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Ahmed M, Bicher S, Combs SE, Lindner R, Raulefs S, Schmid TE, Spasova S, Stolz J, Wilkens JJ, Winter J, Bartzsch S. In Vivo Microbeam Radiation Therapy at a Conventional Small Animal Irradiator. Cancers (Basel) 2024; 16:581. [PMID: 38339332 PMCID: PMC11154279 DOI: 10.3390/cancers16030581] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2023] [Revised: 01/25/2024] [Accepted: 01/27/2024] [Indexed: 02/12/2024] Open
Abstract
Microbeam radiation therapy (MRT) is a still pre-clinical form of spatially fractionated radiotherapy, which uses an array of micrometer-wide, planar beams of X-ray radiation. The dose modulation in MRT has proven effective in the treatment of tumors while being well tolerated by normal tissue. Research on understanding the underlying biological mechanisms mostly requires large third-generation synchrotrons. In this study, we aimed to develop a preclinical treatment environment that would allow MRT independent of synchrotrons. We built a compact microbeam setup for pre-clinical experiments within a small animal irradiator and present in vivo MRT application, including treatment planning, dosimetry, and animal positioning. The brain of an immobilized mouse was treated with MRT, excised, and immunohistochemically stained against γH2AX for DNA double-strand breaks. We developed a comprehensive treatment planning system by adjusting an existing dose calculation algorithm to our setup and attaching it to the open-source software 3D-Slicer. Predicted doses in treatment planning agreed within 10% with film dosimetry readings. We demonstrated the feasibility of MRT exposures in vivo at a compact source and showed that the microbeam pattern is observable in histological sections of a mouse brain. The platform developed in this study will be used for pre-clinical research of MRT.
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Affiliation(s)
- Mabroor Ahmed
- Department of Radiation Oncology, School of Medicine and Klinikum rechts der Isar, Technical University of Munich, 81675 Munich, Germany; (M.A.); (S.B.); (S.E.C.); (S.R.); (T.E.S.); (S.S.); (J.S.); (J.J.W.); (J.W.)
- Helmholtz Zentrum München GmbH, German Research Center for Environmental Health, Institute of Radiation Medicine, 85764 Neuherberg, Germany;
- Department of Physics, School of Natural Sciences, Technical University of Munich, 85748 Garching, Germany
| | - Sandra Bicher
- Department of Radiation Oncology, School of Medicine and Klinikum rechts der Isar, Technical University of Munich, 81675 Munich, Germany; (M.A.); (S.B.); (S.E.C.); (S.R.); (T.E.S.); (S.S.); (J.S.); (J.J.W.); (J.W.)
- Helmholtz Zentrum München GmbH, German Research Center for Environmental Health, Institute of Radiation Medicine, 85764 Neuherberg, Germany;
| | - Stephanie Elisabeth Combs
- Department of Radiation Oncology, School of Medicine and Klinikum rechts der Isar, Technical University of Munich, 81675 Munich, Germany; (M.A.); (S.B.); (S.E.C.); (S.R.); (T.E.S.); (S.S.); (J.S.); (J.J.W.); (J.W.)
- Helmholtz Zentrum München GmbH, German Research Center for Environmental Health, Institute of Radiation Medicine, 85764 Neuherberg, Germany;
| | - Rainer Lindner
- Helmholtz Zentrum München GmbH, German Research Center for Environmental Health, Institute of Radiation Medicine, 85764 Neuherberg, Germany;
| | - Susanne Raulefs
- Department of Radiation Oncology, School of Medicine and Klinikum rechts der Isar, Technical University of Munich, 81675 Munich, Germany; (M.A.); (S.B.); (S.E.C.); (S.R.); (T.E.S.); (S.S.); (J.S.); (J.J.W.); (J.W.)
- Helmholtz Zentrum München GmbH, German Research Center for Environmental Health, Institute of Radiation Medicine, 85764 Neuherberg, Germany;
| | - Thomas E. Schmid
- Department of Radiation Oncology, School of Medicine and Klinikum rechts der Isar, Technical University of Munich, 81675 Munich, Germany; (M.A.); (S.B.); (S.E.C.); (S.R.); (T.E.S.); (S.S.); (J.S.); (J.J.W.); (J.W.)
