Microbeam radiation therapy, an alternative radiosurgical treatment under preclinical investigati... more Microbeam radiation therapy, an alternative radiosurgical treatment under preclinical investigation, aims to safely treat muzzle tumors in pet animals. This will require data on the largely unknown radiation toxicity of microbeam arrays for bones and teeth. To this end, the muzzle of six young adult New Zealand rabbits was irradiated by a lateral array of microplanar beamlets with peak entrance doses of 200, 330 or 500 Gy. The muzzles were examined 431 days postirradiation by computed microtomographic imaging (micro-CT) ex vivo, and extensive histopathology. The boundaries of the radiation field were identified histologically by microbeam tracks in cartilage and other tissues. There was no radionecrosis of facial bones in any rabbit. Conversely, normal incisor teeth exposed to peak entrance doses of 330 Gy or 500 Gy developed marked caries-like damage, whereas the incisors of the two rabbits exposed to 200 Gy remained unscathed. A single, unidirectional array of microbeams with a peak entrance dose ≤200 Gy (valley dose14 Gy) did not damage normal bone, teeth and soft tissues of the muzzle of normal rabbits longer than one year after irradiation. Because of that, Microbeam radiation therapy of muzzle tumors in pet animals is unlikely to cause sizeable damage to normal teeth, bone and soft tissues, if a single array as used here delivers a limited entrance dose of 200 Gy and a valley dose of ≤14 Gy.
The microbeam radiation therapy (MRT), a spatially micro-fractionated synchrotron radiotherapy, l... more The microbeam radiation therapy (MRT), a spatially micro-fractionated synchrotron radiotherapy, leads to better control of incurable high-grade glioma than that obtained upon homogeneous radiotherapy. We evaluated the effect of meloxicam, a non-steroidal anti-inflammatory drug (NSAID), to increase the MRT response. Survival of rats bearing intracranial 9L gliosarcoma treated with meloxicam and/or MRT (400 Gy, 50 μm-wide microbeams, 200 μm spacing) was monitored. Tumor growth was assessed on histological tissue sections and COX-2 transcriptomic expression was studied 1 to 25 days after radiotherapy. Meloxicam significantly extended the median survival of microbeam-irradiated rats (from +10.5 to +20 days). Dual treatment led to last survivors until D90 (D39 for the MRT group) and to tumor 9.5 times smaller than MRT alone. No significant modification of COX-2 expression was induced by MRT in normal and tumor tissues. The meloxicam reinforced the anti-tumor effect of MRT for glioma trea...
Stereotactic body radiation therapy (SBRT) has made the hypofractionation of high doses delivered... more Stereotactic body radiation therapy (SBRT) has made the hypofractionation of high doses delivered in a few sessions more acceptable. While the benefits of hypofractionated SBRT have been attributed to additional vascular, immune effects, or specific cell deaths, a radiobiological and mechanistic model is still needed. By considering each session of SBRT, the dose is divided into hundreds of minibeams delivering some fractions of Gy. In such a dose range, the hypersensitivity to low dose (HRS) phenomenon can occur. HRS produces a biological effect equivalent to that produced by a dose 5-to-10 times higher. To examine whether HRS could contribute to enhancing radiation effects under SBRT conditions, we exposed tumor cells of different HRS statuses to SBRT. Four human HRS-positive and two HRS-negative tumor cell lines were exposed to different dose delivery modes: a single dose of 0.2 Gy, 2 Gy, 10 × 0.2 Gy, and a single dose of 2 Gy using a non-coplanar isocentric minibeams irradiation...
The individual response to ionizing radiation (IR) raises a number of medical, scientific, and so... more The individual response to ionizing radiation (IR) raises a number of medical, scientific, and societal issues. While the term “radiosensitivity” was used by the pioneers at the beginning of the 20st century to describe only the radiation-induced adverse tissue reactions related to cell death, a confusion emerged in the literature from the 1930s, as “radiosensitivity” was indifferently used to describe the toxic, cancerous, or aging effect of IR. In parallel, the predisposition to radiation-induced adverse tissue reactions (radiosensitivity), notably observed after radiotherapy appears to be caused by different mechanisms than those linked to predisposition to radiation-induced cancer (radiosusceptibility). This review aims to document these differences in order to better estimate the different radiation-induced risks. It reveals that there are very few syndromes associated with the loss of biological functions involved directly in DNA damage recognition and repair as their role is ...
