Chromatic bleaching and fractionation effects on optically stimulated luminescent dosimeter reuse.
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| Title: | Chromatic bleaching and fractionation effects on optically stimulated luminescent dosimeter reuse. |
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| Authors: | Scott, Hayden1,2 (AUTHOR), Alvarez, Paola E.1 (AUTHOR), Howell, Rebecca M.1,2 (AUTHOR), Riegel, Adam3 (AUTHOR), Sun, Ryan2,4 (AUTHOR), Liu, Kevin1,2 (AUTHOR), Kry, Stephen F.1,2 (AUTHOR) sfkry@mdanderson.org |
| Source: | Medical Physics. Sep2024, Vol. 51 Issue 9, p6378-6389. 12p. |
| Subjects: | Light sources, Physicists, Dosimeters, Correction factors, Monochromatic light, Radiation, Thermoluminescence |
| Abstract: | Background: Optically stimulated luminescent dosimeters (OSLDs) can be bleached and reused, but questions remain about the effects of repeated bleaching and fractionation schedules on OSLD performance. Purpose: The aim of this study was to investigate how light sources with different wavelengths and different fractionation schemes affect the performance of reused OSLDs. Methods: OSLDs (N = 240) were irradiated on a cobalt‐60 beam in different step sizes until they reached an accumulated dose of 50 Gy. Between irradiations they were bleached using light sources of different wavelengths: the Imaging and Radiation Oncology Core (IROC) bleaching system (our control); monochromatic red, green, yellow, and blue lights; and a polychromatic white light. Sensitivity and linearity‐based correction factors were determined as a function of dose step‐size. The rate of signal removal from different light sources was characterized by sampling these OSLDs at various time points during their bleaching process. Relative doses were calculated according to the American Association of Physicists in Medicine Task Group‐191. Signal repopulation was investigated by irradiating OSLDs (N = 300) to various delivered doses of 2, 10, 20, 30, 40, and 50 Gy in a single fraction, bleached with one of the colors, and read over time. Fractionation effects were evaluated by irradiating OSLDs up to 30 Gy in different size steps. After reading, the OSLDs were bleached following IROC protocol. OSLDs (N = 40) received irradiations in 5, 10, 15, 30 Gy fractions until they had an accumulated dose of 30 Gy; The sensitivity response of these OSLDs was compared with reference OSLDs that had no accumulated dose. Results: Light sources with polychromatic spectrums (IROC and white) bleached OSLDs faster than did sources with monochromatic spectra. Polychromatic light sources (white light and IROC system) provided the greatest dose stability for OSLDs that had larger amounts of accumulated dose. Signal repopulation was related to the choice of bleaching light source, timing of bleaching, and amount of accumulated dose. Changes to relative dosimetry were more pronounced in OSLDs that received larger fractions. At 5‐Gy fractions and above, all OSLDs had heightened sensitivity, with OSLDs exposed to 30‐Gy fractions being 6.4% more sensitive than reference dosimeters. Conclusions: The choice of bleaching light plays a role in how fast an OSLD is bleached and how much accumulated dose an OSLD can be exposed to while maintaining stable signal sensitivity. We have expanded upon investigations into signal repopulation to show that bleaching light plays a role in the migration of deep traps to dosimetric traps after bleaching. Our research concludes that the bleaching light source and fractionation need to be considered when reusing OSLD. [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.) | |
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| Items | – Name: Title Label: Title Group: Ti Data: Chromatic bleaching and fractionation effects on optically stimulated luminescent dosimeter reuse. – Name: Author Label: Authors Group: Au Data: <searchLink fieldCode="AR" term="%22Scott%2C+Hayden%22">Scott, Hayden</searchLink><relatesTo>1,2</relatesTo> (AUTHOR)<br /><searchLink fieldCode="AR" term="%22Alvarez%2C+Paola+E%2E%22">Alvarez, Paola E.</searchLink><relatesTo>1</relatesTo> (AUTHOR)<br /><searchLink fieldCode="AR" term="%22Howell%2C+Rebecca+M%2E%22">Howell, Rebecca M.</searchLink><relatesTo>1,2</relatesTo> (AUTHOR)<br /><searchLink fieldCode="AR" term="%22Riegel%2C+Adam%22">Riegel, Adam</searchLink><relatesTo>3</relatesTo> (AUTHOR)<br /><searchLink fieldCode="AR" term="%22Sun%2C+Ryan%22">Sun, Ryan</searchLink><relatesTo>2,4</relatesTo> (AUTHOR)<br /><searchLink fieldCode="AR" term="%22Liu%2C+Kevin%22">Liu, Kevin</searchLink><relatesTo>1,2</relatesTo> (AUTHOR)<br /><searchLink fieldCode="AR" term="%22Kry%2C+Stephen+F%2E%22">Kry, Stephen F.</searchLink><relatesTo>1,2</relatesTo> (AUTHOR)<i> sfkry@mdanderson.org</i> – Name: TitleSource Label: Source Group: Src Data: <searchLink fieldCode="JN" term="%22Medical+Physics%22">Medical Physics</searchLink>. Sep2024, Vol. 51 Issue 9, p6378-6389. 