- Helmholtz Zentrum München GmbH, German Research Center for Environmental Health, Institute of Radiation Medicine, 85764 Neuherberg, Germany;
| | - Suzana Spasova
- Department of Radiation Oncology, School of Medicine and Klinikum rechts der Isar, Technical University of Munich, 81675 Munich, Germany; (M.A.); (S.B.); (S.E.C.); (S.R.); (T.E.S.); (S.S.); (J.S.); (J.J.W.); (J.W.)
- Helmholtz Zentrum München GmbH, German Research Center for Environmental Health, Institute of Radiation Medicine, 85764 Neuherberg, Germany;
- Department of Physics, School of Natural Sciences, Technical University of Munich, 85748 Garching, Germany
| | - Jessica Stolz
- Department of Radiation Oncology, School of Medicine and Klinikum rechts der Isar, Technical University of Munich, 81675 Munich, Germany; (M.A.); (S.B.); (S.E.C.); (S.R.); (T.E.S.); (S.S.); (J.S.); (J.J.W.); (J.W.)
- Helmholtz Zentrum München GmbH, German Research Center for Environmental Health, Institute of Radiation Medicine, 85764 Neuherberg, Germany;
| | - Jan Jakob Wilkens
- Department of Radiation Oncology, School of Medicine and Klinikum rechts der Isar, Technical University of Munich, 81675 Munich, Germany; (M.A.); (S.B.); (S.E.C.); (S.R.); (T.E.S.); (S.S.); (J.S.); (J.J.W.); (J.W.)
- Department of Physics, School of Natural Sciences, Technical University of Munich, 85748 Garching, Germany
| | - Johanna Winter
- Department of Radiation Oncology, School of Medicine and Klinikum rechts der Isar, Technical University of Munich, 81675 Munich, Germany; (M.A.); (S.B.); (S.E.C.); (S.R.); (T.E.S.); (S.S.); (J.S.); (J.J.W.); (J.W.)
- Helmholtz Zentrum München GmbH, German Research Center for Environmental Health, Institute of Radiation Medicine, 85764 Neuherberg, Germany;
- Department of Physics, School of Natural Sciences, Technical University of Munich, 85748 Garching, Germany
- Heinz Maier-Leibnitz Zentrum (MLZ), 85748 Garching, Germany
| | - Stefan Bartzsch
- Department of Radiation Oncology, School of Medicine and Klinikum rechts der Isar, Technical University of Munich, 81675 Munich, Germany; (M.A.); (S.B.); (S.E.C.); (S.R.); (T.E.S.); (S.S.); (J.S.); (J.J.W.); (J.W.)
- Helmholtz Zentrum München GmbH, German Research Center for Environmental Health, Institute of Radiation Medicine, 85764 Neuherberg, Germany;
- Heinz Maier-Leibnitz Zentrum (MLZ), 85748 Garching, Germany
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2
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Madas BG, Boei J, Fenske N, Hofmann W, Mezquita L. Effects of spatial variation in dose delivery: what can we learn from radon-related lung cancer studies? RADIATION AND ENVIRONMENTAL BIOPHYSICS 2022; 61:561-577. [PMID: 36208308 PMCID: PMC9630403 DOI: 10.1007/s00411-022-00998-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Accepted: 09/28/2022] [Indexed: 05/14/2023]
Abstract
Exposure to radon progeny results in heterogeneous dose distributions in many different spatial scales. The aim of this review is to provide an overview on the state of the art in epidemiology, clinical observations, cell biology, dosimetry, and modelling related to radon exposure and its association with lung cancer, along with priorities for future research. Particular attention is paid on the effects of spatial variation in dose delivery within the organs, a factor not considered in radiation protection. It is concluded that a multidisciplinary approach is required to improve risk assessment and mechanistic understanding of carcinogenesis related to radon exposure. To achieve these goals, important steps would be to clarify whether radon can cause other diseases than lung cancer, and to investigate radon-related health risks in children or persons at young ages. Also, a better understanding of the combined effects of radon and smoking is needed, which can be achieved by integrating epidemiological, clinical, pathological, and molecular oncology data to obtain a radon-associated signature. While in vitro models derived from primary human bronchial epithelial cells can help to identify new and corroborate existing biomarkers, they also allow to study the effects of heterogeneous dose distributions including the effects of locally high doses. These novel approaches can provide valuable input and validation data for mathematical models for risk assessment. These models can be applied to quantitatively translate the knowledge obtained from radon exposure to other exposures resulting in heterogeneous dose distributions within an organ to support radiation protection in general.
