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Dos Santos SN, Wuest M, Jans HS, Woodfield J, Nario AP, Krys D, Dufour J, Glubrecht D, Bergman C, Bernardes ES, Wuest F. Comparison of three 18F-labeled 2-nitroimidazoles for imaging hypoxia in breast cancer xenografts: [ 18F]FBNA, [ 18F]FAZA and [ 18F]FMISO. Nucl Med Biol 2023; 124-125:108383. [PMID: 37651917 DOI: 10.1016/j.nucmedbio.2023.108383] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Revised: 08/24/2023] [Accepted: 08/25/2023] [Indexed: 09/02/2023]
Abstract
BACKGROUND Tumour hypoxia is associated with increased metastasis, invasion, poor therapy response and prognosis. Most PET radiotracers developed and used for clinical hypoxia imaging belong to the 2-nitroimidazole family. Recently we have developed novel 2-nitroimidazole-derived PET radiotracer [18F]FBNA (N-(4-[18F]fluoro-benzyl)-2-(2-nitro-1H-imidazol-1-yl)-acet-amide), an 18F-labeled analogue of antiparasitic drug benznidazole. The present study aimed to analyze its radio-pharmacological properties and systematically compare its PET imaging profiles with [18F]FMISO and [18F]FAZA in preclinical triple-negative (MDA-MB231) and estrogen receptor-positive (MCF-7) breast cancer models. METHODS In vitro cellular uptake experiments were carried out in MDA-MB321 and MCF-7 cells under normoxic and hypoxic conditions. Metabolic stability in vivo was determined in BALB/c mice using radio-TLC analysis. Dynamic PET experiments over 3 h post-injection were performed in MDA-MB231 and MCF-7 tumour-bearing mice. Those PET data were used for kinetic modelling analysis utilizing the reversible two-tissue-compartment model. Autoradiography was carried out in tumour tissue slices and compared to HIF-1α immunohistochemistry. Detailed ex vivo biodistribution was accomplished in BALB/c mice, and this biodistribution data were used for dosimetry calculation. RESULTS Under hypoxic conditions in vitro cellular uptake was elevated in both cell lines, MCF-7 and MDA-MB231, for all three radiotracers. After intravenous injection, [18F]FBNA formed two radiometabolites, resulting in a final fraction of 65 ± 9 % intact [18F]FBNA after 60 min p.i. After 3 h p.i., [18F]FBNA tumour uptake reached SUV values of 0.78 ± 0.01 in MCF-7 and 0.61 ± 0.04 in MDA-MB231 tumours (both n = 3), representing tumour-to-muscle ratios of 2.19 ± 0.04 and 1.98 ± 0.15, respectively. [18F]FMISO resulted in higher tumour uptakes (SUV 1.36 ± 0.04 in MCF-7 and 1.23 ± 0.08 in MDA-MB231 (both n = 4; p < 0.05) than [18F]FAZA (0.66 ± 0.11 in MCF-7 and 0.63 ± 0.14 in MDA-MB231 (both n = 4; n.s.)), representing tumour-to-muscle ratios of 3.24 ± 0.30 and 3.32 ± 0.50 for [18F]FMISO, and 2.92 ± 0.74 and 3.00 ± 0.42 for [18F]FAZA, respectively. While the fraction per time of radiotracer entering the second compartment (k3) was similar within uncertainties for all three radiotracers in MDA-MB231 tumours, it was different in MCF-7 tumours. The ratios k3/(k3 + k2) and K1*k3/(k3 + k2) in MCF-7 tumours were also significantly different, indicating dissimilar fractions of radiotracer bound and trapped intracellularly: K1*k3/(k2 + k3) [18F]FMISO (0.0088 ± 0.001)/min, n = 4; p < 0.001) > [18F]FAZA (0.0052 ± 0.002)/min, n = 4; p < 0.01) > [18F]FBNA (0.003 ± 0.001)/min, n = 3). In contrast, in MDA-MB231 tumours, only K1 was significantly elevated for [18F]FMISO. However, this did not result in significant differences for K1*k3/(k2 + k3) for all three 2-nitroimidazoles in MDA-MB231 tumours. CONCLUSION Novel 2-nitroimidazole PET radiotracer [18F]FBNA showed uptake into hypoxic breast cancer cells and tumour tissue presumably associated with elevated HIF1-α expression. Systematic comparison of PET imaging performance with [18F]FMISO and [18F]FAZA in different types of preclinical breast cancer models revealed a similar tumour uptake profile for [18F]FBNA with [18F]FAZA and, despite its higher lipophilicity, still a slightly higher muscle tissue clearance compared to [18F]FMISO.
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Affiliation(s)
- Sofia Nascimento Dos Santos
- Radiopharmacy Center, Nuclear and Energy Research Institute (IPEN / CNEN - SP), CEP 05508-000 São Paulo, SP, Brazil
| | - Melinda Wuest
- Department of Oncology, University of Alberta, Cross Cancer Institute, Edmonton T6G 2R7, Alberta, Canada
| | - Hans-Sonke Jans
- Department of Oncology, University of Alberta, Cross Cancer Institute, Edmonton T6G 2R7, Alberta, Canada
| | - Jenilee Woodfield
- Department of Oncology, University of Alberta, Cross Cancer Institute, Edmonton T6G 2R7, Alberta, Canada
| | - Arian Pérez Nario
- Radiopharmacy Center, Nuclear and Energy Research Institute (IPEN / CNEN - SP), CEP 05508-000 São Paulo, SP, Brazil
| | - Daniel Krys
- Department of Oncology, University of Alberta, Cross Cancer Institute, Edmonton T6G 2R7, Alberta, Canada
| | - Jennifer Dufour
- Department of Oncology, University of Alberta, Cross Cancer Institute, Edmonton T6G 2R7, Alberta, Canada
| | - Darryl Glubrecht
- Department of Oncology, University of Alberta, Cross Cancer Institute, Edmonton T6G 2R7, Alberta, Canada
| | - Cody Bergman
- Department of Oncology, University of Alberta, Cross Cancer Institute, Edmonton T6G 2R7, Alberta, Canada
| | - Emerson Soares Bernardes
- Radiopharmacy Center, Nuclear and Energy Research Institute (IPEN / CNEN - SP), CEP 05508-000 São Paulo, SP, Brazil
| | - Frank Wuest
- Department of Oncology, University of Alberta, Cross Cancer Institute, Edmonton T6G 2R7, Alberta, Canada.
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Trencsényi G, Képes Z. Scandium-44: Diagnostic Feasibility in Tumor-Related Angiogenesis. Int J Mol Sci 2023; 24:ijms24087400. [PMID: 37108559 PMCID: PMC10138813 DOI: 10.3390/ijms24087400] [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: 03/15/2023] [Revised: 04/12/2023] [Accepted: 04/13/2023] [Indexed: 04/29/2023] Open
Abstract
Angiogenesis-related cell-surface molecules, including integrins, aminopeptidase N, vascular endothelial growth factor, and gastrin-releasing peptide receptor (GRPR), play a crucial role in tumour formation. Radiolabelled imaging probes targeting angiogenic biomarkers serve as valuable vectors in tumour identification. Nowadays, there is a growing interest in novel radionuclides other than gallium-68 (68Ga) or copper-64 (64Cu) to establish selective radiotracers for the imaging of tumour-associated neo-angiogenesis. Given its ideal decay characteristics (Eβ+average: 632 KeV) and a half-life (T1/2 = 3.97 h) that is well matched to the pharmacokinetic profile of small molecules targeting angiogenesis, scandium-44 (44Sc) has gained meaningful attention as a promising radiometal for positron emission tomography (PET) imaging. More recently, intensive research has been centered around the investigation of 44Sc-labelled angiogenesis-directed radiopharmaceuticals. Previous studies dealt with the evaluation of 44Sc-appended avb3 integrin-affine Arg-Gly-Asp (RGD) tripeptides, GRPR-selective aminobenzoyl-bombesin analogue (AMBA), and hypoxia-associated nitroimidazole derivatives in the identification of various cancers using experimental tumour models. Given the tumour-related hypoxia- and angiogenesis-targeting capability of these PET probes, 44Sc seems to be a strong competitor of the currently used positron emitters in radiotracer development. In this review, we summarize the preliminary preclinical achievements with 44Sc-labelled angiogenesis-specific molecular probes.
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Affiliation(s)
- György Trencsényi
- Division of Nuclear Medicine and Translational Imaging, Department of Medical Imaging, Faculty of Medicine, University of Debrecen, Nagyerdei St. 98, H-4032 Debrecen, Hungary
| | - Zita Képes
- Division of Nuclear Medicine and Translational Imaging, Department of Medical Imaging, Faculty of Medicine, University of Debrecen, Nagyerdei St. 98, H-4032 Debrecen, Hungary
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Nario AP, Woodfield J, Dos Santos SN, Bergman C, Wuest M, Araújo YB, Lapolli AL, West FG, Wuest F, Bernardes ES. Synthesis of a 2-nitroimidazole derivative N-(4-[ 18F]fluorobenzyl)-2-(2-nitro-1H-imidazol-1-yl)-acetamide ([ 18 F]FBNA) as PET radiotracer for imaging tumor hypoxia. EJNMMI Radiopharm Chem 2022; 7:13. [PMID: 35697954 PMCID: PMC9192864 DOI: 10.1186/s41181-022-00165-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Accepted: 05/30/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Tissue hypoxia is a pathological condition characterized by reducing oxygen supply. Hypoxia is a hallmark of tumor environment and is commonly observed in many solid tumors. Non-invasive imaging techniques like positron emission tomography (PET) are at the forefront of detecting and monitoring tissue hypoxia changes in vivo. RESULTS We have developed a novel 18F-labeled radiotracer for hypoxia PET imaging based on cytotoxic agent benznidazole. Radiotracer N-(4-[18F]fluorobenzyl)-2-(2-nitro-1H-imidazol-1-yl)acetamide ([18F]FBNA) was synthesized through acylation chemistry with readily available 4-[18F]fluorobenzyl amine. Radiotracer [18F]FBNA was obtained in good radiochemical yields (47.4 ± 5.3%) and high radiochemical purity (> 95%). The total synthesis time was 100 min, including HPLC purification and the molar activity was greater than 40 GBq/µmol. Radiotracer [18F]FBNA was stable in saline and mouse serum for 6 h. [18F]FBNA partition coefficient (logP = 1.05) was found to be more lipophilic than [18F]EF-5 (logP = 0.75), [18F]FMISO (logP = 0.4) and [18F]FAZA (logP = - 0.4). In vitro studies showed that [18F]FBNA accumulates in gastric cancer cell lines AGS and MKN45 under hypoxic conditions. CONCLUSIONS Hence, [18F]FBNA represents a novel and easy-to-prepare PET radioligand for imaging hypoxia.
