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Wu J, Jones N, Chao PH, Chan V, Hohenwarter L, Wu A, Bergamo M, Rodríguez-Rodríguez C, Saatchi K, Liang A, Häfeli UO, Tan Z, Hedtrich S, Andrew LJ, Li SD. Intranasal delivery of low-dose anti-CD124 antibody enhances treatment of chronic rhinosinusitis with nasal polyps. Biomaterials 2024; 308:122567. [PMID: 38603825 DOI: 10.1016/j.biomaterials.2024.122567] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2024] [Revised: 04/04/2024] [Accepted: 04/05/2024] [Indexed: 04/13/2024]
Abstract
Frequent injections of anti-CD124 monoclonal antibody (αCD124) over long periods of time are used to treat chronic rhinosinusitis with nasal polyps (CRSwNP). Needle-free, intranasal administration (i.n.) of αCD124 is expected to provide advantages of localized delivery, improved efficacy, and enhanced medication adherence. However, delivery barriers such as the mucus and epithelium in the nasal tissue impede penetration of αCD124. Herein, two novel protamine nanoconstructs: allyl glycidyl ether conjugated protamine (Nano-P) and polyamidoamine-linked protamine (Dendri-P) were synthesized and showed enhanced αCD124 penetration through multiple epithelial layers compared to protamine in mice. αCD124 was mixed with Nano-P or Dendri-P and then intranasally delivered for the treatment of severe CRSwNP in mice. Micro-CT and pathological changes in nasal turbinates showed that these two nano-formulations achieved ∼50 % and ∼40 % reductions in nasal polypoid lesions and eosinophil count, respectively. Both nano-formulations provided enhanced efficacy in suppressing nasal and systemic Immunoglobulin E (IgE) and nasal type 2 inflammatory biomarkers, such as interleukin 13 (IL-13) and IL-25. These effects were superior to those in the protamine formulation group and subcutaneous (s.c.) αCD124 given at a 12.5-fold higher dose. Intranasal delivery of protamine, Nano-P, or Dendri-P did not induce any measurable toxicities in mice.
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Affiliation(s)
- Jiamin Wu
- Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
| | - Natalie Jones
- Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
| | - Po-Han Chao
- Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
| | - Vanessa Chan
- Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
| | - Lukas Hohenwarter
- Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
| | - Angeline Wu
- Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
| | - Marta Bergamo
- Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
| | - Cristina Rodríguez-Rodríguez
- Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada; Department of Physics and Astronomy, University of British Columbia, Vancouver, BC V6T 1Z1, Canada
| | - Katayoun Saatchi
- Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
| | - Alex Liang
- Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
| | - Urs O Häfeli
- Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
| | - Zheng Tan
- Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
| | - Sarah Hedtrich
- Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada; Center of Biological Design, Berlin Institute of Health at Charité - Universitätsmedizin Berlin, Germany; Department of Infectious Diseases and Respiratory Medicine, Charité - Universitätsmedizin Berlin, Corporate member of Freie Universität Berlin and Humboldt Universität zu Berlin, Germany; Molecular Medicine in the Helmholtz Association (MDC), 13125 Berlin, Germany
| | - Lucas J Andrew
- Department of Chemistry, University of British Columbia, Vancouver, British Columbia, V6T 1Z1, Canada
| | - Shyh-Dar Li
- Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada.
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Esposito TVF, Blackadar C, Wu L, Rodríguez-Rodríguez C, Haney EF, Pletzer D, Saatchi K, Hancock REW, Häfeli UO. Biodistribution of Native and Nanoformulated Innate Defense Regulator Peptide 1002. Mol Pharm 2024; 21:2751-2766. [PMID: 38693707 DOI: 10.1021/acs.molpharmaceut.3c01169] [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: 05/03/2024]
Abstract
Innate defense regulator-1002 (IDR-1002) is a synthetic peptide with promising immunomodulatory and antibiofilm properties. An appreciable body of work exists around its mechanism of action at the cellular and molecular level, along with its efficacy across several infection and inflammation models. However, little is known about its absorption, distribution, and excretion in live organisms. Here, we performed a comprehensive biodistribution assessment with a gallium-67 radiolabeled derivative of IDR-1002 using nuclear tracing techniques. Various dose levels of the radiotracer (2-40 mg/kg) were administered into the blood, peritoneal cavity, and subcutaneous tissue, or instilled into the lungs. The peptide was well tolerated at all subcutaneous and intraperitoneal doses, although higher levels were associated with delayed absorption kinetics and precipitation of the peptide within the tissues. Low intratracheal doses were rapidly absorbed systemically, and small increases in the dose level were lethal. Intravenous doses were rapidly cleared from the blood at lower levels, and upon escalation, were toxic with a high proportion of the dose accumulating within the lung tissue. To improve biocompatibility and prolong its circulation within the blood, IDR-1002 was further formulated onto high molecular weight hyperbranched polyglycerol (HPG) polymers. Constructs prepared at 5:1 and 10:1 peptide-to-polymer ratios were colloidally stable, maintained the biological profile of the peptide payload and helped reduce red blood cell lysis. The 5:1 construct circulated well in the blood, but higher peptide loading was associated with rapid clearance by the reticuloendothelial system. Many peptides face pharmacokinetic and biocompatibility challenges, but formulations such as those with HPG have the potential to overcome these limitations.
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Affiliation(s)
- Tullio V F Esposito
- Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver V6T 1Z4, British Columbia, Canada
| | - Colin Blackadar
- Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver V6T 1Z4, British Columbia, Canada
| | - Lan Wu
- Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver V6T 1Z4, British Columbia, Canada
- Wuya College of Innovation, Shenyang Pharmaceutical University, Wenhua Road No. 103, Shenyang 110016, China
| | - Cristina Rodríguez-Rodríguez
- Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver V6T 1Z4, British Columbia, Canada
- Department of Physics and Astronomy, Faculty of Science, University of British Columbia, Vancouver V6T 1Z4, British Columbia, Canada
| | - Evan F Haney
- Centre for Microbial Disease and Immunity Research, Department of Microbiology and Immunology, Faculty of Science, University of British Columbia, Vancouver V6T 1Z4, British Columbia, Canada
- Asep Medical Holdings, 420 - 730 View Street, Victoria V8W 3Y7, British Columbia, Canada
| | - Daniel Pletzer
- Centre for Microbial Disease and Immunity Research, Department of Microbiology and Immunology, Faculty of Science, University of British Columbia, Vancouver V6T 1Z4, British Columbia, Canada
- Department of Microbiology and Immunology, University of Otago, Dunedin 9054, New Zealand
| | - Katayoun Saatchi
- Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver V6T 1Z4, British Columbia, Canada
| | - Robert E W Hancock
- Centre for Microbial Disease and Immunity Research, Department of Microbiology and Immunology, Faculty of Science, University of British Columbia, Vancouver V6T 1Z4, British Columbia, Canada
| | - Urs O Häfeli
- Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver V6T 1Z4, British Columbia, Canada
- Department of Pharmacy, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen 1172, Denmark
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Cosmi V, Wang B, Goorden MC, Beekman FJ. NaI gamma camera performance for high energies: Effects of crystal thickness, photomultiplier tube geometry and light guide thickness. Med Phys 2024. [PMID: 38569052 DOI: 10.1002/mp.17043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2023] [Revised: 12/18/2023] [Accepted: 03/12/2024] [Indexed: 04/05/2024] Open
Abstract
BACKGROUND Gamma camera imaging, including single photon emission computed tomography (SPECT), is crucial for research, diagnostics, and radionuclide therapy. Gamma cameras are predominantly based on arrays of photon multipliers tubes (PMTs) that read out NaI(Tl) scintillation crystals. In this way, standard gamma cameras can localize ɣ-rays with energies typically ranging from 30 to 360 keV. In the last decade, there has been an increasing interest towards gamma imaging outside this conventional clinical energy range, for example, for theragnostic applications and preclinical multi-isotope positron emission tomography (PET) and PET-SPECT. However, standard gamma cameras are typically equipped with 9.5 mm thick NaI(Tl) crystals which can result in limited sensitivity for these higher energies. PURPOSE Here we investigate to what extent thicker scintillators can improve the photopeak sensitivity for higher energy isotopes while attempting to maintain spatial resolution. METHODS Using Monte Carlo simulations, we analyzed multiple PMT-based configurations of gamma detectors with monolithic NaI (Tl) crystals of 20 and 40 mm thickness. Optimized light guide thickness together with 2-inch round, 3-inch round, 60 × 60 mm2 square, and 76 × 76 mm2 square PMTs were tested. For each setup, we assessed photopeak sensitivity, energy resolution, spatial, and depth-of-interaction (DoI) resolution for conventional (140 keV) and high (511 keV) energy ɣ using a maximum-likelihood algorithm. These metrics were compared to those of a "standard" 9.5 mm-thick crystal detector with 3-inch round PMTs. RESULTS Estimated photopeak sensitivities for 511 keV were 27% and 53% for 20 and 40 mm thick scintillators, which is respectively, 2.2 and 4.4 times higher than for 9.5 mm thickness. In most cases, energy resolution benefits from using square PMTs instead of round ones, regardless of their size. Lateral and DoI spatial resolution are best for smaller PMTs (2-inch round and 60 × 60 mm2 square) which outperform the more cost-effective larger PMT setups (3-inch round and 76 × 76 mm2 square), while PMT layout and shape have negligible (< 10%) effect on resolution. Best spatial resolution was obtained with 60 × 60 mm2 PMTs; for 140 keV, lateral resolution was 3.5 mm irrespective of scintillator thickness, improving to 2.8 and 2.9 mm for 511 keV with 20 and 40 mm thick crystals, respectively. Using the 3-inch round PMTs, lateral resolutions of 4.5 and 3.9 mm for 140 keV and of 3.5 and 3.7 mm for 511 keV were obtained with 20 and 40 mm thick crystals respectively, indicating a moderate performance degradation compared to the 3.5 and 2.9 mm resolution obtained by the standard detector for 140 and 511 keV. Additionally, DoI resolution for 511 keV was 7.0 and 5.6 mm with 20 and 40 mm crystals using 60 × 60 mm2 square PMTs, while with 3-inch round PMTs 12.1 and 5.9 mm were obtained. CONCLUSION Depending on PMT size and shape, the use of thicker scintillator crystals can substantially improve detector sensitivity at high gamma energies, while spatial resolution is slightly improved or mildly degraded compared to standard crystals.
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Affiliation(s)
- Valerio Cosmi
- Department of Radiation Science and Technology, Delft University of Technology, Delft, The Netherlands
| | - Beien Wang
- Department of Radiation Science and Technology, Delft University of Technology, Delft, The Netherlands
| | - Marlies C Goorden
- Department of Radiation Science and Technology, Delft University of Technology, Delft, The Netherlands
| | - Freek J Beekman
- Department of Radiation Science and Technology, Delft University of Technology, Delft, The Netherlands
- Free Bee International, Gouda, The Netherlands
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Wang H, Li X, Xu L, Kuang Y. PET/SPECT/spectral-CT/CBCT imaging in a small-animal radiation therapy platform: A Monte Carlo study-Part I: Quad-modal imaging. Med Phys 2024; 51:2941-2954. [PMID: 38421665 DOI: 10.1002/mp.17007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2023] [Revised: 01/16/2024] [Accepted: 02/12/2024] [Indexed: 03/02/2024] Open
Abstract
BACKGROUND In spite of the tremendous potential of game-changing biological image- and/or biologically guided radiation therapy (RT) and adaptive radiation therapy for cancer treatment, existing limited strategies for integrating molecular imaging and/or biological information with RT have impeded the translation of preclinical research findings to clinical applications. Additionally, there is an urgent need for a highly integrated small-animal radiation therapy (SART) platform that can seamlessly combine therapeutic and diagnostic capabilities to comprehensively enhance RT for cancer treatment. PURPOSE We investigated a highly integrated quad-modal on-board imaging configuration combining positron emission tomography (PET), single-photon emission computed tomography (SPECT), photon-counting spectral CT, and cone-beam computed tomography (CBCT) in a SART platform using a Monte Carlo model as a proof-of-concept. METHODS The quad-modal on-board imaging configuration of the SART platform was designed and evaluated by using the GATE Monte Carlo code. A partial-ring on-board PET imaging subsystem, utilizing advanced semiconductor thallium bromide detector technology, was designed to achieve high sensitivity and spatial resolution. On-board SPECT, photon-counting spectral-CT, and CBCT imaging were performed using a single cadmium zinc telluride flat detector panel. The absolute peak sensitivity and scatter fraction of the PET subsystem were estimated by using simulated phantoms described in the NEMA NU-4 standard. The spatial resolution of the PET image of the platform was evaluated by imaging a simulated micro-Derenzo hot-rod phantom. To evaluate the quantitative imaging capability of the system's spectral CT, the Bayesian eigentissue decomposition (ETD) method was utilized to quantitatively decompose the virtual noncontrast (VNC) electron densities and iodine contrast agent fractions in the Kidney1 inserts mixed with the iodine contrast agent within the simulated phantoms. The performance of the proposed quad-model imaging in the platform was validated by imaging a simulated phantom with multiple imaging probes, including an iodine contrast agent and radioisotopes of 18F and 99mTc. RESULTS The PET subsystem demonstrated an absolute peak sensitivity of 18.5% at the scanner center, with an energy window of 175-560 KeV, and a scatter fraction of only 3.5% for the mouse phantom, with a default energy window of 480-540 KeV. The spatial resolution of PET on-board imaging exceeded 1.2 mm. All imaging probes were identified clearly within the phantom. The PET and SPECT images agreed well with the actual spatial distributions of the tracers within the phantom. Average relative errors on electron density and iodine contrast agent fraction in the Kidney1 inserts were less than 3%. High-quality PET images, SPECT images, spectral-CT images (including iodine contrast agent fraction images and VNC electron density images), and CBCT images of the simulated phantom demonstrated the comprehensive multimodal imaging capability of the system. CONCLUSIONS The results demonstrated the feasibility of the proposed quad-modal imaging configuration in a SART platform. The design incorporates anatomical, molecular, and functional information about tumors, thereby facilitating successful translation of preclinical studies into clinical practices.