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Affiliation(s)
- Balázs G Madas
- Environmental Physics Department, Centre for Energy Research, Budapest, Hungary.
| | - Jan Boei
- Department of Human Genetics, Leiden University Medical Center, Leiden, The Netherlands
| | - Nora Fenske
- Federal Office for Radiation Protection, Munich (Neuherberg), Germany
| | - Werner Hofmann
- Biological Physics, Department of Chemistry and Physics of Materials, University of Salzburg, Salzburg, Austria
| | - Laura Mezquita
- Medical Oncology Department, Hospital Clinic of Barcelona, Barcelona, Spain
- Laboratory of Translational Genomic and Targeted Therapies in Solid Tumors, IDIBAPS, Barcelona, Spain
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Baiocco G, Bartzsch S, Conte V, Friedrich T, Jakob B, Tartas A, Villagrasa C, Prise KM. A matter of space: how the spatial heterogeneity in energy deposition determines the biological outcome of radiation exposure. RADIATION AND ENVIRONMENTAL BIOPHYSICS 2022; 61:545-559. [PMID: 36220965 PMCID: PMC9630194 DOI: 10.1007/s00411-022-00989-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Accepted: 08/03/2022] [Indexed: 05/10/2023]
Abstract
The outcome of the exposure of living organisms to ionizing radiation is determined by the distribution of the associated energy deposition at different spatial scales. Radiation proceeds through ionizations and excitations of hit molecules with an ~ nm spacing. Approaches such as nanodosimetry/microdosimetry and Monte Carlo track-structure simulations have been successfully adopted to investigate radiation quality effects: they allow to explore correlations between the spatial clustering of such energy depositions at the scales of DNA or chromosome domains and their biological consequences at the cellular level. Physical features alone, however, are not enough to assess the entity and complexity of radiation-induced DNA damage: this latter is the result of an interplay between radiation track structure and the spatial architecture of chromatin, and further depends on the chromatin dynamic response, affecting the activation and efficiency of the repair machinery. The heterogeneity of radiation energy depositions at the single-cell level affects the trade-off between cell inactivation and induction of viable mutations and hence influences radiation-induced carcinogenesis. In radiation therapy, where the goal is cancer cell inactivation, the delivery of a homogenous dose to the tumour has been the traditional approach in clinical practice. However, evidence is accumulating that introducing heterogeneity with spatially fractionated beams (mini- and microbeam therapy) can lead to significant advantages, particularly in sparing normal tissues. Such findings cannot be explained in merely physical terms, and their interpretation requires considering the scales at play in the underlying biological mechanisms, suggesting a systemic response to radiation.
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Affiliation(s)
- Giorgio Baiocco
- Radiation Biophysics and Radiobiology Group, Physics Department, University of Pavia, Pavia, Italy.
| | - Stefan Bartzsch
- Institute for Radiation Medicine, Helmholtz Centre Munich, Munich, Germany
- Department of Radiation Oncology, Technical University of Munich, Munich, Germany
| | - Valeria Conte
- Istituto Nazionale Di Fisica Nucleare INFN, Laboratori Nazionali Di Legnaro, Legnaro, Italy
| | - Thomas Friedrich
- Department of Biophysics, GSI Helmholtz Centre for Heavy Ion Research, Darmstadt, Germany
| | - Burkhard Jakob
- Department of Biophysics, GSI Helmholtz Centre for Heavy Ion Research, Darmstadt, Germany
| | - Adrianna Tartas
- Biomedical Physics Division, Institute of Experimental Physics, University of Warsaw, Warsaw, Poland
| | - Carmen Villagrasa
- IRSN, Institut de Radioprotection et de Sûreté Nucléaire, Fontenay aux Roses, France
| | - Kevin M Prise
- Patrick G Johnston Centre for Cancer Research, Queen's University Belfast, Belfast, UK
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Inoue M, Baba T, Takahashi F, Terao M, Yanai S, Shima Y, Saito D, Sugihara K, Miura T, Takada S, Suyama M, Ohkawa Y, Morohashi KI. Tmsb10 triggers fetal Leydig differentiation by suppressing the RAS/ERK pathway. Commun Biol 2022; 5:974. [PMID: 36109592 PMCID: PMC9478096 DOI: 10.1038/s42003-022-03941-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Accepted: 09/02/2022] [Indexed: 11/24/2022] Open
Abstract
Leydig cells in fetal testes play crucial roles in masculinizing fetuses through androgen production. Gene knockout studies have revealed that growth factors are implicated in fetal Leydig cell (FLC) differentiation, but little is known about the mechanisms regulating this process. We investigate this issue by characterizing FLC progenitor cells using single-cell RNA sequencing. The sequence datasets suggest that thymosin β10 (Tmsb10) is transiently upregulated in the progenitors. While studying the function of Tmsb10, we reveal that platelet-derived growth factor (PDGF) regulates ciliogenesis through the RAS/ERK and PI3K/AKT pathways, and thereby promotes desert hedgehog (DHH)-dependent FLC differentiation. Tmsb10 expressed in the progenitor cells induces their differentiation into FLCs by suppressing the RAS/ERK pathway. Through characterizing the transiently expressed Tmsb10 in the FLC progenitors, this study unveils the molecular process of FLC differentiation and shows that it is cooperatively induced by DHH and PDGF. Investigation of fetal Leydig progenitors shows that thymosin β10 (Tmsb10) suppresses the RAS/ERK pathway, inducing progenitor differentiation into fetal Leydig cells.
