Results 141 to 150 of about 757 (155)
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Optimization of Efficiency on DOSXYZnrc Monte Carlo Code Parameters for a 12 MV Photon Beam
2022 2nd International Conference on Innovative Research in Applied Science, Engineering and Technology (IRASET), 2022Abdelkrim. Zeghari +3 more
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A “HOWFARLESS” option to increase efficiency of homogeneous phantom calculations with DOSXYZnrc
Medical Physics, 2007This paper describes a “HOWFARLESS” transport option, which has been added to DOSXYZnrc to increase the efficiency of beam commissioning calculations in homogeneous phantoms. The algorithm speeds up charged particle transport by only considering the distance to the extreme outer boundaries of the phantom, thus eliminating the need to stop at voxel ...
Walters, B. R.B., Kawrakow, I.
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Medical Physics, 2007
Use of the PRESTA‐I (current default) boundary crossing algorithm for charged particles in DOSXYZnrc and BEAMnrc is shown to result in dose overprediction by up to 2.5% in photon and electron beams (less in high‐energy electron beams). The effect is most pronounced when charged particle equilibrium does not exist or when the phantom is not divided into
Walters, B. R.B., Kawrakow, I.
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Use of the PRESTA‐I (current default) boundary crossing algorithm for charged particles in DOSXYZnrc and BEAMnrc is shown to result in dose overprediction by up to 2.5% in photon and electron beams (less in high‐energy electron beams). The effect is most pronounced when charged particle equilibrium does not exist or when the phantom is not divided into
Walters, B. R.B., Kawrakow, I.
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SU‐FF‐T‐246: Implementation of Helical CT Source in DOSXYZnrc/EGSnrc Monte Carlo Code
Medical Physics, 2007Purpose: To implement and verify a new source type — phase‐space source in helical mode in DOSXYZnrc/EGSnrc Monte Carlo (MC) code. Method and Materials: To implement a new source type — “phase space source in helical mode” in DOSXYZnrc/EGSnrc, we modified the mortran and macro files related with DOSXYZnrc user code; dosxyznrc.mortan, srcxyznrc.mortran ...
S Kim, T Yoshizumi, F Yin
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Medical Physics, 2011
Purpose:The commercial release of volumetric modulated arc therapy techniques using a conventional linear accelerator and the growing number of helical tomotherapy users have triggered renewed interest in dose verification methods, and also in tools for exploring the impact of machine tolerance and patient motion on dose distributions without the need ...
Jason, Belec +3 more
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Purpose:The commercial release of volumetric modulated arc therapy techniques using a conventional linear accelerator and the growing number of helical tomotherapy users have triggered renewed interest in dose verification methods, and also in tools for exploring the impact of machine tolerance and patient motion on dose distributions without the need ...
Jason, Belec +3 more
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Medical Physics, 2008
Purpose: Most of Monte Carlo based methods to estimate radiation dose in computed tomography (CT) were performed using MCNP or EGS codes. However, They can't really simulate the CT source, such as the x‐ray tube and the bowtie filter. The purpose of this study is to verify the feasibility of using BEAMnrc/DOSXYZnrc code to develop a real multidetector ...
CC Chiang‐Hsieh +3 more
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Purpose: Most of Monte Carlo based methods to estimate radiation dose in computed tomography (CT) were performed using MCNP or EGS codes. However, They can't really simulate the CT source, such as the x‐ray tube and the bowtie filter. The purpose of this study is to verify the feasibility of using BEAMnrc/DOSXYZnrc code to develop a real multidetector ...
CC Chiang‐Hsieh +3 more
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Medical Physics, 2005
Underdosing of the treatment target in radiation therapy can occur when tumors are situated near natural air cavities due to charged particle disequilibrium around air‐tissue interfaces. These effects increase with energy and decrease with radiation field size. Significant underdosing may occur with small field sizes, which may be critical for IMRT and
C Joshi +3 more
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Underdosing of the treatment target in radiation therapy can occur when tumors are situated near natural air cavities due to charged particle disequilibrium around air‐tissue interfaces. These effects increase with energy and decrease with radiation field size. Significant underdosing may occur with small field sizes, which may be critical for IMRT and
C Joshi +3 more
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Moscow University Physics Bulletin, 2017
Determination and understanding the photon beam attenuation by the photon beam modifier and the radiation beam softening for clinical use is more important part of material study for the beam modifier enhancements and the linac improvements. A Monte Carlo model was used to simulate 6 MeV photon beams from a Varian Clinac 2100 accelerator with the ...
Mohamed Bencheikh +2 more
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Determination and understanding the photon beam attenuation by the photon beam modifier and the radiation beam softening for clinical use is more important part of material study for the beam modifier enhancements and the linac improvements. A Monte Carlo model was used to simulate 6 MeV photon beams from a Varian Clinac 2100 accelerator with the ...
Mohamed Bencheikh +2 more
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