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Tang W, Tang B, Li X, Wang Y, Li Z, Gao Y, Gao H, Yan C, Sun L. Cellular S-value evaluation based on real human cell models using the GATE MC package. Appl Radiat Isot 2020; 168:109509. [PMID: 33214023 DOI: 10.1016/j.apradiso.2020.109509] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Revised: 10/28/2020] [Accepted: 11/06/2020] [Indexed: 11/25/2022]
Abstract
Exploring the spatial distribution of the energy loss of ionising radiation at the subcellular level is indispensable for evaluating the radiobiological effects of targeted radionuclide therapy accurately. Believing that S-values are important for obtaining the target dose, the Committee on Medical Internal Radiation Dose (MIRD) proposed a method to obtain the cellular dosimetric parameter. However, most available data on cellular S-values were calculated based on simple geometric models, such as ellipsoids or spheres, which do not accurately reflect biological reality. To investigate the influence of the cellular model on S-values, calculations were performed for two kinds of polygon-surface phantom models of realistic, individual human cells, the lung epithelial cell model (the B2B Phantom model) and the hepatocyte model (the Liver Phantom model), using the Monte Carlo (MC) software package GATE. To analyse the influence of cell geometry on the final S-value, the differences in the S-values between the realistic cell models and simple geometric sphere and ellipsoid models with similar volumes were calculated and compared for six different combinations of source and target regions. The irradiation conditions were 0.01-1.10 MeV monoenergetic electron sources and the Auger electronic therapy nuclides Ga-67, Tc-99m, In-111, I-125 and Tl-201, which are commonly used in nuclear medicine. The S-values calculated in this study are different from the results of the simple geometry models proposed by previous researchers. Two more precise polygon-surface phantom models of realistic, individual human cells were used, which provided more accurate information about the cell dose and will be very useful for the diagnostic application of radiotherapy in the future.
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Affiliation(s)
- Wei Tang
- State Key Laboratory of Radiation Medicine and Protection, School of Radiation Medicine and Protection, Soochow University, Suzhou, 215123, China; Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions, China
| | - Bo Tang
- State Key Laboratory of Radiation Medicine and Protection, School of Radiation Medicine and Protection, Soochow University, Suzhou, 215123, China; Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions, China; Department of Radiation Protection Safety, Shandong Center for Disease Control and Prevention, Jinan, 250014, China
| | - Xiang Li
- State Key Laboratory of Radiation Medicine and Protection, School of Radiation Medicine and Protection, Soochow University, Suzhou, 215123, China; Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions, China
| | - Yidi Wang
- State Key Laboratory of Radiation Medicine and Protection, School of Radiation Medicine and Protection, Soochow University, Suzhou, 215123, China; Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions, China
| | - Zhanpeng Li
- State Key Laboratory of Radiation Medicine and Protection, School of Radiation Medicine and Protection, Soochow University, Suzhou, 215123, China; Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions, China
| | - Yunan Gao
- State Key Laboratory of Radiation Medicine and Protection, School of Radiation Medicine and Protection, Soochow University, Suzhou, 215123, China; Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions, China
| | - Han Gao
- State Key Laboratory of Radiation Medicine and Protection, School of Radiation Medicine and Protection, Soochow University, Suzhou, 215123, China; Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions, China
| | - Congchong Yan
- State Key Laboratory of Radiation Medicine and Protection, School of Radiation Medicine and Protection, Soochow University, Suzhou, 215123, China; Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions, China
| | - Liang Sun
- State Key Laboratory of Radiation Medicine and Protection, School of Radiation Medicine and Protection, Soochow University, Suzhou, 215123, China; Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions, China.
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Howell RW. Advancements in the use of Auger electrons in science and medicine during the period 2015-2019. Int J Radiat Biol 2020; 99:2-27. [PMID: 33021416 PMCID: PMC8062591 DOI: 10.1080/09553002.2020.1831706] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Revised: 09/01/2020] [Accepted: 09/28/2020] [Indexed: 02/06/2023]
Abstract
Auger electrons can be highly radiotoxic when they are used to irradiate specific molecular sites. This has spurred basic science investigations of their radiobiological effects and clinical investigations of their potential for therapy. Focused symposia on the biophysical aspects of Auger processes have been held quadrennially. This 9th International Symposium on Physical, Molecular, Cellular, and Medical Aspects of Auger Processes at Oxford University brought together scientists from many different fields to review past findings, discuss the latest studies, and plot the future work to be done. This review article examines the research in this field that was published during the years 2015-2019 which corresponds to the period since the last meeting in Japan. In addition, this article points to future work yet to be done. There have been a plethora of advancements in our understanding of Auger processes. These advancements range from basic atomic and molecular physics to new ways to implement Auger electron emitters in radiopharmaceutical therapy. The highly localized doses of radiation that are deposited within a 10 nm of the decay site make them precision tools for discovery across the physical, chemical, biological, and medical sciences.