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5
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Yu K. Role of radiation-induced rescue effect in radiation field size effect. Radiat Phys Chem Oxf Engl 1993 2022. [DOI: 10.1016/j.radphyschem.2022.110143] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Fukunaga H, Yokoya A, Prise KM. A Brief Overview of Radiation-Induced Effects on Spermatogenesis and Oncofertility. Cancers (Basel) 2022; 14:cancers14030805. [PMID: 35159072 PMCID: PMC8834293 DOI: 10.3390/cancers14030805] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Revised: 02/03/2022] [Accepted: 02/03/2022] [Indexed: 02/06/2023] Open
Abstract
Simple Summary Spermatogenesis is one of the most important processes for the propagation of life; however, the testes’ ability to form sperm via this differentiation process is highly radiosensitive and easily impacted by exposure to environmental, occupational, or therapeutic radiation. Furthermore, the possibility that radiation effects on the gonads can be passed on from generation to generation should not be overlooked. This review focuses on the radiation-induced effects on spermatogenesis and the transgenerational effects. We also explore the potential of novel radiobiological approaches to improve male fertility preservation during radiotherapy. Abstract The genotoxicity of radiation on germ cells may be passed on to the next generation, thus its elucidation is not only a scientific issue but also an ethical, legal, and social issue in modern society. In this article, we briefly overview the effects of radiation on spermatogenesis and its associated genotoxicity, including the latest findings in the field of radiobiology. The potential role of transgenerational effects is still poorly understood, and further research in this area is desirable. Furthermore, from the perspective of oncofertility, we discuss the historical background and clinical importance of preserving male fertility during radiation treatment and the potential of microbeam radiotherapy. We hope that this review will contribute to stimulating further discussions and investigations for therapies for pediatric and adolescent/young adult patients.
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Affiliation(s)
- Hisanori Fukunaga
- Center for Environmental and Health Sciences, Hokkaido University, Sapporo 060-0812, Japan
- Correspondence:
| | - Akinari Yokoya
- Institute for Quantum Life Science, National Institutes for Quantum Science and Technology, Ibaraki 319-1106, Japan;
- Graduate School of Science and Engineering, Ibaraki University, Ibaraki 310-8512, Japan
| | - Kevin M. Prise
- Patrick G Johnstone Centre for Cancer Research, Queen’s University Belfast, Belfast BT9 7AE, UK;
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Abstract
AbstractSpatially fractionated radiation therapy (SFRT) challenges some of the classical dogmas in conventional radiotherapy. The highly modulated spatial dose distributions in SFRT have been shown to lead, both in early clinical trials and in small animal experiments, to a significant increase in normal tissue dose tolerances. Tumour control effectiveness is maintained or even enhanced in some configurations as compared with conventional radiotherapy. SFRT seems to activate distinct radiobiological mechanisms, which have been postulated to involve bystander effects, microvascular alterations and/or immunomodulation. Currently, it is unclear which is the dosimetric parameter which correlates the most with both tumour control and normal tissue sparing in SFRT. Additional biological experiments aiming at parametrizing the relationship between the irradiation parameters (beam width, spacing, peak-to-valley dose ratio, peak and valley doses) and the radiobiology are needed. A sound knowledge of the interrelation between the physical parameters in SFRT and the biological response would expand its clinical use, with a higher level of homogenisation in the realisation of clinical trials. This manuscript reviews the state of the art of this promising therapeutic modality, the current radiobiological knowledge and elaborates on future perspectives.
