SU-FF-T-273: Improved Calculation of Energy Spectra From Electron Depth Dose Curves

J Lehmann; E Schreiber; J Chen; B Faddegon

doi:10.1118/1.2241193

Tikhonov regularization modified as improved method for determining electron energy spectra from percentage depth dose curves data of broad beams

10.1063/1.4954116 ◽

2016 ◽

Cited By ~ 1

Author(s):

Jorge Homero Wilches Visbal ◽

Alessandro Martins Da Costa

Keyword(s):

Electron Energy ◽

Tikhonov Regularization ◽

Energy Spectra ◽

Improved Method ◽

Percentage Depth Dose ◽

Depth Dose

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Energy spectra considerations for synchrotron radiotherapy trials on the ID17 bio-medical beamline at the European Synchrotron Radiation Facility

Journal of Synchrotron Radiation ◽

10.1107/s1600577515008115 ◽

2015 ◽

Vol 22 (4) ◽

pp. 1035-1041 ◽

Cited By ~ 28

Author(s):

Jeffrey C. Crosbie ◽

Pauline Fournier ◽

Stefan Bartzsch ◽

Mattia Donzelli ◽

Iwan Cornelius ◽

...

Keyword(s):

Energy Spectrum ◽

Synchrotron Radiation ◽

Treatment Planning ◽

European Synchrotron Radiation Facility ◽

Planning System ◽

Energy Spectra ◽

Treatment Planning System ◽

X Ray ◽

Depth Dose ◽

Cylindrical Ionization Chamber

The aim of this study was to validate the kilovoltage X-ray energy spectrum on the ID17 beamline at the European Synchrotron Radiation Facility (ESRF). The purpose of such validation was to provide an accurate energy spectrum as the input to a computerized treatment planning system, which will be used in synchrotron microbeam radiotherapy trials at the ESRF. Calculated and measured energy spectra on ID17 have been reported previously but recent additions and safety modifications to the beamline for veterinary trials warranted a fresh investigation. The authors used an established methodology to compare X-ray attenuation measurements in copper sheets (referred to as half value layer measurements in the radiotherapy field) with the predictions of a theoretical model. A cylindrical ionization chamber in air was used to record the relative attenuation of the X-ray beam intensity by increasing thicknesses of high-purity copper sheets. The authors measured the half value layers in copper for two beamline configurations, which corresponded to differing spectral conditions. The authors obtained good agreement between the measured and predicted half value layers for the two beamline configurations. The measured first half value layer was 1.754 ± 0.035 mm Cu and 1.962 ± 0.039 mm Cu for the two spectral conditions, compared with theoretical predictions of 1.763 ± 0.039 mm Cu and 1.984 ± 0.044 mm Cu, respectively. The calculated mean energies for the two conditions were 105 keV and 110 keV and there was not a substantial difference in the calculated percentage depth dose curves in water between the different spectral conditions. The authors observed a difference between their calculated energy spectra and the spectra previously reported by other authors, particularly at energies greater than 100 keV. The validation of the beam spectrum by the copper half value layer measurements means the authors can provide an accurate spectrum as an input to a treatment planning system for the forthcoming veterinary trials of microbeam radiotherapy to spontaneous tumours in cats and dogs.

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Energy spectra and depth-dose curves for 70 MeV protons

International Journal of Quantum Chemistry ◽

10.1002/qua.560360858 ◽

2009 ◽

Vol 36 (S23) ◽

pp. 565-574 ◽

Cited By ~ 1

Author(s):

Hans Bichsel ◽

T. Hiraoka

Keyword(s):

Energy Spectra ◽

Depth Dose ◽

Mev Protons

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Calculation of energy spectra for therapeutic electron beams from depth-dose curves

Physics in Medicine and Biology ◽

10.1088/0031-9155/28/12/010 ◽

1983 ◽

Vol 28 (12) ◽

pp. 1441-1446 ◽

Cited By ~ 4

Author(s):

I Kovar ◽

J Novotny ◽

Z Kovar ◽

P Kirousek ◽

S Vavra

Keyword(s):

Electron Beams ◽

Energy Spectra ◽

Depth Dose

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Verification of the use of GEANT4 and MCNPX Monte Carlo Codes for Calculations of the Depth-Dose Distributions in Water for the Proton Therapy of Eye Tumours

Nukleonika ◽

10.2478/nuka-2014-0007 ◽

2014 ◽

Vol 59 (2) ◽

pp. 61-66 ◽

Cited By ~ 2

Author(s):

Małgorzata Grządziel ◽

Adam Konefał ◽

Wiktor Zipper ◽

Robert Pietrzak ◽

Ewelina Bzymek

Keyword(s):

Monte Carlo ◽

Proton Beam ◽

Proton Therapy ◽

Mean Value ◽

Energy Spectra ◽

Primary Proton ◽

Relative Depth ◽

Dose Distributions ◽

Depth Dose

Abstract Verification of calculations of the depth-dose distributions in water, using GEANT4 (version of 4.9.3) and MCNPX (version of 2.7.0) Monte Carlo codes, was performed for the scatterer-phantom system used in the dosimetry measurements in the proton therapy of eye tumours. The simulated primary proton beam had the energy spectra distributed according to the Gauss distribution with the cut at energy greater than that related to the maximum of the spectrum. The energy spectra of the primary protons were chosen to get the possibly best agreement between the measured relative depth-dose distributions along the central-axis of the proton beam in a water phantom and that derived from the Monte Carlo calculations separately for the both tested codes. The local depth-dose differences between results from the calculations and the measurements were mostly less than 5% (the mean value of 2.1% and 3.6% for the MCNPX and GEANT4 calculations). In the case of the MCNPX calculations, the best fit to the experimental data was obtained for the spectrum with maximum at 60.8 MeV (more probable energy), FWHM of the spectrum of 0.4 MeV and the energy cut at 60.85 MeV whereas in the GEANT4 calculations more probable energy was 60.5 MeV, FWHM of 0.5 MeV, the energy cut at 60.7 MeV. Thus, one can say that the results obtained by means of the both considered Monte Carlo codes are similar but they are not the same. Therefore the agreement between the calculations and the measurements has to be verified before each application of the MCNPX and GEANT4 codes for the determination of the depth-dose curves for the therapeutic protons.

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