1
|
Keigley QJ, Fowler AM, O'Brien SR, Dehdashti F. Molecular Imaging of Steroid Receptors in Breast Cancer. Cancer J 2024; 30:142-152. [PMID: 38753748 PMCID: PMC11101139 DOI: 10.1097/ppo.0000000000000715] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/18/2024]
Abstract
ABSTRACT Steroid receptors regulate gene expression for many important physiologic functions and pathologic processes. Receptors for estrogen, progesterone, and androgen have been extensively studied in breast cancer, and their expression provides prognostic information as well as targets for therapy. Noninvasive imaging utilizing positron emission tomography and radiolabeled ligands targeting these receptors can provide valuable insight into predicting treatment efficacy, staging whole-body disease burden, and identifying heterogeneity in receptor expression across different metastatic sites. This review provides an overview of steroid receptor imaging with a focus on breast cancer and radioligands for estrogen, progesterone, and androgen receptors.
Collapse
Affiliation(s)
- Quinton J Keigley
- From the Department of Radiology, University of Wisconsin School of Medicine and Public Health, Madison, WI
| | | | - Sophia R O'Brien
- Department of Radiology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA
| | - Farrokh Dehdashti
- Division of Nuclear Medicine, Edward Mallinckrodt Institute of Radiology, Alvin J. Siteman Cancer Center, Washington University School of Medicine, St Louis, MO
| |
Collapse
|
2
|
Wilson RC, Link JM, Lee YZ, Oldan JD, Young SL, Slayden OD. Uterine Uptake of Estrogen and Progestogen-Based Radiotracers in Rhesus Macaques with Endometriosis. Mol Imaging Biol 2024; 26:334-343. [PMID: 38133866 PMCID: PMC11034810 DOI: 10.1007/s11307-023-01892-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Revised: 12/12/2023] [Accepted: 12/13/2023] [Indexed: 12/23/2023]
Abstract
PURPOSE Endometriosis is an estrogen-dependent disorder of menstruating primates where tissues similar to the inner lining of the uterus exist "ectopically" outside of the uterus. The ectopic endometrium, like the endometrium within the uterus, expresses estrogen receptors (ER) and progesterone receptors (PR) and undergoes hormone-dependent cell proliferation and bleeding each menstrual cycle. The goal of this study was to conduct abdominopelvic positron emission tomography (PET) scans with computed tomography (CT) imaging of rhesus macaques (Macaca mulatta) using radiotracers that target ER and PR [16α-[18F]fluoroestradiol (FES) and 12-[18F]fluoro-furanyl-nor-progesterone (FFNP)] in individuals with and without endometriosis. We also aimed to determine if menstrual cycle phase and/or the presence of endometriosis affected the uptake of these radiotracers. PROCEDURES Rhesus macaques with either clinically diagnosed endometriosis (n = 6) or no endometriosis (n = 4) underwent PET/CT scans with FES. A subset of the animals also underwent PET/CT scans with FFNP. Standard uptake values corrected for body weight (SUVs) were obtained for each radiotracer in target and background tissues (e.g., intestinal). We performed repeated measure analysis of variance tests to determine how uterine and background uptake differed with scan time, phase of the menstrual cycle, and disease state. RESULTS Abdominopelvic PET/CT could not resolve small, individual endometriotic lesions. However, macaques with endometriosis displayed higher uterine uptake compared to those without the disorder. Radiotracer uptake differed by menstrual cycle phase with increased uterine uptake of both radiotracers in the proliferative phase of the menstrual cycle. Background intestinal uptake of FFNP increased over time after infusion, but only during the proliferative phase. CONCLUSIONS PET/CT with FES and FFNP support the concept that ER and PR levels are altered in individuals with endometriosis. This highlights the impact of the disease on typical reproductive tract function and may provide a novel pathway for the identification of individuals with endometriosis.
Collapse
Affiliation(s)
- Rachel C Wilson
- Department of Biology, Whitman College, Walla Walla, WA, USA.
| | - Jeanne M Link
- Center for Radiochemistry Research, Oregon Health & Science University, Portland, OR, USA
| | - Yueh Z Lee
- Department of Radiology, University of North Carolina, Chapel Hill, NC, USA
| | - Jorge D Oldan
- Department of Radiology, University of North Carolina, Chapel Hill, NC, USA
| | - Steven L Young
- Division of Reproduction Endocrinology and Infertility, Department of Obstetrics and Gynecology, Duke University School of Medicine, Durham, NC, USA
| | - Ov D Slayden
- Division of Reproductive and Developmental Sciences, Oregon National Primate Research Center, Oregon Health & Science University, Beaverton, OR, USA
- Department of Obstetrics and Gynecology, Oregon Health & Science University, Portland, OR, USA
| |
Collapse
|
3
|
Wilson RC, Link JM, Lee YZ, Oldan JD, Young SL, Slayden OD. Uterine uptake of estrogen and progestogen-based radiotracers in rhesus macaques with endometriosis. RESEARCH SQUARE 2023:rs.3.rs-3311162. [PMID: 37720028 PMCID: PMC10503868 DOI: 10.21203/rs.3.rs-3311162/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/19/2023]
Abstract
Purpose Few investigations have examined the uptake of radiotracers that target the prominent sex-steroid receptors in the uterus across the menstrual cycle and with disease state. We aimed to determine if uptake of the radiotracers that target estrogen and progesterone receptors (ER and PR) differ with the presence of endometriosis and/or across the menstrual cycle. We performed PET and computed tomography (CT) imaging procedures on rhesus macaques (Macaca mulatta) using 16α-[18F]fluoroestradiol (FES) and 21-[18F]fluoro-furanyl-nor-progesterone (FFNP) in individuals with and without endometriosis in the proliferative and secretory phases of the menstrual cycle. Procedures Macaques with either clinically diagnosed endometriosis (n = 6) or no endometriosis (n = 4) underwent abdominopelvic PET/CT scans with FES. A subset of these animals also underwent PET/CT scans with FFNP. Standard uptake values corrected for body weight (SUVbw) were obtained for each radiotracer in target and background tissues (i.e., intestinal and muscle). We performed repeated measure analysis of variance tests to determine how uterine and background uptake differed with scan time, phase of the menstrual cycle, and disease state. Results PET/CT could not resolve small, individual endometriotic lesions. However, uterine uptake of both radiotracers was elevated in the proliferative phase compared to the secretory phase of the menstrual cycle. Intestinal uptake exhibited greater variation during the proliferative phase compared to the secretory phase. Further, intestinal uptake of FFNP increases as the scan progresses, but only during the proliferative phase. Muscle uptake did not differ with menstrual phase or radiotracer type. Lastly, macaques with endometriosis displayed higher uterine uptake of FES compared to those without endometriosis. Conclusions PET/CT with FES and FFNP support the concept that ER and PR levels are altered in individuals with endometriosis. This highlights the impact of the disease on typical reproductive tract function and may provide a novel pathway for the identification of individuals with endometriosis.
Collapse
Affiliation(s)
| | | | - Yueh Z Lee
- The University of North Carolina at Chapel Hill
| | | | | | | |
Collapse
|
4
|
Sadeghzadeh M, Wenzel B, Nikodemus J, Florea A, Hertel F, Kopka K, Vogg ATJ, Kiessling F, Mottaghy FM. Improved protocol for the radiosynthesis of [ 18 F]FTC-146: A potent and selective sigma-1 receptor radioligand. J Labelled Comp Radiopharm 2023; 66:116-125. [PMID: 36807307 DOI: 10.1002/jlcr.4018] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Revised: 12/19/2022] [Accepted: 02/17/2023] [Indexed: 02/22/2023]
Abstract
[18 F]FTC-146 was introduced as a very potent and selective sigma-1 receptor radioligand, which has shown promising application as an imaging agent for neuropathic pain with positron emission tomography. In line with a multi-laboratory project on animal welfare, we chose this radioligand to investigate its potential for detecting neuropathic pain and tissue damage in tumor-bearing animals. However, the radiochemical yield (RCY) of around 4-7% was not satisfactory to us, and efforts were made to improve it. Herein, we describe an improved approach for the radiosynthesis of [18 F]FTC-146 resulting in a RCY, which is sevenfold higher than that previously reported. A tosylate precursor was synthesized and radio-fluorination experiments were performed via aliphatic nucleophilic substitution reactions using either K[18 F]F-Kryptofix®222 (K2.2.2 )-carbonate system or tetra-n-butylammonium [18 F]fluoride ([18 F]TBAF). Several parameters affecting the radiolabeling reaction such as solvent, 18 F-fluorination agent with the corresponding amount of base, labeling time, and temperature were investigated. Best labeling reaction conditions were found to be [18 F]TBAF and acetonitrile as solvent at 100°C. The new protocol was then translated to an automated procedure using a FX2 N synthesis module. Finally, the radiotracer reproducibly obtained with RCYs of 41.7 ± 4.4% in high radiochemical purity (>98%) and molar activities up to 171 GBq/μmol.