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No Intercellular Regulation of the Cell Cycle among Human Cervical Carcinoma HeLa Cells Expressing Fluorescent Ubiquitination-Based Cell-Cycle Indicators in Modulated Radiation Fields. Int J Mol Sci 2021; 22:ijms222312785. [PMID: 34884589 PMCID: PMC8657989 DOI: 10.3390/ijms222312785] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Revised: 11/22/2021] [Accepted: 11/24/2021] [Indexed: 11/17/2022] Open
Abstract
The non-targeted effects of radiation have been known to induce significant alternations in cell survival. Although the effects might govern the progression of tumor sites following advanced radiotherapy, the impacts on the intercellular control of the cell cycle following radiation exposure with a modified field, remain to be determined. Recently, a fluorescent ubiquitination-based cell-cycle indicator (FUCCI), which can visualize the cell-cycle phases with fluorescence microscopy in real time, was developed for biological cell research. In this study, we investigated the non-targeted effects on the regulation of the cell cycle of human cervical carcinoma (HeLa) cells with imperfect p53 function that express the FUCCI (HeLa–FUCCI cells). The possible effects on the cell-cycle phases via soluble factors were analyzed following exposure to different field configurations, which were delivered using a 150 kVp X-ray irradiator. In addition, using synchrotron-generated, 5.35 keV monochromatic X-ray microbeams, high-precision 200 μm-slit microbeam irradiation was performed to investigate the possible impacts on the cell-cycle phases via cell–cell contacts. Collectively, we could not detect the intercellular regulation of the cell cycle in HeLa–FUCCI cells, which suggested that the unregulated cell growth was a malignant tumor. Our findings indicated that there was no significant intercellular control system of the cell cycle in malignant tumors during or after radiotherapy, highlighting the differences between normal tissue and tumor characteristics.
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Fukunaga H. Stem Cell Migration: A Possible Mechanism for the Tissue-Sparing Effect of Spatially Fractionated Radiation. Radiat Res 2021; 196:680-685. [PMID: 34496025 DOI: 10.1667/rade-21-00134.1] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Accepted: 08/17/2021] [Indexed: 11/03/2022]
Abstract
Stem cell responses in tissues after exposure to radiation are of significance for maintaining tissue functions. From the point of view of stem cell characteristics, this article seeks to illustrate some contributions of microbeam research to spatially fractionated radiotherapy (SFRT), such as grid radiotherapy and microbeam radiotherapy. Although the tissue-sparing response after SFRT was first reported more than a century ago, current radiation dose-volume metrics are still unable to accurately predict such tissue-level changes in response to spatially fractionated radiation fields. However, microbeam approaches could contribute to uncovering the mechanisms of tissue response, significantly improving the outcomes of SFRT and reducing its adverse effects. Studies with microbeams have shown that the testicular tissue-sparing effect for maintaining spermatogenesis after exposure to spatially fractionated radiation depends on biological parameters, such as the radiation dose distribution at the microscale level for tissue-specific stem cells and the microenvironment, or niche. This indicates that stem cell survival, migration, and repopulation are involved in the tissue-level changes during or after SFRT. The illustration of microbeam applications in this article focuses on the stem cell migration as a possible mechanism of the tissue-sparing effect for preserving functionality.
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Affiliation(s)
- Hisanori Fukunaga
- Center for Environmental and Health Sciences, Hokkaido University, N12 W7 Kita-ku, Sapporo 060-0812, Japan
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10
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A Brief Overview of the Preclinical and Clinical Radiobiology of Microbeam Radiotherapy. Clin Oncol (R Coll Radiol) 2021; 33:705-712. [PMID: 34454806 DOI: 10.1016/j.clon.2021.08.011] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Revised: 07/27/2021] [Accepted: 08/17/2021] [Indexed: 11/23/2022]
Abstract
Microbeam radiotherapy (MRT) is the delivery of spatially fractionated beams that have the potential to offer significant improvements in the therapeutic ratio due to the delivery of micron-sized high dose and dose rate beams. They build on longstanding clinical experience of GRID radiotherapy and more recently lattice-based approaches. Here we briefly overview the preclinical evidence for MRT efficacy and highlight the challenges for bringing this to clinical utility. The biological mechanisms underpinning MRT efficacy are still unclear, but involve vascular, bystander, stem cell and potentially immune responses. There is probably significant overlap in the mechanisms underpinning MRT responses and FLASH radiotherapy that needs to be further defined.
