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The Influence of Shielding Reinforcement in a Vault with Limited Dimensions on the Neutron Dose Equivalent in Vicinity of Medical Electron Linear Accelerator
BACKGROUND: High energy electron linear accelerators (LINACs) producing photon beams with energies higher than 10 MeV are widely used in radiation therapy. In these beams, fast neutrons are generated, which results in undesired contamination of the therapeutic beam. In this study, measurements and M...
Autores principales: | , , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Sciendo
2020
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Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7276637/ https://www.ncbi.nlm.nih.gov/pubmed/32374291 http://dx.doi.org/10.2478/raon-2020-0024 |
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author | Ivkovic, Ana Faj, Dario Kasabasic, Mladen Sovilj, Marina Poje Krpan, Ivana Branilovic, Marina Grabar Brkic, Hrvoje |
author_facet | Ivkovic, Ana Faj, Dario Kasabasic, Mladen Sovilj, Marina Poje Krpan, Ivana Branilovic, Marina Grabar Brkic, Hrvoje |
author_sort | Ivkovic, Ana |
collection | PubMed |
description | BACKGROUND: High energy electron linear accelerators (LINACs) producing photon beams with energies higher than 10 MeV are widely used in radiation therapy. In these beams, fast neutrons are generated, which results in undesired contamination of the therapeutic beam. In this study, measurements and Monte Carlo (MC) simulations were used to obtain neutron spectra and dose equivalents in vicinity of linear accelerator. MATERIALS AND METHODS: LINAC Siemens Oncor Expression in Osijek University Hospital is placed in vault that was previously used for (60)Co machine. Then, the shielding of the vault was enhanced using lead and steel plates. Measurements of neutron dose equivalent around LINAC and the vault were done using CR-39 solid state nuclear track detectors. To compensate energy dependence of detectors, neutron energy spectra was calculated in measuring positions using MC simulations. RESULTS: The vault is a source of photoneutrons, but a vast majority of neutrons originates from accelerator head. Neutron spectra obtained from MC simulations show significant changes between the measuring positions. Annual neutron dose equivalent per year was estimated to be less than 324 μSv in the measuring points outside of the vault. CONCLUSIONS: Since detectors used in this paper are very dependent on neutron energy, it is extremely important to know the neutron spectra in measuring points. Though, patient dosimetry should include neutrons, estimated annual neutron doses outside the vault were far below exposure limit of ionizing radiation for workers. |
format | Online Article Text |
id | pubmed-7276637 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2020 |
publisher | Sciendo |
record_format | MEDLINE/PubMed |
spelling | pubmed-72766372020-06-09 The Influence of Shielding Reinforcement in a Vault with Limited Dimensions on the Neutron Dose Equivalent in Vicinity of Medical Electron Linear Accelerator Ivkovic, Ana Faj, Dario Kasabasic, Mladen Sovilj, Marina Poje Krpan, Ivana Branilovic, Marina Grabar Brkic, Hrvoje Radiol Oncol Research Article BACKGROUND: High energy electron linear accelerators (LINACs) producing photon beams with energies higher than 10 MeV are widely used in radiation therapy. In these beams, fast neutrons are generated, which results in undesired contamination of the therapeutic beam. In this study, measurements and Monte Carlo (MC) simulations were used to obtain neutron spectra and dose equivalents in vicinity of linear accelerator. MATERIALS AND METHODS: LINAC Siemens Oncor Expression in Osijek University Hospital is placed in vault that was previously used for (60)Co machine. Then, the shielding of the vault was enhanced using lead and steel plates. Measurements of neutron dose equivalent around LINAC and the vault were done using CR-39 solid state nuclear track detectors. To compensate energy dependence of detectors, neutron energy spectra was calculated in measuring positions using MC simulations. RESULTS: The vault is a source of photoneutrons, but a vast majority of neutrons originates from accelerator head. Neutron spectra obtained from MC simulations show significant changes between the measuring positions. Annual neutron dose equivalent per year was estimated to be less than 324 μSv in the measuring points outside of the vault. CONCLUSIONS: Since detectors used in this paper are very dependent on neutron energy, it is extremely important to know the neutron spectra in measuring points. Though, patient dosimetry should include neutrons, estimated annual neutron doses outside the vault were far below exposure limit of ionizing radiation for workers. Sciendo 2020-05-02 /pmc/articles/PMC7276637/ /pubmed/32374291 http://dx.doi.org/10.2478/raon-2020-0024 Text en © 2020 Ana Ivkovic, Dario Faj, Mladen Kasabasic, Marina Poje Sovilj, Ivana Krpan, Marina Grabar Branilovic, Hrvoje Brkic, published by Sciendo http://creativecommons.org/licenses/by-nc-nd/3.0 This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License. |
spellingShingle | Research Article Ivkovic, Ana Faj, Dario Kasabasic, Mladen Sovilj, Marina Poje Krpan, Ivana Branilovic, Marina Grabar Brkic, Hrvoje The Influence of Shielding Reinforcement in a Vault with Limited Dimensions on the Neutron Dose Equivalent in Vicinity of Medical Electron Linear Accelerator |
title | The Influence of Shielding Reinforcement in a Vault with Limited Dimensions on the Neutron Dose Equivalent in Vicinity of Medical Electron Linear Accelerator |
title_full | The Influence of Shielding Reinforcement in a Vault with Limited Dimensions on the Neutron Dose Equivalent in Vicinity of Medical Electron Linear Accelerator |
title_fullStr | The Influence of Shielding Reinforcement in a Vault with Limited Dimensions on the Neutron Dose Equivalent in Vicinity of Medical Electron Linear Accelerator |
title_full_unstemmed | The Influence of Shielding Reinforcement in a Vault with Limited Dimensions on the Neutron Dose Equivalent in Vicinity of Medical Electron Linear Accelerator |
title_short | The Influence of Shielding Reinforcement in a Vault with Limited Dimensions on the Neutron Dose Equivalent in Vicinity of Medical Electron Linear Accelerator |
title_sort | influence of shielding reinforcement in a vault with limited dimensions on the neutron dose equivalent in vicinity of medical electron linear accelerator |
topic | Research Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7276637/ https://www.ncbi.nlm.nih.gov/pubmed/32374291 http://dx.doi.org/10.2478/raon-2020-0024 |
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