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Affiliation(s)
- Hui Wang
- Medical Imaging and Translational Medicine Laboratory, Department of Radiotherapy, Affiliated Hangzhou Cancer Hospital, Westlake University School of Medicine, Hangzhou, Zhejiang, China
- Medical Physics Program, University of Nevada, Las Vegas, Nevada, USA
| | - Xiadong Li
- Medical Imaging and Translational Medicine Laboratory, Department of Radiotherapy, Affiliated Hangzhou Cancer Hospital, Westlake University School of Medicine, Hangzhou, Zhejiang, China
| | - Lixia Xu
- Medical Imaging and Translational Medicine Laboratory, Department of Radiotherapy, Affiliated Hangzhou Cancer Hospital, Westlake University School of Medicine, Hangzhou, Zhejiang, China
| | - Yu Kuang
- Medical Physics Program, University of Nevada, Las Vegas, Nevada, USA
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Shibutani T, Onoguchi M, Kanno T, Kinuya S. Influence of spill-over for 99mTc images and the effect of scatter correction for dual-isotope simultaneous acquisition with 99mTc and 18F using small-animal SPECT-PET/CT system. Phys Eng Sci Med 2024; 47:135-142. [PMID: 37902935 DOI: 10.1007/s13246-023-01348-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2023] [Accepted: 10/16/2023] [Indexed: 11/01/2023]
Abstract
A dual-isotope simultaneous acquisition (DISA) of 99mTc and 18F affects the image quality of 99mTc by crosstalk and spill-over from 18F. We demonstrated the influence of spill-over and crosstalk on image quality and its correction effect for DISA SPECT with 99mTc and 18F. A fillable cylindrical chamber of 30 mm with NEMA-NU4 image quality phantom was filled with 99mTc only or a mixed 99mTc and 18F solution (C100). Two small-region chambers were filled with 99mTc only or a mixed 99mTc and 18F solution made at half the radioactivity concentration of C100 (C50) and non-radioactive water (C0). The 18F/99mTc ratio for DISA was set at approximately 0.4-12. Two types of 99mTc transverse images with and without scatter correction (SC and nonSC) were created. The 99mTc images of single-isotope acquisition (SIA) were created as a reference. The DISA/SIA ratio and contrast of 99mTc were compared between SIA and DISA. Although the DISA/SIA ratios with nonSC of C100, C50 and C0 gradually increased with increasing 18F/99mTc ratio, it was nearly constant by SC. The contrasts of C100 and C50 were similar to a reference value for both nonSC and SC. In conclusion, DISA images showed lower image quality as the 18F/99mTc ratio increased. The image quality in hot-spot regions such as C100 and C50 was improved by SC, whereas cold-spot regions such as C0 could not completely remove the influence of spill-over even with SC.
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Affiliation(s)
- Takayuki Shibutani
- Department of Quantum Medical Technology, Institute of Medical, Pharmaceutical and Health Sciences, Kanazawa University, Kanazawa, Japan
- Department of Quantum Medical Technology, Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Japan
| | - Masahisa Onoguchi
- Department of Quantum Medical Technology, Institute of Medical, Pharmaceutical and Health Sciences, Kanazawa University, Kanazawa, Japan.
- Department of Quantum Medical Technology, Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Japan.
| | - Takayuki Kanno
- Department of Quantum Medical Technology, Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Japan
- Department of Radiological Technology, Nagoya University Hospital, Nagoya, Japan
- Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
| | - Seigo Kinuya
- Department of Nuclear Medicine, Kanazawa University Hospital, Kanazawa, Japan
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Abstract
Biomedical research has long relied on small-animal studies to elucidate disease process and develop new medical treatments. The introduction of in vivo functional imaging technology, such as PET, has allowed investigators to peer inside their subjects and follow disease progression longitudinally as well as improve understanding of normal biological processes. Recent developments in CRISPR, immuno-PET, and high-resolution in vivo imaging have only increased the importance of small-animal, or preclinical, PET imaging. Other drivers of preclinical PET innovation include new combinations of imaging technologies, such as PET/MR imaging, which require changes to PET hardware.
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Affiliation(s)
- Adrienne L Lehnert
- Department of Radiology, University of Washington, 1959 Northeast Pacific Street, UW Box 356043, Seattle, WA, USA.
| | - Robert S Miyaoka
- Department of Radiology, University of Washington, 1959 Northeast Pacific Street, UW Box 356043, Seattle, WA, USA
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Nekolla SG, Rischpler C, Higuchi T. Preclinical Imaging of Cardiovascular Disesase. Semin Nucl Med 2023; 53:586-598. [PMID: 37268498 DOI: 10.1053/j.semnuclmed.2023.04.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Revised: 04/24/2023] [Accepted: 04/26/2023] [Indexed: 06/04/2023]
Abstract
Noninvasive imaging techniques, such as SPECT, PET, CT, echocardiography, or MRI, have become essential in cardiovascular research. They allow for the evaluation of biological processes in vivo without the need for invasive procedures. Nuclear imaging methods, such as SPECT and PET, offer numerous advantages, including high sensitivity, reliable quantification, and the potential for serial imaging. Modern SPECT and PET imaging systems, equipped with CT and MRI components in order to get access to morphological information with high spatial resolution, are capable of imaging a wide range of established and innovative agents in both preclinical and clinical settings. This review highlights the utility of SPECT and PET imaging as powerful tools for translational research in cardiology. By incorporating these techniques into a well-defined workflow- similar to those used in clinical imaging- the concept of "bench to bedside" can be effectively implemented.
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Affiliation(s)
- Stephan G Nekolla
- Nuklearmedizinische Klinik der TU München, Munich, Germany; DZHK (German Centre for Cardiovascular Research), partner site Munich Heart Alliance, Munich, Germany.
| | | | - Takahiro Higuchi
- Department of Nuclear Medicine, University Hospital Würzburg, Würzburg, Germany; Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
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Wharton L, McNeil SW, Merkens H, Yuan Z, Van de Voorde M, Engudar G, Ingham A, Koniar H, Rodríguez-Rodríguez C, Radchenko V, Ooms M, Kunz P, Bénard F, Schaffer P, Yang H. Preclinical Evaluation of [155/161Tb]Tb-Crown-TATE—A Novel SPECT Imaging Theranostic Agent Targeting Neuroendocrine Tumours. Molecules 2023; 28:molecules28073155. [PMID: 37049918 PMCID: PMC10095901 DOI: 10.3390/molecules28073155] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 03/24/2023] [Accepted: 03/27/2023] [Indexed: 04/05/2023] Open
Abstract
Terbium radioisotopes (149Tb, 152Tb, 155Tb, 161Tb) offer a unique class of radionuclides which encompass all four medicinally relevant nuclear decay modalities (α, β+, γ, β−/e−), and show high potential for the development of element-matched theranostic radiopharmaceuticals. The goal of this study was to design, synthesise, and evaluate the suitability of crown-TATE as a new peptide-conjugate for radiolabelling of [155Tb]Tb3+ and [161Tb]Tb3+, and to assess the imaging and pharmacokinetic properties of each radiotracer in tumour-bearing mice. [155Tb]Tb-crown-TATE and [161Tb]Tb-crown-TATE were prepared efficiently under mild conditions, and exhibited excellent stability in human serum (>99.5% RCP over 7 days). Longitudinal SPECT/CT images were acquired for 155Tb- and 161Tb- labelled crown-TATE in male NRG mice bearing AR42J tumours. The radiotracers, [155Tb]Tb-crown-TATE and [161Tb]Tb-crown-TATE, showed high tumour targeting (32.6 and 30.0 %ID/g, respectively) and minimal retention in non-target organs at 2.5 h post-administration. Biodistribution studies confirmed the SPECT/CT results, showing high tumour uptake (38.7 ± 8.0 %ID/g and 38.5 ± 3.5 %ID/g, respectively) and favourable tumour-to-background ratios. Blocking studies further confirmed SSTR2-specific tumour accumulation. Overall, these findings suggest that crown-TATE has great potential for element-matched molecular imaging and radionuclide therapy using 155Tb and 161Tb.
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Affiliation(s)
- Luke Wharton
- Life Sciences Division, TRIUMF, 4004 Wesbrook Mall, Vancouver, BC V6T 2A3, Canada
| | - Scott W. McNeil
- Life Sciences Division, TRIUMF, 4004 Wesbrook Mall, Vancouver, BC V6T 2A3, Canada
| | - Helen Merkens
- Department of Molecular Oncology, BC Cancer Research Institute, Vancouver, BC V5Z 1L3, Canada
| | - Zheliang Yuan
- Life Sciences Division, TRIUMF, 4004 Wesbrook Mall, Vancouver, BC V6T 2A3, Canada
| | - Michiel Van de Voorde
- Nuclear Medicine Applications, Belgium Nuclear Research Center (SCK CEN), Boeretang, 200, 2400 Mol, Belgium
| | - Gokce Engudar
- Life Sciences Division, TRIUMF, 4004 Wesbrook Mall, Vancouver, BC V6T 2A3, Canada
| | - Aidan Ingham
- Life Sciences Division, TRIUMF, 4004 Wesbrook Mall, Vancouver, BC V6T 2A3, Canada
| | - Helena Koniar
- Life Sciences Division, TRIUMF, 4004 Wesbrook Mall, Vancouver, BC V6T 2A3, Canada
- Department of Physics and Astronomy, University of British Columbia, 6224 Agronomy Road, Vancouver, BC V6T 1Z1, Canada
| | - Cristina Rodríguez-Rodríguez
- Department of Physics and Astronomy, University of British Columbia, 6224 Agronomy Road, Vancouver, BC V6T 1Z1, Canada
- Faculty of Pharmaceutical Sciences, University of British Columbia, 2405 Wesbrook Mall, Vancouver, BC V6T 1Z3, Canada
| | - Valery Radchenko
- Life Sciences Division, TRIUMF, 4004 Wesbrook Mall, Vancouver, BC V6T 2A3, Canada
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, BC V6T 1Z1, Canada
| | - Maarten Ooms
- Nuclear Medicine Applications, Belgium Nuclear Research Center (SCK CEN), Boeretang, 200, 2400 Mol, Belgium
| | - Peter Kunz
- Accelerator Division, TRIUMF, 4004 Wesbrook Mall, Vancouver, BC V6T 2A3, Canada
- Department of Chemistry, Simon Fraser University, Burnaby, BC V5A 1S6, Canada
| | - François Bénard
- Department of Molecular Oncology, BC Cancer Research Institute, Vancouver, BC V5Z 1L3, Canada
- Department of Radiology, University of British Columbia, Vancouver, BC V5Z 1M9, Canada
| | - Paul Schaffer
- Life Sciences Division, TRIUMF, 4004 Wesbrook Mall, Vancouver, BC V6T 2A3, Canada
- Department of Chemistry, Simon Fraser University, Burnaby, BC V5A 1S6, Canada
- Department of Radiology, University of British Columbia, Vancouver, BC V5Z 1M9, Canada
| | - Hua Yang
- Life Sciences Division, TRIUMF, 4004 Wesbrook Mall, Vancouver, BC V6T 2A3, Canada
- Department of Chemistry, Simon Fraser University, Burnaby, BC V5A 1S6, Canada
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Llosá G, Rafecas M. Hybrid PET/Compton-camera imaging: an imager for the next generation. EUROPEAN PHYSICAL JOURNAL PLUS 2023; 138:214. [PMID: 36911362 PMCID: PMC9990967 DOI: 10.1140/epjp/s13360-023-03805-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Accepted: 02/11/2023] [Indexed: 06/18/2023]
Abstract
Compton cameras can offer advantages over gamma cameras for some applications, since they are well suited for multitracer imaging and for imaging high-energy radiotracers, such as those employed in radionuclide therapy. While in conventional clinical settings state-of-the-art Compton cameras cannot compete with well-established methods such as PET and SPECT, there are specific scenarios in which they can constitute an advantageous alternative. The combination of PET and Compton imaging can benefit from the improved resolution and sensitivity of current PET technology and, at the same time, overcome PET limitations in the use of multiple radiotracers. Such a system can provide simultaneous assessment of different radiotracers under identical conditions and reduce errors associated with physical factors that can change between acquisitions. Advances are being made both in instrumentation developments combining PET and Compton cameras for multimodal or three-gamma imaging systems, and in image reconstruction, addressing the challenges imposed by the combination of the two modalities or the new techniques. This review article summarizes the advances made in Compton cameras for medical imaging and their combination with PET.
