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Title: Dosimetry protocol for the preclinical trials in white-beam minibeam radiation therapy

Abstract

Purpose: In the quest of a curative radiotherapy treatment for gliomas, new delivery modes are being explored. At the Biomedical Beamline of the European Synchrotron Radiation Facility, a new spatially fractionated technique, called minibeam radiation therapy (MBRT), is under development. The aims of this work were to assess different dosimetric aspects and to establish a dosimetry protocol to be applied in the forthcoming animal (rat) studies in order to evaluate the therapeutic index of this new radiotherapy approach. Methods: Absolute dosimetry was performed with a thimble ionization chamber (PTW semiflex 31010) whose center was positioned at 2 g cm{sup -2} depth. To translate the dose measured in broad beam configuration to the dose deposited with a minibeam, the scatter factors were used. Those were assessed by using the Monte Carlo simulations and verified experimentally with Gafchromic films and a Bragg Peak chamber. The comparison of the theoretical and experimental data were used to benchmark the calculations. Finally, the dose distributions in a rat phantom were evaluated by using the validated Monte Carlo calculations. Results: The absolute dosimetry in broad beam configuration was measured in reference conditions. The dose rate was in the range between 168 and 224 Gy/min, depending onmore » the storage ring current. A scatter factor of 0.80 {+-} 0.04 was obtained. Percentage depth dose and lateral profiles were evaluated both in homogenous and heterogeneous slab phantoms. The general good agreement between Monte Carlo simulations and experimental data permitted the benchmark of the calculations. Finally, the peak doses in the rat head phantom were assessed from the measurements in reference conditions. In addition, the peak-to-valley dose ratio values as a function of depth in the rat head were evaluated. Conclusions: A new promising radiotherapy approach is being explored at the ESRF: Minibeam Radiation Therapy. To assess the therapeutic index of this new modality, in vivo experiments are being planned, for which an accurate knowledge of the dosimetry is essential. For that purpose, a complete set of measurements and Monte Carlo simulations was performed. The first dosimetry protocol for preclinical trials in minibeam radiation therapy was established. This protocol allows to have reproducibility in terms of dose for the different biological studies.« less

Authors:
; ; ;  [1];  [2];  [3];  [4];  [5]
  1. ID17 Biomedical Beamline, European Synchrotron Radiation Facility (ESRF), 6, Rue Jules Horowitz B.P.220, 38043 Grenoble (France)
  2. (ESRF), 6, Rue Jules Horowitz B.P. 220, 38043 Grenoble Cedex (France) and Institut de Tecniques Energetiques, Universitat Politecnica de Catalunya, Diagonal 647, E-08028 Barcelona (Spain)
  3. (ESRF), 6, Rue Jules Horowitz B.P.220, 38043 Grenoble (France) and Dipartimento di Fisica ''E. Amaldi'', Universita degli Studi Roma Tre, 84, Via della Vasca Navale, 00146 Rome (Italy)
  4. (ESRF), 6, Rue Jules Horowitz B.P.220, 38043 Grenoble (France)
  5. (France) and University Grenoble 1, F-38041 Grenoble (France)
Publication Date:
OSTI Identifier:
22098610
Resource Type:
Journal Article
Journal Name:
Medical Physics
Additional Journal Information:
Journal Volume: 38; Journal Issue: 9; Other Information: (c) 2011 American Association of Physicists in Medicine; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0094-2405
Country of Publication:
United States
Language:
English
Subject:
61 RADIATION PROTECTION AND DOSIMETRY; 62 RADIOLOGY AND NUCLEAR MEDICINE; BEAMS; BENCHMARKS; BRAGG CURVE; COMPUTERIZED SIMULATION; DEPTH DOSE DISTRIBUTIONS; DOSE RATES; DOSIMETRY; EUROPEAN SYNCHROTRON RADIATION FACILITY; GLIOMAS; IN VIVO; IONIZATION CHAMBERS; MONTE CARLO METHOD; PHANTOMS; RADIATION DOSES; RADIOTHERAPY; SYNCHROTRON RADIATION

