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Brender JR, Saida Y, Devasahayam N, Krishna MC, Kishimoto S. Hypoxia Imaging As a Guide for Hypoxia-Modulated and Hypoxia-Activated Therapy. Antioxid Redox Signal 2022; 36:144-159. [PMID: 34428981 PMCID: PMC8856011 DOI: 10.1089/ars.2021.0176] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Accepted: 08/16/2021] [Indexed: 01/03/2023]
Abstract
Significance: Oxygen imaging techniques, which can probe the spatiotemporal heterogeneity of tumor oxygenation, could be of significant clinical utility in radiation treatment planning and in evaluating the effectiveness of hypoxia-activated prodrugs. To fulfill these goals, oxygen imaging techniques should be noninvasive, quantitative, and capable of serial imaging, as well as having sufficient temporal resolution to detect the dynamics of tumor oxygenation to distinguish regions of chronic and acute hypoxia. Recent Advances: No current technique meets all these requirements, although all have strengths in certain areas. The current status of positron emission tomography (PET)-based hypoxia imaging, oxygen-enhanced magnetic resonance imaging (MRI), 19F MRI, and electron paramagnetic resonance (EPR) oximetry are reviewed along with their strengths and weaknesses for planning hypoxia-guided, intensity-modulated radiation therapy and detecting treatment response for hypoxia-targeted prodrugs. Critical Issues: Spatial and temporal resolution emerges as a major concern for these areas along with specificity and quantitative response. Although multiple oxygen imaging techniques have reached the investigative stage, clinical trials to test the therapeutic effectiveness of hypoxia imaging have been limited. Future Directions: Imaging elements of the redox environment besides oxygen by EPR and hyperpolarized MRI may have a significant impact on our understanding of the basic biology of the reactive oxygen species response and may extend treatment possibilities.
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Affiliation(s)
- Jeffrey R. Brender
- Radiation Biology Branch, Center for Cancer Research, National
Institutes of Health, Bethesda, Maryland, USA
| | - Yu Saida
- Radiation Biology Branch, Center for Cancer Research, National
Institutes of Health, Bethesda, Maryland, USA
| | - Nallathamby Devasahayam
- Radiation Biology Branch, Center for Cancer Research, National
Institutes of Health, Bethesda, Maryland, USA
| | - Murali C. Krishna
- Radiation Biology Branch, Center for Cancer Research, National
Institutes of Health, Bethesda, Maryland, USA
| | - Shun Kishimoto
- Radiation Biology Branch, Center for Cancer Research, National
Institutes of Health, Bethesda, Maryland, USA
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Nishihara K, Hori K, Saito T, Omori T, Sunakawa H, Minamide T, Suyama M, Yamamoto Y, Yoda Y, Shinmura K, Ikematsu H, Yano T. A study of evaluating specific tissue oxygen saturation values of gastrointestinal tumors by removing adherent substances in oxygen saturation imaging. PLoS One 2021; 16:e0243165. [PMID: 33411775 PMCID: PMC7790263 DOI: 10.1371/journal.pone.0243165] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Accepted: 11/16/2020] [Indexed: 11/19/2022] Open
Abstract
OBJECTIVES Oxygen saturation (OS) imaging is a new method of endoscopic imaging that has clinical applications in oncology which can directly measure tissue oxygen saturation (Sto2) of the surface of gastrointestinal tract without any additional drugs or devices. This imaging technology is expected to contribute to research into cancer biology which leads to clinical benefit such as prediction to efficacy of chemotherapy or radiotherapy. However, adherent substances on tumors such as blood and white coating, pose a challenge for accurate measurements of the StO2 values in tumors. The aim of this study was to develop algorithms for discriminating between the tumors and their adherent substances, and to investigate whether it is possible to evaluate the tumor specific StO2 values excluding adherent substances during OS imaging. METHODS We plotted areas of tumors and their adherent substances using white-light images of 50 upper digestive tumors: blood (68 plots); reddish tumor (83 plots); white coating (89 plots); and whitish tumor (79 plots). Scatter diagrams and discriminating algorithms using spectrum signal intensity values were constructed and verified using validation datasets. StO2 values were compared between the tumors and tumor adherent substances using OS images of gastrointestinal tumors. RESULTS The discriminating algorithms and their accuracy rates (AR) were as follows: blood vs. reddish tumor: Y> - 4.90X+7.13 (AR: 95.9%) and white coating vs. whitish tumor: Y< -0.52X+0.17 (AR: 96.0%). The StO2 values (median, [range]) were as follows: blood, 79.3% [37.8%-100.0%]; reddish tumor, 74.5% [62.0%-86.9%]; white coating, 73.8% [42.1%-100.0%]; and whitish tumor, 65.7% [53.0%-76.3%]. CONCLUSIONS OS imaging is strongly influenced by adherent substances for evaluating the specific StO2 value of tumors; therefore, it is important to eliminate the information of adherent substances for clinical application of OS imaging.