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Affiliation(s)
- Gabriela Llosá
- Instituto de Física Corpuscular (IFIC), CSIC-UV, Catedrático Beltrán, 2., 46980 Paterna, Valencia, Spain
| | - Magdalena Rafecas
- Institute of Medical Engineering (IMT), Universität zu Lübeck, Ratzeburger Allee 160, 23562 Lübeck, Germany
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10
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Alqahtani FF. SPECT/CT and PET/CT, related radiopharmaceuticals, and areas of application and comparison. Saudi Pharm J 2023; 31:312-328. [PMID: 36942267 PMCID: PMC10023548 DOI: 10.1016/j.jsps.2022.12.013] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Accepted: 12/27/2022] [Indexed: 12/31/2022] Open
Abstract
The paper begins by identifying the key historical elements in the development of nuclear medicine imaging, focusing on the Anger camera and single photon emission computed tomography (SPECT) technologies. In this context, key reference is made to the physics of detection in Anger camera systems, especially key components such as the sodium iodide crystal, the function and performance of photomultiplier tubes, and the collimator design. It is discovered that within each component of technology, there are fundamental physical relationships that govern the performance of each component, and that overall image quality is the result of the complex interaction of all such elements. The increasing use of SPECT/CT imaging is described and illustrated with a range of typical clinical applications, which include brain, spinal, cardiac, and cancer studies. The use of CT imaging functionality allows for SPECT image correction based on compensation for absorption within tissue. Reference is also made to the basics of positron emission tomography (PET) imaging and, in particular, to the integration of PET/CT systems where the anatomy profile of the CT image is used to provide correction for photon absorption. A summary is provided of the radionuclides and radiopharmaceuticals commonly used in PET/CT imaging and a range of image studies referenced includes those of nasopharyngeal carcinoma, lung cancer investigation, brain investigation (cancer detection and dementia) and cardiac function. Reference is made to the development of "time of flight" (TOF) technology for improving of image resolution in PET/CT systems. Furthermore, SPECT/CT and PET/CT imaging systems are compared, where a key factor identified is the significantly higher number of photons detected with PET/CT technology and improved image resolution.
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Affiliation(s)
- Fawaz F. Alqahtani
- Corresponding author at: Department of Radiological Sciences, College of Applied Medical Sciences, Najran University, Najran 1988, Saudi Arabia.
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11
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Du J, Jones T. Technical opportunities and challenges in developing total-body PET scanners for mice and rats. EJNMMI Phys 2023; 10:2. [PMID: 36592266 PMCID: PMC9807733 DOI: 10.1186/s40658-022-00523-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Accepted: 12/20/2022] [Indexed: 01/03/2023] Open
Abstract
Positron emission tomography (PET) is the most sensitive in vivo molecular imaging technique available. Small animal PET has been widely used in studying pharmaceutical biodistribution and disease progression over time by imaging a wide range of biological processes. However, it remains true that almost all small animal PET studies using mouse or rat as preclinical models are either limited by the spatial resolution or the sensitivity (especially for dynamic studies), or both, reducing the quantitative accuracy and quantitative precision of the results. Total-body small animal PET scanners, which have axial lengths longer than the nose-to-anus length of the mouse/rat and can provide high sensitivity across the entire body of mouse/rat, can realize new opportunities for small animal PET. This article aims to discuss the technical opportunities and challenges in developing total-body small animal PET scanners for mice and rats.
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Affiliation(s)
- Junwei Du
- grid.27860.3b0000 0004 1936 9684Department of Biomedical Engineering, University of California at Davis, Davis, CA 95616 USA
| | - Terry Jones
- grid.27860.3b0000 0004 1936 9684Department of Radiology, University of California at Davis, Davis, CA 95616 USA
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12
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Van der Heiden K, Barrett HE, Meester EJ, van Gaalen K, Krenning BJ, Beekman FJ, de Blois E, de Swart J, Verhagen HJM, van der Lugt A, Norenberg JP, de Jong M, Bernsen MR, Gijsen FJH. SPECT/CT imaging of inflammation and calcification in human carotid atherosclerosis to identify the plaque at risk of rupture. J Nucl Cardiol 2022; 29:2487-2496. [PMID: 34318395 PMCID: PMC9553768 DOI: 10.1007/s12350-021-02745-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Accepted: 06/28/2021] [Indexed: 11/29/2022]
Abstract
BACKGROUND Calcification and inflammation are atherosclerotic plaque compositional biomarkers that have both been linked to stroke risk. The aim of this study was to evaluate their co-existing prevalence in human carotid plaques with respect to plaque phenotype to determine the value of hybrid imaging for the detection of these biomarkers. METHODS Human carotid plaque segments, obtained from endarterectomy, were incubated in [111In]In-DOTA-butylamino-NorBIRT ([111In]In-Danbirt), targeting Leukocyte Function-associated Antigen-1 (LFA-1) on leukocytes. By performing SPECT/CT, both inflammation from DANBIRT uptake and calcification from CT imaging were assessed. Plaque phenotype was classified using histology. RESULTS On a total plaque level, comparable levels of calcification volume existed with different degrees of inflammation and vice versa. On a segment level, an inverse relationship between calcification volume and inflammation was evident in highly calcified segments, which classify as fibrocalcific, stable plaque segments. In contrast, segments with little or no calcification presented with a moderate to high degree of inflammation, often coinciding with the more dangerous fibrous cap atheroma phenotype. CONCLUSION Calcification imaging alone can only accurately identify highly calcified, stable, fibrocalcific plaques. To identify high-risk plaques, with little or no calcification, hybrid imaging of calcification and inflammation could provide diagnostic benefit.
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Affiliation(s)
- K Van der Heiden
- Department of Biomedical Engineering, Thorax Center, Erasmus MC, Rotterdam, The Netherlands.
| | - H E Barrett
- Department of Biomedical Engineering, Thorax Center, Erasmus MC, Rotterdam, The Netherlands
- Department of Radiology & Nuclear Medicine, Erasmus MC, Rotterdam, The Netherlands
| | - E J Meester
- Department of Biomedical Engineering, Thorax Center, Erasmus MC, Rotterdam, The Netherlands
- Department of Radiology & Nuclear Medicine, Erasmus MC, Rotterdam, The Netherlands
| | - K van Gaalen
- Department of Biomedical Engineering, Thorax Center, Erasmus MC, Rotterdam, The Netherlands
| | - B J Krenning
- Department of Cardiology, Erasmus MC, Rotterdam, The Netherlands
| | - F J Beekman
- MiLabs, B.V, Utrecht, The Netherlands
- Section Biomedical Imaging, Department Radiation Science & Technology, Delft University of Technology, Delft, The Netherlands
- Department of Translational Neuroscience, Brain Centre Rudolf Magnus, University Medical Centre Utrecht, Utrecht, The Netherlands
| | - E de Blois
- Department of Radiology & Nuclear Medicine, Erasmus MC, Rotterdam, The Netherlands
| | - J de Swart
- Department of Radiology & Nuclear Medicine, Erasmus MC, Rotterdam, The Netherlands
| | - H J M Verhagen
- Department of Vascular Surgery, Erasmus MC, Rotterdam, The Netherlands
| | - A van der Lugt
- Department of Radiology & Nuclear Medicine, Erasmus MC, Rotterdam, The Netherlands
| | - J P Norenberg
- Radiopharmaceutical Sciences, University of New Mexico, Albuquerque, NM, USA
| | - M de Jong
- Department of Radiology & Nuclear Medicine, Erasmus MC, Rotterdam, The Netherlands
| | - M R Bernsen
- Department of Radiology & Nuclear Medicine, Erasmus MC, Rotterdam, The Netherlands
- Applied Molecular Imaging Erasmus Core Facility, Erasmus MC Rotterdam, Rotterdam, The Netherlands
| | - F J H Gijsen
- Department of Biomedical Engineering, Thorax Center, Erasmus MC, Rotterdam, The Netherlands
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Koniar H, Rodríguez-Rodríguez C, Radchenko V, Yang H, Kunz P, Rahmim A, Uribe C, Schaffer P. SPECT imaging of 226Ac as a theranostic isotope for 225Ac radiopharmaceutical development. Phys Med Biol 2022; 67. [DOI: 10.1088/1361-6560/ac8b5f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Accepted: 08/19/2022] [Indexed: 11/12/2022]
Abstract
Abstract
Objective. The development of alpha-emitting radiopharmaceuticals using 225Ac (t
½ = 9.92 d) benefits from the quantitative determination of its biodistribution and is not always easy to directly measure. An element-equivalent matched-pair would allow for more accurate biodistribution and dosimetry estimates. 226Ac (t
½ = 29.4 h) is a candidate isotope for in vivo imaging of preclinical 225Ac radiopharmaceuticals, given its 158 keV and 230 keV gamma emissions making it suitable for quantitative SPECT imaging. This work aimed to conduct a performance assessment for 226Ac imaging and presents the first-ever 226Ac SPECT images. Approach. To establish imaging performance with regards to contrast and noise, image quality phantoms were scanned using a microSPECT/CT system. To assess the resolution, a hot rod phantom with cylindrical rods with diameters between 0.85 and 1.70 mm was additionally imaged. Two collimators were evaluated: a high-energy ultra-high resolution (HEUHR) collimator and an extra ultra-high sensitivity (UHS) collimator. Images were reconstructed from two distinct photopeaks at 158 keV and 230 keV. Main results. The HEUHR SPECT image measurements of high activity concentration regions were consistent with values determined independently via gamma spectroscopy, within 9% error. The lower energy 158 keV photopeak images demonstrated slightly better contrast recovery. In the resolution phantom, the UHS collimator only resolved rods ≥1.30 mm and ≥1.50 mm for the 158 keV and 230 keV photopeaks, respectively, while the HEUHR collimator clearly resolved all rods, with resolution <0.85 mm. Significance. Overall, the feasibility of preclinical imaging with 226Ac was demonstrated with quantitative SPECT imaging achieved for both its 158 keV and 230 keV photopeaks. The HEUHR collimator is recommended for imaging 226Ac activity distributions in small animals due to its resolution <0.85 mm. Future work will explore the feasibility of using 226Ac both as an element-equivalent isotope for 225Ac radiopharmaceuticals, or as a standalone therapeutic isotope.
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V F Esposito T, Rodríguez-Rodríguez C, Blackadar C, Haney EF, Pletzer D, E W Hancock R, Saatchi K, Häfeli UO. Biodistribution and Toxicity of Innate Defense Regulator 1018 (IDR-1018). Eur J Pharm Biopharm 2022; 179:11-25. [PMID: 36028151 DOI: 10.1016/j.ejpb.2022.08.004] [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: 05/21/2022] [Revised: 08/03/2022] [Accepted: 08/10/2022] [Indexed: 11/04/2022]
Abstract
Innate defense regulators (IDRs) are synthetic host-defense peptides (HDPs) with broad-spectrum anti-infective properties, including immunomodulatory, anti-biofilm and direct antimicrobial activities. A lack of pharmacokinetic data about these peptides hinders their development and makes it challenging to fully understand how they work in vivo since their mechanism of action is dependent on tissue concentrations of the peptide. Here, we set out to define in detail the pharmacokinetics of a well-characterized IDR molecule, IDR-1018. To make the peptide traceable, it was radiolabeled with the long-lived gamma-emitting isotope gallium-67. After a series of bench-top characterizations, the radiotracer was administered to healthy mice intravenously (IV) or subcutaneously (SQ) at various dose levels (2.5-13 mg/kg). Nuclear imaging and ex-vivo biodistributions were used to quantify organ and tissue uptake of the radiotracer over time. When administered as an IV bolus, the distribution profile of the radiotracer changed as the dose was escalated. At 2.5 mg/kg, the peptide was well-tolerated, poorly circulated in the blood and was cleared predominately by the reticuloendothelial system. Higher doses (7 and 13 mg/kg) as an IV bolus were almost immediately lethal due to respiratory arrest; significant lung uptake of the radiotracer was observed from nuclear scans of these animals, and histological examination found extensive damage to the pulmonary vasculature and alveoli. When administered SQ at a dose of 3 mg/kg, radiolabeled IDR-1018 was rapidly absorbed from the site of injection and predominately cleared renally. Apart from the SQ injection site, no other tissue had a concentration above the minimum inhibitory concentration that would enable this peptide to exert direct antimicrobial effects against most pathogenic bacteria. Tissue concentrations were sufficient however to disrupt microbial biofilms and alter the host immune response. Overall, this study demonstrated that the administration of synthetic IDR peptide in vivo is best suited to local administration which avoids some of the issues associated with peptide toxicity that are observed when administered systemically by IV injection, an issue that will have to be addressed through formulation.
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Affiliation(s)
- Tullio V F Esposito
- Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, Canada; Department of Pharmacy, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Cristina Rodríguez-Rodríguez
- Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, Canada; Department of Physics and Astronomy, Faculty of Science, University of British Columbia, Vancouver, Canada
| | - Colin Blackadar
- Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, Canada
| | - Evan F Haney
- Centre for Microbial Disease and Immunity Research, Department of Microbiology and Immunology, Faculty of Science, University of British Columbia, Vancouver, Canada; Asep Medical Holdings, Victoria, BC, Canada
| | - Daniel Pletzer
- Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand.
| | - Robert E W Hancock
- Centre for Microbial Disease and Immunity Research, Department of Microbiology and Immunology, Faculty of Science, University of British Columbia, Vancouver, Canada
| | - Katayoun Saatchi
- Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, Canada
| | - Urs O Häfeli
- Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, Canada; Department of Pharmacy, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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Blackadar C, Choi KYG, Embree MF, Hennkens HM, Rodríguez-Rodríguez C, Hancock REW, Saatchi K, Häfeli UO. SPECT/CT Imaging of 111Ag for the Preclinical Evaluation of Silver-Based Antimicrobial Nanomedicines. ACS APPLIED MATERIALS & INTERFACES 2022; 14:26382-26393. [PMID: 35653648 DOI: 10.1021/acsami.2c03609] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
With the growing interest in developing silver-based antimicrobials, there is a need to better understand the behavior of silver within biological systems. To address this, we showed that single-photon emission computed tomography (SPECT) is a suitable method to noninvasively image 111Ag-labeled compounds in mice. Formed by neutron irradiation of palladium foil, 111Ag can be rapidly isolated with a high degree of purity and stably incorporated into antimicrobial silver nanoparticles. The imaging showed that nanoparticles are retained in the lungs for up to 48 h following intratracheal instillation, with limited uptake into the systemic circulation or organs of the reticuloendothelial system. Furthermore, in a mouse model of pulmonary Pseudomonas aeruginosa infection, the nanoparticles reduced the bacterial burden by 11.6-fold without inducing the production of pro-inflammatory mediators. Overall, SPECT imaging with 111Ag is a useful tool for noninvasively visualizing the biodistribution of silver-containing compounds in rodents. This knowledge of how silver nanoparticles distribute in vivo can be used to predict their therapeutic efficacy.