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Ojima M, Ito A, Usami N, Ohara M, Suzuki K, Kai M. Field size effects on DNA damage and proliferation in normal human cell populations irradiated with X-ray microbeams. Sci Rep 2021; 11:7001. [PMID: 33772061 PMCID: PMC7997867 DOI: 10.1038/s41598-021-86416-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Accepted: 03/16/2021] [Indexed: 11/08/2022] Open
Abstract
To clarify the health risks of internal radiation exposure, it is important to investigate the radiological effects of local exposure at cell levels from radioactive materials taken up by organs. Focusing on the response of cell populations post-irradiation, X-ray microbeams are very effective at reproducing the effects of local exposure within an internal exposure in vitro. The present study aims to clarify the effects of local exposure by investigating the response of normal human cell (MRC-5) populations irradiated with X-ray microbeams of different beam sizes to DNA damage. The populations of MRC-5 were locally irradiated with X-ray microbeams of 1 Gy at 0.02-1.89 mm2 field sizes, and analyzed whether the number of 53BP1 foci as DSB (DNA double strand break) per cell changed with the field size. We found that even at the same dose, the number of DSB per cell increased depending on the X-irradiated field size on the cell population. This result indicated that DNA damage repair of X-irradiated cells might be enhanced in small size fields surrounded by non-irradiated cells. This study suggests that X-irradiated cells received some signal (a rescue signal) from surrounding non-irradiated cells may be involved in the response of cell populations post-irradiation.
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Affiliation(s)
- Mitsuaki Ojima
- Department of Environmental Health Science, Oita University of Nursing and Health Sciences, 2944-9 Megusuno, Oita, 840-1201, Japan.
| | - Atsushi Ito
- School of Engineering, Tokai University, Hiratsuka, Kanagawa, 259-1292, Japan
| | - Noriko Usami
- Photon Factory, Institute of Materials Structure Science, KEK, Tsukuba, Ibaraki, 305-0801, Japan
| | - Maki Ohara
- Photon Factory, Institute of Materials Structure Science, KEK, Tsukuba, Ibaraki, 305-0801, Japan
| | - Keiji Suzuki
- Department of Radiation Medical Sciences, Atomic Bomb Disease Institute, Nagasaki University, Nagasaki, 852-8523, Japan
| | - Michiaki Kai
- Department of Environmental Health Science, Oita University of Nursing and Health Sciences, 2944-9 Megusuno, Oita, 840-1201, Japan
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12
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Fukunaga H, Kaminaga K, Sato T, Butterworth KT, Watanabe R, Usami N, Ogawa T, Yokoya A, Prise KM. Spatially Fractionated Microbeam Analysis of Tissue-sparing Effect for Spermatogenesis. Radiat Res 2021; 194:698-706. [PMID: 33348374 DOI: 10.1667/rade-19-00018.1] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Accepted: 06/18/2020] [Indexed: 11/03/2022]
Abstract
Spatially fractionated radiation therapy (SFRT) has been based on the delivery of a single high-dose fraction to a large treatment area that has been divided into several smaller fields, reducing the overall toxicity and adverse effects. Complementary microbeam studies have also shown an effective tissue-sparing effect (TSE) in various tissue types and species after spatially fractionated irradiation at the microscale level; however, the underlying biological mechanism remains elusive. In the current study, using the combination of an ex vivo mouse spermatogenesis model and high-precision X-ray microbeams, we revealed the significant TSE for maintaining spermatogenesis after spatially fractionated microbeam irradiation. We used the following ratios of the irradiated to nonirradiated areas: 50:50, 150:50 and 350:50 µm-slit, where approximately 50, 75 and 87.5% of the sample was irradiated (using center-to-center distances of 100, 200 and 400 µm, respectively). We found that the 50 and 75% micro-slit irradiated testicular tissues showed an almost unadulterated TSE for spermatogenesis, whereas the 87.5% micro-slit irradiated tissues showed an incomplete TSE. This suggests that the TSE efficiency for spermatogenesis is dependent on the size of the nonirradiated spermatogonial stem cell pool in the irradiated testicular tissues. In addition, there would be a spatiotemporal limitation of stem cell migration/competition, resulting in the insufficient TSE for 87.5% micro-slit irradiated tissues. These stem cell characteristics are essential for the accurate prediction of tissue-level responses during or after SFRT, indicating the clinical potential for achieving better outcomes while preventing adverse effects.