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Affiliation(s)
- Arian Pérez Nario
- Nuclear and Energy Research Institute (IPEN/CNEN - SP), São Paulo, SP, CEP 05508-000, Brazil
| | - Jenilee Woodfield
- Department of Oncology, University of Alberta, Edmonton, AB, T6G 2R7, Canada
| | | | - Cody Bergman
- Department of Oncology, University of Alberta, Edmonton, AB, T6G 2R7, Canada
| | - Melinda Wuest
- Department of Oncology, University of Alberta, Edmonton, AB, T6G 2R7, Canada
| | - Yasniel Babí Araújo
- Nuclear and Energy Research Institute (IPEN/CNEN - SP), São Paulo, SP, CEP 05508-000, Brazil
| | - André Luis Lapolli
- Nuclear and Energy Research Institute (IPEN/CNEN - SP), São Paulo, SP, CEP 05508-000, Brazil
| | - Frederick G West
- Department of Chemistry, University of Alberta, Edmonton, AB, T6G 2G2, Canada
| | - Frank Wuest
- Department of Oncology, University of Alberta, Edmonton, AB, T6G 2R7, Canada
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Synthesis, Physicochemical, Labeling and In Vivo Characterization of 44Sc-Labeled DO3AM-NI as a Hypoxia-Sensitive PET Probe. Pharmaceuticals (Basel) 2022; 15:ph15060666. [PMID: 35745585 PMCID: PMC9228955 DOI: 10.3390/ph15060666] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Revised: 05/11/2022] [Accepted: 05/17/2022] [Indexed: 02/04/2023] Open
Abstract
Hypoxia promotes angiogenesis, which is crucial for tumor growth, and induces malignant progression and increases the therapeutic resistance. Positron emission tomography (PET) enables the detection of the hypoxic regions in tumors using 2-nitroimidazole-based radiopharmaceuticals. We describe here a physicochemical study of the Sc(DO3AM-NI) complex, which indicates: (a) relatively slow formation of the Sc(DO3AM-NI) chelate in acidic solution; (b) lower thermodynamic stability than the reference Sc(DOTA); (c) however, it is substantially more inert and consequently can be regarded as an excellent Sc-binder system. In addition, we report a comparison of 44Sc-labeled DO3AM-NI with its known 68Ga-labeled analog as a hypoxia PET probe. The in vivo and ex vivo biodistributions of 44Sc- and 68Ga-labeled DO3AM-NI in healthy and KB tumor-bearing SCID mice were examined 90 and 240 min after intravenous injection. No significant difference was found between the accumulation of 44Sc- and 68Ga-labeled DO3AM-NI in KB tumors. However, a significantly higher accumulation of [68Ga]Ga(DO3AM-NI) was found in liver, spleen, kidney, intestine, lung, heart and brain than for [44Sc]Sc(DO3AM-NI), leading to a lower tumor/background ratio. The tumor-to-muscle (T/M) ratio of [44Sc]Sc(DO3AM-NI) was approximately 10–15-fold higher than that of [68Ga]Ga(DO3AM-NI) at all time points. Thus, [44Sc]Sc(DO3AM-NI) allows the visualization of KB tumors with higher resolution, making it a promising hypoxia-specific PET radiotracer.
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D'Alonzo RA, Gill S, Rowshanfarzad P, Keam S, MacKinnon KM, Cook AM, Ebert MA. In vivo noninvasive preclinical tumor hypoxia imaging methods: a review. Int J Radiat Biol 2021; 97:593-631. [PMID: 33703994 DOI: 10.1080/09553002.2021.1900943] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Revised: 01/28/2021] [Accepted: 03/01/2021] [Indexed: 12/15/2022]
Abstract
Tumors exhibit areas of decreased oxygenation due to malformed blood vessels. This low oxygen concentration decreases the effectiveness of radiation therapy, and the resulting poor perfusion can prevent drugs from reaching areas of the tumor. Tumor hypoxia is associated with poorer prognosis and disease progression, and is therefore of interest to preclinical researchers. Although there are multiple different ways to measure tumor hypoxia and related factors, there is no standard for quantifying spatial and temporal tumor hypoxia distributions in preclinical research or in the clinic. This review compares imaging methods utilized for the purpose of assessing spatio-temporal patterns of hypoxia in the preclinical setting. Imaging methods provide varying levels of spatial and temporal resolution regarding different aspects of hypoxia, and with varying advantages and disadvantages. The choice of modality requires consideration of the specific experimental model, the nature of the required characterization and the availability of complementary modalities as well as immunohistochemistry.
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Affiliation(s)
- Rebecca A D'Alonzo
- School of Physics, Mathematics and Computing, The University of Western Australia, Crawley, Australia
| | - Suki Gill
- School of Physics, Mathematics and Computing, The University of Western Australia, Crawley, Australia
- Department of Radiation Oncology, Sir Charles Gairdner Hospital, Nedlands, Australia
| | - Pejman Rowshanfarzad
- School of Physics, Mathematics and Computing, The University of Western Australia, Crawley, Australia
| | - Synat Keam
- School of Medicine, The University of Western Australia, Crawley, Australia
| | - Kelly M MacKinnon
- School of Physics, Mathematics and Computing, The University of Western Australia, Crawley, Australia
| | - Alistair M Cook
- School of Medicine, The University of Western Australia, Crawley, Australia
| | - Martin A Ebert
- School of Physics, Mathematics and Computing, The University of Western Australia, Crawley, Australia
- Department of Radiation Oncology, Sir Charles Gairdner Hospital, Nedlands, Australia
- 5D Clinics, Claremont, Australia
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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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Zhang L, Yao X, Cao J, Hong H, Zhang A, Zhao R, Zhang Y, Zha Z, Liu Y, Qiao J, Zhu L, Kung HF. In Vivo Ester Hydrolysis as a New Approach in Development of Positron Emission Tomography Tracers for Imaging Hypoxia. Mol Pharm 2019; 16:1156-1166. [PMID: 30676751 DOI: 10.1021/acs.molpharmaceut.8b01131] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Hypoxia is an important biochemical and physiological condition associated with uncontrolled growth of tumor. Measurement of hypoxia in tumor tissue may be useful in characterization of tumor progression and monitoring drug treatment. [18F]FMISO is the most widely employed radiotracer for imaging of hypoxic tissue with positron emission tomography (PET). However, it showed relatively low uptake in hypoxic tissues, which led to low target-to-background contrast in PET images. To overcome these shortcomings, two novel 2-fluoroproprioic acid esters, nitroimidazole derivatives 2-fluoropropionic acid 2-(2-nitro-imidazol-1-yl)-ethyl ester (FNPFT, [19F]5) and 2-fluoropropionic acid 2-(2-methyl-5-nitro-imidazol-1-yl)-ethyl ester (FMNPFT, [19F]8), were prepared and tested. Radiolabeling of [18F]5 and [18F]8 was accomplished in 45 min (radiochemical purity >95%, the decay-corrected radiochemical yield of [18F]5 was 11 ± 2%, and that of [18F]8 was 13 ± 2%, n = 5). In vitro cell uptake studies using EMT-6 tumor cells showed that both radiotracers [18F]5 and [18F]8 displayed significantly higher uptake in hypoxic cells than those under normoxic condition, while 2-[18F]fluoropropionic acid (2-[18F]FPA) displayed no difference. Biodistribution studies in mice bearing EMT-6 tumor showed that [18F]5, [18F]8, and 2-[18F]FPA displayed similar tumor and major organ uptakes. Tumor uptake values for all three agents were higher than those of [18F]FMISO, respectively ( P < 0.05). This is likely due to a rapid in vivo hydrolysis of [18F]5 and [18F]8 to their metabolite, 2-[18F]FPA. Micro PET imaging studies in the same EMT-6 implanted mice tumor model also demonstrated that both [18F]5 and [18F]8 displayed similar tumor uptake comparable to that of 2-[18F]FPA. In conclusion, two new fluorine-18 labeled nitroimidazole derivatives, [18F]5 and [18F]8, showed good tumor uptakes in mice bearing EMT-6 tumor. However, in vivo biodistribution results suggested that they were more likely reflect the predominance of in vivo produced metabolite, 2-[18F]FPA, which may not be related to tumor hypoxic condition.
