<abstract xmlns="http://www.w3.org/1999/xhtml">

<p>External photon beam radiotherapy is often used in tumor treatment. The photons are generated from the target which had stricken by the primary electron beam (incident particles). The photon beam contains the primary photons coming directly from the target and secondary photons coming from the photon interactions with head component materials (scattered photons). Altogether is thereafter used in radiotherapy treatment. This Monte Carlo study aims to investigate and evaluate the secondary radiations (photons) in terms of fluence, energy fluence, spectral distribution, mean energy and angular spread distribution.</p>
<p>The secondary photons, which contributed in radiotherapy treatment, are examined and evaluated in number (fluence) and energy. At the phantom surface, the secondary photons originated in the whole linac head are mainly coming from the primary collimator. In 0.45% of secondary photons coming from the whole linac head, the primary collimator contributes by 86% and they are more energetic. However, the flattening filter and the secondary collimator contribute together by less than 14% and their photons are less energetic and then can deteriorate the beam dosimetry quality. To improve the radiotherapy treatment quality, the number of photons of low energy should be as low as possible in the clinical beam. Our work can be a basic investigation to use in the improvement of linac head configuration and specially the beam modifiers.</p>
</abstract>

External photon beam radiotherapy is often used in tumor treatment. The photons are generated from the target which had stricken by the primary electron beam (incident particles). The photon beam contains the primary photons coming directly from the target and secondary photons coming from the photon interactions with head component materials (scattered photons). Altogether is thereafter used in radiotherapy treatment. This Monte Carlo study aims to investigate and evaluate the secondary radiations (photons) in terms of fluence, energy fluence, spectral distribution, mean energy and angular spread distribution.
The secondary photons, which contributed in radiotherapy treatment, are examined and evaluated in number (fluence) and energy. At the phantom surface, the secondary photons originated in the whole linac head are mainly coming from the primary collimator. In 0.45% of secondary photons coming from the whole linac head, the primary collimator contributes by 86% and they are more energetic. However, the flattening filter and the secondary collimator contribute together by less than 14% and their photons are less energetic and then can deteriorate the beam dosimetry quality. To improve the radiotherapy treatment quality, the number of photons of low energy should be as low as possible in the clinical beam. Our work can be a basic investigation to use in the improvement of linac head configuration and specially the beam modifiers.

Detailed Monte Carlo analysis of the secondary photons coming out of the therapeutic X-ray beam of linear accelerator

Physics Department, Faculty of Sciences and Technologies Mohammedia

Physics Department, Faculty of Sciences Dhar El-Mahraz

Theoretical and Particle Physics and Modelling Laboratory

Polish Journal of Medical Physics and Engineering

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

External photon beam radiotherapy is often used in tumor treatment. The photons are generated from the target which had stricken by the primary electron beam...

Detailed Monte Carlo analysis of the secondary photons coming out of the therapeutic X-ray beam of linear accelerator

Publié en ligne: 01 juil. 2021

Pages: 151 - 156

DOI: https://doi.org/10.2478/pjmpe-2021-0018

Mots clés
beam modifiers, Monte Carlo simulation, secondary photons, BEAMnrc code, BEAMDP code

© 2021 Mohamed Bencheikh et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Detailed Monte Carlo analysis of the secondary photons coming out of the therapeutic X-ray beam of linear accelerator

Publié en ligne: 01 juil. 2021

Pages: 151 - 156

DOI: https://doi.org/10.2478/pjmpe-2021-0018

Mots clésbeam modifiers, Monte Carlo simulation, secondary photons, BEAMnrc code, BEAMDP code

© 2021 Mohamed Bencheikh et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Mots clés
beam modifiers, Monte Carlo simulation, secondary photons, BEAMnrc code, BEAMDP code