An on-site dosimetry audit for high-energy electron beams
Background and purpose: External dosimetry audits are powerful quality assurance instruments for radiotherapy. The aim of this study was to implement an electron dosimetry audit based on a contemporary code of practice within the requirements for calibration laboratories performing proficiency tests...
| Main Authors: | , , , , , , , , , |
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| Format: | Article |
| Language: | English |
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Elsevier
2018-01-01
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| Series: | Physics and Imaging in Radiation Oncology |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S2405631617300507 |
| _version_ | 1811299600642867200 |
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| author | Leon de Prez Stan Heukelom Bartel Jansen Wim Jansen Jeroen van de Kamer Wenze van Klink Elfried Kok Thijs Perik Jacco de Pooter Frits Wittkämper |
| author_facet | Leon de Prez Stan Heukelom Bartel Jansen Wim Jansen Jeroen van de Kamer Wenze van Klink Elfried Kok Thijs Perik Jacco de Pooter Frits Wittkämper |
| author_sort | Leon de Prez |
| collection | DOAJ |
| description | Background and purpose: External dosimetry audits are powerful quality assurance instruments for radiotherapy. The aim of this study was to implement an electron dosimetry audit based on a contemporary code of practice within the requirements for calibration laboratories performing proficiency tests. This involved the determination of suitable acceptance criteria based on thorough uncertainty analyses. Materials and methods: Subject of the audit was the determination of absorbed dose to water, Dw, and the beam quality specifier, R50,dos. Fifteen electron beams were measured in four institutes according to the Belgian-Dutch code of practice for high-energy electron beams. The expanded uncertainty (k = 2) for the Dw values was 3.6% for a Roos chamber calibrated in 60Co and 3.2% for a Roos chamber cross-calibrated against a Farmer chamber. The expanded uncertainty for the beam quality specifier, R50,dos, was 0.14 cm. The audit acceptance levels were based on the expanded uncertainties for the comparison results and estimated to be 2.4%. Results: The audit was implemented and validated successfully. All Dw audit results were satisfactory with differences in Dw values mostly smaller than 0.5% and always smaller than 1%. Except for one, differences in R50,dos were smaller than 0.2 cm and always smaller than 0.3 cm. Conclusions: An electron dosimetry audit based on absorbed dose to water and present-day requirements for calibration laboratories performing proficiency tests was successfully implemented. It proved international traceability of the participants value with an uncertainty better than 3.6% (k = 2). Keywords: Absorbed dose to water, Audit, Code of practice, Dosimetry, Electron beam, Radiation therapy |
| first_indexed | 2024-04-13T06:38:11Z |
| format | Article |
| id | doaj.art-230609f0846e4f2a81dfb84b6a04476a |
| institution | Directory Open Access Journal |
| issn | 2405-6316 |
| language | English |
| last_indexed | 2024-04-13T06:38:11Z |
| publishDate | 2018-01-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Physics and Imaging in Radiation Oncology |
| spelling | doaj.art-230609f0846e4f2a81dfb84b6a04476a2022-12-22T02:57:49ZengElsevierPhysics and Imaging in Radiation Oncology2405-63162018-01-0154451An on-site dosimetry audit for high-energy electron beamsLeon de Prez0Stan Heukelom1Bartel Jansen2Wim Jansen3Jeroen van de Kamer4Wenze van Klink5Elfried Kok6Thijs Perik7Jacco de Pooter8Frits Wittkämper9VSL – Dutch Metrology Institute, Delft, The Netherlands; Corresponding author.VU University Medical Center, Amsterdam, The NetherlandsVSL – Dutch Metrology Institute, Delft, The NetherlandsLeiden University Medical Center, Leiden & Reinier de Graaf, Delft, The NetherlandsThe Netherlands Cancer Institute, Amsterdam, The NetherlandsVU University Medical Center, Amsterdam, The NetherlandsLeiden University Medical Center, Leiden & Reinier de Graaf, Delft, The NetherlandsThe Netherlands Cancer Institute, Amsterdam, The NetherlandsVSL – Dutch Metrology Institute, Delft, The NetherlandsThe Netherlands Cancer Institute, Amsterdam, The NetherlandsBackground and purpose: External dosimetry audits are powerful quality assurance instruments for radiotherapy. The aim of this study was to implement an electron dosimetry audit based on a contemporary code of practice within the requirements for calibration laboratories performing proficiency tests. This involved the determination of suitable acceptance criteria based on thorough uncertainty analyses. Materials and methods: Subject of the audit was the determination of absorbed dose to water, Dw, and the beam quality specifier, R50,dos. Fifteen electron beams were measured in four institutes according to the Belgian-Dutch code of practice for high-energy electron beams. The expanded uncertainty (k = 2) for the Dw values was 3.6% for a Roos chamber calibrated in 60Co and 3.2% for a Roos chamber cross-calibrated against a Farmer chamber. The expanded uncertainty for the beam quality specifier, R50,dos, was 0.14 cm. The audit acceptance levels were based on the expanded uncertainties for the comparison results and estimated to be 2.4%. Results: The audit was implemented and validated successfully. All Dw audit results were satisfactory with differences in Dw values mostly smaller than 0.5% and always smaller than 1%. Except for one, differences in R50,dos were smaller than 0.2 cm and always smaller than 0.3 cm. Conclusions: An electron dosimetry audit based on absorbed dose to water and present-day requirements for calibration laboratories performing proficiency tests was successfully implemented. It proved international traceability of the participants value with an uncertainty better than 3.6% (k = 2). Keywords: Absorbed dose to water, Audit, Code of practice, Dosimetry, Electron beam, Radiation therapyhttp://www.sciencedirect.com/science/article/pii/S2405631617300507 |
| spellingShingle | Leon de Prez Stan Heukelom Bartel Jansen Wim Jansen Jeroen van de Kamer Wenze van Klink Elfried Kok Thijs Perik Jacco de Pooter Frits Wittkämper An on-site dosimetry audit for high-energy electron beams Physics and Imaging in Radiation Oncology |
| title | An on-site dosimetry audit for high-energy electron beams |
| title_full | An on-site dosimetry audit for high-energy electron beams |
| title_fullStr | An on-site dosimetry audit for high-energy electron beams |
| title_full_unstemmed | An on-site dosimetry audit for high-energy electron beams |
| title_short | An on-site dosimetry audit for high-energy electron beams |
| title_sort | on site dosimetry audit for high energy electron beams |
| url | http://www.sciencedirect.com/science/article/pii/S2405631617300507 |
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