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Affiliation(s)
- Keiichiro Nishihara
- Department of Gastroenterology and Endoscopy, National Cancer Center Hospital, Kashiwanoha, Kashiwa, Japan
| | - Keisuke Hori
- Department of Gastroenterology and Endoscopy, National Cancer Center Hospital, Kashiwanoha, Kashiwa, Japan
| | - Takaaki Saito
- Imaging Technology Center, FUJIFILM Corporation, Tokyo, Japan
| | - Toshihiko Omori
- Medical Systems Research & Development Center, Research & Development, Management Headquarters, FUJIFILM Corporation, Tokyo Japan
| | - Hironori Sunakawa
- Department of Gastroenterology and Endoscopy, National Cancer Center Hospital, Kashiwanoha, Kashiwa, Japan
| | - Tatsunori Minamide
- Department of Gastroenterology and Endoscopy, National Cancer Center Hospital, Kashiwanoha, Kashiwa, Japan
| | - Masayuki Suyama
- Department of Gastroenterology and Endoscopy, National Cancer Center Hospital, Kashiwanoha, Kashiwa, Japan
| | - Yoichi Yamamoto
- Department of Gastroenterology and Endoscopy, National Cancer Center Hospital, Kashiwanoha, Kashiwa, Japan
| | - Yusuke Yoda
- Department of Gastroenterology and Endoscopy, National Cancer Center Hospital, Kashiwanoha, Kashiwa, Japan
| | - Kensuke Shinmura
- Department of Gastroenterology and Endoscopy, National Cancer Center Hospital, Kashiwanoha, Kashiwa, Japan
| | - Hiroaki Ikematsu
- Department of Gastroenterology and Endoscopy, National Cancer Center Hospital, Kashiwanoha, Kashiwa, Japan
| | - Tomonori Yano
- Department of Gastroenterology and Endoscopy, National Cancer Center Hospital, Kashiwanoha, Kashiwa, Japan
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Expression of GLUT3 and HIF-1 α in Meningiomas of Various Grades Correlated with Peritumoral Brain Edema. BIOMED RESEARCH INTERNATIONAL 2020; 2020:1682352. [PMID: 32908869 PMCID: PMC7477598 DOI: 10.1155/2020/1682352] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/09/2019] [Revised: 06/24/2020] [Accepted: 07/30/2020] [Indexed: 12/04/2022]
Abstract
Aim To investigate the expression of glucose transporter 3 (GLUT3) and hypoxia-inducible factor-1α protein (HIF-1α) in meningiomas and analyze the correlation between GLUT3 and HIF-1α expression with the pathological grade of peritumoral brain edema (PTBE) of meningiomas. Methods In this cross-sectional study, we analyzed meningioma specimens from 160 patients collected from January 1, 2014, to December 1, 2017, by dividing them into a low-grade (WHO I) or high-grade (WHO II and WHO III) group. Immunohistochemical analyses were used to detect the expression level of GLUT3 and HIF-1α in the tumor specimens. Results The proportion of GLUT3-positive staining in tumors sized <4 cm, 4–6 cm, and>6 cm was 35.9% (37/103), 63.6% (28/44), and 53.8% (7/13), respectively (P = 0.007). The proportion of HIF-1α-positive staining in tumors sized <4 cm, 4–6 cm, and >6 cm was 41.7% (43/103), 68.2% (30/44), and 38.5% (5/13), respectively (P = 0.010). The proportion of GLUT3-positive staining in the high-grade group and low-grade group was 70.8% (34/48) and 33.9% (38/112), respectively (P < 0.001). The proportion of HIF-1α-positive staining in the high-grade group and low-grade group was 62.5% (30/48) and 42.9% (48/112), respectively (P = 0.023). GLUT3-positive expression in meningioma PTBE grades 0, I, II, and III was 20.3% (13/64), 41.2% (14/34), 63.6% (21/33), and 82.8% (24/29), respectively (Bonferroni-corrected, P < 0.001, α/6 = 0.008). HIF-1α-positive expression in meningioma PTBE grades 0, I, II, and III was 34.4% (22/64), 47.1% (16/34), 54.5% (18/33), and 75.9% (22/29), respectively (Bonferroni-corrected, P = 0.003, α/6 = 0.008). Spearman's correlation analysis revealed a correlation between the expression of GLUT3 and HIF-1α in meningiomas (r = 0.463, P < 0.001). Multivariate analysis revealed that GLUT3-positive expression, HIF-1α-positive expression, and high pathological grade were associated with the development of PTBE (P < 0.05). Conclusions GLUT3 and HIF-1α expression in meningiomas was closely related to the tumor size, pathological grade, and PTBE. This study is the first to report a unique map-like multifocal GLUT3 staining pattern in meningiomas.