Citation Formats

Prezado, Y., Martinez-Rovira, I., Thengumpallil, S., Deman, P., ID17 Biomedical Beamline, European Synchrotron Radiation Facility, ID17 Biomedical Beamline, European Synchrotron Radiation Facility, ID17 Biomedical Beamline, European Synchrotron Radiation Facility, and INSERM, U836, Equipe 6, F-38042 Grenoble 9. Dosimetry protocol for the preclinical trials in white-beam minibeam radiation therapy. United States: N. p., 2011. Web. doi:10.1118/1.3608908.
Prezado, Y., Martinez-Rovira, I., Thengumpallil, S., Deman, P., ID17 Biomedical Beamline, European Synchrotron Radiation Facility, ID17 Biomedical Beamline, European Synchrotron Radiation Facility, ID17 Biomedical Beamline, European Synchrotron Radiation Facility, & INSERM, U836, Equipe 6, F-38042 Grenoble 9. Dosimetry protocol for the preclinical trials in white-beam minibeam radiation therapy. United States. doi:10.1118/1.3608908.
Prezado, Y., Martinez-Rovira, I., Thengumpallil, S., Deman, P., ID17 Biomedical Beamline, European Synchrotron Radiation Facility, ID17 Biomedical Beamline, European Synchrotron Radiation Facility, ID17 Biomedical Beamline, European Synchrotron Radiation Facility, and INSERM, U836, Equipe 6, F-38042 Grenoble 9. Thu . "Dosimetry protocol for the preclinical trials in white-beam minibeam radiation therapy". United States. doi:10.1118/1.3608908.
@article{osti_22098610,
title = {Dosimetry protocol for the preclinical trials in white-beam minibeam radiation therapy},
author = {Prezado, Y. and Martinez-Rovira, I. and Thengumpallil, S. and Deman, P. and ID17 Biomedical Beamline, European Synchrotron Radiation Facility and ID17 Biomedical Beamline, European Synchrotron Radiation Facility and ID17 Biomedical Beamline, European Synchrotron Radiation Facility and INSERM, U836, Equipe 6, F-38042 Grenoble 9},
abstractNote = {Purpose: In the quest of a curative radiotherapy treatment for gliomas, new delivery modes are being explored. At the Biomedical Beamline of the European Synchrotron Radiation Facility, a new spatially fractionated technique, called minibeam radiation therapy (MBRT), is under development. The aims of this work were to assess different dosimetric aspects and to establish a dosimetry protocol to be applied in the forthcoming animal (rat) studies in order to evaluate the therapeutic index of this new radiotherapy approach. Methods: Absolute dosimetry was performed with a thimble ionization chamber (PTW semiflex 31010) whose center was positioned at 2 g cm{sup -2} depth. To translate the dose measured in broad beam configuration to the dose deposited with a minibeam, the scatter factors were used. Those were assessed by using the Monte Carlo simulations and verified experimentally with Gafchromic films and a Bragg Peak chamber. The comparison of the theoretical and experimental data were used to benchmark the calculations. Finally, the dose distributions in a rat phantom were evaluated by using the validated Monte Carlo calculations. Results: The absolute dosimetry in broad beam configuration was measured in reference conditions. The dose rate was in the range between 168 and 224 Gy/min, depending on the storage ring current. A scatter factor of 0.80 {+-} 0.04 was obtained. Percentage depth dose and lateral profiles were evaluated both in homogenous and heterogeneous slab phantoms. The general good agreement between Monte Carlo simulations and experimental data permitted the benchmark of the calculations. Finally, the peak doses in the rat head phantom were assessed from the measurements in reference conditions. In addition, the peak-to-valley dose ratio values as a function of depth in the rat head were evaluated. Conclusions: A new promising radiotherapy approach is being explored at the ESRF: Minibeam Radiation Therapy. To assess the therapeutic index of this new modality, in vivo experiments are being planned, for which an accurate knowledge of the dosimetry is essential. For that purpose, a complete set of measurements and Monte Carlo simulations was performed. The first dosimetry protocol for preclinical trials in minibeam radiation therapy was established. This protocol allows to have reproducibility in terms of dose for the different biological studies.},
doi = {10.1118/1.3608908},
journal = {Medical Physics},
issn = {0094-2405},
number = 9,
volume = 38,
place = {United States},
year = {2011},
month = {9}
}