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Affiliation(s)
- Colin Blackadar
- Faculty of Pharmaceutical Sciences, University of British Columbia, 2405 Wesbrook Mall, Vancouver, BC V6T1Z3, Canada
| | - Ka-Yee Grace Choi
- Centre for Microbial Diseases and Immunity Research, Department of Microbiology and Immunology, Faculty of Science, University of British Columbia, Vancouver, BC V6T1Z4, Canada
| | - Mary F Embree
- University of Missouri Research Reactor Center (MURR), 13513 Research Park Drive, Columbia, Missouri 65211, United States
| | - Heather M Hennkens
- University of Missouri Research Reactor Center (MURR), 13513 Research Park Drive, Columbia, Missouri 65211, United States
- Department of Chemistry, University of Missouri, 125 Chemistry Building, Columbia, Missouri 65211, United States
| | - Cristina Rodríguez-Rodríguez
- Faculty of Pharmaceutical Sciences, University of British Columbia, 2405 Wesbrook Mall, Vancouver, BC V6T1Z3, Canada
- Department of Physics and Astronomy, University of British Columbia, 6224 Agricultural Road, Vancouver, BC V6T1Z1, Canada
| | - Robert E W Hancock
- Centre for Microbial Diseases and Immunity Research, Department of Microbiology and Immunology, Faculty of Science, University of British Columbia, Vancouver, BC V6T1Z4, Canada
| | - Katayoun Saatchi
- Faculty of Pharmaceutical Sciences, University of British Columbia, 2405 Wesbrook Mall, Vancouver, BC V6T1Z3, Canada
| | - Urs O Häfeli
- Faculty of Pharmaceutical Sciences, University of British Columbia, 2405 Wesbrook Mall, Vancouver, BC V6T1Z3, Canada
- Department of Pharmacy, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, Copenhagen 2100, Denmark
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Assessment of mouse-specific pharmacokinetics in kidneys based on 131I activity measurements using micro-SPECT. EJNMMI Phys 2022; 9:13. [PMID: 35195790 PMCID: PMC8866625 DOI: 10.1186/s40658-022-00443-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Accepted: 02/10/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND In order to acquire accurate drug pharmacokinetic information, which is required for tissue dosimetry, micro-SPECT must be quantitative to allow for an accurate assessment of radioligand activity in the relevant tissue. This study investigates the feasibility of deriving accurate mouse-specific time-integrated drug pharmacokinetic data in mouse kidneys from activity measurements using micro-SPECT. METHODS An animal experiment was carried out to evaluate the accuracy of 131I activity quantification in mouse kidneys (mean tissue volume of 0.140 mL) using a micro-SPECT system against conventional ex vivo gamma counting (GC) in a NaI(Tl) detector. The imaging setting investigated was that of the mouse biodistribution of a 131I-labelled single-domain antibody fragment (sdAb), currently being investigated for targeted radionuclide therapy of HER2-expressing cancer. SPECT imaging of 131I 365-keV photons was done with a VECTor/CT system (MILabs, Netherlands) using a high-energy mouse collimator with 1.6-mm-diameter pinholes. For both activity quantification techniques, the pharmacokinetic profile of the radioligand from approximately 1-73 h p.i. was derived and the time-integrated activity coefficient per gram of tissue (ã/M) was estimated. Additionally, SPECT activity recovery coefficients were determined in a phantom setting. RESULTS SPECT activities underestimate the reference activities by an amount that is dependent on the 131I activity concentration in the kidney, and thus on the time point of the pharmacokinetic profile. This underestimation is around - 12% at 1.5 h (2.89 MBq mL-1 mean reference activity concentration), - 13% at 6.6 h (149 kBq mL-1), - 40% at 24 h (17.6 kBq mL-1) and - 46% at 73 h (5.2 kBq mL-1) p.i. The ã/M value estimated from SPECT activities is, nevertheless, within - 14% from the reference (GC) ã/M value. Furthermore, better quantitative accuracy (within 2% from GC) in the SPECT ã/M value is achieved when SPECT activities are compensated for partial recovery with a phantom-based recovery coefficient of 0.85. CONCLUSION The SPECT imaging system used, together with a robust activity quantification methodology, allows an accurate estimation of time-integrated pharmacokinetic information of the 131I-labelled sdAb in mouse kidneys. This opens the possibility to perform mouse-specific kidney-tissue dosimetry based on pharmacokinetic data acquired in vivo on the same mice used in nephrotoxicity studies.
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Stroet MCM, de Blois E, de Jong M, Seimbille Y, Mezzanotte L, Löwik CWGM, Panth KM. Improved Multimodal Tumor Necrosis Imaging with IRDye800CW-DOTA Conjugated to an Albumin-Binding Domain. Cancers (Basel) 2022; 14:cancers14040861. [PMID: 35205609 PMCID: PMC8870237 DOI: 10.3390/cancers14040861] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Revised: 01/27/2022] [Accepted: 01/28/2022] [Indexed: 12/10/2022] Open
Abstract
Simple Summary Anti-tumor treatment efficacy is determined by tumor shrinkage, which takes valuable time to become apparent and poses a risk of unnecessary treatment with severe side effects. Therefore, there is an unmet need for more reliable and specific methods to monitor treatment efficacy. We explore radiolabeled cyanines for imaging tumor necrosis as a unique marker for therapy efficacy. Moreover, spontaneous tumor necrosis is a hallmark for aggressively growing tumor types with poor prognosis. We improved the binding properties of a previously reported necrosis-avid contrast agent (NACA) and successfully detected spontaneous and therapy-induced tumor necrosis in mice using radioactivity and fluorescence imaging modalities. This NACA may pave the way to in vivo detection of tumor necrosis for early-stage determination of tumor aggressiveness and therapy efficacy. Abstract Purpose: To assess our improved NACA for the detection of tumor necrosis. Methods: We increased the blood circulation time of our NACA by adding an albumin-binding domain to the molecular structure. We tested the necrosis avidity on dead or alive cultured cells and performed SPECT and fluorescence imaging of both spontaneous and treatment-induced necrosis in murine breast cancer models. We simultaneously recorded [18F]FDG-PET and bioluminescence images for complementary detection of tumor viability. Results: We generated two albumin-binding IRDye800CW derivatives which were labeled with indium-111 with high radiochemical purity. Surprisingly, both albumin-binding NACAs had >10x higher in vitro binding towards dead cells. We selected [111In]3 for in vivo experiments which showed higher dead cell binding in vitro and in vivo stability. The doxorubicin-treated tumors showed increased [111In]3-uptake (1.74 ± 0.08%ID/g after saline treatment, 2.25 ± 0.16%ID/g after doxorubicin treatment, p = 0.044) and decreased [18F]FDG-uptake (3.02 ± 0.51%ID/g after saline treatment, 1.79 ± 0.11%ID/g after doxorubicin treatment, p = 0.040), indicating therapy efficacy. Moreover, we detected increased [111In]3-uptake and tumor necrosis in more rapidly growing EMT6 tumors. Conclusions: Our albumin-binding NACA based on IRDye800CW facilitates tumor-necrosis imaging for assessment of therapy efficacy and aggressiveness in solid tumors using both fluorescence and SPECT imaging.
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Affiliation(s)
- Marcus C. M. Stroet
- Erasmus MC, Department of Radiology & Nuclear Medicine, University Medical Center Rotterdam, 3015 GD Rotterdam, The Netherlands; (M.C.M.S.); (E.d.B.); (Y.S.); (L.M.)
- Erasmus MC, Department of Molecular Genetics, University Medical Center Rotterdam, 3015 GD Rotterdam, The Netherlands
| | - Erik de Blois
- Erasmus MC, Department of Radiology & Nuclear Medicine, University Medical Center Rotterdam, 3015 GD Rotterdam, The Netherlands; (M.C.M.S.); (E.d.B.); (Y.S.); (L.M.)
| | - Marion de Jong
- Erasmus MC, Department of Radiology & Nuclear Medicine, University Medical Center Rotterdam, 3015 GD Rotterdam, The Netherlands; (M.C.M.S.); (E.d.B.); (Y.S.); (L.M.)
| | - Yann Seimbille
- Erasmus MC, Department of Radiology & Nuclear Medicine, University Medical Center Rotterdam, 3015 GD Rotterdam, The Netherlands; (M.C.M.S.); (E.d.B.); (Y.S.); (L.M.)
- Life Sciences Division, TRIUMF, Vancouver, BC V6T 2A3, Canada
| | - Laura Mezzanotte
- Erasmus MC, Department of Radiology & Nuclear Medicine, University Medical Center Rotterdam, 3015 GD Rotterdam, The Netherlands; (M.C.M.S.); (E.d.B.); (Y.S.); (L.M.)
- Erasmus MC, Department of Molecular Genetics, University Medical Center Rotterdam, 3015 GD Rotterdam, The Netherlands
| | - Clemens W. G. M. Löwik
- Erasmus MC, Department of Radiology & Nuclear Medicine, University Medical Center Rotterdam, 3015 GD Rotterdam, The Netherlands; (M.C.M.S.); (E.d.B.); (Y.S.); (L.M.)
- Erasmus MC, Department of Molecular Genetics, University Medical Center Rotterdam, 3015 GD Rotterdam, The Netherlands
- CHUV Department of Oncology, University of Lausanne, CH-1066 Lausanne, Switzerland
- Correspondence: (C.W.G.M.L.); (K.M.P.)
| | - Kranthi M. Panth
- Erasmus MC, Department of Radiology & Nuclear Medicine, University Medical Center Rotterdam, 3015 GD Rotterdam, The Netherlands; (M.C.M.S.); (E.d.B.); (Y.S.); (L.M.)
- Erasmus MC, Department of Molecular Genetics, University Medical Center Rotterdam, 3015 GD Rotterdam, The Netherlands
- Correspondence: (C.W.G.M.L.); (K.M.P.)
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de Vor L, van Dijk B, van Kessel K, Kavanaugh JS, de Haas C, Aerts PC, Viveen MC, Boel EC, Fluit AC, Kwiecinski JM, Krijger GC, Ramakers RM, Beekman FJ, Dadachova E, Lam MGEH, Vogely HC, van der Wal BCH, van Strijp JAG, Horswill AR, Weinans H, Rooijakkers SHM. Human monoclonal antibodies against Staphylococcus aureus surface antigens recognize in vitro and in vivo biofilm. eLife 2022; 11:e67301. [PMID: 34989676 PMCID: PMC8751199 DOI: 10.7554/elife.67301] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2021] [Accepted: 12/06/2021] [Indexed: 12/22/2022] Open
Abstract
Implant-associated Staphylococcus aureus infections are difficult to treat because of biofilm formation. Bacteria in a biofilm are often insensitive to antibiotics and host immunity. Monoclonal antibodies (mAbs) could provide an alternative approach to improve the diagnosis and potential treatment of biofilm-related infections. Here, we show that mAbs targeting common surface components of S. aureus can recognize clinically relevant biofilm types. The mAbs were also shown to bind a collection of clinical isolates derived from different biofilm-associated infections (endocarditis, prosthetic joint, catheter). We identify two groups of antibodies: one group that uniquely binds S. aureus in biofilm state and one that recognizes S. aureus in both biofilm and planktonic state. Furthermore, we show that a mAb recognizing wall teichoic acid (clone 4497) specifically localizes to a subcutaneously implanted pre-colonized catheter in mice. In conclusion, we demonstrate the capacity of several human mAbs to detect S. aureus biofilms in vitro and in vivo.