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De Bruycker S, Vangestel C, Staelens S, Wyffels L, Detrez J, Verschuuren M, De Vos WH, Pauwels P, Van den Wyngaert T, Stroobants S. Effects of metformin on tumor hypoxia and radiotherapy efficacy: a [ 18F]HX4 PET imaging study in colorectal cancer xenografts. EJNMMI Res 2019; 9:74. [PMID: 31375940 PMCID: PMC6677842 DOI: 10.1186/s13550-019-0543-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Accepted: 07/23/2019] [Indexed: 01/23/2023] Open
Abstract
Background In a colorectal cancer xenograft model, we investigated the therapeutic effect of metformin on tumor hypoxia with [18F]flortanidazole ([18F]HX4) small-animal positron emission tomography (μPET). We also assessed the additive effect of metformin on long-term radiotherapy outcome and we studied the potential of [18F]HX4 as a predictive and/or prognostic biomarker within this setup. Methods Colo205-bearing mice (n = 40) underwent a baseline [18F]HX4 hypoxia μPET/computed tomography (CT) scan. The next day, mice received 100 mg/kg metformin or saline intravenously (n = 20/group) and [18F]HX4 was administered intravenously 30 min later, whereupon a second μPET/CT scan was performed to assess changes in tumor hypoxia. Two days later, mice were further divided into four therapy groups (n = 10/group): control (1), metformin (2), radiotherapy (3), and metformin + radiotherapy, i.e., combination (4). Then, they received a second dose of metformin (groups 2 and 4) or saline (groups 1 and 3), followed by a single radiotherapy dose of 15 Gy (groups 3 and 4) or sham irradiation (groups 1 and 2) 30 min later. Tumor growth was followed three times a week by caliper measurements to assess the therapeutic outcome. Results [18F]HX4 uptake decreased in metformin-treated tumors with a mean intratumoral reduction in [18F]HX4 tumor-to-background ratio (TBR) from 2.53 ± 0.30 to 2.28 ± 0.26 (p = 0.04), as opposed to saline treatment (2.56 ± 0.39 to 3.08 ± 0.39; p = 0.2). The median tumor doubling time (TDT) was 6, 8, 41, and 43 days in the control, metformin, radiotherapy and combination group, respectively (log-rank p < 0.0001), but no metformin-specific therapy effects could be detected. Baseline [18F]HX4 TBR was a negative prognostic biomarker for TDT (hazard ratio, 2.39; p = 0.02). Conclusions Metformin decreased [18F]HX4 uptake of Colo205-tumors, but had no additive effect on radiotherapy efficacy. Nevertheless, [18F]HX4 holds promise as a prognostic imaging biomarker.
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Affiliation(s)
- Sven De Bruycker
- Molecular Imaging Center Antwerp (MICA), University of Antwerp, Universiteitsplein 1, Antwerp, 2610, Belgium
| | - Christel Vangestel
- Molecular Imaging Center Antwerp (MICA), University of Antwerp, Universiteitsplein 1, Antwerp, 2610, Belgium.,Department of Nuclear Medicine, Antwerp University Hospital (UZA), Wilrijkstraat 10, Edegem, 2650, Belgium
| | - Steven Staelens
- Molecular Imaging Center Antwerp (MICA), University of Antwerp, Universiteitsplein 1, Antwerp, 2610, Belgium
| | - Leonie Wyffels
- Molecular Imaging Center Antwerp (MICA), University of Antwerp, Universiteitsplein 1, Antwerp, 2610, Belgium
| | - Jan Detrez
- Laboratory of Cell Biology and Histology, University of Antwerp, Universiteitsplein 1, Antwerp, 2610, Belgium
| | - Marlies Verschuuren
- Laboratory of Cell Biology and Histology, University of Antwerp, Universiteitsplein 1, Antwerp, 2610, Belgium
| | - Winnok H De Vos
- Laboratory of Cell Biology and Histology, University of Antwerp, Universiteitsplein 1, Antwerp, 2610, Belgium
| | - Patrick Pauwels
- Center for Oncological Research (CORE), University of Antwerp, Universiteitsplein 1, Antwerp, 2610, Belgium.,Department of Pathology, Antwerp University Hospital (UZA), Wilrijkstraat 10, Edegem, 2650, Belgium
| | - Tim Van den Wyngaert
- Molecular Imaging Center Antwerp (MICA), University of Antwerp, Universiteitsplein 1, Antwerp, 2610, Belgium.,Department of Nuclear Medicine, Antwerp University Hospital (UZA), Wilrijkstraat 10, Edegem, 2650, Belgium
| | - Sigrid Stroobants
- Molecular Imaging Center Antwerp (MICA), University of Antwerp, Universiteitsplein 1, Antwerp, 2610, Belgium. .,Department of Nuclear Medicine, Antwerp University Hospital (UZA), Wilrijkstraat 10, Edegem, 2650, Belgium.
