 30625, Hannover, Germany
| | - Stefanie D Krämer
- Radiopharmaceutical Sciences/Biopharmacy, ETH Zurich, Institute of Pharmaceutical Sciences, Department of Chemistry and Applied Biosciences, Vladimir-Prelog-Weg 4, CH-8093, Zurich, Switzerland
| | - Eric Visser
- Department of Radiology and Nuclear Medicine, Radboudumc, 6525 GA Nijmegen, the Netherlands
| | - Nicola Belcari
- Department of Physics, University of Pisa and INFN sezione di Pisa, 56127 Pisa, Italy
| | - Stefaan Vandenberghe
- Department of Electronics and Information Systems, MEDISIP, Ghent University-iMinds Medical IT-IBiTech, De Pintelaan 185 block B, B-9000, Ghent, Belgium
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Dou S, Wang Y, Barton B, Chen L, Rusckowski M, Shultz LD, Greiner DL, Liu G. Comparison between two labeled agents in mice using a coinjection-ratio approach in contrast to a conventional group approach. Nucl Med Biol 2013; 41:127-31. [PMID: 24210286 DOI: 10.1016/j.nucmedbio.2013.10.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2013] [Revised: 09/10/2013] [Accepted: 10/01/2013] [Indexed: 10/26/2022]
Abstract
INTRODUCTION The differences between two agents often need to be accurately defined in vivo. Usually they are injected respectively into two groups of subjects. However, if the two agents do not interact with each other in vivo, a coinjection would serve the same purpose. We believe some individual differences in biodistribution may be circumvented through this approach by calculating organ level ratios. METHODS A model system of MORF/cMORF pretargeting (MORF/cMORF is a complementary pair of DNA analogues) was employed in connection with an on-going tumor therapeutic project. Human LS174T cells were implanted into the flank of severely immuno-compromised NOD-scid IL2rg(null) mice. The tumor was confirmed to express TAG-72 antigens. At 16 days post tumor inoculation, mice received IV 60 μg of MORF-conjugated CC49 (an antiTAG-72 antibody), followed 2 days later by a low-mass-dose IV coinjection containing 2.5 μg of (90)Y-cMORF and 2.5 μg of (99m)Tc-cMORF. At 3 h post radioactivity injection, the distribution of (99m)Tc was imaged on a SPECT/CT camera and then organs were excised and counted for (90)Y and (99m)Tc. Because the two labeled cMORFs do not react or interact with each other in vivo, the two groups of (90)Y and (99m)Tc data enabled a conventional group comparison. In a new effort, (90)Y/(99m)Tc ratios were calculated. Student's t-test and retrospective power analysis were performed for both approaches. In the new approach, the ratios were set at 1 as the null hypothesis. RESULTS The Student's t-test in the conventional group approach indicated that the two labeled cMORFs distributed similarly, but significant differences were observed in salivary gland and large intestines. The coinjection-ratio approach certainly did not subvert the results of the conventional approach but revealed subtler differences. The P values were reduced, the powers were increased in most organs, and more significant differences were observed. The increased sensitivity was due to the reduced CV%s (SD/average*100%) of the (90)Y/(99m)Tc ratios. Therefore, some individual differences were circumvented and notably the ratio approach differentiated individual differences into ratio-correctable and ratio-uncorrectable. CONCLUSIONS Although the conventional approach is reliable, the coinjection-ratio approach using organ level ratios is more sensitive and therefore is recommended whenever possible. In addition, it differentiates individual differences into "coinjection correctable" and "coinjection uncorrectable".
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Affiliation(s)
- Shuping Dou
- Department of Radiology, University of Massachusetts Medical School, Worcester, MA 01655
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The motivations and methodology for high-throughput PET imaging of small animals in cancer research. Eur J Nucl Med Mol Imaging 2012; 39:1497-509. [PMID: 22790877 PMCID: PMC3411308 DOI: 10.1007/s00259-012-2177-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2012] [Accepted: 06/12/2012] [Indexed: 12/15/2022]
Abstract
Over the last decade, small-animal PET imaging has become a vital platform technology in cancer research. With the development of molecularly targeted therapies and drug combinations requiring evaluation of different schedules, the number of animals to be imaged within a PET experiment has increased. This paper describes experimental design requirements to reach statistical significance, based on the expected change in tracer uptake in treated animals as compared to the control group, the number of groups that will be imaged, and the expected intra-animal variability for a given tracer. We also review how high-throughput studies can be performed in dedicated small-animal PET, high-resolution clinical PET systems and planar positron imaging systems by imaging more than one animal simultaneously. Customized beds designed to image more than one animal in large-bore small-animal PET scanners are described. Physics issues related to the presence of several rodents within the field of view (i.e. deterioration of spatial resolution and sensitivity as the radial and the axial offsets increase, respectively, as well as a larger effect of attenuation and the number of scatter events), which can be assessed by using the NEMA NU 4 image quality phantom, are detailed.