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Affiliation(s)
- Hisanori Fukunaga
- Patrick G. Johnston Centre for Cancer Research, Queen's University Belfast, Belfast BT9 7AE, United Kingdom.,Shonan Kamakura General Hospital, Kamakura 247-8533, Japan
| | - Kiichi Kaminaga
- Institute for Quantum Life Science, National Institutes for Quantum and Radiological Science and Technology (QST), Tokai 319-1106, Japan
| | - Takuya Sato
- Institute of Molecular Medicine and Life Science, Yokohama City University Association of Medical Science, Yokohama 236-0004, Japan
| | - Karl T Butterworth
- Patrick G. Johnston Centre for Cancer Research, Queen's University Belfast, Belfast BT9 7AE, United Kingdom
| | - Ritsuko Watanabe
- Institute for Quantum Life Science, National Institutes for Quantum and Radiological Science and Technology (QST), Tokai 319-1106, Japan
| | - Noriko Usami
- Photon Factory, High Energy Accelerator Research Organization, Tsukuba 305-0801, Japan
| | - Takehiko Ogawa
- Institute of Molecular Medicine and Life Science, Yokohama City University Association of Medical Science, Yokohama 236-0004, Japan
| | - Akinari Yokoya
- Institute for Quantum Life Science, National Institutes for Quantum and Radiological Science and Technology (QST), Tokai 319-1106, Japan
| | - Kevin M Prise
- Patrick G. Johnston Centre for Cancer Research, Queen's University Belfast, Belfast BT9 7AE, United Kingdom
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The Effect of Low Temperatures on Environmental Radiation Damage in Living Systems: Does Hypothermia Show Promise for Space Travel? Int J Mol Sci 2020; 21:ijms21176349. [PMID: 32882991 PMCID: PMC7504535 DOI: 10.3390/ijms21176349] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Revised: 08/31/2020] [Accepted: 08/31/2020] [Indexed: 12/23/2022] Open
Abstract
Low-temperature treatments (i.e., hypothermia) may be one way of regulating environmental radiation damage in living systems. With this in mind, hibernation under hypothermic conditions has been proposed as a useful approach for long-term human space flight. However, the underlying mechanisms of hypothermia-induced radioresistance are as yet undetermined, and the conventional risk assessment of radiation exposure during hibernation remains insufficient for estimating the effects of chronic exposure to galactic cosmic rays (GCRs). To promote scientific discussions on the application of hibernation in space travel, this literature review provides an overview of the progress to date in the interdisciplinary research field of radiation biology and hypothermia and addresses possible issues related to hypothermic treatments as countermeasures against GCRs. At present, there are concerns about the potential effects of chronic radiation exposure on neurological disorders, carcinogenesis, ischemia heat failures, and infertility in astronauts; these require further study. These concerns may be resolved by comparing and integrating data gleaned from experimental and epidemiological studies.
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The Tissue-Sparing Effect of Spatially Fractionated X-rays for Maintaining Spermatogenesis: A Radiobiological Approach for the Preservation of Male Fertility after Radiotherapy. J Clin Med 2020; 9:jcm9041089. [PMID: 32290436 PMCID: PMC7231089 DOI: 10.3390/jcm9041089] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Revised: 04/07/2020] [Accepted: 04/10/2020] [Indexed: 01/15/2023] Open
Abstract
Radiotherapy can result in temporary or permanent gonadal toxicity in male cancer patients despite the high precision and accuracy of modern radiation treatment techniques. Previous radiobiological studies have shown an effective tissue-sparing response in various tissue types and species following exposure to spatially fractionated radiation. In the present study, we used an ex vivo mouse testicular tissue culture model and a conventional X-ray irradiation device to evaluate the tissue-sparing effect (TSE) of spatially fractionated X-rays for the protection of male fertility from radiotherapy-related adverse effects. We revealed a significant TSE for maintaining spermatogenesis in the ex vivo testes model following spatially fractionated X-ray irradiation. Moreover, we experimentally propose a possible mechanism by which the migration of spermatogonial cells, from the non-irradiated areas to the irradiated ones, in irradiated testicular tissue, is essential for the TSE and maintaining spermatogenesis. Therefore, our findings demonstrate that the control of TSE following spatially fractionated X-rays in the testes has a considerable potential for clinical application. Interdisciplinary research will be essential for further expanding the applicability of this method as an approach for the preservation of male fertility during or after radiotherapy.
