Potential High Resolution Dosimeters For MRT

Autor: E. Bräuer-Krisch, A. Rosenfeld, M. Lerch, M. Petasecca, M. Akselrod, J. Sykora, J. Bartz, M. Ptaszkiewicz, P. Olko, A. Berg, M. Wieland, S. Doran, T. Brochard, A. Kamlowski, G. Cellere, A. Paccagnella, E. A. Siegbahn, Y. Prezado, I. Martinez-Rovira, A. Bravin, L. Dusseau, P. Berkvens, Karen K. W. Siu
Přispěvatelé: European Synchrotron Radiation Facility (ESRF), Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie (MBI), Forschungsverbund Berlin e.V. (FVB) (FVB)-Leibniz Gemeinschaft, Czech Technical University in Prague (CTU), Niewodniczanski Institute of Nuclear Physics, Polish Academy of Sciences, 31-342 Krakow, Poland, Centre Interdisciplinaire de Nanoscience de Marseille (CINaM), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), CERN [Genève], Imagerie et Modélisation en Neurobiologie et Cancérologie (IMNC (UMR_8165)), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Institut d’Electronique et des Systèmes (IES), Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Radiations et composants (RADIAC), Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Forschungsverbund Berlin e.V.-Leibniz Gemeinschaft, K.K.W. Siu, Bräuer-Krisch, E, Rosenfeld, A, Lerch, M, Petasecca, M, Akselrod, M, Sykora, J, Bartz, J, Ptaszkiewicz, M, Olko, P, Berg, A, Wieland, M, Doran, S, Brochard, T, Kamlowski, A, Cellere, G, Paccagnella, A, Siegbahn, E, Prezado, Y, Martinez-Rovira, I, Bravin, A, Dusseau, L, Berkvens, P
Rok vydání: 2010
Předmět:
Zdroj: 6th International Conference on Medical Applications of Synchrotron Radiation-AIP Conference
6th International Conference on Medical Applications of Synchrotron Radiation-AIP Conference, 2010, Melbourne, Australia
ResearcherID
CIÊNCIAVITAE
ISSN: 0094-243X
DOI: 10.1063/1.3478205
Popis: Microbeam Radiation Therapy (MRT) uses highly collimated, quasi-parallel arrays of X-ray microbeams of 50-600 keV, produced by 2nd and 3rd generation synchrotron sources, such as the National Synchrotron Light Source (NSLS) in the U.S., and the European Synchrotron Radiation Facility (ESRF) in France, respectively. High dose rates are necessary to deliver therapeutic doses in microscopic volumes, to avoid spreading of the microbeams by cardiosynchronous movement of the tissues. A small beam divergence and a filtered white beam spectrum in the energy range between 30 and 250 keV results in the advantage of steep dose gradients with a sharper penumbra than that produced in conventional radiotherapy. MRT research over the past 20 years has allowed a vast number of results from preclinical trials on different animal models, including mice, rats, piglets and rabbits. Microbeams in the range between 10 and 100 micron width show an unprecedented sparing of normal radiosensitive tissues as well as preferential damage to malignant tumor tissues. Typically, MRT uses arrays of narrow ({approx}25-100 micron-wide) microplanar beams separated by wider (100-400 microns centre-to-centre, c-t-c) microplanar spaces. We note that thicker microbeams of 0.1-0.68 mm used by investigators at the NSLS are still called microbeams, although some invesigators inmore » the community prefer to call them minibeams. This report, however, limits it discussion to 25-100 {mu}m microbeams. Peak entrance doses of several hundreds of Gy are surprisingly well tolerated by normal tissues. High resolution dosimetry has been developed over the last two decades, but typical dose ranges are adapted to dose delivery in conventional Radiation Therapy (RT). Spatial resolution in the sub-millimetric range has been achieved, which is currently required for quality assurance measurements in Gamma-knife RT. Most typical commercially available detectors are not suitable for MRT applications at a dose rate of 16000 Gy/s, micron resolution and a dose range over several orders of magnitude. This paper will give an overview of all dosimeters tested in the past at the ESRF with their advantages and drawbacks. These detectors comprise: Ionization chambers, Alanine Dosimeters, MOSFET detectors, Gafchromic registered films, Radiochromic polymers, TLDs, Polymer gels, Fluorescent Nuclear Track Detectors (Al{sub 2}O{sub 3}:C, Mg single crystal detectors), OSL detectors and Floating Gate-based dosimetry system. The aim of such a comparison shall help with a decision on which of these approaches is most suitable for high resolution dose measurements in MRT. The principle of these detectors will be presented including a comparison for some dosimeters exposed with the same irradiation geometry, namely a 1x1 cm{sup 5} field size with microbeam exposures at the surface, 0.1 cm and 1 cm in depth of a PMMA phantom. For these test exposures, the most relevant irradiation parameters for future clinical trials have been chosen: 50 micron FWHM and 400 micron c-t-c distance. The experimental data are compared with Monte Carlo calculations.« less
Databáze: OpenAIRE
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