Collapse
Affiliation(s)
- Masoud Sadeghzadeh
- Department of Nuclear Medicine, Faculty of Medicine, RWTH Aachen University, Aachen, Germany
| | - Barbara Wenzel
- Department of Neuroradiopharmaceuticals, Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf, Leipzig, Germany
| | - Julia Nikodemus
- Department of Nuclear Medicine, Faculty of Medicine, RWTH Aachen University, Aachen, Germany
| | - Alexandru Florea
- Department of Nuclear Medicine, Faculty of Medicine, RWTH Aachen University, Aachen, Germany
- Department of Radiology and Nuclear Medicine, Maastricht University Medical Center, Maastricht, The Netherlands
- Schools for Cardiovascular Diseases (CARIM), for Oncology and Reproduction (GROW) and Nutrition and Translational Research in Metabolism (NUTRIM), Maastricht University Medical Center, Maastricht, The Netherlands
| | - Fabian Hertel
- Department of Nuclear Medicine, Faculty of Medicine, RWTH Aachen University, Aachen, Germany
| | - Klaus Kopka
- Department of Neuroradiopharmaceuticals, Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf, Leipzig, Germany
| | - Andreas T J Vogg
- Department of Nuclear Medicine, Faculty of Medicine, RWTH Aachen University, Aachen, Germany
| | - Fabian Kiessling
- Department of Nanomedicine and Theranostics, Institute for Experimental Molecular Imaging, Faculty of Medicine, RWTH Aachen University, Aachen, Germany
| | - Felix M Mottaghy
- Department of Nuclear Medicine, Faculty of Medicine, RWTH Aachen University, Aachen, Germany
- Department of Radiology and Nuclear Medicine, Maastricht University Medical Center, Maastricht, The Netherlands
- Schools for Cardiovascular Diseases (CARIM), for Oncology and Reproduction (GROW) and Nutrition and Translational Research in Metabolism (NUTRIM), Maastricht University Medical Center, Maastricht, The Netherlands
| |
Collapse
|
5
|
Parent EE, Fowler AM. Nuclear Receptor Imaging In Vivo-Clinical and Research Advances. J Endocr Soc 2022; 7:bvac197. [PMID: 36655003 PMCID: PMC9838808 DOI: 10.1210/jendso/bvac197] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/15/2022] [Indexed: 01/01/2023] Open
Abstract
Nuclear receptors are transcription factors that function in normal physiology and play important roles in diseases such as cancer, inflammation, and diabetes. Noninvasive imaging of nuclear receptors can be achieved using radiolabeled ligands and positron emission tomography (PET). This quantitative imaging approach can be viewed as an in vivo equivalent of the classic radioligand binding assay. A main clinical application of nuclear receptor imaging in oncology is to identify metastatic sites expressing nuclear receptors that are targets for approved drug therapies and are capable of binding ligands to improve treatment decision-making. Research applications of nuclear receptor imaging include novel synthetic ligand and drug development by quantifying target drug engagement with the receptor for optimal therapeutic drug dosing and for fundamental research into nuclear receptor function in cells and animal models. This mini-review provides an overview of PET imaging of nuclear receptors with a focus on radioligands for estrogen receptor, progesterone receptor, and androgen receptor and their use in breast and prostate cancer.
Collapse
Affiliation(s)
- Ephraim E Parent
- Mayo Clinic Florida, Department of Radiology, Jacksonville, Florida 32224, USA
| | - Amy M Fowler
- Correspondence: Amy M. Fowler, MD, PhD, Department of Radiology, University of Wisconsin School of Medicine and Public Health, 600 Highland Ave, Madison, WI 53792-3252, USA.
| |
Collapse
|
6
|
Pereira MP, Tejería ME, Zeni M, Gambini JP, Duarte P, Rey A, Giglio J. Radiosynthesis and validation of [ 18 F]Fluoroestradiol in a Synthra plus research platform for use in routine clinical practice. J Labelled Comp Radiopharm 2022; 65:292-297. [PMID: 35996821 DOI: 10.1002/jlcr.3998] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Revised: 08/11/2022] [Accepted: 08/17/2022] [Indexed: 11/06/2022]
Abstract
In this practitioner protocol, the optimization of the radiochemical synthesis of [18 F]fluoroestradiol (FES) on the Synthra RNplus research automated platform is described in detail and a QC summary of three validation productions is presented. In comparison to published synthesis methods developed on other platforms, the yield was considerably improved (40-45% ndc). The other important improvement is the reduction of the required concentration of H2 SO4 avoiding the production of high concentrations of acidic vapors that can deteriorate the module. Purification was achieved by solid phase extraction and the required adaptation of an external heating plate to the module to evaporate the ethanol is also described. The product was obtained with high radiochemical purity and fulfilled all the requirements of current Good Manufacturing Practice (cGMP). The final product is formulated as a sterile, pyrogen-free solution suitable for human injection. To the best of our knowledge this is the first report of FES production using this type of module.
Collapse
Affiliation(s)
- María Pía Pereira
- Centro Uruguayo de Imagenología Molecular (CUDIM), Montevideo, Uruguay.,Área Radioquímica, Facultad de Química, Universidad de la República, Montevideo, Uruguay
| | - María Emilia Tejería
- Área Radioquímica, Facultad de Química, Universidad de la República, Montevideo, Uruguay
| | - Maia Zeni
- Centro Uruguayo de Imagenología Molecular (CUDIM), Montevideo, Uruguay.,Área Radioquímica, Facultad de Química, Universidad de la República, Montevideo, Uruguay
| | | | - Pablo Duarte
- Centro Uruguayo de Imagenología Molecular (CUDIM), Montevideo, Uruguay
| | - Ana Rey
- Área Radioquímica, Facultad de Química, Universidad de la República, Montevideo, Uruguay
| | - Javier Giglio
- Centro Uruguayo de Imagenología Molecular (CUDIM), Montevideo, Uruguay
| |
Collapse
|
7
|
Maisto C, Morisco A, de Marino R, Squame E, Porfidia V, D'Ambrosio L, Di Martino D, Gaballo P, Aurilio M, Buonanno M, Esposito A, Raddi M, Lastoria S. On site production of [ 18F]PSMA-1007 using different [ 18F]fluoride activities: practical, technical and economical impact. EJNMMI Radiopharm Chem 2021; 6:36. [PMID: 34643830 PMCID: PMC8514599 DOI: 10.1186/s41181-021-00150-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Accepted: 09/20/2021] [Indexed: 12/03/2022] Open
Abstract
Background Prostate-specific membrane antigen is overexpressed in prostate cancer and it is considered a good target for positron emission tomography/computed tomography imaging of primary cancer and recurrent/metastatic disease, as well as for radioligand therapy. Different PSMA-analogues labeled with [68Ga]gallium have been investigated, showing excellent imaging properties; however, only small amounts can be produced for each radiolabeling. Recently, a [18F]fluoride labeled PSMA-inhibitor, [18F]PSMA-1007, has been introduced, and it has ensured large-scale productions, overcoming this limitation of [68Ga]PSMAs. In this study, PSMA-1007 has been labeled with low (A), medium (B) and high (C) starting activities of [18F]fluoride, in order to verify if radiochemical yield, radiochemical purity and stability of [18F]PSMA-1007 were affected. These parameters have been measured in sixty-five consecutive batches. In addition, the estimation of [18F]PSMA-1007 production costs is provided. Results The radiochemical yield for low and medium activities of [18F]fluoride was 52%, while for the high one it decreased to 40%. The radiochemical purity was 99% for all three activities. [18F]PSMA-1007 did not show radiolysis up to 8 h after the end of synthesis, confirming that the radiopharmaceutical is stable and suitable to perform diagnostic studies in humans for a long period of time after the end of radiolabeling. Furthermore, radiochemical stability was demonstrated in fetal bovine serum at 4 °C and 37 °C for 120′. Conclusions A starting activity of [18F]fluoride of 90 GBq (B) seems to be the best option enabling a final amount of about of 50 GBq of [18F]PSMA-1007, which is promising as it allows to: (a) perform a large number of scans, and/or (b) supply the radiopharmaceutical to any peripheral diagnostic centers in need.