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Affiliation(s)
- Lifang Zhang
- Key Laboratory of Radiopharmaceuticals, Ministry of Education, College of Chemistry , Beijing Normal University , Beijing 100875 , P. R. China
| | - Xinyue Yao
- Key Laboratory of Radiopharmaceuticals, Ministry of Education, College of Chemistry , Beijing Normal University , Beijing 100875 , P. R. China
| | - Jianhua Cao
- Key Laboratory of Radiopharmaceuticals, Ministry of Education, College of Chemistry , Beijing Normal University , Beijing 100875 , P. R. China
| | - Haiyan Hong
- Key Laboratory of Radiopharmaceuticals, Ministry of Education, College of Chemistry , Beijing Normal University , Beijing 100875 , P. R. China
| | - Aili Zhang
- Key Laboratory of Radiopharmaceuticals, Ministry of Education, College of Chemistry , Beijing Normal University , Beijing 100875 , P. R. China
| | - Ruiyue Zhao
- Key Laboratory of Radiopharmaceuticals, Ministry of Education, College of Chemistry , Beijing Normal University , Beijing 100875 , P. R. China
| | - Yan Zhang
- Key Laboratory of Radiopharmaceuticals, Ministry of Education, College of Chemistry , Beijing Normal University , Beijing 100875 , P. R. China
| | - Zhihao Zha
- Beijing Institute for Brain Disorders , Capital Medical University , Beijing 100069 , P. R. China.,Department of Radiology , University of Pennsylvania , Philadelphia , Pennsylvania 19014 , United States
| | - Yajing Liu
- Beijing Institute for Brain Disorders , Capital Medical University , Beijing 100069 , P. R. China
| | - Jinping Qiao
- Key Laboratory of Radiopharmaceuticals, Ministry of Education, College of Chemistry , Beijing Normal University , Beijing 100875 , P. R. China
| | - Lin Zhu
- Key Laboratory of Radiopharmaceuticals, Ministry of Education, College of Chemistry , Beijing Normal University , Beijing 100875 , P. R. China.,Beijing Institute for Brain Disorders , Capital Medical University , Beijing 100069 , P. R. China
| | - Hank F Kung
- Beijing Institute for Brain Disorders , Capital Medical University , Beijing 100069 , P. R. China.,Department of Radiology , University of Pennsylvania , Philadelphia , Pennsylvania 19014 , United States
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Iakovou I, Giannoula E, Gkantaifi A, Levva S, Frangos S. Positron emission tomography in breast cancer: 18F- FDG and other radiopharmaceuticals. Eur J Hybrid Imaging 2018. [DOI: 10.1186/s41824-018-0039-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
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9
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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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Bonnitcha P, Grieve S, Figtree G. Clinical imaging of hypoxia: Current status and future directions. Free Radic Biol Med 2018; 126:296-312. [PMID: 30130569 DOI: 10.1016/j.freeradbiomed.2018.08.019] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/06/2018] [Revised: 07/30/2018] [Accepted: 08/14/2018] [Indexed: 12/20/2022]
Abstract
Tissue hypoxia is a key feature of many important causes of morbidity and mortality. In pathologies such as stroke, peripheral vascular disease and ischaemic heart disease, hypoxia is largely a consequence of low blood flow induced ischaemia, hence perfusion imaging is often used as a surrogate for hypoxia to guide clinical diagnosis and treatment. Importantly, ischaemia and hypoxia are not synonymous conditions as it is not universally true that well perfused tissues are normoxic or that poorly perfused tissues are hypoxic. In pathologies such as cancer, for instance, perfusion imaging and oxygen concentration are less well correlated, and oxygen concentration is independently correlated to radiotherapy response and overall treatment outcomes. In addition, the progression of many diseases is intricately related to maladaptive responses to the hypoxia itself. Thus there is potentially great clinical and scientific utility in direct measurements of tissue oxygenation. Despite this, imaging assessment of hypoxia in patients is rarely performed in clinical settings. This review summarises some of the current methods used to clinically evaluate hypoxia, the barriers to the routine use of these methods and the newer agents and techniques being explored for the assessment of hypoxia in pathological processes.
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Affiliation(s)
- Paul Bonnitcha
- Northern and Central Clinical Schools, Faculty of Medicine, Sydney University, Sydney, NSW 2006, Australia; Chemical Pathology Department, NSW Health Pathology, Royal Prince Alfred Hospital, Camperdown, NSW 2050, Australia; Kolling Institute of Medical Research, University of Sydney, St Leonards, New South Wales 2065, Australia.
| | - Stuart Grieve
- Sydney Translational Imaging Laboratory, Heart Research Institute, Charles Perkins Centre and Sydney Medical School, University of Sydney, NSW 2050, Australia
| | - Gemma Figtree
- Kolling Institute of Medical Research, University of Sydney, St Leonards, New South Wales 2065, Australia; Cardiology Department, Royal North Shore Hospital, St Leonards, New South Wales 2065, Australia
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Marcu LG, Moghaddasi L, Bezak E. Imaging of Tumor Characteristics and Molecular Pathways With PET: Developments Over the Last Decade Toward Personalized Cancer Therapy. Int J Radiat Oncol Biol Phys 2018; 102:1165-1182. [PMID: 29907486 DOI: 10.1016/j.ijrobp.2018.04.055] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2018] [Revised: 04/09/2018] [Accepted: 04/19/2018] [Indexed: 02/08/2023]
Abstract
PURPOSE Improvements in personalized therapy are made possible by the advances in molecular biology that led to developments in molecular imaging, allowing highly specific in vivo imaging of biological processes. Positron emission tomography (PET) is the most specific and sensitive imaging technique for in vivo molecular targets and pathways, offering quantification and evaluation of functional properties of the targeted anatomy. MATERIALS AND METHODS This work is an integrative research review that summarizes and evaluates the accumulated current status of knowledge of recent advances in PET imaging for cancer diagnosis and treatment, concentrating on novel radiotracers and evaluating their advantages and disadvantages in cancer characterization. Medline search was conducted, limited to English publications from 2007 onward. Identified manuscripts were evaluated for most recent developments in PET imaging of cancer hypoxia, angiogenesis, proliferation, and clonogenic cancer stem cells (CSC). RESULTS There is an expansion observed from purely metabolic-based PET imaging toward antibody-based PET to achieve more information on cancer characteristics to identify hypoxia, proangiogenic factors, CSC, and others. 64Cu-ATSM, for example, can be used both as a hypoxia and a CSC marker. CONCLUSIONS Progress in the field of functional imaging will possibly lead to more specific tumor targeting and personalized treatment, increasing tumor control and improving quality of life.
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Affiliation(s)
- Loredana Gabriela Marcu
- Faculty of Science, University of Oradea, Oradea, Romania; Cancer Research Institute and School of Health Sciences, University of South Australia, Adelaide SA, Australia
| | - Leyla Moghaddasi
- GenesisCare, Tennyson Centre, Adelaide SA, Australia; Department of Physics, University of Adelaide, Adelaide SA, Australia
| | - Eva Bezak
- Cancer Research Institute and School of Health Sciences, University of South Australia, Adelaide SA, Australia; Department of Physics, University of Adelaide, Adelaide SA, Australia.
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Challapalli A, Carroll L, Aboagye EO. Molecular mechanisms of hypoxia in cancer. Clin Transl Imaging 2017; 5:225-253. [PMID: 28596947 PMCID: PMC5437135 DOI: 10.1007/s40336-017-0231-1] [Citation(s) in RCA: 102] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2017] [Accepted: 04/21/2017] [Indexed: 02/07/2023]
Abstract
PURPOSE Hypoxia is a condition of insufficient oxygen to support metabolism which occurs when the vascular supply is interrupted, or when a tumour outgrows its vascular supply. It is a negative prognostic factor due to its association with an aggressive tumour phenotype and therapeutic resistance. This review provides an overview of hypoxia imaging with Positron emission tomography (PET), with an emphasis on the biological relevance, mechanism of action, highlighting advantages, and limitations of the currently available hypoxia radiotracers. METHODS A comprehensive PubMed literature search was performed, identifying articles relating to biological significance and measurement of hypoxia, MRI methods, and PET imaging of hypoxia in preclinical and clinical settings, up to December 2016. RESULTS A variety of approaches have been explored over the years for detecting and monitoring changes in tumour hypoxia, including regional measurements with oxygen electrodes placed under CT guidance, MRI methods that measure either oxygenation or lactate production consequent to hypoxia, different nuclear medicine approaches that utilise imaging agents the accumulation of which is inversely related to oxygen tension, and optical methods. The advantages and disadvantages of these approaches are reviewed, along with individual strategies for validating different imaging methods. PET is the preferred method for imaging tumour hypoxia due to its high specificity and sensitivity to probe physiological processes in vivo, as well as the ability to provide information about intracellular oxygenation levels. CONCLUSION Even though hypoxia could have significant prognostic and predictive value in the clinic, the best method for hypoxia assessment has in our opinion not been realised.
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Affiliation(s)
- Amarnath Challapalli
- Department of Clinical Oncology, Bristol Cancer Institute, Horfield Road, Bristol, United Kingdom
| | - Laurence Carroll
- Department of Surgery and Cancer, Imperial College, GN1, Commonwealth Building, Hammersmith Hospital, Du Cane Road, London, W120NN United Kingdom
| | - Eric O. Aboagye
- Department of Surgery and Cancer, Imperial College, GN1, Commonwealth Building, Hammersmith Hospital, Du Cane Road, London, W120NN United Kingdom
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Kumar P, Bacchu V, Wiebe LI. The chemistry and radiochemistry of hypoxia-specific, radiohalogenated nitroaromatic imaging probes. Semin Nucl Med 2015; 45:122-35. [PMID: 25704385 DOI: 10.1053/j.semnuclmed.2014.10.005] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Hypoxia is prevalent in many solid tumors. Hypoxic tumors tend to exhibit rapid growth and aberrant vasculature, which lead to oxygen (O2) depletion and impaired drug delivery. The reductive environment in hypoxic tumors alters cellular metabolism, which can trigger transcriptional responses; induce genetic alterations; promote invasion, metastasis, resistance to radiotherapy and chemotherapy, tumor progression, and recurrence; and leads to poor local control and reduced survival rates. Therefore, exploiting the reductive microenvironment in hypoxic tumors by delivering electron-affinic, O2-mimetic radioactive drugs that bioreductively activate selectively in the hypoxic microenvironment offers a logical approach to molecular imaging of focal hypoxia. Because these agents also radiosensitize hypoxic cells, they provide an innovative approach to the therapy management of such tumors. To date, nuclear imaging of hypoxic tumor has proven to be clinically effective, whereas chemical radiosensitization by these compounds has not been helpful. The current review provides an insight into the chemistry, radiochemistry, and purification strategies for selected nitroaromatics that directly exploit the bioreductive environment in hypoxic cells. Both experimental and calculated single-electron reduction potentials of electron-affinic compounds, nitroimidazoles in particular, correlate with in vitro radiosensitizing properties, making them preferred choices for use as radiopharmaceuticals for diagnostic imaging and as sensitizers to enhance the killing effects of low-energy-transfer x-rays (O2-mimetic radiosensitization). Extensive research and careful drug design have led to the development of several potentially useful hypoxia-targeting drugs, for example, [(18)F]FAZA, [(18)F]FMISO, [(18)F]EF5, and [(123)I]IAZA, that accrue selectively in hypoxic cells. These molecular probes are now globally used in clinical hypoxia imaging, including cancer. Future innovative developments must, however, consider hypoxia-selective molecular processes and the physicochemical properties of the drugs that dictate their biodistribution, hypoxia-selective accumulation, pharmacokinetics, clearance, biochemical behavior, and metabolism. This will facilitate their ultimate transformation to effective molecular theranostics, leading to improved multimodal management of cancer.