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Affiliation(s)
- Roger W Howell
- Division of Radiation Research, Department of Radiology, New Jersey Medical School, Rutgers University, Newark, NJ, USA
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Cellular S values in spindle-shaped cells: a dosimetry study on more realistic cell geometries using Geant4-DNA Monte Carlo simulation toolkit. Ann Nucl Med 2020; 34:742-756. [PMID: 32632563 DOI: 10.1007/s12149-020-01498-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2020] [Accepted: 07/01/2020] [Indexed: 01/11/2023]
Abstract
OBJECTIVE Cellular dosimetry plays a crucial role in radiobiology and evaluation of the relative merits of radiopharmaceuticals used for targeted radionuclide therapy. The present study aims to investigate the effects of various cell geometries on dosimetric characteristics of several Auger emitters distributed in different subcellular compartments using Monte Carlo simulation. METHODS The Geant4-DNA extension of the Geant4 Monte Carlo simulation toolkit was employed to calculate the mean absorbed dose per unit cumulated activity (S value) for different subcellular distributions of several Auger electron-emitting theranostic radionuclides including 99mTc, 111In, 123I, 125I, and 201Tl. The simulations were carried out in various single-cell models of liquid water including spherical, ellipsoidal, spherical spindle, and ellipsoidal spindle cell models. The latter two models which are generalized from the first two models were inspired by the morphologies of spindle-shaped (fusiform) cells, and were developed to provide more realistic modeling of this common geometry observed in many healthy and cancerous cells. RESULTS Evaluation of the S values calculated for the examined cell models reveals that the differences are small (less than 9%) for the cell ← cell, cell ← cell surface, and nucleus ← nucleus source-target combinations. However, moderate discrepancies are seen (up to 28%) when the nucleus is considered as the target, as well as the radioactivity is either internalized into the cytoplasm or bound to the cell membrane. CONCLUSIONS The findings of the present work suggest that the assumption of spherical cell geometry may provide reasonably accurate estimates of the cellular/nuclear dose for the considered Auger emitters, even for spindle-shaped cells. Of course, this approximation should be used with caution for the nucleus ← cytoplasm and nucleus ← cell surface configurations, since the S-value sensitivity to the cell geometry is somewhat significant in these cases.
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Bordes J, Incerti S, Mora-Ramirez E, Tranel J, Rossi C, Bezombes C, Bordenave J, Bardiès M, Brown R, Bordage MC. Monte Carlo dosimetry of a realistic multicellular model of follicular lymphoma in a context of radioimmunotherapy. Med Phys 2020; 47:5222-5234. [PMID: 32623743 DOI: 10.1002/mp.14370] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Revised: 04/20/2020] [Accepted: 06/15/2020] [Indexed: 12/31/2022] Open
Abstract
PURPOSE Small-scale dosimetry studies generally consider an artificial environment where the tumors are spherical and the radionuclides are homogeneously biodistributed. However, tumor shapes are irregular and radiopharmaceutical biodistributions are heterogeneous, impacting the energy deposition in targeted radionuclide therapy. To bring realism, we developed a dosimetric methodology based on a three-dimensional in vitro model of follicular lymphoma incubated with rituximab, an anti-CD20 monoclonal antibody used in the treatment of non-Hodgkin lymphomas, which might be combined with a radionuclide. The effects of the realistic geometry and biodistribution on the absorbed dose were highlighted by comparison with literature data. Additionally, to illustrate the possibilities of this methodology, the effect of different radionuclides on the absorbed dose distribution delivered to the in vitro tumor were compared. METHODS The starting point was a model named multicellular aggregates of lymphoma cells (MALC). Three MALCs of different dimensions and their rituximab biodistribution were considered. Geometry, antibody location and concentration were extracted from selective plane illumination microscopy. Assuming antibody radiolabeling with Auger electron (125 I and 111 In) and β- particle emitters (177 Lu, 131 I and 90 Y), we simulated energy deposition in MALCs using