After having been an instrument of the Cold War, space exploration has become a major technologic... more After having been an instrument of the Cold War, space exploration has become a major technological, scientific and societal challenge for a number of countries. With new projects to return to the Moon and go to Mars, radiobiologists have been called upon to better assess the risks linked to exposure to radiation emitted from space (IRS), one of the major hazards for astronauts. To this aim, a major task is to identify the specificities of the different sources of IRS that concern astronauts. By considering the probabilities of the impact of IRS against spacecraft shielding, three conclusions can be drawn: (1) The impacts of heavy ions are rare and their contribution to radiation dose may be low during low Earth orbit; (2) secondary particles, including neutrons emitted at low energy from the spacecraft shielding, may be common in deep space and may preferentially target surface tissues such as the eyes and skin; (3) a “bath of radiation” composed of residual rays and fast neutrons ...
International Journal of Radiation Oncology*Biology*Physics, 2016
Conclusion: Our data suggests that patients with larger brain lesions (> 3 cm, > 12 cm3) and larg... more Conclusion: Our data suggests that patients with larger brain lesions (> 3 cm, > 12 cm3) and larger post-op cavities (> 15 cm3) are more likely to benefit from delayed post-operative radiation, as they have larger absolute and relative cavity volume reductions, on average. These patients likely account for the larger volume reductions at time intervals more than three weeks after surgery.
Synchrotron microbeam radiation therapy (MRT) is based on the spatial fractionation of the incide... more Synchrotron microbeam radiation therapy (MRT) is based on the spatial fractionation of the incident synchrotron beam into arrays of parallel microbeams, typically a few tens of micrometres wide and depositing several hundred Gray. This high dose, high dose rate, spatially fractionated radiotherapy has a high therapeutic impact on tumors, especially in intracranial locations. MRT leads to better control of incurable high-grade glioma than from homogeneous radiotherapy. The schedule of MRT within a conventional irradiation protocol (three fractions of 11 Gy) of brain tumors was evaluated on the 9L glioma model in rats. MRT delivered as a first fraction increased the median survival time of the animals by four days compared with conventional radiotherapy, while the last MRT fraction improved the lifespan by 148% (+15.5 days compared with conventional radiotherapy, p < 0.0001). The most efficient radiation regimen was obtained when the MRT-boost was applied as the last fraction, foll...
Yohan van de Looij, Audrey Bouchet, Benoit Pouyatos, Luc Renaud, Elke Bräuer-Krisch, Géraldine Le... more Yohan van de Looij, Audrey Bouchet, Benoit Pouyatos, Luc Renaud, Elke Bräuer-Krisch, Géraldine Le Duc, Jean A Laissue, and Raphaël Serduc Division of Child Growth & Development, University of Geneva, Geneva, Switzerland, Laboratory for Functional and Metabolic Imaging, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland, Grenoble Institut des Neurosciences UMR836, Université Joseph Fourier, Grenoble, France, European Synchrotron Radiation Facility, Grenoble, France, Centre de Recherche Cerveau et Cognition, Université de Toulouse, Toulouse, France, Institute of Pathology, University of Bern, Bern, Switzerland
The purpose of this study is to use a multi-technique approach to detect the effects of spatially... more The purpose of this study is to use a multi-technique approach to detect the effects of spatially fractionated X-ray Microbeam (MRT) and Minibeam Radiation Therapy (MB) and to compare them to seamless Broad Beam (BB) irradiation. Healthy- and Glioblastoma (GBM)-bearing male Fischer rats were irradiated in-vivo on the right brain hemisphere with MRT, MB and BB delivering three different doses for each irradiation geometry. Brains were analyzed post mortem by multi-scale X-ray Phase Contrast Imaging–Computed Tomography (XPCI-CT), histology, immunohistochemistry, X-ray Fluorescence (XRF), Small- and Wide-Angle X-ray Scattering (SAXS/WAXS). XPCI-CT discriminates with high sensitivity the effects of MRT, MB and BB irradiations on both healthy and GBM-bearing brains producing a first-time 3D visualization and morphological analysis of the radio-induced lesions, MRT and MB induced tissue ablations, the presence of hyperdense deposits within specific areas of the brain and tumor evolution o...