Collapse
Affiliation(s)
- Costantina Maisto
- Nuclear Medicine Division, Istituto Nazionale Tumori - IRCCS Fondazione G. Pascale, Naples, Italy
| | - Anna Morisco
- Nuclear Medicine Division, Istituto Nazionale Tumori - IRCCS Fondazione G. Pascale, Naples, Italy
| | - Roberta de Marino
- Nuclear Medicine Division, Istituto Nazionale Tumori - IRCCS Fondazione G. Pascale, Naples, Italy
| | - Elisabetta Squame
- Nuclear Medicine Division, Istituto Nazionale Tumori - IRCCS Fondazione G. Pascale, Naples, Italy
| | - Valentina Porfidia
- Nuclear Medicine Division, Istituto Nazionale Tumori - IRCCS Fondazione G. Pascale, Naples, Italy
| | - Laura D'Ambrosio
- Nuclear Medicine Division, Istituto Nazionale Tumori - IRCCS Fondazione G. Pascale, Naples, Italy
| | - Daria Di Martino
- Nuclear Medicine Division, Istituto Nazionale Tumori - IRCCS Fondazione G. Pascale, Naples, Italy
| | - Paolo Gaballo
- Nuclear Medicine Division, Istituto Nazionale Tumori - IRCCS Fondazione G. Pascale, Naples, Italy
| | - Michela Aurilio
- Nuclear Medicine Division, Istituto Nazionale Tumori - IRCCS Fondazione G. Pascale, Naples, Italy
| | - Monica Buonanno
- Nuclear Medicine Division, Istituto Nazionale Tumori - IRCCS Fondazione G. Pascale, Naples, Italy
| | - Aureliana Esposito
- Nuclear Medicine Division, Istituto Nazionale Tumori - IRCCS Fondazione G. Pascale, Naples, Italy
| | - Marco Raddi
- Nuclear Medicine Division, Istituto Nazionale Tumori - IRCCS Fondazione G. Pascale, Naples, Italy
| | - Secondo Lastoria
- Nuclear Medicine Division, Istituto Nazionale Tumori - IRCCS Fondazione G. Pascale, Naples, Italy.
| |
Collapse
|
8
|
Bratteby K, Shalgunov V, Herth MM. Aliphatic 18 F-Radiofluorination: Recent Advances in the Labeling of Base-Sensitive Substrates*. ChemMedChem 2021; 16:2612-2622. [PMID: 34169672 DOI: 10.1002/cmdc.202100303] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Indexed: 12/19/2022]
Abstract
Aliphatic fluorine-18 radiolabeling is the most commonly used method to synthesize tracers for PET-imaging. With an increasing demand for 18 F-radiotracers for clinical applications, new labeling strategies aiming to increase radiochemical yields of established tracers or, more importantly, to enable 18 F-labeling of new scaffolds have been developed. In recent years, increased attention has been focused on the direct aliphatic 18 F-fluorination of base-sensitive substrates in this respect. This minireview gives a concise overview of the recent advances within this field and aims to highlight the advantages and limitations of these methods.
Collapse
Affiliation(s)
- Klas Bratteby
- Department of Drug Design and Pharmacology Faculty of Health and Medical Sciences, University of Copenhagen, Jagtvej 160, 2100, Copenhagen, Denmark.,Department of Radiation Physics, Skåne University Hospital, Barngatan 3, 222 42, Lund, Sweden.,Department of Clinical Physiology, Nuclear Medicine & PET Rigshospitalet, Blegdamsvej 9, 2100, Copenhagen, Denmark
| | - Vladimir Shalgunov
- Department of Drug Design and Pharmacology Faculty of Health and Medical Sciences, University of Copenhagen, Jagtvej 160, 2100, Copenhagen, Denmark
| | - Matthias Manfred Herth
- Department of Drug Design and Pharmacology Faculty of Health and Medical Sciences, University of Copenhagen, Jagtvej 160, 2100, Copenhagen, Denmark.,Department of Clinical Physiology, Nuclear Medicine & PET Rigshospitalet, Blegdamsvej 9, 2100, Copenhagen, Denmark
| |
Collapse
|
9
|
Katzenellenbogen JA. The quest for improving the management of breast cancer by functional imaging: The discovery and development of 16α-[ 18F]fluoroestradiol (FES), a PET radiotracer for the estrogen receptor, a historical review. Nucl Med Biol 2021; 92:24-37. [PMID: 32229068 PMCID: PMC7442693 DOI: 10.1016/j.nucmedbio.2020.02.007] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Accepted: 02/16/2020] [Indexed: 12/21/2022]
Abstract
INTRODUCTION 16α-[18F]Fluoroestradiol (FES), a PET radiotracer for the estrogen receptor (ER) in breast cancer, was the first receptor-targeted PET radiotracer for oncology and is continuing to prove its value in clinical research, antiestrogen development, and breast cancer care. The story of its conception, design, evaluation and use in clinical studies parallels the evolution of the whole field of receptor-targeted radiotracers, one greatly influenced by the research and intellectual contributions of William C. Eckelman. METHODS AND RESULTS The development of methods for efficient production of fluorine-18, for conversion of [18F]fluoride ion into chemically reactive form, and for its rapid and efficient incorporation into suitable estrogen precursor molecules at high molar activity, were all methodological underpinnings required for the preparation of FES. FES binds to ER with very high affinity, and its in vivo uptake by ER-dependent target tissues in animal models was efficient and selective, findings that preceded its use for PET imaging in patients with breast cancer. ADVANCES IN KNOWLEDGE AND IMPLICATIONS FOR PATIENT CARE Comparisons between ER levels measured by FES-PET imaging of breast tumors with tissue-specimen ER quantification by IHC and other methods show that imaging provided improved prediction of benefit from endocrine therapies. Serial imaging of ER by FES-PET, before and after dosing patients with antiestrogens, is used to determine the efficacious dose for established antiestrogens and to facilitate clinical development of new ER antagonists. Beyond FES imaging, PET-based hormone challenge tests, which evaluate the functional status of ER by monitoring rapid changes in tumor metabolic or transcriptional activity after a brief estrogen challenge, provide highly sensitive and selective predictions of whether or not there will be a favorable response to endocrine therapies. There is sufficient interest in the clinical applications of FES that FDA approval is being sought for its wider use in breast cancer. CONCLUSIONS FES was the first PET probe for a receptor in cancer, and its development and clinical applications in breast cancer parallel the conceptual evolution of the whole field of receptor-binding radiotracers.
Collapse
Affiliation(s)
- John A Katzenellenbogen
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801, United States of America.
| |
Collapse
|
10
|
Automated synthesis of the 16α-[18F]fluoroestradiol ([18F]FES): minimization of precursor amount and resulting benefits. RADIOCHIM ACTA 2020. [DOI: 10.1515/ract-2020-0058] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Abstract
The 16α-[18F]Fluoroestradiol ([18F]FES) is an established PET radiotracer for estrogen positive (ER+) breast cancer. Although the radiosynthesis is well-described, the majority of the published methods suffer from modest or irreproducible yields and time-intensive purification procedures. In view of the considerable clinical applications, development of a more efficient and faster synthesis of [18F]FES still remains a task of a significant practical importance. [18F]FES was produced by a direct nucleophilic radiofluorination of 3-O-methoxymethyl-16,17-O-sulfuryl-16-epiestriol (MMSE), followed by acidic hydrolysis using HCl/CH3CN. [18F]Fluoride retained on a QMA carb cartridge (46 mg) was eluted by solution of 1.2 mg of tetrabutylammonium tosylate (TBAOTs) in EtOH. After fluorination reaction (0.3 mg MMSE, 1 ml of CH3CN/100 °C, 5 min) [18F]FES was isolated by single-cartridge SPE purification using OASIS WAX 3cc, elution accomplished with aqueous ethanol of different concentrations. On а GE TRACERlab FX N Pro automated module [18F]FES (formulated in normal saline with 5% EtOH) was obtained in 33 ± 3% yield (n = 5, non-decay corrected) within 32 min. Reduction of precursor amount, exclusion of azeotropic drying step and simplification of purification make the suggested method readily adaptable to various automated synthesizers and offers significant cost decrease.
