Journal ArticleDOI
Effects of pulsed, spatially fractionated, microscopic synchrotron X-ray beams on normal and tumoral brain tissue.
Elke Bräuer-Krisch,Raphaël Serduc,E.A. Siegbahn,G. Le Duc,Yolanda Prezado,Alberto Bravin,Hans Blattmann,Jean A. Laissue +7 more
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The paper highlights the history of MRT including salient biological findings after microbeam irradiation with emphasis on the vascular components and the tolerance of the central nervous system and details on experimental and theoretical dosimetry of microbeams, core issues and possible therapeutic applications of M RT are presented.Abstract:
Microbeam radiation therapy (MRT) uses highly collimated, quasi-parallel arrays of X-ray microbeams of 50–600 keV, produced by third generation synchrotron sources, such as the European Synchrotron Radiation Facility (ESRF), in France. The main advantages of highly brilliant synchrotron sources are an extremely high dose rate and very small beam divergence. High dose rates are necessary to deliver therapeutic doses in microscopic volumes, to avoid spreading of the microbeams by cardiosynchronous movement of the tissues. The minimal beam divergence results in the advantage of steeper dose gradients delivered to a tumor target, thus achieving a higher dose deposition in the target volume in fractions of seconds, with a sharper penumbra than that produced in conventional radiotherapy. MRT research over the past 20 years has yielded many results from preclinical trials based on different animal models, including mice, rats, piglets and rabbits. Typically, MRT uses arrays of narrow (∼25–100 μm wide) microplanar beams separated by wider (100–400 μm centre-to-centre) microplanar spaces. The height of these microbeams typically varies from 1 to 100 mm, depending on the target and the desired preselected field size to be irradiated. Peak entrance doses of several hundreds of Gy are surprisingly well tolerated by normal tissues, up to ∼2 yr after irradiation, and at the same time show a preferential damage of malignant tumor tissues; these effects of MRT have now been extensively studied over nearly two decades. More recently, some biological in vivo effects of synchrotron X-ray beams in the millimeter range (0.68–0.95 mm, centre-to-centre distances 1.2–4 mm), which may differ to some extent from those of microscopic beams, have been followed up to ∼7 months after irradiation. Comparisons between broad-beam irradiation and MRT indicate a higher tumor control for the same sparing of normal tissue in the latter, even if a substantial fraction of tumor cells are not receiving a radiotoxic level of radiation. The hypothesis of a selective radiovulnerability of the tumor vasculature versus normal blood vessels by MRT, and of the cellular and molecular mechanisms involved remains under investigation. The paper highlights the history of MRT including salient biological findings after microbeam irradiation with emphasis on the vascular components and the tolerance of the central nervous system. Details on experimental and theoretical dosimetry of microbeams, core issues and possible therapeutic applications of MRT are presented.read more
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X-rays can trigger the FLASH effect: Ultra-high dose-rate synchrotron light source prevents normal brain injury after whole brain irradiation in mice.
Pierre Montay-Gruel,Audrey Bouchet,Maud Jaccard,David Patin,Raphaël Serduc,Warren Aim,Kristoffer Petersson,Benoit Petit,Claude Bailat,Jean Bourhis,Elke Bräuer-Krisch,Marie-Catherine Vozenin +11 more
TL;DR: 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.
Journal ArticleDOI
Toward an image-guided microbeam radiation therapy using gadolinium-based nanoparticles.
Géraldine Le Duc,Imen Miladi,Christophe Alric,Pierre Mowat,Elke Bräuer-Krisch,Audrey Bouchet,Enam A. Khalil,Claire Billotey,Marc Janier,François Lux,Thierry Epicier,Pascal Perriat,Stéphane Roux,Stéphane Roux,Olivier Tillement +14 more
TL;DR: GBNs exhibit an interesting potential for image-guided radiotherapy since the radiosensitizing effect of GBNs can be activated by X-ray microbeams when the gadolinium content is enough in the tumor and low in the surrounding healthy tissue.
Journal ArticleDOI
Preferential effect of synchrotron microbeam radiation therapy on intracerebral 9L gliosarcoma vascular networks.
Audrey Bouchet,Benjamin Lemasson,Benjamin Lemasson,Géraldine Le Duc,Cécile Maisin,Cécile Maisin,Elke Bräuer-Krisch,E.A. Siegbahn,Luc Renaud,Luc Renaud,Enam A. Khalil,Chantal Rémy,Cathy Poillot,Alberto Bravin,Jean A. Laissue,Emmanuel L. Barbier,Raphaël Serduc +16 more
TL;DR: It is shown for the first time that preferential damage of MRT to tumor vessels versus preservation of radioresistant normal brain vessels contributes to the efficient palliation of 9L gliosarcomas in rats.
Journal ArticleDOI
The in vivo radiosensitizing effect of gold nanoparticles based MRI contrast agents
Imen Miladi,Christophe Alric,Sandrine Dufort,Pierre Mowat,Aurélie Dutour,Céline A. Mandon,Gautier Laurent,Elke Bräuer-Krisch,Nirmitha I. Herath,Jean-Luc Coll,Marie Dutreix,François Lux,Rana Bazzi,Claire Billotey,Marc Janier,Pascal Perriat,Géraldine Le Duc,Stéphane Roux,Olivier Tillement +18 more
TL;DR: Comet assays and in vivo experiments suggest that these particles appear well suited for improving the selectivity of the radiotherapy, and the increase in the lifespan of tumor bearing rats is more important when the irradiation is performed after the injection of the gold nanoparticles.
Journal ArticleDOI
Proton-minibeam radiation therapy: a proof of concept.
Yolanda Prezado,G. Fois +1 more
TL;DR: The high PVDR obtained for some configurations and the small penumbras in comparison with existing radiosurgery techniques, suggest a potential gain in healthy tissue sparing in this new technique.
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Whole body irradiation; radiobiology or medicine?
TL;DR: General principles of radiobiology are shown to need modification if they are to be applied to whole body irradiation of mammals.