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Affiliation(s)
- Piyush Kumar
- Department of Oncology, University of Alberta, Edmonton, Alberta, Canada.
| | - Veena Bacchu
- Department of Oncology, University of Alberta, Edmonton, Alberta, Canada
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Rajendran JG, Krohn KA. F-18 fluoromisonidazole for imaging tumor hypoxia: imaging the microenvironment for personalized cancer therapy. Semin Nucl Med 2015; 45:151-62. [PMID: 25704387 DOI: 10.1053/j.semnuclmed.2014.10.006] [Citation(s) in RCA: 85] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Hypoxia in solid tumors is one of the seminal mechanisms for developing aggressive trait and treatment resistance in solid tumors. This evolutionarily conserved biological mechanism along with derepression of cellular functions in cancer, although resulting in many challenges, provide us with opportunities to use these adversities to our advantage. Our ability to use molecular imaging to characterize therapeutic targets such as hypoxia and apply this information for therapeutic interventions is growing rapidly. Evaluation of hypoxia and its biological ramifications to effectively plan appropriate therapy that can overcome the cure-limiting effects of hypoxia provides an objective means for treatment selection and planning. Fluoromisonidazole (FMISO) continues to be the lead radiopharmaceutical in PET imaging for the evaluation, prognostication, and quantification of tumor hypoxia, one of the key elements of the tumor microenvironment. FMISO is less confounded by blood flow, and although the images have less contrast than FDG-PET, its uptake after 2 hours is an accurate reflection of inadequate regional oxygen partial pressure at the time of radiopharmaceutical administration. By virtue of extensive clinical utilization, FMISO remains the lead candidate for imaging and quantifying hypoxia. The past decade has seen significant technological advances in investigating hypoxia imaging in radiation treatment planning and in providing us with the ability to individualize radiation delivery and target volume coverage. The presence of widespread hypoxia in the tumor can be effectively targeted with a systemic hypoxic cell cytotoxin or other agents that are more effective with diminished oxygen partial pressure, either alone or in combination. Molecular imaging in general and hypoxia imaging in particular will likely become an important in vivo imaging biomarker of the future, complementing the traditional direct tissue sampling methods by providing a snap shot of a primary tumor and metastatic disease and in following treatment response and will serve as adjuncts to personalized therapy.
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Affiliation(s)
- Joseph G Rajendran
- Department of Radiology, University of Washington, Seattle, WA; Department of Radiation Oncology, University of Washington, Seattle, WA.
| | - Kenneth A Krohn
- Department of Radiology, University of Washington, Seattle, WA; Department of Radiation Oncology, University of Washington, Seattle, WA
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Alam IS, Arshad MA, Nguyen QD, Aboagye EO. Radiopharmaceuticals as probes to characterize tumour tissue. Eur J Nucl Med Mol Imaging 2015; 42:537-61. [PMID: 25647074 DOI: 10.1007/s00259-014-2984-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Accepted: 12/18/2014] [Indexed: 01/06/2023]
Abstract
Tumour cells exhibit several properties that allow them to grow and divide. A number of these properties are detectable by nuclear imaging methods. We discuss crucial tumour properties that can be described by current radioprobe technologies, further discuss areas of emerging radioprobe development, and finally articulate need areas that our field should aspire to develop. The review focuses largely on positron emission tomography and draws upon the seminal 'Hallmarks of Cancer' review article by Hanahan and Weinberg in 2011 placing into context the present and future roles of radiotracer imaging in characterizing tumours.
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Affiliation(s)
- Israt S Alam
- Comprehensive Cancer Imaging Centre, Imperial College London, London, W12 0NN, UK
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Chitneni SK, Bida GT, Zalutsky MR, Dewhirst MW. Reply: Pharmacokinetic and Pharmacodynamic Modifiers of EF5 Uptake and Binding. J Nucl Med 2015; 56:653-4. [PMID: 25745087 DOI: 10.2967/jnumed.115.154054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Affiliation(s)
| | - Gerald T Bida
- Duke University Medical Center Box 3808Durham, NC 27710 E-mail:
| | | | - Mark W Dewhirst
- Duke University Medical Center Box 3808Durham, NC 27710 E-mail:
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Wuest M, Wuest F. Positron emission tomography radiotracers for imaging hypoxia. J Labelled Comp Radiopharm 2014; 56:244-50. [PMID: 24285331 DOI: 10.1002/jlcr.2997] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2012] [Revised: 07/27/2012] [Accepted: 11/06/2012] [Indexed: 11/11/2022]
Abstract
Localized hypoxia, the physiological hallmark of many clinical pathologies, is the consequence of acute or chronic ischemia in the affected region or tissue. The versatility, sensitivity, quantitative nature, and increasing availability of positron emission tomography (PET) make it the preclinical and clinical method of choice for functional imaging of tissue hypoxia at the molecular level. The progress and current status of radiotracers for hypoxia-specific PET imaging are reviewed in this article including references mainly focused on radiochemistry and also relevant to molecular imaging of hypoxia in preclinical and clinical studies.
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Affiliation(s)
- Melinda Wuest
- Department of Oncology, University of Alberta, Edmonton, AB, T6G 1Z2, Canada
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Lopci E, Grassi I, Chiti A, Nanni C, Cicoria G, Toschi L, Fonti C, Lodi F, Mattioli S, Fanti S. PET radiopharmaceuticals for imaging of tumor hypoxia: a review of the evidence. AMERICAN JOURNAL OF NUCLEAR MEDICINE AND MOLECULAR IMAGING 2014; 4:365-84. [PMID: 24982822 PMCID: PMC4074502] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 04/17/2014] [Accepted: 04/28/2014] [Indexed: 06/03/2023]
Abstract
Hypoxia is a pathological condition arising in living tissues when oxygen supply does not adequately cover the cellular metabolic demand. Detection of this phenomenon in tumors is of the utmost clinical relevance because tumor aggressiveness, metastatic spread, failure to achieve tumor control, increased rate of recurrence, and ultimate poor outcome are all associated with hypoxia. Consequently, in recent decades there has been increasing interest in developing methods for measurement of oxygen levels in tumors. Among the image-based modalities for hypoxia assessment, positron emission tomography (PET) is one of the most extensively investigated based on the various advantages it offers, i.e., broad range of radiopharmaceuticals, good intrinsic resolution, three-dimensional tumor representation, possibility of semiquantification/quantification of the amount of hypoxic tumor burden, overall patient friendliness, and ease of repetition. Compared with the other non-invasive techniques, the biggest advantage of PET imaging is that it offers the highest specificity for detection of hypoxic tissue. Starting with the 2-nitroimidazole family of compounds in the early 1980s, a great number of PET tracers have been developed for the identification of hypoxia in living tissue and solid tumors. This paper provides an overview of the principal PET tracers applied in cancer imaging of hypoxia and discusses in detail their advantages and pitfalls.
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Affiliation(s)
- Egesta Lopci
- Department of Nuclear Medicine, University Hospital S. Orsola-MalpighiBologna, Italy
- Department of Nuclear Medicine, Humanitas Clinical and Research CenterRozzano, Italy
| | - Ilaria Grassi
- Department of Nuclear Medicine, University Hospital S. Orsola-MalpighiBologna, Italy
| | - Arturo Chiti
- Department of Nuclear Medicine, Humanitas Clinical and Research CenterRozzano, Italy
| | - Cristina Nanni
- Department of Nuclear Medicine, University Hospital S. Orsola-MalpighiBologna, Italy
| | - Gianfranco Cicoria
- Department of Medical Physics, University Hospital S. Orsola-MalpighiBologna, Italy
| | - Luca Toschi
- Department of Medical Oncology, Humanitas Clinical and Research CenterRozzano, Italy
| | - Cristina Fonti
- Department of Nuclear Medicine, University Hospital S. Orsola-MalpighiBologna, Italy
| | - Filippo Lodi
- Department of Nuclear Medicine, University Hospital S. Orsola-MalpighiBologna, Italy
| | - Sandro Mattioli
- Division of Thoracic Surgery, University Hospital S. Orsola-MalpighiBologna, Italy
| | - Stefano Fanti
- Department of Nuclear Medicine, University Hospital S. Orsola-MalpighiBologna, Italy
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Merchant S, Witney TH, Aboagye EO. Imaging as a pharmacodynamic and response biomarker in cancer. Clin Transl Imaging 2014. [DOI: 10.1007/s40336-014-0049-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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Perumal M, Stronach EA, Gabra H, Aboagye EO. Evaluation of 2-deoxy-2-[18F]fluoro-D-glucose- and 3'-deoxy-3'-[18F]fluorothymidine-positron emission tomography as biomarkers of therapy response in platinum-resistant ovarian cancer. Mol Imaging Biol 2013; 14:753-61. [PMID: 22484552 DOI: 10.1007/s11307-012-0554-2] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
PURPOSE We evaluated whether 2-deoxy-2-[(18)F]fluoro-D-glucose ([(18)F]FDG) and 3'-deoxy-3'-[(18)F]fluorothymidine ([(18)F]FLT) positron emission tomography (PET) could be used as imaging biomarkers of platinum resensitization in ovarian cancer. PROCEDURES Paired platinum-sensitive and platinum-resistant ovarian cancer cells from the same patient, PEO1 and PEO4, grown as tumor xenografts in nude mice, were assessed by PET. RESULTS The AKT inhibitor, API-2, resensitized platinum-resistant PEO4 tumors to cisplatin, leading to a markedly lower Ki67 labeling index (p ≤ 0.006, n = 6 per group). [(18)F]FDG-PET and [(18)F]FLT-PET imaging variables were lower after combination treatment compared with vehicle treatment (p ≤ 0.006, n = 6 per group). No changes were seen with either drug alone. PRAS40 phosphorylation status was a sensitive biochemical marker of pathway inhibition, whereas reductions thymidine kinase 1 expression defined the [(18)F]FLT response. CONCLUSIONS Therapeutic inhibition of AKT activation in acquired platinum-resistant disease can be imaged noninvasively by [(18)F]FDG-PET and [(18)F]FLT-PET warranting further assessment.
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Affiliation(s)
- Meg Perumal
- Comprehensive Cancer Imaging Centre, Department of Cancer & Surgery, Faculty of Medicine, Imperial College London, Hammersmith Hospital, 240 MRC Cyclotron Building, Du Cane Road, London, W12 0NN, UK
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21
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Smith G, Carroll L, Aboagye EO. New frontiers in the design and synthesis of imaging probes for PET oncology: current challenges and future directions. Mol Imaging Biol 2013; 14:653-66. [PMID: 22948535 DOI: 10.1007/s11307-012-0590-y] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Despite being developed over 30 years ago, 2-deoxy-2-[(18)F]fluoro-D-glucose remains the most frequently used radiotracer in PET oncology. In the last decade, interest in new and more specific radiotracers for imaging biological processes of oncologic interest has increased exponentially. This review summarizes the strategies underlying the development of those probes together with their validation and status of clinical translation; a brief summary of new radiochemistry strategies applicable to PET imaging is also included. The article finishes with a consideration of the challenges imaging scientists must overcome to bring about increased adoption of PET as a diagnostic or pharmacologic tool.