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Walke G, Ruthstein S. Does the ATSM-Cu(II) Biomarker Integrate into the Human Cellular Copper Cycle? ACS OMEGA 2019; 4:12278-12285. [PMID: 31460344 PMCID: PMC6681976 DOI: 10.1021/acsomega.9b01748] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Accepted: 07/04/2019] [Indexed: 06/10/2023]
Abstract
Hypoxia is commonly encountered in the tumor microenvironment and drives proliferation, angiogenesis, and resistance to therapy. Imaging of hypoxia is important in many disease states in oncology, cardiology, and neurology. Finding clinically approved imaging biomarkers for hypoxia has proved challenging. Candidate biomarkers have shown low uptake into tumors and low signal to background ratios that adversely affect imaging quality. Copper complexes have been identified as potential biomarkers for hypoxia owing to their redox ability. Active uptake of copper complexes into cells could ensure selectivity and high sensitivity. We explored the reactivity and selectivity of the ATSM-Cu(II) biomarker to proteins that are involved in the copper cycle using electron paramagnetic resonance (EPR) spectroscopy and UV-vis measurements. We show that the affinity of the ATSM-Cu(II) complex to proteins in the copper cycle is low and the cell probably does not actively uptake ATSM-Cu(II).
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Evaluation of [ 18F]FDG/[ 18F]FLT/[ 18F]FMISO-based micro-positron emission tomography in detection of liver metastasis in human colorectal cancer. Nucl Med Biol 2019; 72-73:36-44. [PMID: 31330410 DOI: 10.1016/j.nucmedbio.2019.07.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2019] [Revised: 06/10/2019] [Accepted: 07/06/2019] [Indexed: 01/21/2023]
Abstract
INTRODUCTION Positron emission tomography (PET) is extensively used in clinical oncology for tumor detection. This study aimed to explore the application of the radiotracers [18F]fluorodeoxyglucose ([18F]FDG), 3'-deoxy-3'- [18F]fluorothymidine ([18F]FLT), and [18F]fluoromisonidazole ([18F]FMISO) in the diagnosis and monitoring of hepatic metastasis in human colorectal cancer (CRC). METHODS A mouse model of human CRC with hepatic metastasis was established by intrasplenic implantation of human CRC cell lines LoVo or HCT8. Metastatic potential of these two cell lines was evaluated by wound healing assay in vitro and survival analysis. Uptake of radiotracers between LoVo and HCT8 cells and uptake of radiotracers in the resulting mouse tumor models were examined by in vivo and in vitro experiments. Uptake of each radiotracer in hepatic metastatic lesions was quantified and expressed as standard uptake value (SUV). Protein expression of multiple tumor biomarkers was determined in metastatic lesions. The correlation between tracer uptake and tumor marker expression was evaluated using linear regression. RESULTS LoVo cells exhibited a stronger metastatic potential and a higher radiotracer uptake ability than HCT8 cells, as evidenced by significantly greater wound closure percentage, shorter survival, higher incidence of liver metastases, and higher cellular radiotracer levels in LoVo cells or LoVo cell-xenografted mice. SUV values of [18F]FLT and [18F]FMISO, but not [18F]FDG, in LoVo cell-derived metastatic lesions were significantly greater than those in HCT8 lesions. Mechanistically, the expression of MACC1, HIF-1α, and GLUT-1(metastasis associated in colon cancer 1, MACC1; hypoxia-inducible factor 1-alpha, HIF-1α; and glucose transporter 1, GLUT-1, respectively) in LoVo cell-derived metastatic lesions was more effectively induced than in HCT8-derived ones. A linear regression analysis demonstrated significant positive correlations between [18F]FLT/[18F]FMISO uptake and tumor biomarker expression in metastatic tissues. CONCLUSIONS [18F]FLT and [18F]FMISO-based PET imaging may serve as a promising method for early detection and monitoring of hepatic metastasis in patients with CRC.