Delivery of high-radiation doses to brain tumors via multiple arrays of synchrotron X-ray microbe... more Delivery of high-radiation doses to brain tumors via multiple arrays of synchrotron X-ray microbeams permits huge therapeutic advantages. Brain tumor (9LGS)-bearing and normal rats were irradiated using a conventional, homogeneous Broad Beam (BB), or Microbeam Radiation Therapy (MRT), then studied by behavioral tests, MRI, and histopathology. A valley dose of 10 Gy deposited between microbeams, delivered by a single port, improved tumor control and median survival time of tumor-bearing rats better than a BB isodose. An increased number of ports and an accumulated valley dose maintained at 10 Gy delayed tumor growth and improved survival. Histopathologically, cell death, vascular damage, and inflammatory response increased in tumors. At identical valley isodose, each additional MRT port extended survival, resulting in an exponential correlation between port numbers and animal lifespan (r2 = 0.9928). A 10 Gy valley dose, in MRT mode, delivered through 5 ports, achieved the same surviv...
International Journal of Radiation Oncology*Biology*Physics, 2019
Synchrotron microbeam radiation therapy (MRT) is a unique treatment that spatially distributes th... more Synchrotron microbeam radiation therapy (MRT) is a unique treatment that spatially distributes the x-ray beam into several microbeams of very high dose. MRT significantly delays tumor regrowth compared with uniform radiation therapy. The underlying mechanisms include tumor vascular disruption, senescence, and inflammatory and antitumor Purpose: Synchrotron microbeam radiation therapy (MRT) is a method that spatially distributes the x-ray beam into several microbeams of very high dose (peak dose), regularly separated by low-dose intervals (valley dose). MRT selectively spares normal tissues, relative to conventional (uniform broad beam [BB]) radiation therapy. Methods and Materials: To evaluate the effect of MRT on radioresistant melanoma, B16-F10 murine melanomas were implanted into mice ears. Tumors were either treated with MRT (407.6 Gy peak; 6.2 Gy valley dose) or uniform BB irradiation (6.2 Gy). Results: MRT induced significantly longer tumor regrowth delay than did BB irradiation. A significant 24% reduction in blood vessel perfusion was observed 5 days after MRT, and the cell proliferation index was significantly lower in melanomas treated by MRT compared with BB. MRT provoked a greater induction of senescence in melanoma cells. Bio-Plex analyses revealed enhanced concentration of monocyteattracting chemokines in the MRT group: MCP-1 at D5, MIP-1a, MIP-1b, IL12p40,
HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific re... more HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés. Distributed under a Creative Commons Attribution-NonCommercial| 4.0 International License
This study is the first proof of concept that the FLASH effect can be triggered by X-rays. Our re... more This study is the first proof of concept that the FLASH effect can be triggered by X-rays. Our results show that a 10 Gy whole-brain irradiation delivered at ultra-high dose-rate with synchrotron generated X-rays does not induce memory deficit; it reduces hippocampal cell-division impairment and induces less reactive astrogliosis.
International Journal of Radiation Oncology*Biology*Physics, 2017
The authors thank the Bernische Krebsliga for the support via the grant n.37223, as well as the "... more The authors thank the Bernische Krebsliga for the support via the grant n.37223, as well as the "Conseil Régional Rhône-Alpes", la "Ligue contre le Cancer, comité de la Drome", "l'Association pour la Recherche contre le Cancer" and Imoxy ANR for research funding. Grenoble MRI facility IRMaGe was partly funded by the French program "Investissement d'Avenir" run by the "Agence Nationale pour la Recherche"; grant "Infrastructure d'avenir en Biologie Santé"-ANR-11-INBS-0006.
Our goal was the visualizing the vascular damage and acute inflammatory response to micro- and mi... more Our goal was the visualizing the vascular damage and acute inflammatory response to micro- and minibeam irradiation in vivo. Microbeam (MRT) and minibeam radiation therapies (MBRT) are tumor treatment approaches of potential clinical relevance, both consisting of parallel X-ray beams and allowing the delivery of thousands of Grays within tumors. We compared the effects of microbeams (25-100 μm wide) and minibeams (200-800 μm wide) on vasculature, inflammation and surrounding tissue changes during zebrafish caudal fin regeneration in vivo. Microbeam irradiation triggered an acute inflammatory response restricted to the regenerating tissue. Six hours post irradiation (6 hpi), it was infiltrated by neutrophils and fli1a(+) thrombocytes adhered to the cell wall locally in the beam path. The mature tissue was not affected by microbeam irradiation. In contrast, minibeam irradiation efficiently damaged the immature tissue at 6 hpi and damaged both the mature and immature tissue at 48 hpi. ...