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Affiliation(s)
- Lisanne de Vor
- Department of Medical Microbiology, University Medical Centre UtrechtUtrechtNetherlands
| | - Bruce van Dijk
- Department of Orthopedics, University Medical Centre UtrechtUtrechtNetherlands
| | - Kok van Kessel
- Department of Medical Microbiology, University Medical Centre UtrechtUtrechtNetherlands
| | - Jeffrey S Kavanaugh
- Department of Immunology and Microbiology, University of Colorado School of MedicineAuroraUnited States
| | - Carla de Haas
- Department of Medical Microbiology, University Medical Centre UtrechtUtrechtNetherlands
| | - Piet C Aerts
- Department of Medical Microbiology, University Medical Centre UtrechtUtrechtNetherlands
| | - Marco C Viveen
- Department of Medical Microbiology, University Medical Centre UtrechtUtrechtNetherlands
| | - Edwin C Boel
- Department of Medical Microbiology, University Medical Centre UtrechtUtrechtNetherlands
| | - Ad C Fluit
- Department of Medical Microbiology, University Medical Centre UtrechtUtrechtNetherlands
| | - Jakub M Kwiecinski
- Department of Immunology and Microbiology, University of Colorado School of MedicineAuroraUnited States
| | - Gerard C Krijger
- Department of Radiology and Nuclear Medicine, University Medical Centre UtrechtUtrechtNetherlands
| | - Ruud M Ramakers
- MILabs B.VUtrechtNetherlands
- Department of Translational Neuroscience, Brain Center Rudolf Magnus, University Medical CenterUtrechtNetherlands
- Department of Radiation Science and Technology, Delft University of TechnologyDelftNetherlands
| | - Freek J Beekman
- MILabs B.VUtrechtNetherlands
- Department of Translational Neuroscience, Brain Center Rudolf Magnus, University Medical CenterUtrechtNetherlands
- Department of Radiation Science and Technology, Delft University of TechnologyDelftNetherlands
| | - Ekaterina Dadachova
- College of Pharmacy and Nutrition, University of SaskatchewanSaskatoonCanada
| | - Marnix GEH Lam
- Department of Radiology and Nuclear Medicine, University Medical Centre UtrechtUtrechtNetherlands
| | - H Charles Vogely
- Department of Orthopedics, University Medical Centre UtrechtUtrechtNetherlands
| | - Bart CH van der Wal
- Department of Orthopedics, University Medical Centre UtrechtUtrechtNetherlands
| | - Jos AG van Strijp
- Department of Medical Microbiology, University Medical Centre UtrechtUtrechtNetherlands
| | - Alexander R Horswill
- Department of Immunology and Microbiology, University of Colorado School of MedicineAuroraUnited States
- Department of Veterans Affairs, Eastern Colorado Health Care SystemDenverUnited States
| | - Harrie Weinans
- Department of Orthopedics, University Medical Centre UtrechtUtrechtNetherlands
- Department of Biomechanical engineering, TU DelftDelftNetherlands
| | - Suzan HM Rooijakkers
- Department of Medical Microbiology, University Medical Centre UtrechtUtrechtNetherlands
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Feasibility of 125I-RGD uptake as a marker of angiogenesis after myocardial infarction. Ann Nucl Med 2021; 36:235-243. [PMID: 34837162 DOI: 10.1007/s12149-021-01695-4] [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: 08/10/2021] [Accepted: 11/10/2021] [Indexed: 10/19/2022]
Abstract
OBJECTIVE Angiogenesis is an important process facilitating the healing process after myocardial infarction. 125I-RGD imaging may be a promising candidate to image angiogenesis but may also detect inflammation. METHODS Left coronary artery was occluded for 30 min, followed by reperfusion in a rat model (n = 31). One, 3, 7 and 14 days, 1 and 2 months later, Triple-tracer autoradiography was performed. 125I-RGD (1.5 MBq) and 201Tl (15 MBq) were injected at 80 and 10 min before sacrifice. Left coronary artery was reoccluded and 99mTc-MIBI (150-180 MBq) was injected 1 min before sacrifice to verify the area at risk. Angiogenesis and macrophage infiltration were evaluated by immunohistochemical analysis with anti-alpha-smooth muscle actin and anti-CD68, respectively. RESULTS 125I-RGD uptake ratio in the area at risk was weak at day 3 (1.23 ± 0.23 but increased markedly and peaked at day 7 (2.27 ± 0.37) followed by a gradual reduction until 1 and 2 months later (1.93 ± 0.16 at 1 month, 1.58 ± 0.15 at 2 month). In the immunohistochemical analysis, copious staining of anti-CD68 cells was observed, with anti-SMA cells stained only minimally at day 3. The number of anti-CD68 cells was decreased significantly at day 7 but largely absent at 1 month. Anti-SMA positive cells peaked at day 7 and reduced gradually until 1 month. CONCLUSIONS Myocardial 125I-RGD uptake reflects angiogenesis rather than inflammation after myocardial infarction.
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20
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Uenomachi M, Takahashi M, Shimazoe K, Takahashi H, Kamada K, Orita T, Ogane K, Tsuji AB. Simultaneous in vivo imaging with PET and SPECT tracers using a Compton-PET hybrid camera. Sci Rep 2021; 11:17933. [PMID: 34504184 PMCID: PMC8429650 DOI: 10.1038/s41598-021-97302-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Accepted: 08/24/2021] [Indexed: 01/11/2023] Open
Abstract
Positron-emission tomography (PET) and single-photon-emission computed tomography (SPECT) are well-established nuclear-medicine imaging methods used in modern medical diagnoses. Combining PET with 18F-fluorodeoxyglucose (FDG) and SPECT with an 111In-labelled ligand provides clinicians with information about the aggressiveness and specific types of tumors. However, it is difficult to integrate a SPECT system with a PET system because SPECT requires a collimator. Herein, we describe a novel method that provides simultaneous imaging with PET and SPECT nuclides by combining PET imaging and Compton imaging. The latter is an imaging method that utilizes Compton scattering to visualize gamma rays over a wide range of energies without requiring a collimator. Using Compton imaging with SPECT nuclides, instead of the conventional SPECT imaging method, enables PET imaging and Compton imaging to be performed with one system. In this research, we have demonstrated simultaneous in vivo imaging of a tumor-bearing mouse injected with 18F-FDG and an 111In-antibody by using a prototype Compton-PET hybrid camera. We have succeeded in visualizing accumulations of 18F-FDG and 111In-antibody by performing PET imaging and Compton imaging simultaneously. As simultaneous imaging utilizes the same coordinate axes, it is expected to improve the accuracy of diagnoses.
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Affiliation(s)
- Mizuki Uenomachi
- Department of Nuclear Engineering and Management, School of Engineering, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo, Japan
| | - Miwako Takahashi
- National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, 4-9-1, Inage, Chiba, Chiba, Japan
| | - Kenji Shimazoe
- Department of Bioengineering, School of Engineering, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo, Japan. .,JST, PRESTO, Saitama, 332-0012, Japan.
| | - Hiroyuki Takahashi
- Institute of Engineering Innovation, School of Engineering, The University of Tokyo, 2-11-16, Yayoi, Bunkyo-ku, Tokyo, Japan
| | - Kei Kamada
- Tohoku University, 2-1-1, Katahira, Sendai, Miyagi, Japan
| | - Tadashi Orita
- Kavli Institute for the Physics and Mathematics of the Universe (WPI), The University of Tokyo, Kashiwa, Chiba, Japan
| | - Kenichiro Ogane
- Department of Surgery, Graduate School of Medicine, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo, Japan.,Department of Nuclear Medicine, International University of Health and Welfare, 1-4-3, Minato-ku, Tokyo, Japan
| | - Atsushi B Tsuji
- National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, 4-9-1, Inage, Chiba, Chiba, Japan
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21
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Nosrati Z, Esquinas PL, Rodríguez-Rodríguez C, Tran T, Maharaj A, Saatchi K, Häfeli UO. Simultaneous SPECT imaging with 123I and 125I - a practical approach to assessing a drug and its carrier at the same time with dual imaging. Int J Pharm 2021; 606:120884. [PMID: 34271154 DOI: 10.1016/j.ijpharm.2021.120884] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Revised: 07/07/2021] [Accepted: 07/11/2021] [Indexed: 11/24/2022]
Abstract
Radiolabeling of a drug with radioactive iodine is a good method to determine its pharmacokinetics and biodistribution in vivo that only minimally alters its physicochemical properties. With dual labeling, using the two radioactive iodine isotopes 123I and 125I, two different drugs can be evaluated at the same time, or one can follow both a drug and its drug delivery system using a single photon emission computed tomography (SPECT) imager. One difficulty is that the two radioisotopes have overlapping gamma spectra. Our aim was therefore to develop a technique that overcomes this problem and allows for quantitative analysis of the two radioisotopes present at varied isotope ratios. For this purpose, we developed a simple method that included scatter and attenuation corrections and fully compensated for 123I/125I crosstalk, and then tested it in phantom measurements. The method was applied to the study of an orally administered lipid formulation for the delivery of fenofibrate in rats. To directly compare a traditional study, where fenofibrate was determined in plasma samples to SPECT imaging with 123I-labeled fenofibrate and 125I-labeled triolein over 24 h, the drug concentrations were converted to standardized uptake values (SUVs), an unusual unit for pharmaceutical scientists, but the standard unit for radiologists. A generally good agreement between the traditional and the radioactive imaging method was found in the pharmacokinetics and biodistribution results. Small differences are discussed in detail. Overall, SPECT imaging is an excellent method to pilot a new formulation with just a few animals, replaces blood sampling, and can very quickly highlight potential administration problems, the excretion pathways and the kinetics. Furthermore, dual labeling with the two radioisotopes 123I and 125I clearly shows if a drug and its drug delivery system stay together when traveling through the body, if slow drug release takes place, and where degradation/excretion of the components occurs.
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Affiliation(s)
- Zeynab Nosrati
- Faculty of Pharmaceutical Sciences, University of British Columbia, 2405 Wesbrook Mall, Vancouver, British Columbia V6T 1Z3, Canada
| | - Pedro L Esquinas
- IBM Watson Health Imaging, 6303 Airport Road, Mississauga, Ontario, L4V 1R8 Canada
| | - Cristina Rodríguez-Rodríguez
- Faculty of Pharmaceutical Sciences, University of British Columbia, 2405 Wesbrook Mall, Vancouver, British Columbia V6T 1Z3, Canada; Department of Physics and Astronomy, University of British Columbia, 6224 Agricultural Road, Vancouver, British Columbia V6T 1Z1, Canada
| | - Thuy Tran
- Department of Pharmacy, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen 2100, Denmark
| | - Anil Maharaj
- Faculty of Pharmaceutical Sciences, University of British Columbia, 2405 Wesbrook Mall, Vancouver, British Columbia V6T 1Z3, Canada
| | - Katayoon Saatchi
- Faculty of Pharmaceutical Sciences, University of British Columbia, 2405 Wesbrook Mall, Vancouver, British Columbia V6T 1Z3, Canada.
| | - Urs O Häfeli
- Faculty of Pharmaceutical Sciences, University of British Columbia, 2405 Wesbrook Mall, Vancouver, British Columbia V6T 1Z3, Canada; Department of Pharmacy, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen 2100, Denmark.
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22
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Nguyen MP, Goorden MC, Ramakers RM, Beekman FJ. Efficient Monte-Carlo based system modelling for image reconstruction in preclinical pinhole SPECT. Phys Med Biol 2021; 66. [PMID: 34049291 DOI: 10.1088/1361-6560/ac0682] [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: 02/06/2021] [Accepted: 05/28/2021] [Indexed: 11/11/2022]
Abstract
The use of multi-pinhole collimation has enabled ultra-high-resolution imaging of SPECT and PET tracers in small animals. Key for obtaining high-quality images is the use of statistical iterative image reconstruction with accurate energy-dependent photon transport modelling through collimator and detector. This can be incorporated in a system matrix that contains the probabilities that a photon emitted from a certain voxel is detected at a specific detector pixel. Here we introduce a fast Monte-Carlo based (FMC-based) matrix generation method for pinhole imaging that is easy to apply to various radionuclides. The method is based on accelerated point source simulations combined with model-based interpolation to straightforwardly change or combine photon energies of the radionuclide of interest. The proposed method was evaluated for a VECTor PET-SPECT system with (i) a HE-UHR-M collimator and (ii) an EXIRAD-3D 3D autoradiography collimator. Both experimental scans with99mTc,111In, and123I, and simulated scans with67Ga and90Y were performed for evaluation. FMC was compared with two currently used approaches, one based on a set of point source measurements with99mTc (dubbed traditional method), and the other based on an energy-dependent ray-tracing simulation (ray-tracing method). The reconstruction results show better image quality when using FMC-based matrices than when applying the traditional or ray-tracing matrices in various cases. FMC-based matrices generalise better than the traditional matrices when imaging radionuclides with energies deviating too much from the energy used in the calibration and are computationally more efficient for very-high-resolution imaging than the ray-tracing matrices. In addition, FMC has the advantage of easily combining energies in a single matrix which is relevant when imaging radionuclides with multiple photopeak energies (e.g.67Ga and111In) or with a continuous energy spectrum (e.g.90Y). To conclude, FMC is an efficient, accurate, and versatile tool for creating system matrices for ultra-high-resolution pinhole SPECT.
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Affiliation(s)
- Minh Phuong Nguyen
- Section Biomedical Imaging, Delft University of Technology, Delft, The Netherlands
| | - Marlies C Goorden
- Section Biomedical Imaging, Delft University of Technology, Delft, The Netherlands
| | - Ruud M Ramakers
- Section Biomedical Imaging, Delft University of Technology, Delft, The Netherlands.,MILabs B.V., Utrecht, The Netherlands.,Department of Translational Neuroscience, Brain Center Rudolf Magnus, University Medical Center Utrecht, The Netherlands
| | - Freek J Beekman
- Section Biomedical Imaging, Delft University of Technology, Delft, The Netherlands.,MILabs B.V., Utrecht, The Netherlands.,Department of Translational Neuroscience, Brain Center Rudolf Magnus, University Medical Center Utrecht, The Netherlands
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23
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Esposito TVF, Stütz H, Rodríguez-Rodríguez C, Bergamo M, Charles L, Geczy R, Blackadar C, Kutter JP, Saatchi K, Häfeli UO. Preparation of Heat-Denatured Macroaggregated Albumin for Biomedical Applications Using a Microfluidics Platform. ACS Biomater Sci Eng 2021; 7:2823-2834. [PMID: 33826291 DOI: 10.1021/acsbiomaterials.1c00284] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Albumin is widely used in pharmaceutical applications to alter the pharmacokinetic profile, improve efficacy, or decrease the toxicity of active compounds. Various drug delivery systems using albumin have been reported, including microparticles. Macroaggregated albumin (MAA) is one of the more common forms of albumin microparticles, which is predominately used for lung perfusion imaging when labeled with radionuclide technetium-99m (99mTc). These microparticles are formed by heat-denaturing albumin in a bulk solution, making it very challenging to control the size and dispersity of the preparations (coefficient of variation, CV, ∼50%). In this work, we developed an integrated microfluidics platform to create more tunable and precise MAA particles, the so-called microfluidic-MAA (M2A2). The microfluidic chips, prepared using off-stoichiometry thiol-ene chemistry, consist of a flow-focusing region followed by an extended and water-heated curing channel (85 °C). M2A2 particles with diameters between 70 and 300 μm with CVs between 10 and 20% were reliably prepared by adjusting the flow rates of the dispersed and continuous phases. To demonstrate the pharmaceutical utility of M2A2, particles were labeled with indium-111 (111In) and their distribution was assessed in healthy mice using nuclear imaging. 111In-M2A2 behaved similarly to 99mTc-MAA, with lung uptake predominately observed early on followed by clearance over time by the reticuloendothelial and renal systems. Our microfluidic chip represents an elegant and controllable method to prepare albumin microparticles for biomedical applications.