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Affiliation(s)
- Graham Smith
- Post-Graduate Medical Institute, University of Hull, Cottingham Road, Hull, HU6 7RX, UK
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Abstract
Imaging hypoxia using positron emission tomography (PET) is of great importance for therapy of cancer. [(18)F]Fluoromisonidazole (FMISO) was the first PET agent for hypoxia imaging, and various radiolabeled nitroimidazole derivatives such as [(18)F]fluoroerythronitroimidazole (FETNIM), [(18)F]1-α-D: -(2-deoxy-2-fluoroarabinofuranosyl)-2-nitroimidazole (FAZA), [(18)F]2-(2-nitro-1H-imidazol-1-yl)-N-(2,2,3,3,3-pentafluoropropyl) acetamide (EF-5), and [(18)F]fluoroetanidazole (FETA) have been developed successively. To overcome the high cost of cyclotron installation, (68)Ga-labeled nitroimidazole derivatives also have been developed. Another important hypoxia imaging agent is (64)Cu-diacetyl-bis(N (4)-methylthiosemicarbazone) ((64)Cu-ATSM), which can distribute in cancer tissue rapidly due to high lipophilicity. However, its application is limited due to high cost of radionuclide production. Although various hypoxia imaging agents have been reported and tested, hypoxia PET images still have to be improved, because of the low blood flow in hypoxic tissues and resulting low uptake of the agents.
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Affiliation(s)
- Lathika Hoigebazar
- Department of Nuclear Medicine, Seoul National University College of Medicine, Seoul, Korea
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Horsman MR, Mortensen LS, Petersen JB, Busk M, Overgaard J. Imaging hypoxia to improve radiotherapy outcome. Nat Rev Clin Oncol 2012; 9:674-87. [DOI: 10.1038/nrclinonc.2012.171] [Citation(s) in RCA: 422] [Impact Index Per Article: 35.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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24
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Lin A, Hahn SM. Hypoxia Imaging Markers and Applications for Radiation Treatment Planning. Semin Nucl Med 2012; 42:343-52. [DOI: 10.1053/j.semnuclmed.2012.04.002] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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25
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Bonnitcha PD, Kim BJ, Hocking RK, Clegg JK, Turner P, Neville SM, Hambley TW. Cobalt complexes with tripodal ligands: implications for the design of drug chaperones. Dalton Trans 2012; 41:11293-304. [PMID: 22885674 DOI: 10.1039/c2dt30727h] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Extensive research is currently being conducted into metal complexes that can selectively deliver cytotoxins to hypoxic regions in tumours. The development of pharmacologically suitable agents requires an understanding of appropriate ligand-metal systems for chaperoning cytotoxins. In this study, cobalt complexes with tripodal tren (tris-(2-aminoethyl)amine) and tpa (tris-(2-pyridylmethyl)amine) ligands were prepared with ancillary hydroxamic acid, β-diketone and catechol ligands and several parameters, including: pK(a), reduction potential and cytotoxicity were investigated. Fluorescence studies demonstrated that only tpa complexes with β-diketones showed any reduction by ascorbate in situ and similarly, cellular cytotoxicity results demonstrated that ligation to cobalt masked the cytotoxicity of the ancillary groups in all complexes except the tpa diketone derivative [Co(naac)tpa](ClO(4))(2) (naac = 1-methyl-3-(2-naphthyl)propane-1,3-dione). Additionally, it was shown that the hydroxamic acid complexes could be isolated in both the hydroxamate and hydroximate form and the pK(a) values (5.3-8.5) reveal that the reversible protonation/deprotonation of the complexes occurs at physiologically relevant pHs. These results have clear implications for the future design of prodrugs using cobalt moieties as chaperones, providing a basis for the design of cobalt complexes that are both more readily reduced and more readily taken up by cells in hypoxic and acidic environments.
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Affiliation(s)
- Paul D Bonnitcha
- School of Chemistry, The University of Sydney, NSW 2006, Australia
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Du J, Zhu L, Zhou X, Yin W, Deng A, Qiao J. Dose-response relationships of FMISO between trace dose and various macro-doses in rat by ultra-performance liquid chromatography with mass spectrometry and radioactivity analysis. J Pharm Biomed Anal 2012; 70:499-504. [PMID: 22867691 DOI: 10.1016/j.jpba.2012.07.016] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2012] [Revised: 07/13/2012] [Accepted: 07/14/2012] [Indexed: 12/27/2022]
Abstract
Screening the pharmacokinetics of candidates using liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) may be efficacious and safe for the research and development of new PET imaging agents. However, the PET imaging agent is administered as trace dose and the sensitivity of LC-MS/MS is often insufficient. If the dose was increased to be quantifiable, it should be necessary to prove whether the pharmacokinetics between trace and macro-doses is consistent or not. In this paper, fluoromisonidazole (FMISO), a tumor PET imaging agent, was chosen to evaluate the dose-response pharmacokinetics by administering various single intravenous doses (0.1, 0.4, 1.6 and 6.4 mg/kg) in male Sprague-Dawley rats. The plasma concentration of FMISO was determined by an ultra-performance liquid chromatography-tandem mass spectrometric (UPLC-MS/MS) method, and the blood radioactivity of [(18)F]FMISO was detected by a gamma counter. By calculating and comparing the pharmacokinetic parameters, the total area under the plasma concentration-time curve from time zero to infinity (AUC(0-∞)) and peak plasma concentration (C(max)) values increased with the selected FMISO doses, and showing linear dose-dependent. On the other hand, some parameters related to time, such as the elimination half-lives (t(1/2)) and elimination rate constant (K(e)) were dose-independent, and there is no significant deference between trace dose and various macro-doses. The data should be useful to evaluate the novel 2-nitroimidazole derivatives as potential PET tumor imaging agents.
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Affiliation(s)
- Jinglei Du
- Key Laboratory of Radiopharmaceuticals, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, PR China
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Bejot R, Carroll L, Bhakoo K, Declerck J, Gouverneur V. A fluorous and click approach for screening potential PET probes: Evaluation of potential hypoxia biomarkers. Bioorg Med Chem 2012; 20:324-9. [DOI: 10.1016/j.bmc.2011.10.084] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2011] [Revised: 10/26/2011] [Accepted: 10/29/2011] [Indexed: 11/30/2022]
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Patnaik JL, Byers T, Diguiseppi C, Denberg TD, Dabelea D. The influence of comorbidities on overall survival among older women diagnosed with breast cancer. J Natl Cancer Inst 2011; 103:1101-11. [PMID: 21719777 DOI: 10.1093/jnci/djr188] [Citation(s) in RCA: 227] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Previous studies have shown that summary measures of comorbid conditions are associated with decreased overall survival in breast cancer patients. However, less is known about associations between specific comorbid conditions on the survival of breast cancer patients. METHODS The Surveillance, Epidemiology, and End Results-Medicare database was used to identify primary breast cancers diagnosed from 1992 to 2000 among women aged 66 years or older. Inpatient, outpatient, and physician visits within the Medicare system were searched to determine the presence of 13 comorbid conditions present at the time of diagnosis. Overall survival was estimated using age-specific Kaplan-Meier curves, and mortality was estimated using Cox proportional hazards models adjusted for age, race and/or ethnicity, tumor stage, cancer prognostic markers, and treatment. All statistical tests were two-sided. RESULTS The study population included 64,034 patients with breast cancer diagnosed at a median age of 75 years. None of the selected comorbid conditions were identified in 37,306 (58%) of the 64,034 patients in the study population. Each of the 13 comorbid conditions examined was associated with decreased overall survival and increased mortality (from prior myocardial infarction, adjusted hazard ratio [HR] of death = 1.11, 95% CI = 1.03 to 1.19, P = .006; to liver disease, adjusted HR of death = 2.32, 95% CI = 1.97 to 2.73, P < .001). When patients of age 66-74 years were stratified by stage and individual comorbidity status, patients with each comorbid condition and a stage I tumor had similar or poorer overall survival compared with patients who had no comorbid conditions and stage II tumors. CONCLUSIONS In a US population of older breast cancer patients, 13 individual comorbid conditions were associated with decreased overall survival and increased mortality.
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Affiliation(s)
- Jennifer L Patnaik
- Department of Epidemiology, Colorado School of Public Health, University of Colorado Denver, Aurora, CO 80045, USA.
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Zha Z, Zhu L, Liu Y, Du F, Gan H, Qiao J, Kung HF. Synthesis and evaluation of two novel 2-nitroimidazole derivatives as potential PET radioligands for tumor imaging. Nucl Med Biol 2011; 38:501-8. [PMID: 21531287 DOI: 10.1016/j.nucmedbio.2010.11.001] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2010] [Revised: 10/29/2010] [Accepted: 11/01/2010] [Indexed: 11/28/2022]
Abstract
INTRODUCTION Nitroimidazole (azomycin) derivatives labeled with radioisotopes have been developed as cancer imaging and radiotherapeutic agents based on the oncological hypoxic mechanism. By attaching nitroimidazole core with different functional groups, we synthesized new nitroimidazole derivatives and evaluated their potentiality as tumor imaging agents. METHODS Starting with commercially available 2-nitroimidazole, 2-fluoro-N-(2-(2-nitro-1H-imidazol-1-yl)ethyl)acetamide (NEFA, [(19)F]7) and 2-(2-methyl-5-nitro-1H-imidazol-1-yl)ethyl 2-fluoroacetate (NEFT, [(19)F]8), as well as radiolabeling precursors, the bromo-substituted analogs were quickly synthesized through a three-step synthetic pathway. The precursors were radiolabeled with [(18)F]F(-)/18-crown-6/KHCO(3) in dimethyl sulfoxide at 90°C for 10 min followed by purification with an Oasis HLB cartridge. Biodistribution studies were carried out in EMT-6 tumor-bearing mice. The uptake (%ID/g) in tumors and normal tissues were measured at 30 min postinjection. Liquid chromatography-electrospray ionization mass spectrometry (LC/MS) was used to distinguish metabolites from parent drugs in urine and plasma of rat injected with "cold" NEFA ([(19)F]7) and NEFT ([(19)F]8). RESULTS Two radiotracers, [(18)F]NEFA ([(18)F]7) and [(18)F]NEFT ([(18)F]8), were prepared with average yields of 6%-7% and 9%-10% (not decay corrected). Radiochemical purity for both tracers was >95% as determined by HPLC. Biodistribution studies in EMT-6 tumor-bearing mice indicated that the tumor to blood and tumor to liver ratios of both [(18)F]7 (0.96, 0.61) and [(18)F]8 (0.98, 1.10) at 30 min were higher than those observed for [(18)F]FMISO (1) (0.91, 0.59), a well-investigated azomycin-type hypoxia radiotracer. Liquid chromatography-electrospray ionization mass spectrometry analysis demonstrated that fluoroacetate was the main in vivo metabolite for both NEFA ([(19)F]7) and NEFT ([(19)F]8). CONCLUSIONS In this research, two new fluorine-18 labeled 2-nitroimidazole derivatives, [(18)F]7 and [(18)F]8, both of which containing in vivo hydrolyzable group, were successfully prepared. Further biological evaluations are warranted to investigate their potential as PET radioligands for imaging tumor.