Microbeam radiation therapy, an alternative radiosurgical treatment under preclinical investigati... more Microbeam radiation therapy, an alternative radiosurgical treatment under preclinical investigation, aims to safely treat muzzle tumors in pet animals. This will require data on the largely unknown radiation toxicity of microbeam arrays for bones and teeth. To this end, the muzzle of six young adult New Zealand rabbits was irradiated by a lateral array of microplanar beamlets with peak entrance doses of 200, 330 or 500 Gy. The muzzles were examined 431 days postirradiation by computed microtomographic imaging (micro-CT) ex vivo, and extensive histopathology. The boundaries of the radiation field were identified histologically by microbeam tracks in cartilage and other tissues. There was no radionecrosis of facial bones in any rabbit. Conversely, normal incisor teeth exposed to peak entrance doses of 330 Gy or 500 Gy developed marked caries-like damage, whereas the incisors of the two rabbits exposed to 200 Gy remained unscathed. A single, unidirectional array of microbeams with a peak entrance dose ≤200 Gy (valley dose14 Gy) did not damage normal bone, teeth and soft tissues of the muzzle of normal rabbits longer than one year after irradiation. Because of that, Microbeam radiation therapy of muzzle tumors in pet animals is unlikely to cause sizeable damage to normal teeth, bone and soft tissues, if a single array as used here delivers a limited entrance dose of 200 Gy and a valley dose of ≤14 Gy.
The microbeam radiation therapy (MRT), a spatially micro-fractionated synchrotron radiotherapy, l... more The microbeam radiation therapy (MRT), a spatially micro-fractionated synchrotron radiotherapy, leads to better control of incurable high-grade glioma than that obtained upon homogeneous radiotherapy. We evaluated the effect of meloxicam, a non-steroidal anti-inflammatory drug (NSAID), to increase the MRT response. Survival of rats bearing intracranial 9L gliosarcoma treated with meloxicam and/or MRT (400 Gy, 50 μm-wide microbeams, 200 μm spacing) was monitored. Tumor growth was assessed on histological tissue sections and COX-2 transcriptomic expression was studied 1 to 25 days after radiotherapy. Meloxicam significantly extended the median survival of microbeam-irradiated rats (from +10.5 to +20 days). Dual treatment led to last survivors until D90 (D39 for the MRT group) and to tumor 9.5 times smaller than MRT alone. No significant modification of COX-2 expression was induced by MRT in normal and tumor tissues. The meloxicam reinforced the anti-tumor effect of MRT for glioma trea...
Stereotactic body radiation therapy (SBRT) has made the hypofractionation of high doses delivered... more Stereotactic body radiation therapy (SBRT) has made the hypofractionation of high doses delivered in a few sessions more acceptable. While the benefits of hypofractionated SBRT have been attributed to additional vascular, immune effects, or specific cell deaths, a radiobiological and mechanistic model is still needed. By considering each session of SBRT, the dose is divided into hundreds of minibeams delivering some fractions of Gy. In such a dose range, the hypersensitivity to low dose (HRS) phenomenon can occur. HRS produces a biological effect equivalent to that produced by a dose 5-to-10 times higher. To examine whether HRS could contribute to enhancing radiation effects under SBRT conditions, we exposed tumor cells of different HRS statuses to SBRT. Four human HRS-positive and two HRS-negative tumor cell lines were exposed to different dose delivery modes: a single dose of 0.2 Gy, 2 Gy, 10 × 0.2 Gy, and a single dose of 2 Gy using a non-coplanar isocentric minibeams irradiation...
The individual response to ionizing radiation (IR) raises a number of medical, scientific, and so... more The individual response to ionizing radiation (IR) raises a number of medical, scientific, and societal issues. While the term “radiosensitivity” was used by the pioneers at the beginning of the 20st century to describe only the radiation-induced adverse tissue reactions related to cell death, a confusion emerged in the literature from the 1930s, as “radiosensitivity” was indifferently used to describe the toxic, cancerous, or aging effect of IR. In parallel, the predisposition to radiation-induced adverse tissue reactions (radiosensitivity), notably observed after radiotherapy appears to be caused by different mechanisms than those linked to predisposition to radiation-induced cancer (radiosusceptibility). This review aims to document these differences in order to better estimate the different radiation-induced risks. It reveals that there are very few syndromes associated with the loss of biological functions involved directly in DNA damage recognition and repair as their role is ...