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Affiliation(s)
- Tullio V F Esposito
- Faculty of Pharmaceutical Sciences, University of British Columbia, 2405 Wesbrook Mall, Vancouver, British Columbia V6T 1Z3, Canada.,Department of Pharmacy, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen, Denmark
| | - Helene Stütz
- Faculty of Pharmaceutical Sciences, University of British Columbia, 2405 Wesbrook Mall, Vancouver, British Columbia V6T 1Z3, Canada.,Department of Life Science, IMC University of Applied Sciences, Piaristengasse 1, 3500 Krems, Austria
| | - Cristina Rodríguez-Rodríguez
- Faculty of Pharmaceutical Sciences, University of British Columbia, 2405 Wesbrook Mall, Vancouver, British Columbia V6T 1Z3, Canada.,Department of Physics and Astronomy, Faculty of Science, University of British Columbia, 6224 Agricultural Road, Vancouver, British Columbia V6T 1Z3, Canada
| | - Marta Bergamo
- Faculty of Pharmaceutical Sciences, University of British Columbia, 2405 Wesbrook Mall, Vancouver, British Columbia V6T 1Z3, Canada
| | - Lovelyn Charles
- Faculty of Pharmaceutical Sciences, University of British Columbia, 2405 Wesbrook Mall, Vancouver, British Columbia V6T 1Z3, Canada
| | - Reka Geczy
- Faculty of Pharmaceutical Sciences, University of British Columbia, 2405 Wesbrook Mall, Vancouver, British Columbia V6T 1Z3, Canada.,Department of Pharmacy, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen, Denmark
| | - Colin Blackadar
- Faculty of Pharmaceutical Sciences, University of British Columbia, 2405 Wesbrook Mall, Vancouver, British Columbia V6T 1Z3, Canada
| | - Jörg P Kutter
- Department of Pharmacy, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen, Denmark
| | - Katayoun Saatchi
- Faculty of Pharmaceutical Sciences, University of British Columbia, 2405 Wesbrook Mall, Vancouver, British Columbia V6T 1Z3, Canada
| | - Urs O Häfeli
- Faculty of Pharmaceutical Sciences, University of British Columbia, 2405 Wesbrook Mall, Vancouver, British Columbia V6T 1Z3, Canada.,Department of Pharmacy, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen, Denmark
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24
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Suárez-García S, Esposito TVF, Neufeld-Peters J, Bergamo M, Yang H, Saatchi K, Schaffer P, Häfeli UO, Ruiz-Molina D, Rodríguez-Rodríguez C, Novio F. Hybrid Metal-Phenol Nanoparticles with Polydopamine-like Coating for PET/SPECT/CT Imaging. ACS APPLIED MATERIALS & INTERFACES 2021; 13:10705-10718. [PMID: 33635046 DOI: 10.1021/acsami.0c20612] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The validation of metal-phenolic nanoparticles (MPNs) in preclinical imaging studies represents a growing field of interest due to their versatility in forming predesigned structures with unique properties. Before MPNs can be used in medicine, their pharmacokinetics must be optimized so that accumulation in nontargeted organs is prevented and toxicity is minimized. Here, we report the fabrication of MPNs made of a coordination polymer core that combines In(III), Cu(II), and a mixture of the imidazole 1,4-bis(imidazole-1-ylmethyl)-benzene and the catechol 3,4-dihydroxycinnamic acid ligands. Furthermore, a phenolic-based coating was used as an anchoring platform to attach poly(ethylene glycol) (PEG). The resulting MPNs, with effective hydrodynamic diameters of around 120 nm, could be further derivatized with surface-embedded molecules, such as folic acid, to facilitate in vivo targeting and multifunctionality. The prepared MPNs were evaluated for in vitro plasma stability, cytotoxicity, and cell internalization and found to be biocompatible under physiological conditions. First, biomedical evaluations were then performed by intrinsically incorporating trace amounts of the radioactive metals 111In or 64Cu during the MPN synthesis directly into their polymeric matrix. The resulting particles, which had identical physicochemical properties to their nonradioactive counterparts, were used to perform in vivo single-photon emission computed tomography (SPECT) and positron emission tomography (PET) in tumor-bearing mice. The ability to incorporate multiple metals and radiometals into MPNs illustrates the diverse range of functional nanoparticles that can be prepared with this approach and broadens the scope of these nanoconstructs as multimodal preclinical imaging agents.
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Affiliation(s)
- Salvio Suárez-García
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and BIST, Campus UAB, Bellaterra 08193, Barcelona, Spain
| | - Tullio V F Esposito
- Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
- Department of Pharmacy, Faculty of Health and Medical Sciences, University of Copenhagen, 2100 Copenhagen, Denmark
| | - Jenna Neufeld-Peters
- Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
| | - Marta Bergamo
- Department of Pharmacy, Faculty of Health and Medical Sciences, University of Copenhagen, 2100 Copenhagen, Denmark
| | - Hua Yang
- TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada
| | - Katayoun Saatchi
- Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
| | - Paul Schaffer
- TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada
| | - Urs O Häfeli
- Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
- Department of Pharmacy, Faculty of Health and Medical Sciences, University of Copenhagen, 2100 Copenhagen, Denmark
| | - Daniel Ruiz-Molina
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and BIST, Campus UAB, Bellaterra 08193, Barcelona, Spain
| | - Cristina Rodríguez-Rodríguez
- Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
| | - Fernando Novio
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and BIST, Campus UAB, Bellaterra 08193, Barcelona, Spain
- Departament de Química, Universitat Autònoma de Barcelona (UAB), Campus UAB, Cerdanyola del Vallès 08193, Barcelona, Spain
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25
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Chen Y, Goorden MC, Beekman FJ. Automatic attenuation map estimation from SPECT data only for brain perfusion scans using convolutional neural networks. Phys Med Biol 2021; 66:065006. [PMID: 33571975 DOI: 10.1088/1361-6560/abe557] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
In clinical brain SPECT, correction for photon attenuation in the patient is essential to obtain images which provide quantitative information on the regional activity concentration per unit volume (kBq.[Formula: see text]). This correction generally requires an attenuation map ([Formula: see text] map) denoting the attenuation coefficient at each voxel which is often derived from a CT or MRI scan. However, such an additional scan is not always available and the method may suffer from registration errors. Therefore, we propose a SPECT-only-based strategy for [Formula: see text] map estimation that we apply to a stationary multi-pinhole clinical SPECT system (G-SPECT-I) for 99mTc-HMPAO brain perfusion imaging. The method is based on the use of a convolutional neural network (CNN) and was validated with Monte Carlo simulated scans. Data acquired in list mode was used to employ the energy information of both primary and scattered photons to obtain information about the tissue attenuation as much as possible. Multiple SPECT reconstructions were performed from different energy windows over a large energy range. Locally extracted 4D SPECT patches (three spatial plus one energy dimension) were used as input for the CNN which was trained to predict the attenuation coefficient of the corresponding central voxel of the patch. Results show that Attenuation Correction using the Ground Truth [Formula: see text] maps (GT-AC) or using the CNN estimated [Formula: see text] maps (CNN-AC) achieve comparable accuracy. This was confirmed by a visual assessment as well as a quantitative comparison; the mean deviation from the GT-AC when using the CNN-AC is within 1.8% for the standardized uptake values in all brain regions. Therefore, our results indicate that a CNN-based method can be an automatic and accurate tool for SPECT attenuation correction that is independent of attenuation data from other imaging modalities or human interpretations about head contours.
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Affiliation(s)
- Yuan Chen
- Section Biomedical Imaging, Department of Radiation, Science and Technology, Delft University of Technology, Delft, The Netherlands
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26
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Beekman FJ, Kamphuis C, Koustoulidou S, Ramakers RM, Goorden MC. Positron range-free and multi-isotope tomography of positron emitters. Phys Med Biol 2021; 66:065011. [PMID: 33578400 DOI: 10.1088/1361-6560/abe5fc] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Despite improvements in small animal PET instruments, many tracers cannot be imaged at sufficiently high resolutions due to positron range, while multi-tracer PET is hampered by the fact that all annihilation photons have equal energies. Here we realize multi-isotope and sub-mm resolution PET of isotopes with several mm positron range by utilizing prompt gamma photons that are commonly neglected. A PET-SPECT-CT scanner (VECTor/CT, MILabs, The Netherlands) equipped with a high-energy cluster-pinhole collimator was used to image 124I and a mix of 124I and 18F in phantoms and mice. In addition to positrons (mean range 3.4 mm) 124I emits large amounts of 603 keV prompt gammas that-aided by excellent energy discrimination of NaI-were selected to reconstruct 124I images that are unaffected by positron range. Photons detected in the 511 keV window were used to reconstruct 18F images. Images were reconstructed iteratively using an energy dependent matrix for each isotope. Correction of 18F images for contamination with 124I annihilation photons was performed by Monte Carlo based range modelling and scaling of the 124I prompt gamma image before subtracting it from the 18F image. Additionally, prompt gamma imaging was tested for 89Zr that emits very high-energy prompts (909 keV). In Derenzo resolution phantoms 0.75 mm rods were clearly discernable for 124I, 89Zr and for simultaneously acquired 124I and 18F imaging. Image quantification in phantoms with reservoirs filled with both 124I and 18F showed excellent separation of isotopes and high quantitative accuracy. Mouse imaging showed uptake of 124I in tiny thyroid parts and simultaneously injected 18F-NaF in bone structures. The ability to obtain PET images at sub-mm resolution both for isotopes with several mm positron range and for multi-isotope PET adds to many other unique capabilities of VECTor's clustered pinhole imaging, including simultaneous sub-mm PET-SPECT and theranostic high energy SPECT.
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Affiliation(s)
- F J Beekman
- Department of Radiation Science and Technology, Delft University of Technology, Mekelweg 15, 2629 JB Delft, The Netherlands. MILabs B.V., Heidelberglaan 100, 3584 CX, Utrecht, The Netherlands. Department of Translational Neuroscience, Brain Center Rudolf Magnus, University Medical Center Utrecht, The Netherlands
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27
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Groll AN, Levin CS. Instrumentation and Methods to Combine Small-Animal PET With Other Imaging Modalities. Mol Imaging 2021. [DOI: 10.1016/b978-0-12-816386-3.00005-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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28
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SPECT and SPECT/CT. Mol Imaging 2021. [DOI: 10.1016/b978-0-12-816386-3.00008-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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29
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Nguyen MP, Goorden MC, Beekman FJ. EXIRAD-HE: multi-pinhole high-resolution ex vivo imaging of high-energy isotopes. ACTA ACUST UNITED AC 2020; 65:225029. [DOI: 10.1088/1361-6560/abbb77] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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30
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Ozsahin I, Chen L, Könik A, King MA, Beekman FJ, Mok GSP. The clinical utilities of multi-pinhole single photon emission computed tomography. Quant Imaging Med Surg 2020; 10:2006-2029. [PMID: 33014732 PMCID: PMC7495312 DOI: 10.21037/qims-19-1036] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Accepted: 07/30/2020] [Indexed: 11/06/2022]
Abstract
Single photon emission computed tomography (SPECT) is an important imaging modality for various applications in nuclear medicine. The use of multi-pinhole (MPH) collimators can provide superior resolution-sensitivity trade-off when imaging small field-of-view compared to conventional parallel-hole and fan-beam collimators. Besides the very successful application in small animal imaging, there has been a resurgence of the use of MPH collimators for clinical cardiac and brain studies, as well as other small field-of-view applications. This article reviews the basic principles of MPH collimators and introduces currently available and proposed clinical MPH SPECT systems.
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Affiliation(s)
- Ilker Ozsahin
- Biomedical Imaging Laboratory, Department of Electrical and Computer Engineering, Faculty of Science and Technology, University of Macau, Macau, China
- Department of Biomedical Engineering, Faculty of Engineering, Near East University, Nicosia/TRNC, Mersin-10, Turkey
- DESAM Institute, Near East University, Nicosia/TRNC, Mersin-10, Turkey
| | - Ling Chen
- Biomedical Imaging Laboratory, Department of Electrical and Computer Engineering, Faculty of Science and Technology, University of Macau, Macau, China
| | - Arda Könik
- Department of Imaging, Dana Farber Cancer Institute, Boston, MA, USA
| | - Michael A. King
- Department of Radiology, University of Massachusetts Medical School, Worcester, MA, USA
| | - Freek J. Beekman
- Section of Biomedical Imaging, Department of Radiation Science and Technology, Delft University of Technology, Mekelweg 15, 2629 JB Delft, The Netherlands
- MILabs B.V, Heidelberglaan 100, 3584 CX, Utrecht, The Netherlands
- Department of Translational Neuroscience, Brain Center Rudolf Magnus, University Medical Center Utrecht, The Netherlands
| | - Greta S. P. Mok
- Biomedical Imaging Laboratory, Department of Electrical and Computer Engineering, Faculty of Science and Technology, University of Macau, Macau, China
- Center for Cognitive and Brain Sciences, Institute of Collaborative Innovation, University of Macau, Macau, China
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Nguyen MP, Ramakers RM, Kamphuis C, Koustoulidou S, Goorden MC, Beekman FJ. EXIRAD-3D: Fast automated three-dimensional autoradiography. Nucl Med Biol 2020; 86-87:59-65. [DOI: 10.1016/j.nucmedbio.2020.06.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Revised: 05/15/2020] [Accepted: 06/02/2020] [Indexed: 12/12/2022]
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33
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Goorden MC, Kamphuis C, Ramakers RM, Beekman FJ. Accelerated image reconstruction by a combined dual-matrix dual-voxel approach. ACTA ACUST UNITED AC 2020; 65:105014. [DOI: 10.1088/1361-6560/ab82e9] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Miyaoka RS, Lehnert A. Small animal PET: a review of what we have done and where we are going. Phys Med Biol 2020; 65. [PMID: 32357344 DOI: 10.1088/1361-6560/ab8f71] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Accepted: 05/01/2020] [Indexed: 02/07/2023]
Abstract
Small animal research is an essential tool in studying both pharmaceutical biodistributions and disease progression over time. Furthermore, through the rapid development of in vivo imaging technology over the last few decades, small animal imaging (also referred to as preclinical imaging) has become a mainstay for all fields of biologic research and a center point for most preclinical cancer research. Preclinical imaging modalities include optical, MRI and MRS, microCT, small animal PET, ultrasound, and photoacoustic, each with their individual strengths. The strong points of small animal PET are its translatability to the clinic; its quantitative imaging capabilities; its whole-body imaging ability to dynamically trace functional/biochemical processes; its ability to provide useful images with only nano- to pico‑ molar concentrations of administered compounds; and its ability to study animals serially over time. This review paper gives an overview of the development and evolution of small animal PET imaging. It provides an overview of detector designs; system configurations; multimodality PET imaging systems; image reconstruction and analysis tools; and an overview of research and commercially available small animal PET systems. It concludes with a look toward developing technologies/methodologies that will further enhance the impact of small animal PET imaging on medical research in the future.