Collapse
|
11
|
Katzenellenbogen JA. PET Imaging Agents (FES, FFNP, and FDHT) for Estrogen, Androgen, and Progesterone Receptors to Improve Management of Breast and Prostate Cancers by Functional Imaging. Cancers (Basel) 2020; 12:E2020. [PMID: 32718075 PMCID: PMC7465097 DOI: 10.3390/cancers12082020] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 06/30/2020] [Accepted: 07/17/2020] [Indexed: 12/20/2022] Open
Abstract
Many breast and prostate cancers are driven by the action of steroid hormones on their cognate receptors in primary tumors and in metastases, and endocrine therapies that inhibit hormone production or block the action of these receptors provide clinical benefit to many but not all of these cancer patients. Because it is difficult to predict which individuals will be helped by endocrine therapies and which will not, positron emission tomography (PET) imaging of estrogen receptor (ER) and progesterone receptor (PgR) in breast cancer, and androgen receptor (AR) in prostate cancer can provide useful, often functional, information on the likelihood of endocrine therapy response in individual patients. This review covers our development of three PET imaging agents, 16α-[18F]fluoroestradiol (FES) for ER, 21-[18F]fluoro-furanyl-nor-progesterone (FFNP) for PgR, and 16β-[18F]fluoro-5α-dihydrotestosterone (FDHT) for AR, and the evolution of their clinical use. For these agents, the pathway from concept through development tracks with an emerging understanding of critical performance criteria that is needed for successful PET imaging of these low-abundance receptor targets. Progress in the ongoing evaluation of what they can add to the clinical management of breast and prostate cancers reflects our increased understanding of these diseases and of optimal strategies for predicting the success of clinical endocrine therapies.
Collapse
Affiliation(s)
- John A Katzenellenbogen
- Department of Chemistry and Cancer Center at Illinois, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| |
Collapse
|
12
|
Fully automated radiosynthesis and quality control of estrogen receptor targeting radiopharmaceutical 16α-[18F]fluoroestradiol ([18F]FES) for human breast cancer imaging. Appl Radiat Isot 2020; 160:109109. [DOI: 10.1016/j.apradiso.2020.109109] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2019] [Revised: 02/10/2020] [Accepted: 02/27/2020] [Indexed: 11/17/2022]
|
13
|
Mattingly SJ, Wuest M, Fine EJ, Schirrmacher R, Wuest F. Synthesis and in vivo evaluation of a radiofluorinated ketone body derivative. RSC Med Chem 2020; 11:297-306. [PMID: 33479637 PMCID: PMC7580772 DOI: 10.1039/c9md00486f] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Accepted: 02/02/2020] [Indexed: 12/28/2022] Open
Abstract
The ketone bodies d-beta-hydroxybutyric acid and acetoacetic acid represent the principal oxidative energy sources of most tissues when dietary glucose is scarce. An 18F-labeled ketone body could be a useful tool for studying ketone body metabolism using positron emission tomography (PET). Here, we report the first radiofluorinated ketone body derivative (3S)-4-[18F]fluoro-3-hydroxybutyric acid ([18F]FBHB) as well as its enantiomer and l-beta-hydroxybutyric acid derivative, (3R)-4-[18F]fluoro-3-hydroxybutyric acid ((R)-[18F]F3HB). PET imaging in mice showed biodistribution profiles of the radiotracers that were consistent with the biodistribution of the respective endogenous compounds. Moreover, both enantiomers visualized breast cancer xenografts in vivo. Fasting over 24 h showed significantly enhanced brain and heart uptake of [18F]FBHB and tumor uptake of (R)-[18F]F3HB. Disorders exhibiting altered energy substrate utilization, such as Alzheimer's disease, epilepsy, diabetes, and cancer may be of interest for PET imaging studies using [18F]FBHB.
Collapse
Affiliation(s)
| | - Melinda Wuest
- Department of Oncology , University of Alberta , Edmonton , Canada .
- Cancer Research Institute of Northern Alberta , University of Alberta , Edmonton , Canada
| | - Eugene J Fine
- Department of Radiology (Nuclear Medicine) , Albert Einstein College of Medicine/Montefiore Medical Center , NY , NY , USA
| | - Ralf Schirrmacher
- Department of Oncology , University of Alberta , Edmonton , Canada .
- Department of Chemistry , University of Alberta , Edmonton , Canada
| | - Frank Wuest
- Department of Oncology , University of Alberta , Edmonton , Canada .
- Cancer Research Institute of Northern Alberta , University of Alberta , Edmonton , Canada
- Department of Chemistry , University of Alberta , Edmonton , Canada
- Faculty of Pharmacy and Pharmaceutical Sciences , University of Alberta , Edmonton , Canada
| |
Collapse
|
14
|
Ermert J, Benešová M, Hugenberg V, Gupta V, Spahn I, Pietzsch HJ, Liolios C, Kopka K. Radiopharmaceutical Sciences. Clin Nucl Med 2020. [DOI: 10.1007/978-3-030-39457-8_2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
|
15
|
Basuli F, Zhang X, Blackman B, White ME, Jagoda EM, Choyke PL, Swenson RE. Fluorine-18 Labeled Fluorofuranylnorprogesterone ([ 18F]FFNP) and Dihydrotestosterone ([ 18F]FDHT) Prepared by "Fluorination on Sep-Pak" Method. Molecules 2019; 24:molecules24132389. [PMID: 31261651 PMCID: PMC6651117 DOI: 10.3390/molecules24132389] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2019] [Revised: 06/25/2019] [Accepted: 06/25/2019] [Indexed: 12/31/2022] Open
Abstract
To further explore the scope of our recently developed “fluorination on Sep-Pak” method, we prepared two well-known positron emission tomography (PET) tracers 21-[18F]fluoro-16α,17α-[(R)-(1′-α-furylmethylidene)dioxy]-19-norpregn-4-ene-3,20-dione furanyl norprogesterone ([18F]FFNP) and 16β-[18F]fluoro-5α-dihydrotestosterone ([18F]FDHT). Following the “fluorination on Sep-Pak” method, over 70% elution efficiency was observed with 3 mg of triflate precursor of [18F]FFNP. The overall yield of [18F]FFNP was 64–72% (decay corrected) in 40 min synthesis time with a molar activity of 37–81 GBq/µmol (1000–2200 Ci/mmol). Slightly lower elution efficiency (~55%) was observed with the triflate precursor of [18F]FDHT. Fluorine-18 labeling, reduction, and deprotection to prepare [18F]FDHT were performed on Sep-Pak cartridges (PS-HCO3 and Sep-Pak plus C-18). The overall yield of [18F]FDHT was 25–32% (decay corrected) in 70 min. The molar activity determined by using mass spectrometry was 63–148 GBq/µmol (1700–4000 Ci/mmol). Applying this quantitative measure of molar activity to in vitro assays [18F]FDHT exhibited high-affinity binding to androgen receptors (Kd~2.5 nM) providing biological validation of this method.