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Changes in Tumor Biology During Chemoradiation of Cervix Cancer Assessed by Multiparametric MRI and Hypoxia PET. Mol Imaging Biol 2018; 20:160-169. [PMID: 28540524 PMCID: PMC5775363 DOI: 10.1007/s11307-017-1087-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
PURPOSE Imaging biomarkers assessed with magnetic resonance imaging (MRI) and/or positron emission tomography (PET) enable non-invasive tumor characterization in cervix cancer patients. We investigated the spatio-temporal stability of hypoxia, perfusion, and the cell density of tumors over time by repetitive imaging prior to, during, and after radio-chemotherapy. PROCEDURES Thirteen patients were included in this prospective study. The imaging protocol included the following: [18F]fluoromisonidazole ([18F]FMISO)-PET/x-ray computed tomography (CT) and multiparametric (mp)-MRI at four time-points (TP): baseline (BL); and weeks 2 (TP1), 5 (TP2), and 19 after treatment start (follow-up FU). Complete datasets for six patients could be assessed for tumor volume, enhancement kinetics, diffusivity, and [18F]FMISO-avidity (P1-P6). In addition, two patients completed all PET/CT examinations (P7-P8) but not all MR scans; however, one of them had no hypoxia (P8). Descriptive statistics, correlations, and voxel-by-voxel analysis were performed. For various, independent reasons, five patients could not complete the study according to the protocol with all imaging sequences. RESULTS Median tumor ADCs (in ×10-3 mm2/s) were 0.99 ± 0.10 at BL, 1.20 ± 0.12 at TP1, 1.33 ± 0.14 at TP2, and 1.38 ± 0.21 at FU. The median TBRpeak (tumor-to-background) was 2.7 ± 0.8 at BL, 1.6 ± 0.2 at TP1, 1.8 ± 0.3 at TP2, and 1.7 ± 0.3 at FU. The voxel-by-voxel analysis of the [18F]FMISO uptake at BL and TP1 showed no correlation. Between TP2 and TP1 and FU and TP2, weak correlations were found for two patients. CONCLUSIONS Longitudinal mp-MR and PET imaging enables the in vivo tumor characterization over time. While perfusion and cell density decreased, there was a non-uniform change of hypoxia observed during radiotherapy. To assess the potential impact with regard to more personalized treatment approaches, hypoxia imaging-based dose painting for cervix cancer requires further research.
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How to Modulate Tumor Hypoxia for Preclinical In Vivo Imaging Research. CONTRAST MEDIA & MOLECULAR IMAGING 2018; 2018:4608186. [PMID: 30420794 PMCID: PMC6211155 DOI: 10.1155/2018/4608186] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Revised: 07/24/2018] [Accepted: 08/13/2018] [Indexed: 01/20/2023]
Abstract
Tumor hypoxia is related with tumor aggressiveness, chemo- and radiotherapy resistance, and thus a poor clinical outcome. Therefore, over the past decades, every effort has been made to develop strategies to battle the negative prognostic influence of tumor hypoxia. For appropriate patient selection and follow-up, noninvasive imaging biomarkers such as positron emission tomography (PET) radiolabeled ligands are unprecedentedly needed. Importantly, before being able to implement these new therapies and potential biomarkers into the clinical setting, preclinical in vivo validation in adequate animal models is indispensable. In this review, we provide an overview of the different attempts that have been made to create differential hypoxic in vivo cancer models with a particular focus on their applicability in PET imaging studies.