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Affiliation(s)
- Zhihao Zha
- Key Laboratory of Radiopharmaceuticals, Beijing Normal University, Ministry of Education, Beijing 100875, P.R. China
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Shibahara I, Kumabe T, Kanamori M, Saito R, Sonoda Y, Watanabe M, Iwata R, Higano S, Takanami K, Takai Y, Tominaga T. Imaging of hypoxic lesions in patients with gliomas by using positron emission tomography with 1-(2-[18F] fluoro-1-[hydroxymethyl]ethoxy)methyl-2-nitroimidazole, a new 18F-labeled 2-nitroimidazole analog. J Neurosurg 2010; 113:358-68. [PMID: 19895196 DOI: 10.3171/2009.10.jns09510] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECT Assessment of hypoxic conditions in brain tumors is important for predicting tumor aggressiveness and treatment response. A new hypoxia imaging agent, 1-(2-[(18)F]fluoro-1-[hydroxymethyl]ethoxy)methyl-2-nitroimidazole (FRP-170), with higher image contrast and faster clearance than preexisting hypoxia tracers for PET, was used to visualize hypoxic tissues in 8 patients with glioma. METHODS The FRP-170 was injected and PET imaging was performed 2 hours later in 8 patients, including 3 with glioblastoma multiforme, 2 with oligodendroglioma, and 1 each with diffuse astrocytoma, anaplastic ganglioglioma, and recurrent anaplastic astrocytoma. All 8 patients also underwent MR imaging, and some patients underwent [(11)C]methionine or [(18)F]fluorodeoxyglucose PET, and proton MR spectroscopy for comparison. Tissues obtained at biopsy or radical resection were immunostained with hypoxia-inducible factor-1alpha (HIF-1alpha) antibody for the confirmation of hypoxia, except in the patient with recurrent anaplastic astrocytoma who was treated using Gamma Knife surgery. RESULTS The FRP-170 PET images showed marked uptake with upregulation of HIF-1alpha in the 3 glioblastomas multiforme, and moderate uptake in the recurrent anaplastic astrocytoma and one oligodendroglioma, but no uptake in the other tumors. The FRP-170 PET images showed positive correlation with HIF-1alpha immunoreactivity and some correlation with FDG PET and MR imaging enhancement, but no correlation with [(11)C]methionine PET. Imaging with FRP-170 PET seemed to be more sensitive for detecting hypoxia than identifying the lactate peak on proton MR spectroscopy. CONCLUSIONS Imaging with FRP-170 PET can visualize hypoxic lesions in patients with glioma, as confirmed by histological examination. This new method can assess tumor hypoxia preoperatively and noninvasively.
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Affiliation(s)
- Ichiyo Shibahara
- Department of Neurosurgery, Tohoku University Graduate School of Medicine, Sendai, Japan
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Hoigebazar L, Jeong JM, Choi SY, Choi JY, Shetty D, Lee YS, Lee DS, Chung JK, Lee MC, Chung YK. Synthesis and Characterization of Nitroimidazole Derivatives for 68Ga-Labeling and Testing in Tumor Xenografted Mice. J Med Chem 2010; 53:6378-85. [DOI: 10.1021/jm100545a] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- Lathika Hoigebazar
- Department of Nuclear Medicine, Radiation Applied Life Sciences, Institute of Radiation Medicine, Seoul National University College of Medicine, 101 Daehangno, Jongno-gu, Seoul 110-744, Korea
- Cancer Research Institute, Seoul National University College of Medicine, Seoul 110-744, Korea
| | - Jae Min Jeong
- Department of Nuclear Medicine, Radiation Applied Life Sciences, Institute of Radiation Medicine, Seoul National University College of Medicine, 101 Daehangno, Jongno-gu, Seoul 110-744, Korea
- Cancer Research Institute, Seoul National University College of Medicine, Seoul 110-744, Korea
| | - Soo Young Choi
- Intelligent Textile System Research Centre and Department of Chemistry, Seoul National University, Seoul, Korea
| | - Jae Yeon Choi
- Department of Nuclear Medicine, Radiation Applied Life Sciences, Institute of Radiation Medicine, Seoul National University College of Medicine, 101 Daehangno, Jongno-gu, Seoul 110-744, Korea
- Cancer Research Institute, Seoul National University College of Medicine, Seoul 110-744, Korea
| | - Dinesh Shetty
- Department of Nuclear Medicine, Radiation Applied Life Sciences, Institute of Radiation Medicine, Seoul National University College of Medicine, 101 Daehangno, Jongno-gu, Seoul 110-744, Korea
- Cancer Research Institute, Seoul National University College of Medicine, Seoul 110-744, Korea
| | - Yun-Sang Lee
- Department of Nuclear Medicine, Radiation Applied Life Sciences, Institute of Radiation Medicine, Seoul National University College of Medicine, 101 Daehangno, Jongno-gu, Seoul 110-744, Korea
- Cancer Research Institute, Seoul National University College of Medicine, Seoul 110-744, Korea
| | - Dong Soo Lee
- Department of Nuclear Medicine, Radiation Applied Life Sciences, Institute of Radiation Medicine, Seoul National University College of Medicine, 101 Daehangno, Jongno-gu, Seoul 110-744, Korea
- Cancer Research Institute, Seoul National University College of Medicine, Seoul 110-744, Korea
| | - June-Key Chung
- Department of Nuclear Medicine, Radiation Applied Life Sciences, Institute of Radiation Medicine, Seoul National University College of Medicine, 101 Daehangno, Jongno-gu, Seoul 110-744, Korea
- Cancer Research Institute, Seoul National University College of Medicine, Seoul 110-744, Korea
| | - Myung Chul Lee
- Department of Nuclear Medicine, Radiation Applied Life Sciences, Institute of Radiation Medicine, Seoul National University College of Medicine, 101 Daehangno, Jongno-gu, Seoul 110-744, Korea
- Cancer Research Institute, Seoul National University College of Medicine, Seoul 110-744, Korea
| | - Young Keun Chung
- Intelligent Textile System Research Centre and Department of Chemistry, Seoul National University, Seoul, Korea
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Small animal tumour imaging with MRI and the ECAT EXACT scanner: application of partial volume correction and comparison with microPET data. Nucl Med Commun 2010; 31:294-300. [PMID: 20023592 DOI: 10.1097/mnm.0b013e328334fc2a] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE Partial volume effects caused by limited spatial resolution of conventional positron emission tomography (PET) scanners result in an underestimation of the activity concentration in small tumours. The aim of the study was to evaluate the feasibility of small animal tumour imaging with the clinical PET scanner ECAT EXACT after partial volume correction based on MRI calculations. The same tumour model was examined additionally with the small animal PET system, microPET focus 120. METHODS Before the ECAT EXACT studies recovery coefficients for different sphere volumes were generated with phantom experiments. For the following in-vivo study DS-sarcoma cells were implanted on both hind foot dorsum of male Sprague-Dawley rats. In-vivo tumour volume calculations were done with the high-resolution MRI system, Magnetom Vision Experimental. Dynamic F-fluorodeoxyglucose (FDG) PET was performed with the scanner ECAT EXACT (5 MBq intravenous, two-dimensional mode, n = 16 tumours) or with the microPET focus 120 (20 MBq intravenous, two-dimensional mode, n = 10 tumours). The animals were then killed, the tumours rapidly explanted, weighed and homogenized. The concentration of F-FDG was measured with a gamma counter and decay corrected; the ex-vivo F-FDG concentration was compared with the mean tumour activity concentration of the PET data. RESULTS Using the ECAT EXACT mean underestimation of actual tumour F-FDG concentration was 35.4%, for partial volume-corrected data this error decreased to 1.7%. In addition, after partial volume correction congruence and linear correlation between the regions of interest-based activity concentration and ex-vivo measurements were excellent (r = 0.98). These results were quite similar to the microPET experiments without partial volume correction: r = 0.99. CONCLUSION These data indicate that partial volume correction might allow use of the clinical PET system, ECAT EXACT, for the metabolic assessment of small animal tumours >/=10 mm with sufficient accuracy if no dedicated animal PET is available.
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Sun XY, Jiang X, Jiang HC. Novel therapeutic strategies targeting the hypoxic microenvironment of tumors. Shijie Huaren Xiaohua Zazhi 2010; 18:1741-1746. [DOI: 10.11569/wcjd.v18.i17.1741] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Hypoxic microenvironment is closely related to tumorigenesis, progression, metastasis and prognosis and has become a hot topic in cancer research. This article discusses investigations seeking novel therapies targeting the hypoxic microenvironment of tumors, including hypoxic conversion of non-toxic pro-drugs to cytotoxic drugs, and regulation of upstream and downstream genes of hypoxia-inducible factors (HIFs). Additionally, the article reviews our serial studies on tumor hypoxia, including blockade of HIF-1α expression or overexpression of von Hippel-Lindau to enhance the efficacy of immunotherapy, anti-angiogenic therapy, chemotherapy and transarterial embolization to combat malignancies.
