Secondary neutron spectra from modern Varian, Siemens, and Elekta linacs with multileaf collimators.
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| Title: | Secondary neutron spectra from modern Varian, Siemens, and Elekta linacs with multileaf collimators. |
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| Authors: | Howell, Rebecca M.1 rhowell@mdanderson.org, Kry, Stephen F.1, Burgett, Eric2, Hertel, Nolan E.2, Followill, David S.1 |
| Source: | Medical Physics. Sep2009, Vol. 36 Issue 9, p4027-4038. 12p. 1 Diagram, 4 Charts, 8 Graphs. |
| Subjects: | Cancer treatment, Neutrons, Atomic spectra, Variances, Radiotherapy, Radiation |
| Abstract: | Neutrons are a by-product of high-energy x-ray radiation therapy (threshold for [γ,n] reactions in high-Z material ∼7 MeV). Neutron production varies depending on photon beam energy as well as on the manufacturer of the accelerator. Neutron production from modern linear accelerators (linacs) has not been extensively compared, particularly in terms of the differences in the strategies that various manufacturers have used to implement multileaf collimators (MLCs) into their linac designs. However, such information is necessary to determine neutron dose equivalents for different linacs and to calculate vault shielding requirements. The purpose of the current study, therefore, was to measure the neutron spectra from the most up-to-date linacs from three manufacturers: Varian 21EX operating at 15, 18, and 20 MV, Siemens ONCOR operating at 15 and 18 MV, and Elekta Precise operating at 15 and 18 MV. Neutron production was measured by means of gold foil activation in Bonner spheres. Based on the measurements, the authors determined neutron spectra and calculated the average energy, total neutron fluence, ambient dose equivalent, and neutron source strength. The shapes of the neutron spectra did not change significantly between accelerators or even as a function of treatment energy. However, the neutron fluence, and therefore the ambient dose equivalent, did vary, increasing with increasing treatment energy. For a given nominal treatment energy, these values were always highest for the Varian linac. The current study thus offers medical physicists extensive information about the neutron production of MLC-equipped linacs currently in operation and provides them information vital for accurate comparison and prediction of neutron dose equivalents and calculation of vault shielding requirements. [ABSTRACT FROM AUTHOR] |
| Copyright of Medical Physics is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.) | |
| Database: | Engineering Source |
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| Header | DbId: egs DbLabel: Engineering Source An: 43944934 AccessLevel: 6 PubType: Academic Journal PubTypeId: academicJournal PreciseRelevancyScore: 0 |
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| Items | – Name: Title Label: Title Group: Ti Data: Secondary neutron spectra from modern Varian, Siemens, and Elekta linacs with multileaf collimators. – Name: Author Label: Authors Group: Au Data: <searchLink fieldCode="AR" term="%22Howell%2C+Rebecca+M%2E%22">Howell, Rebecca M.</searchLink><relatesTo>1</relatesTo><i> rhowell@mdanderson.org</i><br /><searchLink fieldCode="AR" term="%22Kry%2C+Stephen+F%2E%22">Kry, Stephen F.</searchLink><relatesTo>1</relatesTo><br /><searchLink fieldCode="AR" term="%22Burgett%2C+Eric%22">Burgett, Eric</searchLink><relatesTo>2</relatesTo><br /><searchLink fieldCode="AR" term="%22Hertel%2C+Nolan+E%2E%22">Hertel, Nolan E.</searchLink><relatesTo>2</relatesTo><br /><searchLink fieldCode="AR" term="%22Followill%2C+David+S%2E%22">Followill, David S.</searchLink><relatesTo>1</relatesTo> – Name: TitleSource Label: Source Group: Src Data: <searchLink fieldCode="JN" term="%22Medical+Physics%22">Medical Physics</searchLink>. Sep2009, Vol. 36 Issue 9, p4027-4038. 12p. 1 Diagram, 4 Charts, 8 Graphs. – Name: Subject Label: Subjects Group: Su Data: <searchLink fieldCode="DE" term="%22Cancer+treatment%22">Cancer treatment</searchLink><br /><searchLink fieldCode="DE" term="%22Neutrons%22">Neutrons</searchLink><br /><searchLink fieldCode="DE" term="%22Atomic+spectra%22">Atomic spectra</searchLink><br /><searchLink fieldCode="DE" term="%22Variances%22">Variances</searchLink><br /><searchLink fieldCode="DE" term="%22Radiotherapy%22">Radiotherapy</searchLink><br /><searchLink fieldCode="DE" term="%22Radiation%22">Radiation</searchLink> – Name: Abstract Label: Abstract Group: Ab Data: Neutrons are a by-product of high-energy x-ray radiation therapy (threshold for [γ,n] reactions in high-Z material ∼7 MeV). Neutron production varies depending on photon beam energy as well as on the manufacturer of the accelerator. Neutron production from modern linear accelerators (linacs) has not been extensively compared, particularly in terms of the differences in the strategies that various manufacturers have used to implement multileaf collimators (MLCs) into their linac designs. However, such information is necessary to determine neutron dose equivalents for different linacs and to calculate vault shielding requirements. The purpose of the current study, therefore, was to measure the neutron spectra from the most up-to-date linacs from three manufacturers: Varian 21EX operating at 15, 18, and 20 MV, Siemens ONCOR operating at 15 and 18 MV, and Elekta Precise operating at 15 and 18 MV. Neutron production was measured by means of gold foil activation in Bonner spheres. Based on the measurements, the authors determined neutron spectra and calculated the average energy, total neutron fluence, ambient dose equivalent, and neutron source strength. The shapes of the neutron spectra did not change significantly between accelerators or even as a function of treatment energy. However, the neutron fluence, and therefore the ambient dose equivalent, did vary, increasing with increasing treatment energy. For a given nominal treatment energy, these values were always highest for the Varian linac. The current study thus offers medical physicists extensive information about the neutron production of MLC-equipped linacs currently in operation and provides them information vital for accurate comparison and prediction of neutron dose equivalents and calculation of vault shielding requirements. [ABSTRACT FROM AUTHOR] – Name: AbstractSuppliedCopyright Label: Group: Ab Data: <i>Copyright of Medical Physics is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract.</i> (Copyright applies to all Abstracts.) |
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| RecordInfo | BibRecord: BibEntity: Identifiers: – Type: doi Value: 10.1118/1.3159300 Languages: – Code: eng Text: English PhysicalDescription: Pagination: PageCount: 12 StartPage: 4027 Subjects: – SubjectFull: Cancer treatment Type: general – SubjectFull: Neutrons Type: general – SubjectFull: Atomic spectra Type: general – SubjectFull: Variances Type: general – SubjectFull: Radiotherapy Type: general – SubjectFull: Radiation Type: general Titles: – TitleFull: Secondary neutron spectra from modern Varian, Siemens, and Elekta linacs with multileaf collimators. Type: main BibRelationships: HasContributorRelationships: – PersonEntity: Name: NameFull: Howell, Rebecca M. – PersonEntity: Name: NameFull: Kry, Stephen F. – PersonEntity: Name: NameFull: Burgett, Eric – PersonEntity: Name: NameFull: Hertel, Nolan E. – PersonEntity: Name: NameFull: Followill, David S. IsPartOfRelationships: – BibEntity: Dates: – D: 01 M: 09 Text: Sep2009 Type: published Y: 2009 Identifiers: – Type: issn-print Value: 00942405 Numbering: – Type: volume Value: 36 – Type: issue Value: 9 Titles: – TitleFull: Medical Physics Type: main |
| ResultId | 1 |