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Rapic S, Vangestel C, Verhaeghe J, Van den Wyngaert T, Hinz R, Verhoye M, Pauwels P, Staelens S, Stroobants S. Characterization of an Orthotopic Colorectal Cancer Mouse Model and Its Feasibility for Accurate Quantification in Positron Emission Tomography. Mol Imaging Biol 2018; 19:762-771. [PMID: 28194632 DOI: 10.1007/s11307-017-1051-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
PURPOSE Quantification in positron emission tomography (PET) imaging of an orthotopic mouse model of colorectal cancer (CRC) is challenging due to difficult tumor delineation. We aimed to establish a reproducible delineation approach, evaluate its feasibility for reliable PET quantification and compare its added translational value with its subcutaneous counterpart. PROCEDURES A subcutaneous Colo205-luc2 tumor fragment harvested from a donor mouse was transplanted onto the caecum of nude mice, with (n = 10) or without (n = 10) the addition of an X-ray detectable thread. Animals underwent 2-deoxy-2-[18F]fluoro-D-glucose ([18F]FDG) PET imaging, complemented with X-ray computed tomography (CT) and magnetic resonance imaging (MRI, 7T). Animals without a thread underwent additional contrast enhanced (Exitron) CT imaging. Tumors were delineated on the MRI, μPET image or contrast enhanced μCT images and correlations between in vivo and ex vivo [18F]FDG tumor uptake as well as between image-derived and caliper-measured tumor volume were evaluated. Finally, cancer hallmarks were assessed immunohistochemically for the characterization of both models. RESULTS Our results showed the strongest correlation between both in vivo and ex vivo uptake (r = 0.84, p < 0.0001) and image-derived and caliper-measured tumor volume (r = 0.96, p < 0.0001) when the tumor was delineated on the MR image. Orthotopic tumors displayed an abundance of stroma, higher levels of proliferation (p = 0.0007), apoptosis (p = 0.02), and necrosis (p < 0.0001), a higher number of blood vessels (p < 0.0001); yet lower tumor hypoxia (p < 0.0001) as compared with subcutaneous tumors. CONCLUSIONS This orthotopic mouse model proved to be a promising tool for the investigation of CRC through preclinical imaging studies provided the availability of anatomical MR images for accurate tumor delineation. Furthermore, the tumor microenvironment of the orthotopic tumor resembled more that of human CRC, increasing its likelihood to advance translational nuclear imaging studies of CRC.
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Affiliation(s)
- Sara Rapic
- Molecular Imaging Center Antwerp (MICA), Faculty of Medicine and Health Sciences, University of Antwerp, Universiteitsplein 1, 2610, Wilrijk, Belgium
| | - Christel Vangestel
- Molecular Imaging Center Antwerp (MICA), Faculty of Medicine and Health Sciences, University of Antwerp, Universiteitsplein 1, 2610, Wilrijk, Belgium.,Department of Nuclear Medicine, Antwerp University Hospital, Wilrijkstraat 10, 2650, Edegem, Belgium
| | - Jeroen Verhaeghe
- Molecular Imaging Center Antwerp (MICA), Faculty of Medicine and Health Sciences, University of Antwerp, Universiteitsplein 1, 2610, Wilrijk, Belgium
| | - Tim Van den Wyngaert
- Molecular Imaging Center Antwerp (MICA), Faculty of Medicine and Health Sciences, University of Antwerp, Universiteitsplein 1, 2610, Wilrijk, Belgium.,Department of Nuclear Medicine, Antwerp University Hospital, Wilrijkstraat 10, 2650, Edegem, Belgium
| | - Rukun Hinz
- Bio-Imaging Lab (BIL), Faculty of Pharmaceutical, Biomedical and Veterinary Sciences, University of Antwerp, Universiteitsplein 1, 2610, Wilrijk, Belgium
| | - Marleen Verhoye
- Bio-Imaging Lab (BIL), Faculty of Pharmaceutical, Biomedical and Veterinary Sciences, University of Antwerp, Universiteitsplein 1, 2610, Wilrijk, Belgium
| | - Patrick Pauwels
- Department of Pathological Anatomy, Antwerp University Hospital, Wilrijkstraat 10, 2650, Edegem, Belgium.,Center for Oncological Research (CORE), Faculty of Medicine and Health Sciences, University of Antwerp, Universiteitsplein 1, 2610, Wilrijk, Belgium
| | - Steven Staelens
- Molecular Imaging Center Antwerp (MICA), Faculty of Medicine and Health Sciences, University of Antwerp, Universiteitsplein 1, 2610, Wilrijk, Belgium
| | - Sigrid Stroobants
- Molecular Imaging Center Antwerp (MICA), Faculty of Medicine and Health Sciences, University of Antwerp, Universiteitsplein 1, 2610, Wilrijk, Belgium. .,Department of Nuclear Medicine, Antwerp University Hospital, Wilrijkstraat 10, 2650, Edegem, Belgium.