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Mason RP, Zhao D, Pacheco-Torres J, Cui W, Kodibagkar VD, Gulaka PK, Hao G, Thorpe P, Hahn EW, Peschke P. Multimodality imaging of hypoxia in preclinical settings. THE QUARTERLY JOURNAL OF NUCLEAR MEDICINE AND MOLECULAR IMAGING : OFFICIAL PUBLICATION OF THE ITALIAN ASSOCIATION OF NUCLEAR MEDICINE (AIMN) [AND] THE INTERNATIONAL ASSOCIATION OF RADIOPHARMACOLOGY (IAR), [AND] SECTION OF THE SOCIETY OF... 2010; 54:259-280. [PMID: 20639813 PMCID: PMC3044928] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Hypoxia has long been recognized to influence solid tumor response to therapy. Increasingly, hypoxia has also been implicated in tumor aggressiveness, including growth, development and metastatic potential. Thus, there is a fundamental, as well as a clinical interest, in assessing in situ tumor hypoxia. This review will examine diverse approaches focusing on the preclinical setting, particularly, in rodents. The strategies are inevitably a compromise in terms of sensitivity, precision, temporal and spatial resolution, as well as cost, feasibility, ease and robustness of implementation. We will review capabilities of multiple modalities and examine what makes them particularly suitable for investigating specific aspects of tumor pathophysiology. Current approaches range from nuclear imaging to magnetic resonance and optical, with varying degrees of invasiveness and ability to examine spatial heterogeneity, as well as dynamic response to interventions. Ideally, measurements would be non-invasive, exploiting endogenous reporters to reveal quantitatively local oxygen tension dynamics. A primary focus of this review is magnetic resonance imaging (MRI) based techniques, such as ¹⁹F MRI oximetry, which reveals not only hypoxia in vivo, but more significantly, spatial distribution of pO₂ quantitatively, with a precision relevant to radiobiology. It should be noted that preclinical methods may have very different criteria for acceptance, as compared with potential investigations for prognostic radiology or predictive biomarkers suitable for use in patients.
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Affiliation(s)
- R P Mason
- Department of Radiology, U.T. Southwestern Medical Center, Dallas, TX 75390-9058, USA.
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Bejot R, Kersemans V, Kelly C, Carroll L, King RC, Gouverneur V, Elizarov AM, Ball C, Zhang J, Miraghaie R, Kolb HC, Smart S, Hill S. Pre-clinical evaluation of a 3-nitro-1,2,4-triazole analogue of [18F]FMISO as hypoxia-selective tracer for PET. Nucl Med Biol 2010; 37:565-75. [PMID: 20610161 DOI: 10.1016/j.nucmedbio.2010.03.011] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2010] [Revised: 03/18/2010] [Accepted: 03/21/2010] [Indexed: 11/25/2022]
Abstract
Hypoxia in solid tumours is associated with the promotion of various metabolic mechanisms and induces resistance to radio- and chemotherapy. Non-invasive positron emission tomography (PET) or single photon emission computed tomography by use of selective biomarkers has emerged as valuable tools for the detection of hypoxic areas within tumours so treatment can be modified accordingly. The aim of this investigation was to evaluate [(18)F]3-NTR, a 3-nitro-1,2,4-triazole analogue (N(1) substituted) of [(18)F]FMISO as a potential hypoxia selective tracer. 3-NTR and its (18)F-radiolabelled isotopic isomer were synthesised and compared with FMISO in vitro and in vivo. Their physicochemical properties were measured, the enzymatic reduction was evaluated, and the reactivity of their metabolites was investigated. Biodistribution and PET scans were performed on CBA mice bearing hypoxic CaNT tumour cells, using (18)F-labelled versions of the tracers. [(18)F]3-NTR uptake within hypoxic cells was lower than [(18)F]FMISO and [(18)F]3-NTR did not exhibit any better selectivity than FMISO as a PET tracer in vivo. Both (18)F-radiolabelled compounds are relatively evenly distributed within the whole body and the radioactive uptake within hypoxic tumours reaches a maximum at 30 min post injection and decreases thereafter. Xanthine oxidase exhibited a nitroreductase activity toward 3-NTR under anaerobic conditions, but reduced metabolites did not bind covalently. It is confirmed that 3-NTR is an electron acceptor. It is postulated that radiolabelled metabolites and fragments of [(18)F]3-NTR are freely diffusing due to their poor binding capacities. Thus [(18)F]3-NTR cannot be used as a hypoxia selective tracer for PET. The investigation provides insights into the importance of the propensity to form covalent adducts for such biomarkers.
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Affiliation(s)
- Romain Bejot
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3TA, United Kingdom.
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Nomikou N, Li YS, McHale AP. Ultrasound-enhanced drug dispersion through solid tumours and its possible role in aiding ultrasound-targeted cancer chemotherapy. Cancer Lett 2010; 288:94-8. [DOI: 10.1016/j.canlet.2009.06.028] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2009] [Revised: 06/23/2009] [Accepted: 06/24/2009] [Indexed: 10/20/2022]
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Contribution of hypoxia-measuring molecular imaging techniques to radiotherapy planning and treatment. Clin Transl Oncol 2010; 12:22-6. [DOI: 10.1007/s12094-010-0462-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Dalah E, Bradley D, Nisbet A. Simulation of tissue activity curves of64Cu-ATSM for sub-target volume delineation in radiotherapy. Phys Med Biol 2010; 55:681-94. [DOI: 10.1088/0031-9155/55/3/009] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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Koch CJ, Shuman AL, Jenkins WT, Kachur AV, Karp JS, Freifelder R, Dolbier WR, Evans SM. The radiation response of cells from 9L gliosarcoma tumours is correlated with [F18]-EF5 uptake. Int J Radiat Biol 2010; 85:1137-47. [PMID: 19995239 DOI: 10.3109/09553000903242172] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
PURPOSE Tumour hypoxia affects cancer biology and therapy-resistance in both animals and humans. The purpose of this study was to determine whether EF5 ([2-(2-nitro-1-H-imidazol-1-yl)-N-(2,2,3,3,3-pentafluoropropyl)-acetamide]) binding and/or radioactive drug uptake correlated with single-dose radiation response in 9L gliosarcoma tumours. MATERIALS AND METHODS Twenty-two 9L tumours were grown in male Fischer rats. Rats were administered low specific activity (18)F-EF5 and their tumours irradiated and assessed for cell survival and hypoxia. Hypoxia assays included EF5 binding measured by antibodies against bound-drug adducts and gamma counts of (18)F-EF5 tumour uptake compared with uptake by normal muscle and blood. These assays were compared with cellular radiation response (in vivo to in vitro assay). In six cases, uptake of tumour versus muscle was also assayed using images from a PET (positron emission tomography) camera (PENN G-PET). RESULTS The intertumoural variation in radiation response of 9L tumour-cells was significantly correlated with uptake of (18)F-labelled EF5 (i.e., including both bound and non-bound drug) using either tumour to muscle or tumour to blood gamma count ratios. In the tumours where imaging was performed, there was a significant correlation between the image analysis and gamma count analysis. Intertumoural variation in cellular radiation response of the same 22 tumours was also correlated with mean flow cytometry signal due to EF5 binding. CONCLUSION To our knowledge, this is the first animal model/drug combination demonstrating a correlation of radioresponse for tumour-cells from individual tumours with drug metabolism using either immunohistochemical or non-invasive techniques.
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Affiliation(s)
- Cameron J Koch
- Departments of Radiation Oncology, University of Pennsylvania, 195 John Morgan Bldg., 37th St & Hamilton Walk, Philadelphia, PA, 19104-6072, USA.
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Electrokinetic dispersion of a cancer chemotherapeutic drug for the treatment of solid tumours. Cancer Lett 2009; 279:202-8. [DOI: 10.1016/j.canlet.2009.01.038] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2008] [Revised: 01/21/2009] [Accepted: 01/27/2009] [Indexed: 11/24/2022]
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Molecular imaging of hypoxia with radiolabelled agents. Eur J Nucl Med Mol Imaging 2009; 36:1674-86. [PMID: 19565239 PMCID: PMC2758191 DOI: 10.1007/s00259-009-1195-9] [Citation(s) in RCA: 124] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2009] [Accepted: 06/07/2009] [Indexed: 01/29/2023]
Abstract
Tissue hypoxia results from an inadequate supply of oxygen (O2) that compromises biological functions. Structural and functional abnormalities of the tumour vasculature together with altered diffusion conditions inside the tumour seem to be the main causes of tumour hypoxia. Evidence from experimental and clinical studies points to a role for tumour hypoxia in tumour propagation, resistance to therapy and malignant progression. This has led to the development of assays for the detection of hypoxia in patients in order to predict outcome and identify patients with a worse prognosis and/or patients that would benefit from appropriate treatments. A variety of invasive and non-invasive approaches have been developed to measure tumour oxygenation including oxygen-sensitive electrodes and hypoxia marker techniques using various labels that can be detected by different methods such as positron emission tomography (PET), single photon emission computed tomography (SPECT), magnetic resonance imaging (MRI), autoradiography and immunohistochemistry. This review aims to give a detailed overview of non-invasive molecular imaging modalities with radiolabelled PET and SPECT tracers that are available to measure tumour hypoxia.
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Smith G, Glaser M, Perumal M, Nguyen QD, Shan B, Arstad E, Aboagye EO. Design, synthesis, and biological characterization of a caspase 3/7 selective isatin labeled with 2-[18F]fluoroethylazide. J Med Chem 2009; 51:8057-67. [PMID: 19049429 DOI: 10.1021/jm801107u] [Citation(s) in RCA: 109] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Imaging of programmed cell death (apoptosis) is important in the assessment of therapeutic response in oncology and for diagnosis in cardiac and neurodegenerative disorders. The executioner caspases 3 and 7 ultimately effect cellular death, thus providing selective molecular targets for in vivo quantification of apoptosis. To realize this potential, we aimed to develop 18F-labeled isatin sulfonamides with high metabolic stability and moderate lipophilicity while retaining selectivity and affinity for caspase 3/7. A small library of isatins modified with fluorinated aromatic groups and heterocycles was synthesized. A lead compound incorporating 2'-fluoroethyl-1,2,3-triazole was identified with subnanomolar affinity for caspase 3. "Click labeling" provided the 18F-labeled tracer in 65 +/- 6% decay-corrected radiochemical yield from 2-[18F]fluoroethylazide. The compound showed high stability in vivo with rapid uptake and elimination in healthy tissues and tumor. The novel 18F-labeled isatin is a candidate radiotracer for further preclinical evaluation for imaging of apoptosis.