two Monte Carlo codes: Geant4-DNA with "CPA100" physics models for Auger electron emitters and Geant4 with "Livermore" physics models for β- particle emitters. RESULTS MALCs had ellipsoid-like shapes with major radii, r, of ~0.25, ~0.5 and ~1.3 mm. Rituximab was concentrated in the periphery of the MALCs. The absorbed doses delivered by 177 Lu, 131 I and 90 Y in MALCs were compared with literature data for spheres with two types of homogeneous biodistributions (on the surface or throughout the volume). Compared to the MALCs, the mean absorbed doses delivered in spheres with surface biodistributions were between 18% and 38% lower, while with volume biodistribution they were between 15% and 29% higher. Regarding the radionuclides comparison, the relationship between MALC dimensions, rituximab biodistribution and energy released per decay impacted the absorbed doses. Despite releasing less energy, 125 I delivered a greater absorbed dose per decay than 111 In in the r ~ 0.25 mm MALC (6.78·10-2 vs 6.26·10-2 µGy·Bq-1 ·s-1 ). Similarly, the absorbed doses per decay in the r ~ 0.5 mm MALC for 177 Lu (2.41·10-2 µGy·Bq-1 ·s-1 ) and 131 I (2.46·10-2 µGy·Bq-1 ·s-1 ) are higher than for 90 Y (1.98·10-2 µGy·Bq-1 ·s-1 ). Furthermore, radionuclides releasing more energy per decay delivered absorbed dose more uniformly through the MALCs. Finally, when considering the radiopharmaceutical effective half-life, due to the biological half-life of rituximab being best matched by the physical half-life of 177 Lu and 131 I compared to 90 Y, the first two radionuclides delivered higher absorbed doses. CONCLUSION In the simulated configurations, β- emitters delivered higher and more uniform absorbed dose than Auger electron emitters. When considering radiopharmaceutical half-lives, 177 Lu and 131 I delivered absorbed doses higher than 90 Y. In view of real irradiation of MALCs, such a work may be useful to select suited radionuclides and to help explain the biological effects.
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Affiliation(s)
- Julien Bordes
- CRCT, UMR 1037 INSERM, Université Paul Sabatier, Toulouse, F-31037, France.,UMR 1037, CRCT, Université Toulouse III-Paul Sabatier, Toulouse, F-31037, France
| | - Sébastien Incerti
- Université de Bordeaux, CENBG, UMR 5797, Gradignan, F-33170, France.,CNRS, IN2P3, CENBG, UMR 5797, Gradignan, F-33170, France
| | - Erick Mora-Ramirez
- CRCT, UMR 1037 INSERM, Université Paul Sabatier, Toulouse, F-31037, France.,UMR 1037, CRCT, Université Toulouse III-Paul Sabatier, Toulouse, F-31037, France.,Escuela de Física, CICANUM, Universidad de Costa Rica, San José, 11501-2060, Costa Rica
| | - Jonathan Tranel
- CRCT, UMR 1037 INSERM, Université Paul Sabatier, Toulouse, F-31037, France.,UMR 1037, CRCT, Université Toulouse III-Paul Sabatier, Toulouse, F-31037, France.,Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA, 94143, USA
| | - Cédric Rossi
- CRCT, UMR 1037 INSERM, Université Paul Sabatier, Toulouse, F-31037, France.,UMR 1037, CRCT, Université Toulouse III-Paul Sabatier, Toulouse, F-31037, France.,CHU Dijon, Hématologie Clinique, Hôpital François Mitterand, Dijon, 21000, France
| | - Christine Bezombes
- CRCT, UMR 1037 INSERM, Université Paul Sabatier, Toulouse, F-31037, France.,UMR 1037, CRCT, Université Toulouse III-Paul Sabatier, Toulouse, F-31037, France
| | - Julie Bordenave
- CRCT, UMR 1037 INSERM, Université Paul Sabatier, Toulouse, F-31037, France.,UMR 1037, CRCT, Université Toulouse III-Paul Sabatier, Toulouse, F-31037, France
| | - Manuel Bardiès
- CRCT, UMR 1037 INSERM, Université Paul Sabatier, Toulouse, F-31037, France.,UMR 1037, CRCT, Université Toulouse III-Paul Sabatier, Toulouse, F-31037, France
| | - Richard Brown
- Institute of Nuclear Medicine, University College London, 235 Euston Road, London, NW1 2BU, UK
| | - Marie-Claude Bordage
- CRCT, UMR 1037 INSERM, Université Paul Sabatier, Toulouse, F-31037, France.,UMR 1037, CRCT, Université Toulouse III-Paul Sabatier, Toulouse, F-31037, France
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Dosimetric assessment in different tumour phenotypes with auger electron emitting radionuclides: 99mTc, 125I, 161Tb, and 177Lu. Radiat Phys Chem Oxf Engl 1993 2020. [DOI: 10.1016/j.radphyschem.2020.108763] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Salim R, Taherparvar P. Monte Carlo single-cell dosimetry using Geant4-DNA: the effects of cell nucleus displacement and rotation on cellular S values. RADIATION AND ENVIRONMENTAL BIOPHYSICS 2019; 58:353-371. [PMID: 30927051 DOI: 10.1007/s00411-019-00788-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Accepted: 03/18/2019] [Indexed: 06/09/2023]