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De Bruycker S, Vangestel C, Van den Wyngaert T, Pauwels P, Wyffels L, Staelens S, Stroobants S. 18F-Flortanidazole Hypoxia PET Holds Promise as a Prognostic and Predictive Imaging Biomarker in a Lung Cancer Xenograft Model Treated with Metformin and Radiotherapy. J Nucl Med 2018; 60:34-40. [PMID: 29980581 DOI: 10.2967/jnumed.118.212225] [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] [Received: 03/30/2018] [Accepted: 06/23/2018] [Indexed: 12/15/2022] Open
Abstract
Metformin may improve tumor oxygenation and thus radiotherapy response, but imaging biomarkers for selection of suitable patients are still under investigation. First, we assessed the effect of acute metformin administration on non-small cell lung cancer xenograft tumor hypoxia using PET imaging with the hypoxia tracer 18F-flortanidazole. Second, we verified the effect of a single dose of metformin before radiotherapy on long-term treatment outcome. Third, we examined the potential of baseline 18F-flortanidazole as a prognostic or predictive biomarker for treatment response. Methods: A549 tumor-bearing mice underwent a 18F-flortanidazole PET/CT scan to determine baseline tumor hypoxia. The next day, mice received a 100 mg/kg intravenous injection of metformin. 18F-flortanidazole was administered intravenously 30 min later, and a second PET/CT scan was performed to assess changes in tumor hypoxia. Two days later, the mice were divided into 3 therapy groups: controls (group 1), radiotherapy (group 2), and metformin + radiotherapy (group 3). Animals received saline (groups 1-2) or metformin (100 mg/kg; group 3) intravenously, followed by a single radiotherapy dose of 10 Gy (groups 2-3) or sham irradiation (group 1) 30 min later. Tumor growth was monitored triweekly by caliper measurement, and tumor volume relative to baseline was calculated. The tumor doubling time (TDT), that is, the time to reach twice the preirradiation tumor volume, was defined as the endpoint. Results: Thirty minutes after metformin treatment, 18F-flortanidazole demonstrated a significant change in tumor hypoxia, with a mean intratumoral reduction in 18F-flortanidazole tumor-to-background ratio (TBR) from 3.21 ± 0.13 to 2.87 ± 0.13 (P = 0.0001). Overall, relative tumor volume over time differed across treatment groups (P < 0.0001). Similarly, the median TDT was 19, 34, and 52 d in controls, the radiotherapy group, and the metformin + radiotherapy group, respectively (log-rank P < 0.0001). Both baseline 18F-flortanidazole TBR (hazard ratio, 2.0; P = 0.0004) and change from baseline TBR (hazard ratio, 0.39; P = 0.04) were prognostic biomarkers for TDT irrespective of treatment, and baseline TBR predicted metformin-specific treatment effects that were dependent on baseline tumor hypoxia. Conclusion: Using 18F-flortanidazole PET imaging in a non-small cell lung cancer xenograft model, we showed that metformin may act as a radiosensitizer by increasing tumor oxygenation and that baseline 18F-flortanidazole shows promise as an imaging biomarker.
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Affiliation(s)
- Sven De Bruycker
- Molecular Imaging Center Antwerp (MICA), University of Antwerp, Wilrijk, Belgium
| | - Christel Vangestel
- Molecular Imaging Center Antwerp (MICA), University of Antwerp, Wilrijk, Belgium.,Department of Nuclear Medicine, Antwerp University Hospital, Edegem, Belgium; and
| | - Tim Van den Wyngaert
- Molecular Imaging Center Antwerp (MICA), University of Antwerp, Wilrijk, Belgium.,Department of Nuclear Medicine, Antwerp University Hospital, Edegem, Belgium; and
| | - Patrick Pauwels
- Center for Oncological Research (CORE), University of Antwerp, Wilrijk, Belgium
| | - Leonie Wyffels
- Molecular Imaging Center Antwerp (MICA), University of Antwerp, Wilrijk, Belgium.,Department of Nuclear Medicine, Antwerp University Hospital, Edegem, Belgium; and
| | - Steven Staelens
- Molecular Imaging Center Antwerp (MICA), University of Antwerp, Wilrijk, Belgium
| | - Sigrid Stroobants
- Molecular Imaging Center Antwerp (MICA), University of Antwerp, Wilrijk, Belgium .,Department of Nuclear Medicine, Antwerp University Hospital, Edegem, Belgium; and