After having been an instrument of the Cold War, space exploration has become a major technologic... more After having been an instrument of the Cold War, space exploration has become a major technological, scientific and societal challenge for a number of countries. With new projects to return to the Moon and go to Mars, radiobiologists have been called upon to better assess the risks linked to exposure to radiation emitted from space (IRS), one of the major hazards for astronauts. To this aim, a major task is to identify the specificities of the different sources of IRS that concern astronauts. By considering the probabilities of the impact of IRS against spacecraft shielding, three conclusions can be drawn: (1) The impacts of heavy ions are rare and their contribution to radiation dose may be low during low Earth orbit; (2) secondary particles, including neutrons emitted at low energy from the spacecraft shielding, may be common in deep space and may preferentially target surface tissues such as the eyes and skin; (3) a “bath of radiation” composed of residual rays and fast neutrons ...
International Journal of Radiation Oncology*Biology*Physics, 2016
Conclusion: Our data suggests that patients with larger brain lesions (> 3 cm, > 12 cm3) and larg... more Conclusion: Our data suggests that patients with larger brain lesions (> 3 cm, > 12 cm3) and larger post-op cavities (> 15 cm3) are more likely to benefit from delayed post-operative radiation, as they have larger absolute and relative cavity volume reductions, on average. These patients likely account for the larger volume reductions at time intervals more than three weeks after surgery.
Synchrotron microbeam radiation therapy (MRT) is based on the spatial fractionation of the incide... more Synchrotron microbeam radiation therapy (MRT) is based on the spatial fractionation of the incident synchrotron beam into arrays of parallel microbeams, typically a few tens of micrometres wide and depositing several hundred Gray. This high dose, high dose rate, spatially fractionated radiotherapy has a high therapeutic impact on tumors, especially in intracranial locations. MRT leads to better control of incurable high-grade glioma than from homogeneous radiotherapy. The schedule of MRT within a conventional irradiation protocol (three fractions of 11 Gy) of brain tumors was evaluated on the 9L glioma model in rats. MRT delivered as a first fraction increased the median survival time of the animals by four days compared with conventional radiotherapy, while the last MRT fraction improved the lifespan by 148% (+15.5 days compared with conventional radiotherapy, p < 0.0001). The most efficient radiation regimen was obtained when the MRT-boost was applied as the last fraction, foll...
Yohan van de Looij, Audrey Bouchet, Benoit Pouyatos, Luc Renaud, Elke Bräuer-Krisch, Géraldine Le... more Yohan van de Looij, Audrey Bouchet, Benoit Pouyatos, Luc Renaud, Elke Bräuer-Krisch, Géraldine Le Duc, Jean A Laissue, and Raphaël Serduc Division of Child Growth & Development, University of Geneva, Geneva, Switzerland, Laboratory for Functional and Metabolic Imaging, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland, Grenoble Institut des Neurosciences UMR836, Université Joseph Fourier, Grenoble, France, European Synchrotron Radiation Facility, Grenoble, France, Centre de Recherche Cerveau et Cognition, Université de Toulouse, Toulouse, France, Institute of Pathology, University of Bern, Bern, Switzerland
The purpose of this study is to use a multi-technique approach to detect the effects of spatially... more The purpose of this study is to use a multi-technique approach to detect the effects of spatially fractionated X-ray Microbeam (MRT) and Minibeam Radiation Therapy (MB) and to compare them to seamless Broad Beam (BB) irradiation. Healthy- and Glioblastoma (GBM)-bearing male Fischer rats were irradiated in-vivo on the right brain hemisphere with MRT, MB and BB delivering three different doses for each irradiation geometry. Brains were analyzed post mortem by multi-scale X-ray Phase Contrast Imaging–Computed Tomography (XPCI-CT), histology, immunohistochemistry, X-ray Fluorescence (XRF), Small- and Wide-Angle X-ray Scattering (SAXS/WAXS). XPCI-CT discriminates with high sensitivity the effects of MRT, MB and BB irradiations on both healthy and GBM-bearing brains producing a first-time 3D visualization and morphological analysis of the radio-induced lesions, MRT and MB induced tissue ablations, the presence of hyperdense deposits within specific areas of the brain and tumor evolution o...