Collapse
Affiliation(s)
- Falguni Basuli
- Imaging Probe Development Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Rockville, MD 20850, USA.
| | - Xiang Zhang
- Imaging Probe Development Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Rockville, MD 20850, USA
| | - Burchelle Blackman
- Imaging Probe Development Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Rockville, MD 20850, USA
| | - Margaret E White
- Molecular Imaging Program, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
- Laboratory of Genitourinary Cancer Pathogenesis, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Elaine M Jagoda
- Molecular Imaging Program, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Peter L Choyke
- Molecular Imaging Program, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Rolf E Swenson
- Imaging Probe Development Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Rockville, MD 20850, USA
| |
Collapse
|
16
|
Shamni O, Nebeling B, Grievink H, Mishani E. Fine-tuning of the automated [18
F]PSMA-1007 radiosynthesis. J Labelled Comp Radiopharm 2019; 62:252-258. [DOI: 10.1002/jlcr.3732] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Revised: 03/25/2019] [Accepted: 03/27/2019] [Indexed: 01/25/2023]
Affiliation(s)
- Ofer Shamni
- Cyclotron/Radiochemistry/MicroPET Unit; Hadassah Hebrew University Hospital, Hadassah Medical Organization; Jerusalem Israel
| | | | - Hilbert Grievink
- Cyclotron/Radiochemistry/MicroPET Unit; Hadassah Hebrew University Hospital, Hadassah Medical Organization; Jerusalem Israel
| | - Eyal Mishani
- Cyclotron/Radiochemistry/MicroPET Unit; Hadassah Hebrew University Hospital, Hadassah Medical Organization; Jerusalem Israel
| |
Collapse
|
17
|
Verhoog S, Brooks AF, Winton WP, Viglianti BL, Sanford MS, Scott PJH. Ring opening of epoxides with [ 18F]FeF species to produce [ 18F]fluorohydrin PET imaging agents. Chem Commun (Camb) 2019; 55:6361-6364. [PMID: 31062010 DOI: 10.1039/c9cc02779c] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
A simple technique for the preparation of [18F]HF has been developed and applied to the generation of an [18F]FeF species for opening sterically hindered epoxides. This method has been successfully employed to prepare four drug-like molecules, including 5-[18F]fluoro-6-hydroxy-cholesterol, a potential adrenal/endocrine PET imaging agent. This easily automated one-pot procedure produces sterically hindered fluorohydrin PET imaging agents in good yields and high molar activities.
Collapse
Affiliation(s)
- Stefan Verhoog
- Division of Nuclear Medicine, Department of Radiology, The University of Michigan Medical School, Ann Arbor, Michigan 48109, USA.
| | | | | | | | | | | |
Collapse
|
18
|
Automated SPE-based synthesis of 16α-[18F]fluoroestradiol without HPLC purification step. Appl Radiat Isot 2018; 141:57-63. [DOI: 10.1016/j.apradiso.2018.08.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2018] [Revised: 07/04/2018] [Accepted: 08/08/2018] [Indexed: 11/17/2022]
|
19
|
Larimer BM, Dubois F, Bloch E, Nesti S, Placzek M, Zadra G, Hooker JM, Loda M, Mahmood U. Specific 18F-FDHT Accumulation in Human Prostate Cancer Xenograft Murine Models Is Facilitated by Prebinding to Sex Hormone-Binding Globulin. J Nucl Med 2018; 59:1538-1543. [PMID: 29853654 DOI: 10.2967/jnumed.118.208785] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Accepted: 05/03/2018] [Indexed: 11/16/2022] Open
Abstract
Tremendous efforts are currently dedicated to the development of novel therapies targeting the androgen receptor (AR), the major driver of prostate cancer disease and its progression to castration resistance. The ability to noninvasively interrogate AR expression over time in murine models of prostate cancer would permit longitudinal preclinical analysis of novel compounds that could not otherwise be accomplished ex vivo. Although PET imaging with 16β-18F-fluoro-5α-dihydrotestosterone (18F-FDHT) has successfully quantified AR levels clinically, no rodent model of 18F-FDHT imaging has been reported so far. One difference between humans and rodents is the absence in the latter of the sex hormone-binding globulin (SHBG), a glycoprotein that binds to testosterone in the bloodstream, Here, we explore the role of SHBG in developing a working model of rodent AR imaging. Methods: Three human prostate cancer cell lines and xenografts (LNCaP, 22Rv1, and PC3) were used to examine the uptake of free 18F-FDHT and SHBG-bound 18F-FDHT. Both ligands were examined for stability and competitive binding to AR over time in vitro before in vivo studies. PET/CT imaging was used to dynamically measure the uptake of both tracers over 4 h, whereas specificity was determined by competitive binding with the AR antagonist enzalutamide. Results: AR levels correlated with the uptake of both 18F-FDHT and SHBG-18F-FDHT in prostate cancer cell lines. Interestingly, whereas both free and SHBG-bound 18F-FDHT had a similar cellular accumulation at 1 and 2.5 h, SHBG-18F-FDHT accumulated at significantly higher levels after 4 h-evidence that receptor-mediated uptake of SHBG accounted for later time-point differences. This observation was also seen in 22Rv1 tumor-bearing mice, in which SHBG-18F-FDHT exhibited a significantly increased uptake (average tumor-to-background ratio [TBR], 1.62 ± 0.62) in comparison to unbound 18F-FDHT (TBR, 0.81 ± 0.08) at 4 h. Furthermore, the specificity of the SHBG-18F-FDHT accumulation at 4 h was demonstrated by a reduced tumor uptake after AR blockade with enzalutamide (TBR, 1.07 ± 0.13). Conclusion: Prebinding of 18F-FDHT to SHBG allows accurate and quantitative PET imaging of AR levels in murine models of prostate cancer. This procedure may permit the use of PET imaging to study the longitudinal effects of AR-targeting therapies, accelerating novel-drug development.
Collapse
Affiliation(s)
- Benjamin M Larimer
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Boston, Massachusetts
| | - Frank Dubois
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Boston, Massachusetts
| | - Emily Bloch
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Boston, Massachusetts
| | - Sarah Nesti
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Boston, Massachusetts
| | - Michael Placzek
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Boston, Massachusetts
| | - Giorgia Zadra
- Department of Medical Oncology, Center for Molecular Oncologic Pathology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts; and.,Department of Pathology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Jacob M Hooker
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Boston, Massachusetts
| | - Massimo Loda
- Department of Medical Oncology, Center for Molecular Oncologic Pathology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts; and.,Department of Pathology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Umar Mahmood
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Boston, Massachusetts
| |
Collapse
|
20
|
Salem K, Kumar M, Kloepping KC, Michel CJ, Yan Y, Fowler AM. Determination of binding affinity of molecular imaging agents for steroid hormone receptors in breast cancer. AMERICAN JOURNAL OF NUCLEAR MEDICINE AND MOLECULAR IMAGING 2018; 8:119-126. [PMID: 29755845 PMCID: PMC5944827] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 02/13/2018] [Accepted: 04/20/2018] [Indexed: 06/08/2023]
Abstract
16α-[18F]Fluoro-17β-estradiol ([18F]FES) and 21-[18F]-Fluoro-16α,17α-[(R)-(1'-α-furylmethylidene)dioxyl]-19-norpregn-4-ene-3,20-dione ([18F]FFNP) are being investigated as imaging biomarkers for breast cancer patients. Quantitative positron emission tomography (PET) reflects both total receptor content and binding affinity. To study factors that may alter radiopharmaceutical binding and impact PET accuracy, assays that can separate receptor amount from binding affinity are needed. The study purpose was to quantify the binding parameters of [18F]FES and [18F]FFNP in breast cancer. Estrogen receptor-alpha (ER) and progesterone receptor (PR) positive breast cancer cell lines (MCF-7 and T47D) were used to measure [18F]FES and [18F]FFNP binding parameters via saturation and competitive binding curves. The equilibrium dissociation constant (Kd) and total receptor density (Bmax) were determined using nonlinear regression of the saturation binding curves. Half-maximal inhibitory concentration (IC50) was determined using nonlinear regression of the competitive binding curves. Linear correlation between increasing cell number and tracer uptake was observed for both [18F]FES and [18F]FFNP (R2=0.99 and 0.91, respectively). Using [18F]FES, the Kd for ER in MCF-7 cells was 0.13±0.02 nM with a Bmax of 1901±89.3 fmol/mg protein and IC50 of 0.085 nM (95% CI: 0.069-0.104 nM). Using [18F]FFNP, the Kd for PR in T47D cells was 0.41±0.05 nM with a Bmax of 1984±75.6 fmol/mg protein and IC50 of 2.6 nM (95% CI: 2.0-3.4 nM). The ligand binding function of ER and PR can be quantified using [18F]FES and [18F]FFNP and are comparable to previous studies using tritiated radioligands. [18F]FES and [18F]FFNP can be used in cell-based assays to quantify receptor-radioligand binding affinity, which cannot be obtained from a single PET examination.