Abstract
Investigation of biological effects of low-dose ionizing radiation at the (sub-) cellular level, which is referred to as microdosimetry, remains a major challenge of today's radiobiology research. Monte Carlo simulation of radiation tracks can provide a detailed description of the physical processes involved in dimensions as small as the critical substructures of the cell. Hereby, in the present study, microdosimetric calculations of cellular S values for mono-energetic electrons and six Auger-emitting radionuclides were performed in single-cell models of liquid water using Geant4-DNA. The effects of displacement and rotation of the nucleus within the cell on the cellular S values were studied in spherical and ellipsoidal geometries. It was found that for the examined electron energies and radionuclides, in the case of nucleus cross-absorption where the radioactivity is either localized in the cytoplasm of the cell or distributed on the cell surface, rotation of the nucleus within the cell affects cellular S values less than displacement of the nucleus. Especially, the considerable differences observed in S(nucleus ← cell surface) values between an eccentric and a concentric cell-nucleus configuration in spherical and ellipsoidal geometries (up to 63% and up to 44%, respectively) suggests that the approximation of concentricity should be used with caution, at least for localized irradiation of the cell membrane by an Auger-emitter in targeted radionuclide cancer therapy. The obtained results, which are based on a more realistic modeling of the cell than was done before, provide more accurate information about nuclear dose. This can be useful for theranostic applications.
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Affiliation(s)
- Ramak Salim
- Department of Physics, Faculty of Science, University of Guilan, Namjoo Avenue, P.O. Box 41335-19141, Rasht, 4193833697, Iran
| | - Payvand Taherparvar
- Department of Physics, Faculty of Science, University of Guilan, Namjoo Avenue, P.O. Box 41335-19141, Rasht, 4193833697, Iran.
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Di Maria S, Belchior A, Romanets Y, Paulo A, Vaz P. Monte Carlo dose distribution calculation at nuclear level for Auger-emitting radionuclide energies. Appl Radiat Isot 2018; 135:72-77. [DOI: 10.1016/j.apradiso.2018.01.013] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2017] [Revised: 11/26/2017] [Accepted: 01/12/2018] [Indexed: 02/02/2023]
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van der Kroon I, Woliner-van der Weg W, Brom M, Joosten L, Frielink C, Konijnenberg MW, Visser EP, Gotthardt M. Whole organ and islet of Langerhans dosimetry for calculation of absorbed doses resulting from imaging with radiolabeled exendin. Sci Rep 2017; 7:39800. [PMID: 28067253 PMCID: PMC5220322 DOI: 10.1038/srep39800] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2016] [Accepted: 11/07/2016] [Indexed: 12/26/2022] Open
Abstract
Radiolabeled exendin is used for non-invasive quantification of beta cells in the islets of Langerhans in vivo. High accumulation of radiolabeled exendin in the islets raised concerns about possible radiation-induced damage to these islets in man. In this work, islet absorbed doses resulting from exendin-imaging were calculated by combining whole organ dosimetry with small scale dosimetry for the islets. Our model contains the tissues with high accumulation of radiolabeled exendin: kidneys, pancreas and islets. As input for the model, data from a clinical study (radiolabeled exendin distribution in the human body) and from a preclinical study with Biobreeding Diabetes Prone (BBDP) rats (islet-to-exocrine uptake ratio, beta cell mass) were used. We simulated 111In-exendin and 68Ga-exendin absorbed doses in patients with differences in gender, islet size, beta cell mass and radiopharmaceutical uptake in the kidneys. In all simulated cases the islet absorbed dose was small, maximum 1.38 mGy for 68Ga and 66.0 mGy for 111In. The two sources mainly contributing to the islet absorbed dose are the kidneys (33-61%) and the islet self-dose (7.5-57%). In conclusion, all islet absorbed doses are low (<70 mGy), so even repeated imaging will hardly increase the risk on diabetes.