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Affiliation(s)
- Graham Smith
- Molecular Therapy Group, Faculty of Medicine, Imperial College London, Hammersmith Hospital, Du Cane Road, London W12 0NN, United Kingdom
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South CP, Partridge M, Evans PM. A theoretical framework for prescribing radiotherapy dose distributions using patient-specific biological information. Med Phys 2008; 35:4599-611. [PMID: 18975706 DOI: 10.1118/1.2975229] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
We present a formalism for using functional imaging both to derive patient-specific radiobiological properties and consequently to prescribe optimal nonuniform radiotherapy dose distributions. The ability to quantitatively assess the response to an initial course of radiotherapy would allow the derivation of radiobiological parameters for individual patients. Both an iterative optimization and an analytical approach to this problem were investigated and illustrated by application to the linear-quadratic model of cell killing using simulated parametric data for a modeled tumor. Potential gains in local control were assessed by comparing uniform dose distributions with optimized dose distributions of equal integral dose. The effect on local prescribed dose of variations in effective radiosensitivity, tumor burden, and proliferation rate was investigated, with results suggesting that dose variations would be significant but clinically achievable. The sensitivity of derived parameters to image noise and the effect of varying the initial fractionation and imaging schedule were assessed. The analytical approach proved remarkably robust, with 10% image noise resulting in dose errors of approximately 1% for a clinically relevant set of parameters. Potential benefits were demonstrated by using this formalism to prescribe nonuniform dose distributions for model tumors using a range of literature-derived parameters. The redistribution of dose improved tumor control probability by factors between 1.03 and 4.27 for a range of model tumors.
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Affiliation(s)
- C P South
- Joint Department of Physics, The Institute of Cancer Research and The Royal Marsden NHS Foundation Trust, Downs Road, Sutton, SM2 5PT, UK.
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Riedl CC, Brader P, Zanzonico PB, Chun YS, Woo Y, Singh P, Carlin S, Wen B, Ling CC, Hricak H, Fong Y. Imaging hypoxia in orthotopic rat liver tumors with iodine 124-labeled iodoazomycin galactopyranoside PET. Radiology 2008; 248:561-70. [PMID: 18641253 DOI: 10.1148/radiol.2482071421] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
PURPOSE To evaluate iodine 124 (124I)-labeled iodoazomycin galactopyranoside (IAZGP) positron emission tomography (PET) in the detection of hypoxia in an orthotopic rat liver tumor model by comparing regions of high (124)I-IAZGP uptake with independent measures of hypoxia and to determine the optimal time after injection to depict hypoxia. MATERIALS AND METHODS The institutional animal care and use committee approved this study. Morris hepatoma tumors were established in the livers of 15 rats. Tumor oxygenation was measured in two rats with a fluorescence fiberoptic oxygen probe. (124)I-IAZGP was coadministered with the established hypoxia markers pimonidazole and EF5 in nine rats; 12-hour PET data acquisition was performed 24 hours later. Tumor cryosections were analyzed with immunofluorescence and autoradiography. In the four remaining rats, serial 20- and 60-minute PET data acquisition was peformed up to 48 hours after tracer administration. RESULTS Oxygen probe measurements showed severe hypoxia (<1 mm Hg) distributed evenly throughout tumor tissue. Analysis of cryosections showed diffuse homogeneous uptake of (124)I-IAZGP throughout all tumors. The (124)I-IAZGP distribution correlated positively with pimonidazole (r = 0.78) and EF5 (r = 0.76) distribution. Tracer uptake in tumors was detectable with PET after 24 hours in seven of nine rats. In rats that underwent serial PET, tumor-to-liver contrast was sufficient to enable detection of hypoxia between 6 and 48 hours after tracer administration. The optimal ratio between signal intensity and tumor-to-liver contrast occurred 6 hours after tracer administration. CONCLUSION Regions of high (124)I-IAZGP uptake in orthotopic rat liver tumors are consistent with independent measures of hypoxia; visualization of hypoxia with (124)I-IAZGP PET is optimal 6 hours after injection.
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Affiliation(s)
- Christopher C Riedl
- Department of Radiology, Memorial Sloan-Kettering Cancer Center, 1275 York Ave, Room C-278, New York, NY 10021, USA
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Abstract
Hypoxia, a condition of insufficient O2 to support metabolism, occurs when the vascular supply is interrupted, as in stroke or myocardial infarction, or when a tumor outgrows its vascular supply. When otherwise healthy tissues lose their O2 supply acutely, the cells usually die, whereas when cells gradually become hypoxic, they adapt by up-regulating the production of numerous proteins that promote their survival. These proteins slow the rate of growth, switch the mitochondria to glycolysis, stimulate growth of new vasculature, inhibit apoptosis, and promote metastatic spread. The consequence of these changes is that patients with hypoxic tumors invariably experience poor outcome to treatment. This has led the molecular imaging community to develop assays for hypoxia in patients, including regional measurements from O2 electrodes placed under CT guidance, several nuclear medicine approaches with imaging agents that accumulate with an inverse relationship to O2, MRI methods that measure either oxygenation directly or lactate production as a consequence of hypoxia, and optical methods with NIR and bioluminescence. The advantages and disadvantages of these approaches are reviewed, along with the individual strategies for validating different imaging methods. Ultimately the proof of value is in the clinical performance to predict outcome, select an appropriate cohort of patients to benefit from a hypoxia-directed treatment, or plan radiation fields that result in better local control. Hypoxia imaging in support of molecular medicine has become an important success story over the last decade and provides a model and some important lessons for development of new molecular imaging probes or techniques.
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Affiliation(s)
- Kenneth A Krohn
- Department of Radiology, University of Washington, Seattle, Washington 98195-6004, USA.
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Comparative pharmacokinetics, biodistribution, metabolism and hypoxia-dependent uptake of [18F]-EF3 and [18F]-MISO in rodent tumor models. Radiother Oncol 2008; 89:353-60. [PMID: 18649964 DOI: 10.1016/j.radonc.2008.06.008] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2008] [Revised: 05/30/2008] [Accepted: 06/18/2008] [Indexed: 12/12/2022]
Abstract
BACKGROUND AND PURPOSE [18F]-EF3 allows non-invasive detection of hypoxia. In the framework of its validation, we aimed at comparing its pharmacokinetics, biodistribution, metabolism and specificity for hypoxia with the hypoxia tracer [18F]-FMISO. MATERIALS AND METHODS C3H mice were injected IV with 3.7-18.5 MBq of one of the two tracers. For pharmacokinetics experiments, blood, urines and feces were collected. For biodistribution experiments, 13 different organs were harvested. To assess the hypoxia-specificity of the tracers, intramuscular syngeneic FSA II tumor bearing mice breathing air or carbogen were used. Animals were sacrificed from 5 to 440 min after injection. Radioactivity was assessed ex-vivo in a gamma counter. Tracer metabolites were assessed with radio-HPLC of acetonitrile soluble fractions of tissues. RESULTS Elimination half-life in blood (mono-exponential fit) reached 81.8 and 99.7 min for [18F]-EF3 and [18F]-MISO, respectively (NS). After 440 min, 71+/-7% (mean+/-SD) of injected activity of [18F]-EF3 was collected in the urine while 9+/-2% was collected in the feces, compared to 71+/-15% and 23+/-15% for [18F]-MISO (NS). Biodistribution was similar with a homogeneous distribution in most organs as early as 5 min after injection. With time, an increased activity in organs involved in excretion (kidney, bladder, liver and GI tract) was measured for both tracers; however, an increased background activity in "oxic" normal tissues (brain, lung, and esophagus) was also observed for [18F]-MISO. The percentage of metabolites was higher for [18F]-MISO compared to [18F]-EF3 in nearly all samples. Tumor-to-muscle ratios (TMRs) ranging from 2 to 4 were obtained under air-breathing condition for both tracers. CONCLUSION Both tracers exhibited a similar pharmacokinetics and biodistribution in mice and accumulated in an hypoxia-dependent manner in tumors. However, more aspecific activity was observed with [18F]-MISO at late time points after tracer injection in normal tissues.
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Busk M, Horsman MR, Jakobsen S, Keiding S, van der Kogel AJ, Bussink J, Overgaard J. Imaging hypoxia in xenografted and murine tumors with 18F-fluoroazomycin arabinoside: a comparative study involving microPET, autoradiography, PO2-polarography, and fluorescence microscopy. Int J Radiat Oncol Biol Phys 2008; 70:1202-12. [PMID: 18313528 DOI: 10.1016/j.ijrobp.2007.11.034] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2007] [Revised: 10/17/2007] [Accepted: 11/08/2007] [Indexed: 01/06/2023]
Abstract
PURPOSE Positron emission tomography (PET) allows noninvasive assessment of tumor hypoxia; however the combination of low resolution and slow tracer clearance from nonhypoxic tissue is problematic. The aim of this study was to examine the in vivo hypoxia selectivity of fluoroazomycin arabinoside ([18F]-FAZA), a promising tracer with improved washout kinetics from oxygenated tissue. METHODS AND MATERIALS Three squamous cell carcinomas and one fibrosarcoma with widely differing spatial patterns of vascularization, hypoxia, and necrosis were grown in mice and evaluated with PET and complementary methods. RESULTS Eppendorf electrode measurements consistently demonstrated median PO2 values<1 mm Hg. In accordance with that, PET revealed that all tumors accumulated [18F]-FAZA in excess of reference tissue. Next the two-dimensional spatial distribution of [18F]-FAZA (from autoradiography) was compared with fluorescence images of the same tumor sections showing localization of the hypoxia marker pimonidazole and the perfusion marker Hoechst 33342. Pixel-by-pixel analysis of co-registered images showed a highly significant co-localization between the two hypoxia markers and an inverse correlation (except for the fibrosarcoma) between the distribution of [18F]-FAZA and Hoechst dye. Moreover intratumoral heterogeneity in tracer distribution was clearly visible on autoradiograms, with a [18F]-FAZA concentration approximately six times higher in poorly oxygenated areas than in vascular hot spots. CONCLUSIONS The distribution of [18F]-FAZA is consistent with hypoxia as the key driving force for tracer tissue retention in a selection of tumors with widely differing physiology.
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Affiliation(s)
- Morten Busk
- Department of Experimental Clinical Oncology, Aarhus University Hospital, Aarhus, Denmark.
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Brugola E, Buck AK, Tagliabue L, Reske SN, Lucignani G. PET Imaging of Breast Cancer Molecular Biomarkers. Breast Cancer 2007. [DOI: 10.1007/978-3-540-36781-9_11] [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]
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Affiliation(s)
- John P Kirkpatrick
- Department of Radiation Oncology and the Preston Robert Tisch Brain Tumor Center, Duke University Medical Center, Durham, North Carolina 27710, USA.
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