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Affiliation(s)
- Robert S Miyaoka
- Radiology, University of Washington, Seattle, Washington, UNITED STATES
| | - Adrienne Lehnert
- Radiology, University of Washington, Seattle, Washington, UNITED STATES
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Imaging of inflammatory cellular protagonists in human atherosclerosis: a dual-isotope SPECT approach. Eur J Nucl Med Mol Imaging 2020; 47:2856-2865. [PMID: 32291511 PMCID: PMC7567726 DOI: 10.1007/s00259-020-04776-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Accepted: 03/18/2020] [Indexed: 01/20/2023]
Abstract
Purpose Atherosclerotic plaque development and progression signifies a complex inflammatory disease mediated by a multitude of proinflammatory leukocyte subsets. Using single photon emission computed tomography (SPECT) coupled with computed tomography (CT), this study tested a new dual-isotope acquisition protocol to assess each radiotracer’s capability to identify plaque phenotype and inflammation levels pertaining to leukocytes expressing leukocyte function-associated antigen-1 (LFA-1) and the leukocyte subset of proinflammatory macrophages expressing somatostatin receptor subtype-2 (SST2). Individual radiotracer uptake was quantified and the presence of corresponding immunohistological cell markers was assessed. Methods Human symptomatic carotid plaque segments were obtained from endarterectomy. Segments were incubated in dual-isotope radiotracers [111In]In-DOTA-butylamino-NorBIRT ([111In]In-Danbirt) and [99mTc]Tc-[N0–14,Asp0,Tyr3]-octreotate ([99mTc]Tc-Demotate 2) before scanning with SPECT/CT. Plaque phenotype was classified as pathological intimal thickening, fibrous cap atheroma or fibrocalcific using histology sections based on distinct morphological characteristics. Plaque segments were subsequently immuno-stained with LFA-1 and SST2 and quantified in terms of positive area fraction and compared against the corresponding SPECT images. Results Focal uptake of co-localising dual-radiotracers identified the heterogeneous distribution of inflamed regions in the plaques which co-localised with positive immuno-stained regions of LFA-1 and SST2. [111In]In-Danbirt and [99mTc]Tc-Demotate 2 uptake demonstrated a significant positive correlation (r = 0.651; p = 0.001). Fibrous cap atheroma plaque phenotype correlated with the highest [111In]In-Danbirt and [99mTc]Tc-Demotate 2 uptake compared with fibrocalcific plaques and pathological intimal thickening phenotypes, in line with the immunohistological analyses. Conclusion A dual-isotope acquisition protocol permits the imaging of multiple leukocyte subsets and the pro-inflammatory macrophages simultaneously in atherosclerotic plaque tissue. [111In]In-Danbirt may have added value for assessing the total inflammation levels in atherosclerotic plaques in addition to classifying plaque phenotype.
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Chen Y, Goorden MC, Vastenhouw B, Beekman FJ. Optimized sampling for high resolution multi-pinhole brain SPECT with stationary detectors. ACTA ACUST UNITED AC 2020; 65:015002. [DOI: 10.1088/1361-6560/ab5bc6] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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Abstract
SPECT and PET are nuclear tomographic imaging modalities that visualize functional information based on the accumulation of radioactive tracer molecules. However, SPECT and PET lack anatomical information, which has motivated their combination with an anatomical imaging modality such as CT or MRI. This chapter begins with an overview over the fundamental physics of SPECT and PET followed by a presentation of the respective detector technologies, including detection requirements, principles and different detector concepts. The reader is subsequently provided with an introduction into hybrid imaging concepts, before a dedicated section presents the challenges that arise when hybridizing SPECT or PET with MRI, namely, mutual distortions of the different electromagnetic fields in MRI on the nuclear imaging system and vice versa. The chapter closes with an overview about current hybrid imaging systems of both clinical and preclinical kind. Finally, future developments in hybrid SPECT and PET technology are discussed.
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Affiliation(s)
- Teresa Nolte
- Physics of Molecular Imaging Systems, Experimental Molecular Imaging, RWTH Aachen University, Aachen, Germany
| | - Nicolas Gross-Weege
- Physics of Molecular Imaging Systems, Experimental Molecular Imaging, RWTH Aachen University, Aachen, Germany
| | - Volkmar Schulz
- Physics of Molecular Imaging Systems, Experimental Molecular Imaging, RWTH Aachen University, Aachen, Germany.
- Hyperion Hybrid Imaging Systems GmbH, Aachen, Germany.
- Fraunhofer Institute for Digital Medicine MEVIS, Bremen, Germany.
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Van Oosterom MN, Rietbergen DDD, Welling MM, Van Der Poel HG, Maurer T, Van Leeuwen FWB. Recent advances in nuclear and hybrid detection modalities for image-guided surgery. Expert Rev Med Devices 2019; 16:711-734. [PMID: 31287715 DOI: 10.1080/17434440.2019.1642104] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Introduction: Radioguided surgery is an ever-evolving part of nuclear medicine. In fact, this nuclear medicine sub-discipline actively bridges non-invasive molecular imaging with surgical care. Next to relying on the availability of radio- and bimodal-tracers, the success of radioguided surgery is for a large part dependent on the imaging modalities and imaging concepts available for the surgical setting. With this review, we have aimed to provide a comprehensive update of the most recent advances in the field. Areas covered: We have made an attempt to cover all aspects of radioguided surgery: 1) the use of radioisotopes that emit γ, β+, and/or β- radiation, 2) hardware developments ranging from probes to 2D cameras and even the use of advanced 3D interventional imaging solutions, and 3) multiplexing solutions such as dual-isotope detection or combined radionuclear and optical detection. Expert opinion: Technical refinements in the field of radioguided surgery should continue to focus on supporting its implementation in the increasingly complex minimally invasive surgical setting, e.g. by accommodating robot-assisted laparoscopic surgery. In addition, hybrid concepts that integrate the use of radioisotopes with other image-guided surgery modalities such as fluorescence or ultrasound are likely to expand in the future.
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Affiliation(s)
- Matthias N Van Oosterom
- a Interventional Molecular Imaging laboratory, Department of Radiology, Leiden University Medical Center , Leiden , the Netherlands.,b Department of Urology, Netherlands Cancer Institute-Antoni van Leeuwenhoek Hospital , Amsterdam , the Netherlands
| | - Daphne D D Rietbergen
- a Interventional Molecular Imaging laboratory, Department of Radiology, Leiden University Medical Center , Leiden , the Netherlands.,c Department of Radiology, Section Nuclear Medicine, Leiden University Medical Center , Leiden , the Netherlands
| | - Mick M Welling
- a Interventional Molecular Imaging laboratory, Department of Radiology, Leiden University Medical Center , Leiden , the Netherlands
| | - Henk G Van Der Poel
- b Department of Urology, Netherlands Cancer Institute-Antoni van Leeuwenhoek Hospital , Amsterdam , the Netherlands
| | - Tobias Maurer
- d Martini-Clinic, University Medical Center Hamburg-Eppendorf , Hamburg , Germany
| | - Fijs W B Van Leeuwen
- a Interventional Molecular Imaging laboratory, Department of Radiology, Leiden University Medical Center , Leiden , the Netherlands.,b Department of Urology, Netherlands Cancer Institute-Antoni van Leeuwenhoek Hospital , Amsterdam , the Netherlands.,e Orsi Academy , Melle , Belgium
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Nguyen MP, Goorden MC, Kamphuis C, Beekman FJ. Evaluation of pinhole collimator materials for micron-resolution ex vivo SPECT. ACTA ACUST UNITED AC 2019; 64:105017. [DOI: 10.1088/1361-6560/ab1618] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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40
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Meester EJ, Krenning BJ, de Swart J, Segbers M, Barrett HE, Bernsen MR, Van der Heiden K, de Jong M. Perspectives on Small Animal Radionuclide Imaging; Considerations and Advances in Atherosclerosis. Front Med (Lausanne) 2019; 6:39. [PMID: 30915335 PMCID: PMC6421263 DOI: 10.3389/fmed.2019.00039] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Accepted: 02/11/2019] [Indexed: 12/20/2022] Open
Abstract
This review addresses nuclear SPECT and PET imaging in small animals in relation to the atherosclerotic disease process, one of our research topics of interest. Imaging of atherosclerosis in small animal models is challenging, as it operates at the limits of current imaging possibilities regarding sensitivity, and spatial resolution. Several topics are discussed, including technical considerations that apply to image acquisition, reconstruction, and analysis. Moreover, molecules developed for or applied in these small animal nuclear imaging studies are listed, including target-directed molecules, useful for imaging organs or tissues that have elevated expression of the target compared to other tissues, and molecules that serve as substrates for metabolic processes. Differences between animal models and human pathophysiology that should be taken into account during translation from animal to patient as well as differences in tracer behavior in animal vs. man are also described. Finally, we give a future outlook on small animal radionuclide imaging in atherosclerosis, followed by recommendations. The challenges and solutions described might be applicable to other research fields of health and disease as well.
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Affiliation(s)
- Eric J Meester
- Department of Radiology and Nuclear Medicine, Erasmus Medical Center, Rotterdam, Netherlands.,Department of Biomedical Engineering, Thorax Center, Erasmus Medical Center, Rotterdam, Netherlands
| | - B J Krenning
- Department of Cardiology, Thorax Center, Erasmus Medical Center, Rotterdam, Netherlands
| | - J de Swart
- Department of Radiology and Nuclear Medicine, Erasmus Medical Center, Rotterdam, Netherlands
| | - M Segbers
- Department of Radiology and Nuclear Medicine, Erasmus Medical Center, Rotterdam, Netherlands
| | - H E Barrett
- Department of Radiology and Nuclear Medicine, Erasmus Medical Center, Rotterdam, Netherlands.,Department of Biomedical Engineering, Thorax Center, Erasmus Medical Center, Rotterdam, Netherlands
| | - M R Bernsen
- Department of Radiology and Nuclear Medicine, Erasmus Medical Center, Rotterdam, Netherlands
| | - K Van der Heiden
- Department of Biomedical Engineering, Thorax Center, Erasmus Medical Center, Rotterdam, Netherlands
| | - Marion de Jong
- Department of Radiology and Nuclear Medicine, Erasmus Medical Center, Rotterdam, Netherlands
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Knight JC, Mosley MJ, Kersemans V, Dias GM, Allen PD, Smart S, Cornelissen B. Dual-isotope imaging allows in vivo immunohistochemistry using radiolabelled antibodies in tumours. Nucl Med Biol 2019; 70:14-22. [PMID: 30825614 PMCID: PMC6599172 DOI: 10.1016/j.nucmedbio.2019.01.010] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Revised: 01/23/2019] [Accepted: 01/30/2019] [Indexed: 01/18/2023]
Abstract
While radiolabelled antibodies have found great utility as PET and SPECT imaging agents in oncological investigations, a notable shortcoming of these agents is their propensity to accumulate non-specifically within tumour tissue. The degree of this non-specific contribution to overall tumour uptake is highly variable and can ultimately lead to false conclusions. Therefore, in an effort to obtain a reliable measure of inter-individual differences in non-specific tumour uptake of radiolabelled antibodies, we demonstrate that the use of dual-isotope imaging overcomes this issue, enables true quantification of epitope expression levels, and allows non-invasive in vivo immunohistochemistry. The approach involves co-administration of (i) an antigen-targeting antibody labelled with zirconium-89 (89Zr), and (ii) an isotype-matched non-specific control IgG antibody labelled with indium-111 (111In). As an example, the anti-HER2 antibody trastuzumab was radiolabelled with 89Zr, and co-administered intravenously together with its 111In-labelled non-specific counterpart to mice bearing human breast cancer xenografts with differing HER2 expression levels (MDA-MB-468 [HER2-negative], MDA-MB-231 [low-HER2], MDA-MB-231/H2N [medium-HER2], and SKBR3 [high-HER2]). Simultaneous PET/SPECT imaging using a MILabs Vector4 small animal scanner revealed stark differences in the intratumoural distribution of [89Zr]Zr-trastuzumab and [111In]In-IgG, highlighting regions of HER2-mediated uptake and non-specific uptake, respectively. Normalisation of the tumour uptake values and tumour-to-blood ratios obtained with [89Zr]Zr-trastuzumab against those obtained with [111In]In-IgG yielded values which were most strongly correlated (R = 0.94; P = 0.02) with HER2 expression levels for each breast cancer type determined by Western blot and in vitro saturation binding assays, but not non-normalised uptake values. Normalised intratumoural distribution of [89Zr]Zr-trastuzumab correlated well with intratumoural heterogeneity HER2 expression.