Delivery of high-radiation doses to brain tumors via multiple arrays of synchrotron X-ray microbe... more Delivery of high-radiation doses to brain tumors via multiple arrays of synchrotron X-ray microbeams permits huge therapeutic advantages. Brain tumor (9LGS)-bearing and normal rats were irradiated using a conventional, homogeneous Broad Beam (BB), or Microbeam Radiation Therapy (MRT), then studied by behavioral tests, MRI, and histopathology. A valley dose of 10 Gy deposited between microbeams, delivered by a single port, improved tumor control and median survival time of tumor-bearing rats better than a BB isodose. An increased number of ports and an accumulated valley dose maintained at 10 Gy delayed tumor growth and improved survival. Histopathologically, cell death, vascular damage, and inflammatory response increased in tumors. At identical valley isodose, each additional MRT port extended survival, resulting in an exponential correlation between port numbers and animal lifespan (r2 = 0.9928). A 10 Gy valley dose, in MRT mode, delivered through 5 ports, achieved the same surviv...
International Journal of Radiation Oncology*Biology*Physics, 2019
Synchrotron microbeam radiation therapy (MRT) is a unique treatment that spatially distributes th... more Synchrotron microbeam radiation therapy (MRT) is a unique treatment that spatially distributes the x-ray beam into several microbeams of very high dose. MRT significantly delays tumor regrowth compared with uniform radiation therapy. The underlying mechanisms include tumor vascular disruption, senescence, and inflammatory and antitumor Purpose: Synchrotron microbeam radiation therapy (MRT) is a method that spatially distributes the x-ray beam into several microbeams of very high dose (peak dose), regularly separated by low-dose intervals (valley dose). MRT selectively spares normal tissues, relative to conventional (uniform broad beam [BB]) radiation therapy. Methods and Materials: To evaluate the effect of MRT on radioresistant melanoma, B16-F10 murine melanomas were implanted into mice ears. Tumors were either treated with MRT (407.6 Gy peak; 6.2 Gy valley dose) or uniform BB irradiation (6.2 Gy). Results: MRT induced significantly longer tumor regrowth delay than did BB irradiation. A significant 24% reduction in blood vessel perfusion was observed 5 days after MRT, and the cell proliferation index was significantly lower in melanomas treated by MRT compared with BB. MRT provoked a greater induction of senescence in melanoma cells. Bio-Plex analyses revealed enhanced concentration of monocyteattracting chemokines in the MRT group: MCP-1 at D5, MIP-1a, MIP-1b, IL12p40,
HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific re... more HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés. Distributed under a Creative Commons Attribution-NonCommercial| 4.0 International License
This study is the first proof of concept that the FLASH effect can be triggered by X-rays. Our re... more This study is the first proof of concept that the FLASH effect can be triggered by X-rays. Our results show that a 10 Gy whole-brain irradiation delivered at ultra-high dose-rate with synchrotron generated X-rays does not induce memory deficit; it reduces hippocampal cell-division impairment and induces less reactive astrogliosis.
International Journal of Radiation Oncology*Biology*Physics, 2017
The authors thank the Bernische Krebsliga for the support via the grant n.37223, as well as the "... more The authors thank the Bernische Krebsliga for the support via the grant n.37223, as well as the "Conseil Régional Rhône-Alpes", la "Ligue contre le Cancer, comité de la Drome", "l'Association pour la Recherche contre le Cancer" and Imoxy ANR for research funding. Grenoble MRI facility IRMaGe was partly funded by the French program "Investissement d'Avenir" run by the "Agence Nationale pour la Recherche"; grant "Infrastructure d'avenir en Biologie Santé"-ANR-11-INBS-0006.
Our goal was the visualizing the vascular damage and acute inflammatory response to micro- and mi... more Our goal was the visualizing the vascular damage and acute inflammatory response to micro- and minibeam irradiation in vivo. Microbeam (MRT) and minibeam radiation therapies (MBRT) are tumor treatment approaches of potential clinical relevance, both consisting of parallel X-ray beams and allowing the delivery of thousands of Grays within tumors. We compared the effects of microbeams (25-100 μm wide) and minibeams (200-800 μm wide) on vasculature, inflammation and surrounding tissue changes during zebrafish caudal fin regeneration in vivo. Microbeam irradiation triggered an acute inflammatory response restricted to the regenerating tissue. Six hours post irradiation (6 hpi), it was infiltrated by neutrophils and fli1a(+) thrombocytes adhered to the cell wall locally in the beam path. The mature tissue was not affected by microbeam irradiation. In contrast, minibeam irradiation efficiently damaged the immature tissue at 6 hpi and damaged both the mature and immature tissue at 48 hpi. ...
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