Collapse
Affiliation(s)
- Kelley Salem
- Department of Radiology, University of Wisconsin School of Medicine and Public Health600 Highland Avenue, Madison, WI 53792, USA
| | - Manoj Kumar
- Department of Radiology, University of Wisconsin School of Medicine and Public Health600 Highland Avenue, Madison, WI 53792, USA
| | - Kyle C Kloepping
- Department of Radiology, University of Wisconsin School of Medicine and Public Health600 Highland Avenue, Madison, WI 53792, USA
- Perkin ElmerWaltham, MA, USA
| | - Ciara J Michel
- Department of Radiology, University of Wisconsin School of Medicine and Public Health600 Highland Avenue, Madison, WI 53792, USA
| | - Yongjun Yan
- Department of Radiology, University of Wisconsin School of Medicine and Public Health600 Highland Avenue, Madison, WI 53792, USA
- Department of Medical Physics, University of Wisconsin School of Medicine and Public Health1111 Highland Avenue, Madison, WI 53705, USA
| | - Amy M Fowler
- Department of Radiology, University of Wisconsin School of Medicine and Public Health600 Highland Avenue, Madison, WI 53792, USA
- University of Wisconsin Carbone Cancer Center600 Highland Avenue, Madison, WI 53792, USA
- Department of Medical Physics, University of Wisconsin School of Medicine and Public Health1111 Highland Avenue, Madison, WI 53705, USA
| |
Collapse
|
21
|
Iwata R, Pascali C, Terasaki K, Ishikawa Y, Furumoto S, Yanai K. Practical microscale one-pot radiosynthesis of 18 F-labeled probes. J Labelled Comp Radiopharm 2018. [PMID: 29520821 DOI: 10.1002/jlcr.3618] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
High specific activity is often a significant requirement for radiopharmaceuticals. To achieve that with fluorine-18 (18 F)-labeled probes, it is mandatory to start from no-carrier-added fluoride and to reduce to a minimum the amount of precursor in order to decrease the presence of any pseudocarrier. In the present study, a feasible and efficient method for microscale one-pot radiosynthesis of 18 F-labeled probes is described. It allows a substantial reduction in precursor, solvent, and reagents, thus reducing also possible side reaction in the case of base-sensitive precursors. The method is based on the use of a small amount of Kryptofix 2.2.2/potassium [18 F]fluoride in MeOH (K.222/K[18 F]F-MeOH) obtained using Oasis MAX and MCX cartridges. Five methods, differing in terms of MeOH evaporation and precursor addition, for the radiosynthesis of [18 F]fallypride and [18 F]FET in ≤50-μL scale, were examined and evaluated. The method using the addition of DMSO to the K.222/K[18 F]F-MeOH solution prior to MeOH evaporation is proposed as a versatile procedure for feasible one-pot 10- to 20-μL scale radiosyntheses. This method was successfully applied also to the radiosynthesis of [18 F]FES, [18 F]FLT, and [18 F]FMISO, with radiochemical yields comparable with those reported in the literature. Purification of a crude product by an analytical HPLC column was also demonstrated.
Collapse
Affiliation(s)
- Ren Iwata
- Cyclotron and Radioisotope Center, Tohoku University, Sendai, Japan
| | - Claudio Pascali
- S.C. Medicina Nucleare, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy
| | | | - Yoichi Ishikawa
- Cyclotron and Radioisotope Center, Tohoku University, Sendai, Japan
| | - Shozo Furumoto
- Cyclotron and Radioisotope Center, Tohoku University, Sendai, Japan
| | - Kazuhiko Yanai
- Cyclotron and Radioisotope Center, Tohoku University, Sendai, Japan.,Graduate School of Medicine, Tohoku University, Sendai, Japan
| |
Collapse
|
22
|
Salem K, Kumar M, Powers GL, Jeffery JJ, Yan Y, Mahajan AM, Fowler AM. 18F-16α-17β-Fluoroestradiol Binding Specificity in Estrogen Receptor-Positive Breast Cancer. Radiology 2017; 286:856-864. [PMID: 28956736 DOI: 10.1148/radiol.2017162956] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Purpose To determine the binding specificity of 18F-16α-17β-fluoroestradiol (FES) in estrogen receptor (ER) α-positive breast cancer cells and tumor xenografts. Materials and Methods Protocols were approved by the office of biologic safety and institutional animal care and use committee. By using ER-negative MDA-MB-231 breast cancer cells, clonal lines were created that expressed either wild-type (WT; 231 WT ER) or G521R mutant ERα (231 G521R ER), which is defective in estradiol binding. ERα protein levels, subcellular localization, and transcriptional function were confirmed. FES binding was measured by using an in vitro cell uptake assay. In vivo FES uptake was measured in tumor xenografts by using small-animal positron emission tomographic/computed tomographic imaging of 24 mice (17 WT ER tumors, nine mutant G521R ER tumors, eight MDA-MB-231 tumors, and four MCF-7 ER-positive tumors). Statistical significance was determined by using Mann-Whitney (Wilcoxon rank sum) test. Results ERα transcriptional function was abolished in the mutated 231 G521R ER cells despite appropriate receptor protein expression and nuclear localization. In vitro FES binding in the 231 G521R ER cells was reduced to that observed in the parental cells. Similarly, there was no significant FES uptake in the 231 G521R ER xenografts (percent injected dose [ID] per gram, 0.49 ± 0.042), which was similar to the negative control MDA-MB-231 xenografts (percent ID per gram, 0.42 ± 0.051; P = .20) and nonspecific muscle uptake (percent ID per gram, 0.41 ± 0.0095; P = .06). Conclusion This study showed that FES retention in ER-positive breast cancer is strictly dependent on an intact receptor ligand-binding pocket and that FES binds to ERα with high specificity. These results support the utility of FES imaging for assessing tumor heterogeneity by localizing immunohistochemically ER-positive metastases that lack receptor-binding functionality. © RSNA, 2017 Online supplemental material is available for this article.
Collapse
Affiliation(s)
- Kelley Salem
- From the Department of Radiology (K.S., M.K., G.L.P., Y.Y., A.M.F.), Carbone Cancer Center (J.J.J., A.M.F.), Department of Medical Physics (Y.Y., A.M.F.), and Department of Pathology and Laboratory Medicine (A.M.M.), University of Wisconsin School of Medicine and Public Health, 600 Highland Ave, Madison, WI 53792
| | - Manoj Kumar
- From the Department of Radiology (K.S., M.K., G.L.P., Y.Y., A.M.F.), Carbone Cancer Center (J.J.J., A.M.F.), Department of Medical Physics (Y.Y., A.M.F.), and Department of Pathology and Laboratory Medicine (A.M.M.), University of Wisconsin School of Medicine and Public Health, 600 Highland Ave, Madison, WI 53792
| | - Ginny L Powers
- From the Department of Radiology (K.S., M.K., G.L.P., Y.Y., A.M.F.), Carbone Cancer Center (J.J.J., A.M.F.), Department of Medical Physics (Y.Y., A.M.F.), and Department of Pathology and Laboratory Medicine (A.M.M.), University of Wisconsin School of Medicine and Public Health, 600 Highland Ave, Madison, WI 53792
| | - Justin J Jeffery
- From the Department of Radiology (K.S., M.K., G.L.P., Y.Y., A.M.F.), Carbone Cancer Center (J.J.J., A.M.F.), Department of Medical Physics (Y.Y., A.M.F.), and Department of Pathology and Laboratory Medicine (A.M.M.), University of Wisconsin School of Medicine and Public Health, 600 Highland Ave, Madison, WI 53792
| | - Yongjun Yan
- From the Department of Radiology (K.S., M.K., G.L.P., Y.Y., A.M.F.), Carbone Cancer Center (J.J.J., A.M.F.), Department of Medical Physics (Y.Y., A.M.F.), and Department of Pathology and Laboratory Medicine (A.M.M.), University of Wisconsin School of Medicine and Public Health, 600 Highland Ave, Madison, WI 53792
| | - Aparna M Mahajan
- From the Department of Radiology (K.S., M.K., G.L.P., Y.Y., A.M.F.), Carbone Cancer Center (J.J.J., A.M.F.), Department of Medical Physics (Y.Y., A.M.F.), and Department of Pathology and Laboratory Medicine (A.M.M.), University of Wisconsin School of Medicine and Public Health, 600 Highland Ave, Madison, WI 53792
| | - Amy M Fowler
- From the Department of Radiology (K.S., M.K., G.L.P., Y.Y., A.M.F.), Carbone Cancer Center (J.J.J., A.M.F.), Department of Medical Physics (Y.Y., A.M.F.), and Department of Pathology and Laboratory Medicine (A.M.M.), University of Wisconsin School of Medicine and Public Health, 600 Highland Ave, Madison, WI 53792
| |
Collapse
|
23
|
Pandit-Taskar N, Veach DR, Fox JJ, Scher HI, Morris MJ, Larson SM. Evaluation of Castration-Resistant Prostate Cancer with Androgen Receptor-Axis Imaging. J Nucl Med 2017; 57:73S-78S. [PMID: 27694177 DOI: 10.2967/jnumed.115.170134] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Accepted: 08/15/2016] [Indexed: 12/28/2022] Open
Abstract
Castration-resistant prostate cancer (CRPC) is the lethal form of prostate cancer, and more than 26,000 men will die from this disease in 2016. The pathophysiology of CRPC is clearly multifactorial, but most often, androgen receptor (AR) upregulation is associated with its earliest beginnings and the AR increase is part of the multimolecular complex including downstream effector proteins linked to AR (AR-axis) responsible for rapid proliferation and malignant features of the malignant cell. In both animal models and patients, glycolysis (Warburg effect) is also an early manifestation of CRPC transformation. At Memorial Sloan Kettering Cancer Center, we have focused our energies on imaging studies of the AR-axis in CRPC, using 18F-FDG, 18F-16β-fluoro-5α-dihydrotestosterone (18F-FDHT), and a variety of radiolabeled antibodies targeting downstream effectors, such as prostate-specific membrane antigen (PSMA). Small-molecular-weight PSMA-targeting agents are not part of this review. In this review, we will focus on molecular imaging of the AR-axis in metastatic CRPC (mCRPC) and discuss our personal experience with these tracers. Our goal is to put these radiopharmaceuticals in the context of mCRPC biology and diagnosis (e.g., 18F-FDHT).