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Affiliation(s)
- James C Knight
- CRUK/MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, United Kingdom
| | - Michael J Mosley
- CRUK/MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, United Kingdom
| | - Veerle Kersemans
- CRUK/MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, United Kingdom
| | - Gemma M Dias
- CRUK/MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, United Kingdom
| | - P Danny Allen
- CRUK/MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, United Kingdom
| | - Sean Smart
- CRUK/MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, United Kingdom
| | - Bart Cornelissen
- CRUK/MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, United Kingdom.
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Esquinas PL, Rodríguez-Rodríguez C, Esposito TVF, Harboe J, Bergamo M, Celler A, Saatchi K, Sossi V, Häfeli UO. Dual SPECT imaging of 111In and 67Ga to simultaneously determine in vivo the pharmacokinetics of different radiopharmaceuticals: a quantitative tool in pre-clinical research. ACTA ACUST UNITED AC 2018; 63:235029. [DOI: 10.1088/1361-6560/aaef63] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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43
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Chen Y, Vastenhouw B, Wu C, Goorden MC, Beekman FJ. Optimized image acquisition for dopamine transporter imaging with ultra-high resolution clinical pinhole SPECT. ACTA ACUST UNITED AC 2018; 63:225002. [DOI: 10.1088/1361-6560/aae76c] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
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44
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Wakabayashi H, Taki J, Inaki A, Hiromasa T, Yamase T, Akatani N, Okuda K, Shibutani T, Shiba K, Kinuya S. Prognostic Value of Early Evaluation of Left Ventricular Dyssynchrony After Myocardial Infarction. Mol Imaging Biol 2018; 21:654-659. [DOI: 10.1007/s11307-018-1279-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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Georgiou M, Fysikopoulos E, Mikropoulos K, Fragogeorgi E, Loudos G. Characterization of "γ-Eye": a Low-Cost Benchtop Mouse-Sized Gamma Camera for Dynamic and Static Imaging Studies. Mol Imaging Biol 2018; 19:398-407. [PMID: 27730469 DOI: 10.1007/s11307-016-1011-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
PURPOSE Several preclinical imaging systems are commercially available, but their purchase and maintenance costs make them unaffordable for the majority of small- and medium-sized groups. Taking into account the needs of average users, we developed "γ-eye", a mouse-sized, benchtop γ-camera suitable for in vivo scintigraphic imaging. PROCEDURES The γ-eye is based on two position-sensitive photomultiplier tubes, coupled to a CsI(Na) pixelated scintillator and a low-energy lead collimator with parallel hexagonal holes. RESULTS The spatial resolution of the system is 2 mm at 0 mm. The energy resolution is 26 % at 140 keV and the maximum recorded sensitivity 210 cps/MBq. The system was evaluated in a proof-of-concept animal study, using three different clinical Tc-99m-labeled radiopharmaceuticals. Phantom and animal studies demonstrate its ability to provide semiquantitative results even for short scans. CONCLUSIONS Systems' performance, dimensions, and cost make γ-eye a unique solution for efficient whole-body mouse nuclear imaging.
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Affiliation(s)
| | | | - Konstantinos Mikropoulos
- Department of Biomedical Engineering, Technological Educational Institute of Athens, Athens, Greece
| | - Eirini Fragogeorgi
- National Centre for Scientific Research NCSR "Demokritos", Institute of Nuclear and Radiological Sciences and Technology, Energy and Safety, Athens, Greece
| | - George Loudos
- Department of Biomedical Engineering, Technological Educational Institute of Athens, Athens, Greece.,National Centre for Scientific Research NCSR "Demokritos", Institute of Nuclear and Radiological Sciences and Technology, Energy and Safety, Athens, Greece
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Crawford JR, Robertson AKH, Yang H, Rodríguez-Rodríguez C, Esquinas PL, Kunz P, Blinder S, Sossi V, Schaffer P, Ruth TJ. Evaluation of209At as a theranostic isotope for209At-radiopharmaceutical development using high-energy SPECT. ACTA ACUST UNITED AC 2018; 63:045025. [DOI: 10.1088/1361-6560/aaaa95] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Yoshii Y, Yoshimoto M, Matsumoto H, Furukawa T, Zhang MR, Inubushi M, Tsuji AB, Fujibayashi Y, Higashi T, Saga T. 64Cu-ATSM internal radiotherapy to treat tumors with bevacizumab-induced vascular decrease and hypoxia in human colon carcinoma xenografts. Oncotarget 2017; 8:88815-88826. [PMID: 29179478 PMCID: PMC5687648 DOI: 10.18632/oncotarget.21323] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2017] [Accepted: 08/17/2017] [Indexed: 11/25/2022] Open
Abstract
Bevacizumab, an anti-vascular endothelial growth factor (VEGF) antibody, is an antiangiogenic agent clinically used for various cancers. However, repeated use of this agent leads to tumor-decreased vascularity and hypoxia with activation of an HIF-1 signaling pathway, which results in drug delivery deficiency and induction of malignant behaviors in tumors. Here, we developed a novel strategy to treat tumors with bevacizumab-induced vascular decrease and hypoxia using 64Cu-diacetyl-bis (N4-methylthiosemicarbazone) (64Cu-ATSM), a potential theranostic agent, which possesses high tissue permeability and can target over-reduced conditions under hypoxia in tumors, with a human colon carcinoma HT-29 tumor-bearing mouse model. The long-term treatment with bevacizumab caused decreased blood vessel density and activation of an HIF-1 signaling pathway; increased uptake of 64Cu-ATSM was also observed despite limited blood vessel density in HT-29 tumors. In vivo high-resolution SPECT/PET/CT imaging confirmed reduced vascularity and increased proportion of 64Cu-ATSM uptake areas within the bevacizumab-treated tumors. 64Cu-ATSM therapy was effective to inhibit tumor growth and prolong survival of the bevacizumab-treated tumor-bearing mice without major adverse effects. In conclusion, 64Cu-ATSM therapy effectively enhanced anti-tumor effects in tumors with bevacizumab-induced vascular decrease and hypoxia. 64Cu-ATSM therapy could represent a novel approach as an add-on to antiangiogenic therapy.
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Affiliation(s)
- Yukie Yoshii
- National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan
| | - Mitsuyoshi Yoshimoto
- Division of Functional Imaging, National Cancer Center Hospital East, Kashiwa, Japan
| | | | - Takako Furukawa
- National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan.,Department of Radiological and Medical Laboratory Sciences, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Ming-Rong Zhang
- National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan
| | - Masayuki Inubushi
- Department of Nuclear Medicine, Kawasaki Medical School, Kurashiki, Japan
| | - Atsushi B Tsuji
- National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan
| | - Yasuhisa Fujibayashi
- National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan
| | - Tatsuya Higashi
- National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan
| | - Tsuneo Saga
- National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan.,Department of Diagnostic Radiology, Kyoto University Hospital, Kyoto, Japan
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DiFilippo FP. Design of a Tri-PET collimator for high-resolution whole-body mouse imaging. Med Phys 2017; 44:4230-4238. [PMID: 28556264 DOI: 10.1002/mp.12379] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Revised: 03/30/2017] [Accepted: 05/22/2017] [Indexed: 11/10/2022] Open
Abstract
PURPOSE Tri-PET refers to high-resolution 511-keV emission tomography using a multipinhole collimator in conjunction with lower resolution PET detectors operating in coincidence mode. Tri-PET is unique in that three spatial locations are associated with each event (two detector coordinates and one pinhole location). Spatial resolution and sensitivity are similar to that of 511-keV SPECT and are governed mainly by the collimator design. However because of a third spatial location in Tri-PET, the line-of-response is overdetermined. This feature permits new opportunities in data processing which impact collimator design. In particular, multiplexing can be avoided since the coincidence data identify the pinhole through which the photon passed. In this paper, the principles of Tri-PET collimator design are reviewed and then applied to the case of high-resolution imaging of a small animal in a clinical PET scanner. METHODS The design of a 148-pinhole collimator for whole-body imaging of a mouse is presented. Two pinhole designs were investigated: knife-edge pinholes with 1.1 mm aperture and novel hyperboloidal pinholes with 1.2 mm aperture, both having 18° cone angle. The pinhole configuration is unfocused, covering a whole-body mouse field of view with nearly uniform sensitivity. Computer simulations were performed of a micro hot rods phantom imaged with this collimator in a clinical PET scanner. Sensitivity was estimated by simulating a point source centered on-axis at locations spanning a 70-mm axial range, similar to the NEMA NU-4 standard for whole-body mouse imaging. RESULTS Reconstructed images of the hot rods phantom demonstrated the ability to resolve 1.1 mm structures with the knife-edge pinholes and 1.0 mm structures with the hyperboloidal pinholes. Sensitivity was found to be 0.093% and 0.054% for the knife-edge and hyperboloidal pinholes, respectively. CONCLUSIONS With a properly designed multipinhole collimator, high-resolution and acceptable sensitivity are achievable with Tri-PET using ordinary clinical PET detectors.
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Affiliation(s)
- Frank P DiFilippo
- Department of Nuclear Medicine, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH, 44195, USA
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Park SM, Aalipour A, Vermesh O, Yu JH, Gambhir SS. Towards clinically translatable in vivo nanodiagnostics. NATURE REVIEWS. MATERIALS 2017; 2:17014. [PMID: 29876137 PMCID: PMC5985817 DOI: 10.1038/natrevmats.2017.14] [Citation(s) in RCA: 208] [Impact Index Per Article: 29.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Nanodiagnostics as a field makes use of fundamental advances in nanobiotechnology to diagnose, characterize and manage disease at the molecular scale. As these strategies move closer to routine clinical use, a proper understanding of different imaging modalities, relevant biological systems and physical properties governing nanoscale interactions is necessary to rationally engineer next-generation bionanomaterials. In this Review, we analyse the background physics of several clinically relevant imaging modalities and their associated sensitivity and specificity, provide an overview of the materials currently used for in vivo nanodiagnostics, and assess the progress made towards clinical translation. This work provides a framework for understanding both the impressive progress made thus far in the nanodiagnostics field as well as presenting challenges that must be overcome to obtain widespread clinical adoption.
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Affiliation(s)
- Seung-Min Park
- Department of Radiology, Stanford University School of Medicine
- Molecular Imaging Program at Stanford, Stanford University School of Medicine, 300 Pasteur Drive, Stanford, California 94305, USA
| | - Amin Aalipour
- Department of Radiology, Stanford University School of Medicine
- Molecular Imaging Program at Stanford, Stanford University School of Medicine, 300 Pasteur Drive, Stanford, California 94305, USA
| | - Ophir Vermesh
- Department of Radiology, Stanford University School of Medicine
- Molecular Imaging Program at Stanford, Stanford University School of Medicine, 300 Pasteur Drive, Stanford, California 94305, USA
| | - Jung Ho Yu
- Department of Radiology, Stanford University School of Medicine
- Molecular Imaging Program at Stanford, Stanford University School of Medicine, 300 Pasteur Drive, Stanford, California 94305, USA
| | - Sanjiv S Gambhir
- Department of Radiology, Stanford University School of Medicine
- Molecular Imaging Program at Stanford, Stanford University School of Medicine, 300 Pasteur Drive, Stanford, California 94305, USA
- Canary Center at Stanford for Cancer Early Detection, Stanford University School of Medicine, 3155 Porter Drive, Palo Alto, California 94304, USA
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50
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Robertson AKH, Ramogida CF, Rodríguez-Rodríguez C, Blinder S, Kunz P, Sossi V, Schaffer P. Multi-isotope SPECT imaging of the 225Ac decay chain: feasibility studies. Phys Med Biol 2017; 62:4406-4420. [PMID: 28362640 DOI: 10.1088/1361-6560/aa6a99] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Effective use of the [Formula: see text] decay chain in targeted internal radioimmunotherapy requires the retention of both [Formula: see text] and progeny isotopes at the target site. Imaging-based pharmacokinetic tests of these pharmaceuticals must therefore separately yet simultaneously image multiple isotopes that may not be colocalized despite being part of the same decay chain. This work presents feasibility studies demonstrating the ability of a microSPECT/CT scanner equipped with a high energy collimator to simultaneously image two components of the [Formula: see text] decay chain: [Formula: see text] (218 keV) and [Formula: see text] (440 keV). Image quality phantoms were used to assess the performance of two collimators for simultaneous [Formula: see text] and [Formula: see text] imaging in terms of contrast and noise. A hotrod resolution phantom containing clusters of thin rods with diameters ranging between 0.85 and 1.70 mm was used to assess resolution. To demonstrate ability to simultaneously image dynamic [Formula: see text] and [Formula: see text] activity distributions, a phantom containing a [Formula: see text] generator from [Formula: see text] was imaged. These tests were performed with two collimators, a high-energy ultra-high resolution (HEUHR) collimator and an ultra-high sensitivity (UHS) collimator. Values consistent with activity concentrations determined independently via gamma spectroscopy were observed in high activity regions of the images. In hotrod phantom images, the HEUHR collimator resolved all rods for both [Formula: see text] and [Formula: see text] images. With the UHS collimator, no rods were resolvable in [Formula: see text] images and only rods ⩾1.3 mm were resolved in [Formula: see text] images. After eluting the [Formula: see text] generator, images accurately visualized the reestablishment of transient equilibrium of the [Formula: see text] decay chain. The feasibility of evaluating the pharmacokinetics of the [Formula: see text] decay chain in vivo has been demonstrated. This presented method requires the use of a high-performance high-energy collimator.
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Affiliation(s)
- A K H Robertson
- Life Sciences Division, TRIUMF, 4004 Wesbrook Mall, Vancouver BC, V6T 2A3, Canada. Department of Physics and Astronomy, University of British Columbia (UBC), 6224 Agronomy Road, Vancouver BC, V6T 1Z1, Canada
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