12p. – Name: Subject Label: Subjects Group: Su Data: <searchLink fieldCode="DE" term="%22Light+sources%22">Light sources</searchLink><br /><searchLink fieldCode="DE" term="%22Physicists%22">Physicists</searchLink><br /><searchLink fieldCode="DE" term="%22Dosimeters%22">Dosimeters</searchLink><br /><searchLink fieldCode="DE" term="%22Correction+factors%22">Correction factors</searchLink><br /><searchLink fieldCode="DE" term="%22Monochromatic+light%22">Monochromatic light</searchLink><br /><searchLink fieldCode="DE" term="%22Radiation%22">Radiation</searchLink><br /><searchLink fieldCode="DE" term="%22Thermoluminescence%22">Thermoluminescence</searchLink> – Name: Abstract Label: Abstract Group: Ab Data: Background: Optically stimulated luminescent dosimeters (OSLDs) can be bleached and reused, but questions remain about the effects of repeated bleaching and fractionation schedules on OSLD performance. Purpose: The aim of this study was to investigate how light sources with different wavelengths and different fractionation schemes affect the performance of reused OSLDs. Methods: OSLDs (N = 240) were irradiated on a cobalt‐60 beam in different step sizes until they reached an accumulated dose of 50 Gy. Between irradiations they were bleached using light sources of different wavelengths: the Imaging and Radiation Oncology Core (IROC) bleaching system (our control); monochromatic red, green, yellow, and blue lights; and a polychromatic white light. Sensitivity and linearity‐based correction factors were determined as a function of dose step‐size. The rate of signal removal from different light sources was characterized by sampling these OSLDs at various time points during their bleaching process. Relative doses were calculated according to the American Association of Physicists in Medicine Task Group‐191. Signal repopulation was investigated by irradiating OSLDs (N = 300) to various delivered doses of 2, 10, 20, 30, 40, and 50 Gy in a single fraction, bleached with one of the colors, and read over time. Fractionation effects were evaluated by irradiating OSLDs up to 30 Gy in different size steps. After reading, the OSLDs were bleached following IROC protocol. OSLDs (N = 40) received irradiations in 5, 10, 15, 30 Gy fractions until they had an accumulated dose of 30 Gy; The sensitivity response of these OSLDs was compared with reference OSLDs that had no accumulated dose. Results: Light sources with polychromatic spectrums (IROC and white) bleached OSLDs faster than did sources with monochromatic spectra. Polychromatic light sources (white light and IROC system) provided the greatest dose stability for OSLDs that had larger amounts of accumulated dose. Signal repopulation was related to the choice of bleaching light source, timing of bleaching, and amount of accumulated dose. Changes to relative dosimetry were more pronounced in OSLDs that received larger fractions. At 5‐Gy fractions and above, all OSLDs had heightened sensitivity, with OSLDs exposed to 30‐Gy fractions being 6.4% more sensitive than reference dosimeters. Conclusions: The choice of bleaching light plays a role in how fast an OSLD is bleached and how much accumulated dose an OSLD can be exposed to while maintaining stable signal sensitivity. We have expanded upon investigations into signal repopulation to show that bleaching light plays a role in the migration of deep traps to dosimetric traps after bleaching. Our research concludes that the bleaching light source and fractionation need to be considered when reusing OSLD. [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: 10.1002/mp.17231 Languages: – Code: eng Text: English PhysicalDescription: Pagination: PageCount: 12 StartPage: 6378 Subjects: – SubjectFull: Light sources Type: general – SubjectFull: Physicists Type: general – SubjectFull: Dosimeters Type: general – SubjectFull: Correction factors Type: general – SubjectFull: Monochromatic light Type: general – SubjectFull: Radiation Type: general – SubjectFull: Thermoluminescence Type: general Titles: – TitleFull: Chromatic bleaching and fractionation effects on optically stimulated luminescent dosimeter reuse. Type: main BibRelationships: HasContributorRelationships: – PersonEntity: Name: NameFull: Scott, Hayden – PersonEntity: Name: NameFull: Alvarez, Paola E. – PersonEntity: Name: NameFull: Howell, Rebecca M. – PersonEntity: Name: NameFull: Riegel, Adam – PersonEntity: Name: NameFull: Sun, Ryan – PersonEntity: Name: NameFull: Liu, Kevin – PersonEntity: Name: NameFull: Kry, Stephen F. IsPartOfRelationships: – BibEntity: Dates: – D: 01 M: 09 Text: Sep2024 Type: published Y: 2024 Identifiers: – Type: issn-print Value: 00942405 Numbering: – Type: volume Value: 51 – Type: issue Value: 9 Titles: – TitleFull: Medical Physics Type: main |
| ResultId | 1 |