Collapse
Affiliation(s)
- Neeta Pandit-Taskar
- Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, New York; and
| | - Darren R Veach
- Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, New York; and
| | - Josef J Fox
- Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, New York; and
| | - Howard I Scher
- Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Michael J Morris
- Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Steven M Larson
- Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, New York; and
| |
Collapse
|
24
|
Kit-like 18F-labeling of an estradiol derivative as a potential PET imaging agent for estrogen receptor-positive breast cancer. J Radioanal Nucl Chem 2017. [DOI: 10.1007/s10967-017-5245-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
|
25
|
Recommendations and Technical Aspects of 16α-[18F]Fluoro-17β-Estradiol PET to Image the Estrogen Receptor In Vivo. Clin Nucl Med 2016; 41:844-851. [DOI: 10.1097/rlu.0000000000001347] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
|
26
|
Ackermann U, Lewis JS, Young K, Morris MJ, Weickhardt A, Davis ID, Scott AM. Fully automated synthesis of [(18) F]fluoro-dihydrotestosterone ([(18) F]FDHT) using the FlexLab module. J Labelled Comp Radiopharm 2016; 59:424-8. [PMID: 27378195 DOI: 10.1002/jlcr.3417] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2016] [Revised: 05/16/2016] [Accepted: 05/17/2016] [Indexed: 01/08/2023]
Abstract
Imaging of androgen receptor expression in prostate cancer using F-18 FDHT is becoming increasingly popular. With the radiolabelling precursor now commercially available, developing a fully automated synthesis of [(18) F] FDHT is important. We have fully automated the synthesis of F-18 FDHT using the iPhase FlexLab module using only commercially available components. Total synthesis time was 90 min, radiochemical yields were 25-33% (n = 11). Radiochemical purity of the final formulation was > 99% and specific activity was > 18.5 GBq/µmol for all batches. This method can be up-scaled as desired, thus making it possible to study multiple patients in a day. Furthermore, our procedure uses 4 mg of precursor only and is therefore cost-effective. The synthesis has now been validated at Austin Health and is currently used for [(18) F]FDHT studies in patients. We believe that this method can easily adapted by other modules to further widen the availability of [(18) F]FDHT.
Collapse
Affiliation(s)
- Uwe Ackermann
- Department of Molecular Imaging and Therapy, Austin Health, Heidelberg, Australia.,Olivia Newton-John Cancer Research Institute, Heidelberg, Australia.,School of Medicine, Dentistry and Health Sciences, The University of Melbourne, Parkville, Australia.,School of Cancer Medicine, LaTrobe University, Australia
| | - Jason S Lewis
- Radiochemistry & Molecular Imaging Probe Core, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Kenneth Young
- Department of Molecular Imaging and Therapy, Austin Health, Heidelberg, Australia
| | - Michael J Morris
- Genitourinary Oncology Service, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | | | - Ian D Davis
- Monash University Faculty of Medicine, Nursing and Health Sciences, Monash University, Melbourne, Australia.,Eastern Health, Melbourne, Australia
| | - Andrew M Scott
- Department of Molecular Imaging and Therapy, Austin Health, Heidelberg, Australia.,Olivia Newton-John Cancer Research Institute, Heidelberg, Australia.,School of Medicine, Dentistry and Health Sciences, The University of Melbourne, Parkville, Australia.,School of Cancer Medicine, LaTrobe University, Australia
| |
Collapse
|
27
|
Okamoto M, Shibayama H, Naka K, Kitagawa Y, Ishiwata K, Shimizu I, Toyohara J. Optimization of the alkyl side chain length of fluorine-18-labeled 7α-alkyl-fluoroestradiol. Nucl Med Biol 2016; 43:512-9. [PMID: 27289329 DOI: 10.1016/j.nucmedbio.2016.05.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2016] [Revised: 05/16/2016] [Accepted: 05/19/2016] [Indexed: 10/21/2022]
Abstract
INTRODUCTION Several lines of evidence suggest that 7α-substituted estradiol derivatives bind to the estrogen receptor (ER). In line with this hypothesis, we designed and synthesized (18)F-labeled 7α-fluoroalkylestradiol (Cn-7α-[(18)F]FES) derivatives as molecular probes for visualizing ERs. Previously, we successfully synthesized 7α-(3-[(18)F]fluoropropyl)estradiol (C3-7α-[(18)F]FES) and showed promising results for quantification of ER density in vivo, although extensive metabolism was observed in rodents. Therefore, optimization of the alkyl side chain length is needed to obtain suitable radioligands based on Cn-7α-substituted estradiol pharmacophores. METHODS We synthesized fluoromethyl (23; C1-7α-[(18)F]FES) to fluorohexyl (26; C6-7α-[(18)F]FES) derivatives, except fluoropropyl (C3-7α-[(18)F]FES) and fluoropentyl derivatives (C5-7α-[(18)F]FES), which have been previously synthesized. In vitro binding to the α-subtype (ERα) isoform of ERs and in vivo biodistribution studies in mature female mice were carried out. RESULTS The in vitro IC50 value of Cn-7α-FES tended to gradually decrease depending on the alkyl side chain length. C1-7α-[(18)F]FES (23) showed the highest uptake in ER-rich tissues such as the uterus. Uterus uptake also gradually decreased depending on the alkyl side chain length. As a result, in vivo uterus uptake reflected the in vitro ERα affinity of each compound. Bone uptake, which indicates de-fluorination, was marked in 7α-(2-[(18)F]fluoroethyl)estradiol (C2-7α-[(18)F]FES) (24) and 7α-(4-[(18)F]fluorobutyl)estradiol (C4-7α-[(18)F]FES) (25) derivatives. However, C1-7α-[(18)F]FES (23) and C6-7α-[(18)F]FES (26) showed limited uptake in bone. As a result, in vivo bone uptake (de-fluorination) showed a bell-shaped pattern, depending on the alkyl side chain length. C1-7α-[(18)F]FES (23) showed the same levels of uptake in uterus and bone compared with those of 16α-[(18)F]fluoro-17β-estradiol. CONCLUSIONS The optimal alkyl side chain length of (18)F-labeled 7α-fluoroalkylestradiol was the shortest: C1-7α-[(18)F]FES. Our results indicate that shorter chain lengths within the 4-Å ligand binding cavities of ERα are suitable for 7α-fluoroalkylestradiol derivatives.