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Melsens E, De Vlieghere E, Descamps B, Vanhove C, Kersemans K, De Vos F, Goethals I, Brans B, De Wever O, Ceelen W, Pattyn P. Hypoxia imaging with 18F-FAZA PET/CT predicts radiotherapy response in esophageal adenocarcinoma xenografts. Radiat Oncol 2018. [PMID: 29514673 PMCID: PMC5842657 DOI: 10.1186/s13014-018-0984-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Background Esophageal cancer is an aggressive disease with poor survival rates. A more patient-tailored approach based on predictive biomarkers could improve outcome. We aimed to predict radiotherapy (RT) response by imaging tumor hypoxia with 18F-FAZA PET/CT in an esophageal adenocarcinoma (EAC) mouse model. Additionally, we investigated the radiosensitizing effect of the hypoxia modifier nimorazole in vitro and in vivo. Methods In vitro MTS cell proliferation assays (OACM5 1.C SC1, human EAC cell line) were performed under normoxic and hypoxic (< 1%) conditions: control (100 μL PBS), nimorazole, irradiation (5, 10 or 20 Gy) with or without nimorazole. In vivo, subcutaneous xenografts were induced in nude mice (OACM5 1.C SC1). Treatment was given daily for 5 consecutive days: (A) control (600 μl NaCl 0.9% intraperitoneally (IP)) (N = 5, n = 7), (B) RT (5 Gy/d) (N = 11, n = 20), (C) combination (nimorazole (200 mg/kg/d IP) 30 min before RT) (N = 13, n = 21). N = number of mice, n = number of tumors. 18F-FAZA PET/CT was performed before treatment and tumor to background (T/B) ratios were calculated. Relative tumor growth was calculated and tumor sections were examined histologically (hypoxia, proliferation). Results A T/B ≥ 3.59 on pre-treatment 18F-FAZA PET/CT was predictive for worse RT response (sensitivity 92.3%, specificity 71.4%). Radiation was less effective in hypoxic tumors (T/B ≥ 3.59) compared to normoxic tumors (T/B < 3.59) (P = 0.0025). In vitro, pre-treatment with nimorazole significantly decreased hypoxic radioresistance (P < 0.01) while in vivo, nimorazole enhanced the efficacy of RT to suppress cancer cell proliferation in hypoxic tumor areas (Ki67, P = 0.064), but did not affect macroscopic tumor growth. Conclusions Tumor tissue hypoxia as measured with 18F-FAZA PET/CT is predictive for RT response in an EAC xenograft model. The radiosensitizing effect of nimorazole was questionable and requires further investigation. Electronic supplementary material The online version of this article (10.1186/s13014-018-0984-3) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Elodie Melsens
- Laboratory of Experimental Surgery, Department of Gastro- Intestinal Surgery, Ghent University Hospital, De Pintelaan 185, B-9000, Ghent, Belgium.
| | - Elly De Vlieghere
- Laboratory of Experimental Cancer Research, Department of Radiation Oncology and Experimental Cancer Research, Ghent University, Ghent, Belgium.,Cancer Research Institute Ghent (CRIG), Ghent University, Ghent, Belgium
| | - Benedicte Descamps
- Infinity (IBiTech-MEDISIP), Department of Electronics and Information Systems, Ghent University, Ghent, Belgium
| | - Christian Vanhove
- Infinity (IBiTech-MEDISIP), Department of Electronics and Information Systems, Ghent University, Ghent, Belgium
| | - Ken Kersemans
- Department of Nuclear Medicine, Ghent University Hospital, Ghent, Belgium
| | - Filip De Vos
- Department of Pharmaceutical Analysis, Ghent University, Ghent, Belgium
| | - Ingeborg Goethals
- Department of Nuclear Medicine, Ghent University Hospital, Ghent, Belgium
| | - Boudewijn Brans
- Department of Nuclear Medicine, Ghent University Hospital, Ghent, Belgium
| | - Olivier De Wever
- Laboratory of Experimental Cancer Research, Department of Radiation Oncology and Experimental Cancer Research, Ghent University, Ghent, Belgium.,Cancer Research Institute Ghent (CRIG), Ghent University, Ghent, Belgium
| | - Wim Ceelen
- Laboratory of Experimental Surgery, Department of Gastro- Intestinal Surgery, Ghent University Hospital, De Pintelaan 185, B-9000, Ghent, Belgium.,Cancer Research Institute Ghent (CRIG), Ghent University, Ghent, Belgium
| | - Piet Pattyn
- Laboratory of Experimental Surgery, Department of Gastro- Intestinal Surgery, Ghent University Hospital, De Pintelaan 185, B-9000, Ghent, Belgium.,Cancer Research Institute Ghent (CRIG), Ghent University, Ghent, Belgium
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