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Affiliation(s)
- Inge van der Kroon
- Department of Radiology and Nuclear Medicine, Radboud University Medical Center, Nijmegen, Netherlands
| | | | - Maarten Brom
- Department of Radiology and Nuclear Medicine, Radboud University Medical Center, Nijmegen, Netherlands
| | - Lieke Joosten
- Department of Radiology and Nuclear Medicine, Radboud University Medical Center, Nijmegen, Netherlands
| | - Cathelijne Frielink
- Department of Radiology and Nuclear Medicine, Radboud University Medical Center, Nijmegen, Netherlands
| | - Mark W Konijnenberg
- Department of Nuclear Medicine, Erasmus Medical Center, Rotterdam, Netherlands
| | - Eric P Visser
- Department of Radiology and Nuclear Medicine, Radboud University Medical Center, Nijmegen, Netherlands
| | - Martin Gotthardt
- Department of Radiology and Nuclear Medicine, Radboud University Medical Center, Nijmegen, Netherlands
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Reissig F, Mamat C, Steinbach J, Pietzsch HJ, Freudenberg R, Navarro-Retamal C, Caballero J, Kotzerke J, Wunderlich G. Direct and Auger Electron-Induced, Single- and Double-Strand Breaks on Plasmid DNA Caused by 99mTc-Labeled Pyrene Derivatives and the Effect of Bonding Distance. PLoS One 2016; 11:e0161973. [PMID: 27583677 PMCID: PMC5008623 DOI: 10.1371/journal.pone.0161973] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2016] [Accepted: 08/15/2016] [Indexed: 11/29/2022] Open
Abstract
It is evident that 99mTc causes radical-mediated DNA damage due to Auger electrons, which were emitted simultaneously with the known γ-emission of 99mTc. We have synthesized a series of new 99mTc-labeled pyrene derivatives with varied distances between the pyrene moiety and the radionuclide. The pyrene motif is a common DNA intercalator and allowed us to test the influence of the radionuclide distance on damages of the DNA helix. In general, pUC 19 plasmid DNA enables the investigation of the unprotected interactions between the radiotracers and DNA that results in single-strand breaks (SSB) or double-strand breaks (DSB). The resulting DNA fragments were separated by gel electrophoresis and quantified by fluorescent staining. Direct DNA damage and radical-induced indirect DNA damage by radiolysis products of water were evaluated in the presence or absence of the radical scavenger DMSO. We demonstrated that Auger electrons directly induced both SSB and DSB in high efficiency when 99mTc was tightly bound to the plasmid DNA and this damage could not be completely prevented by DMSO, a free radical scavenger. For the first time, we were able to minimize this effect by increasing the carbon chain lengths between the pyrene moiety and the 99mTc nuclide. However, a critical distance between the 99mTc atom and the DNA helix could not be determined due to the significantly lowered DSB generation resulting from the interaction which is dependent on the type of the 99mTc binding motif. The effect of variable DNA damage caused by the different chain length between the pyrene residue and the Tc-core as well as the possible conformations of the applied Tc-complexes was supplemented with molecular dynamics (MD) calculations. The effectiveness of the DNA-binding 99mTc-labeled pyrene derivatives was demonstrated by comparison to non-DNA-binding 99mTcO4–, since nearly all DNA damage caused by 99mTcO4– was prevented by incubating with DMSO.
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Affiliation(s)
- Falco Reissig
- University Hospital/ Faculty of Medicine Carl Gustav Carus, Technische Universität Dresden, Department of Nuclear Medicine, Dresden, Germany
- * E-mail: (GW); (FR)
| | - Constantin Mamat
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiopharmaceutical Cancer Research, Dresden, Germany
| | - Joerg Steinbach
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiopharmaceutical Cancer Research, Dresden, Germany
| | - Hans-Juergen Pietzsch
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiopharmaceutical Cancer Research, Dresden, Germany
| | - Robert Freudenberg
- University Hospital/ Faculty of Medicine Carl Gustav Carus, Technische Universität Dresden, Department of Nuclear Medicine, Dresden, Germany
| | - Carlos Navarro-Retamal
- Centro de Bioinformática y Simulación Molecular, Facultad de Ingeniería, Universidad de Talca, 2 Norte 685, Casilla 721, Talca, Chile
| | - Julio Caballero
- Centro de Bioinformática y Simulación Molecular, Facultad de Ingeniería, Universidad de Talca, 2 Norte 685, Casilla 721, Talca, Chile
| | - Joerg Kotzerke
- University Hospital/ Faculty of Medicine Carl Gustav Carus, Technische Universität Dresden, Department of Nuclear Medicine, Dresden, Germany
| | - Gerd Wunderlich
- University Hospital/ Faculty of Medicine Carl Gustav Carus, Technische Universität Dresden, Department of Nuclear Medicine, Dresden, Germany
- * E-mail: (GW); (FR)
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