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Rowland DJ, Cherry SR. Small-animal preclinical nuclear medicine instrumentation and methodology. Semin Nucl Med 2008; 38:209-22. [PMID: 18396180 DOI: 10.1053/j.semnuclmed.2008.01.004] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Molecular medicine enhances the clinician's ability to accurately diagnose and treat disease, and many technological advances in diverse fields have made the translation of molecular medicine to the clinic possible. Nuclear medicine encompasses 2 technologies--single-photon emission computed tomography (SPECT) and positron emission tomography (PET)--that have driven the field of molecular medicine forward. SPECT and PET, inherently molecular imaging techniques, have been at the forefront of molecular medicine for several decades. These modalities exploit the radioactive decay of nuclides with specific decay properties that make them useful for in vivo imaging. As recently as the mid-1990s, SPECT and PET were mostly restricted to use in the clinical setting because their relatively coarse spatial resolution limited their usefulness in studying animal (especially rodent) models of human disease. About a decade ago, several groups began making significant strides in improving resolution to the point that small-animal SPECT and PET as a molecular imaging technique was useful in the study of rodent disease models. The advances in these 2 techniques progressed as the result of improvements in instrumentation and data reconstruction software. Here, we review the impact of small-animal imaging and, specifically, nuclear medicine imaging techniques on the understanding of the biological basis of disease and the expectation that these advances will be translated to clinical medicine.
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Affiliation(s)
- Douglas J Rowland
- Center for Molecular and Genomic Imaging, Department of Biomedical Engineering, University of California, Davis, Davis, CA 95616, USA.
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Wang JL, Parhi AK, Oya S, Lieberman B, Kung MP, Kung HF. 2-(2'-((Dimethylamino)methyl)-4'-(3-[(18)F]fluoropropoxy)-phenylthio)benzenamine for positron emission tomography imaging of serotonin transporters. Nucl Med Biol 2008; 35:447-58. [PMID: 18482682 PMCID: PMC2474748 DOI: 10.1016/j.nucmedbio.2008.02.009] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2007] [Revised: 02/06/2008] [Accepted: 02/14/2008] [Indexed: 11/21/2022]
Abstract
INTRODUCTION A new (18)F ligand, 2-(2'-((dimethylamino)methyl)-4'-(3-[(18)F]fluoropropoxy)-phenylthio)benzenamine ([(18)F]1), for positron emission tomography (PET) imaging of serotonin transporters (SERT) was evaluated. METHODS Binding affinity was determined through in vitro binding assays with LLC-PK1 cells overexpressing SERT, NET or DAT (LLC-SERT, LLC-NET and LLC-DAT) and with rat cortical homogenates. Localization and selectivity of [(18)F]1 binding in vivo were evaluated by biodistribution, autoradiography and A-PET imaging studies in rats. RESULTS This compound displayed excellent binding affinity for SERT in vitro with K(i)=0.33 and 0.24 nM in LLC-SERT and rat cortical homogenates, respectively. Biodistribution studies with [(18)F]1 showed good brain uptake (1.61% dose/g at 2 min postinjection), high uptake into the hypothalamus (1.22% dose/g at 30 min) and a high target-to-nontarget (hypothalamus to cerebellum) ratio of 9.66 at 180 min postinjection. Pretreatment with a SERT selective inhibitor considerably inhibited [(18)F]1 binding in biodistribution studies. Ex vivo autoradiography reveals [(18)F]1 localization to brain regions with high SERT density, and this binding was blocked by pretreatment with SERT selective inhibitors. Small animal PET (A-PET) imaging in rats provided clear images of tracer localization in the thalamus, midbrain and striatum. In A-PET chasing experiments, injecting a SERT selective inhibitor 75 min post-tracer injection causes a dramatic reduction in regional radioactivity and the target-to-nontarget ratio. CONCLUSION The results of the biological studies and the ease of radiosynthesis with moderately good radiochemical yield (RCY=10-35%) make [(18)F]1 an excellent candidate for SERT PET imaging.
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Affiliation(s)
- Julie L. Wang
- Department of Pharmacology, University of Pennsylvania School of Medicine, Philadelphia, PA 19104
| | - Ajit K. Parhi
- Department of Radiology, University of Pennsylvania School of Medicine, Philadelphia, PA 19104
| | - Shunichi Oya
- Department of Radiology, University of Pennsylvania School of Medicine, Philadelphia, PA 19104
| | - Brian Lieberman
- Department of Radiology, University of Pennsylvania School of Medicine, Philadelphia, PA 19104
| | - Mei-Ping Kung
- Department of Radiology, University of Pennsylvania School of Medicine, Philadelphia, PA 19104
| | - Hank F. Kung
- Department of Pharmacology, University of Pennsylvania School of Medicine, Philadelphia, PA 19104
- Department of Radiology, University of Pennsylvania School of Medicine, Philadelphia, PA 19104
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