Collapse
Affiliation(s)
- Mayumi Okamoto
- Research Team for Neuroimaging, Tokyo Metropolitan Institute of Gerontology, Tokyo, Japan; Research Institute for Science and Engineering, Waseda University, Tokyo, Japan
| | - Hiromitsu Shibayama
- School of Advanced Science and Engineering, Waseda University, Tokyo, Japan; Fine Organic Chemistry, Institute for Chemical Research, Kyoto University, Kyoto, Japan
| | - Kyosuke Naka
- School of Advanced Science and Engineering, Waseda University, Tokyo, Japan
| | - Yuya Kitagawa
- School of Advanced Science and Engineering, Waseda University, Tokyo, Japan
| | - Kiichi Ishiwata
- Research Team for Neuroimaging, Tokyo Metropolitan Institute of Gerontology, Tokyo, Japan; Institute for Cyclotron and Drug Discovery Research, Southern Tohoku Research Institute of Neuroscience, Koriyama, Japan; Department of Biofunctional Imaging, Fukushima Medical University, Fukushima, Japan
| | - Isao Shimizu
- School of Advanced Science and Engineering, Waseda University, Tokyo, Japan
| | - Jun Toyohara
- Research Team for Neuroimaging, Tokyo Metropolitan Institute of Gerontology, Tokyo, Japan.
| |
Collapse
|
28
|
Fowler AM, Clark AS, Katzenellenbogen JA, Linden HM, Dehdashti F. Imaging Diagnostic and Therapeutic Targets: Steroid Receptors in Breast Cancer. J Nucl Med 2016; 57 Suppl 1:75S-80S. [PMID: 26834106 DOI: 10.2967/jnumed.115.157933] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Estrogen receptor alpha (ERα) and progesterone receptor (PR) are important steroid hormone receptor biomarkers used to determine prognosis and to predict benefit from endocrine therapies for breast cancer patients. Receptor expression is routinely measured in biopsy specimens using immunohistochemistry, although such testing can be challenging, particularly in the setting of metastatic disease. ERα and PR can be quantitatively assayed noninvasively with PET. This approach provides the opportunity to assess receptor expression and function in real time, within the entire tumor, and across distant sites of metastatic disease. This article reviews the current evidence of ERα and PR PET imaging as predictive and early-response biomarkers for endocrine therapy.
Collapse
Affiliation(s)
- Amy M Fowler
- Department of Radiology, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin
| | - Amy S Clark
- Division of Hematology and Oncology, Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | | | - Hannah M Linden
- Division of Medical Oncology, Department of Medicine, University of Washington, Seattle, Washington; and
| | - Farrokh Dehdashti
- Division of Nuclear Medicine, Mallinckrodt Institute of Radiology, Washington University, St. Louis, Missouri
| |
Collapse
|
29
|
|
30
|
Lazari M, Lyashchenko SK, Burnazi EM, Lewis JS, van Dam RM, Murphy JM. Fully-automated synthesis of 16β-(18)F-fluoro-5α-dihydrotestosterone (FDHT) on the ELIXYS radiosynthesizer. Appl Radiat Isot 2015; 103:9-14. [PMID: 26046518 DOI: 10.1016/j.apradiso.2015.05.010] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2015] [Revised: 04/30/2015] [Accepted: 05/18/2015] [Indexed: 01/30/2023]
Abstract
Noninvasive in vivo imaging of androgen receptor (AR) levels with positron emission tomography (PET) is becoming the primary tool in prostate cancer detection and staging. Of the potential (18)F-labeled PET tracers, (18)F-FDHT has clinically shown to be of highest diagnostic value. We demonstrate the first automated synthesis of (18)F-FDHT by adapting the conventional manual synthesis onto the fully-automated ELIXYS radiosynthesizer. Clinically-relevant amounts of (18)F-FDHT were synthesized on ELIXYS in 90 min with decay-corrected radiochemical yield of 29±5% (n=7). The specific activity was 4.6 Ci/µmol (170 GBq/µmol) at end of formulation with a starting activity of 1.0 Ci (37 GBq). The formulated (18)F-FDHT yielded sufficient activity for multiple patient doses and passed all quality control tests required for routine clinical use.
Collapse
Affiliation(s)
- Mark Lazari
- Department of Bioengineering, Henry Samueli School of Engineering, UCLA, Los Angeles, CA, USA; Crump Institute for Molecular Imaging, David Geffen School of Medicine, UCLA, Los Angeles, CA, USA; Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, UCLA, Los Angeles, CA, USA
| | - Serge K Lyashchenko
- Radiochemistry & Molecular Imaging Probe Core, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Eva M Burnazi
- Radiochemistry & Molecular Imaging Probe Core, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Jason S Lewis
- Radiochemistry & Molecular Imaging Probe Core, Memorial Sloan Kettering Cancer Center, New York, NY, USA; Radiochemistry and Imaging Sciences Service, Radiology, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - R Michael van Dam
- Department of Bioengineering, Henry Samueli School of Engineering, UCLA, Los Angeles, CA, USA; Crump Institute for Molecular Imaging, David Geffen School of Medicine, UCLA, Los Angeles, CA, USA; Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, UCLA, Los Angeles, CA, USA
| | - Jennifer M Murphy
- Crump Institute for Molecular Imaging, David Geffen School of Medicine, UCLA, Los Angeles, CA, USA; Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, UCLA, Los Angeles, CA, USA.
| |
Collapse
|
31
|
Chan SR, Fowler AM, Allen JA, Zhou D, Dence CS, Sharp TL, Fettig NM, Dehdashti F, Katzenellenbogen JA. Longitudinal noninvasive imaging of progesterone receptor as a predictive biomarker of tumor responsiveness to estrogen deprivation therapy. Clin Cancer Res 2014; 21:1063-70. [PMID: 25520392 DOI: 10.1158/1078-0432.ccr-14-1715] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
PURPOSE To investigate whether longitudinal functional PET imaging of mammary tumors using the radiopharmaceuticals [(18)F]FDG (to measure glucose uptake), [(18)F]FES [to measure estrogen receptor (ER) levels], or [(18)F]FFNP [to measure progesterone receptor (PgR) levels] is predictive of response to estrogen-deprivation therapy. EXPERIMENTAL DESIGN [(18)F]FDG, [(18)F]FES, and [(18)F]FFNP uptake in endocrine-sensitive and -resistant mammary tumors was quantified serially by PET before ovariectomy or estrogen withdrawal in mice, and on days 3 and 4 after estrogen-deprivation therapy. Specificity of [(18)F]FFNP uptake in ERα(+) mammary tumors was determined by competition assay using unlabeled ligands for PgR or glucocorticoid receptor (GR). PgR expression was also assayed by immunohistochemistry (IHC). RESULTS The levels of [(18)F]FES and [(18)F]FDG tumor uptake remained unchanged in endocrine-sensitive tumors after estrogen-deprivation therapy compared with those at pretreatment. In contrast, estrogen-deprivation therapy led to a reduction in PgR expression and [(18)F]FFNP uptake in endocrine-sensitive tumors, but not in endocrine-resistant tumors, as early as 3 days after treatment; the changes in PgR levels were confirmed by IHC. Unlabeled PgR ligand R5020 but not GR ligand dexamethasone blocked [(18)F]FFNP tumor uptake, indicating that [(18)F]FFNP bound specifically to PgR. Therefore, a reduction in FFNP tumor to muscle ratio in mammary tumors predicts sensitivity to estrogen-deprivation therapy. CONCLUSIONS Monitoring the acute changes in ERα activity by measuring [(18)F]FFNP uptake in mammary tumors predicts tumor response to estrogen-deprivation therapy. Longitudinal noninvasive PET imaging using [(18)F]FFNP is a robust and effective approach to predict tumor responsiveness to endocrine treatment.
Collapse
Affiliation(s)
- Szeman Ruby Chan
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, Missouri.
| | - Amy M Fowler
- Department of Radiology, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin
| | - Julie A Allen
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, Missouri
| | - Dong Zhou
- Division of Radiological Sciences, Edward Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, Missouri
| | - Carmen S Dence
- Division of Radiological Sciences, Edward Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, Missouri
| | - Terry L Sharp
- Division of Radiological Sciences, Edward Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, Missouri
| | - Nicole M Fettig
- Division of Radiological Sciences, Edward Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, Missouri
| | - Farrokh Dehdashti
- Division of Radiological Sciences, Edward Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, Missouri
| | | |
Collapse
|