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Fernandez-Palomo C, Fazzari J, Trappetti V, Smyth L, Janka H, Laissue J, Djonov V. Animal Models in Microbeam Radiation Therapy: A Scoping Review. Cancers (Basel) 2020; 12:cancers12030527. [PMID: 32106397 PMCID: PMC7139755 DOI: 10.3390/cancers12030527] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2020] [Revised: 02/19/2020] [Accepted: 02/21/2020] [Indexed: 01/04/2023] Open
Abstract
BACKGROUND Microbeam Radiation Therapy (MRT) is an innovative approach in radiation oncology where a collimator subdivides the homogeneous radiation field into an array of co-planar, high-dose beams which are tens of micrometres wide and separated by a few hundred micrometres. OBJECTIVE This scoping review was conducted to map the available evidence and provide a comprehensive overview of the similarities, differences, and outcomes of all experiments that have employed animal models in MRT. METHODS We considered articles that employed animal models for the purpose of studying the effects of MRT. We searched in seven databases for published and unpublished literature. Two independent reviewers screened citations for inclusion. Data extraction was done by three reviewers. RESULTS After screening 5688 citations and 159 full-text papers, 95 articles were included, of which 72 were experimental articles. Here we present the animal models and pre-clinical radiation parameters employed in the existing MRT literature according to their use in cancer treatment, non-neoplastic diseases, or normal tissue studies. CONCLUSIONS The study of MRT is concentrated in brain-related diseases performed mostly in rat models. An appropriate comparison between MRT and conventional radiotherapy (instead of synchrotron broad beam) is needed. Recommendations are provided for future studies involving MRT.
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Affiliation(s)
| | - Jennifer Fazzari
- Institute of Anatomy, University of Bern, 3012 Bern, Switzerland; (C.F.-P.); (J.F.); (V.T.); (J.L.)
| | - Verdiana Trappetti
- Institute of Anatomy, University of Bern, 3012 Bern, Switzerland; (C.F.-P.); (J.F.); (V.T.); (J.L.)
| | - Lloyd Smyth
- Department of Obstetrics & Gynaecology, University of Melbourne, 3057 Parkville, Australia;
| | - Heidrun Janka
- Medical Library, University Library Bern, University of Bern, 3012 Bern, Switzerland;
| | - Jean Laissue
- Institute of Anatomy, University of Bern, 3012 Bern, Switzerland; (C.F.-P.); (J.F.); (V.T.); (J.L.)
| | - Valentin Djonov
- Institute of Anatomy, University of Bern, 3012 Bern, Switzerland; (C.F.-P.); (J.F.); (V.T.); (J.L.)
- Correspondence: ; Tel.: +41-31-631-8432
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Targeting Specific Sites in Biological Systems with Synchrotron X-Ray Microbeams for Radiobiological Studies at the Photon Factory. QUANTUM BEAM SCIENCE 2020. [DOI: 10.3390/qubs4010002] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
X-ray microbeams have been used to explore radiobiological effects induced by targeting a specific site in living systems. Synchrotron radiation from the Photon Factory, Japan, with high brilliance and highly parallel directionality is a source suitable for delivering a particular beam size or shape, which can be changed according to target morphology by using a simple metal slit system (beam size from 5 μm to several millimeters). Studies have examined the non-targeted effects, called bystander cellular responses, which are thought to be fundamental mechanisms of low-dose or low-dose-rate effects in practical radiation risk research. Narrow microbeams several tens of micrometers or less in their size targeted both the cell nucleus and the cytoplasm. Our method combined with live-cell imaging techniques has challenged the traditional radiobiological dogma that DNA damage is the only major cause of radiation-induced genetic alterations and is gradually revealing the role of organelles, such as mitochondria, in these biological effects. Furthermore, three-dimensionally cultured cell systems have been used as microbeam targets to mimic organs. Combining the spatial fractionation of X-ray microbeams and a unique ex vivo testes organ culture technique revealed that the tissue-sparing effect was induced in response to the non-uniform radiation fields. Spatially fractionated X-ray beams may be a promising tool in clinical radiation therapy.
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