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Effect of output variation with dose rate on the Virtual Wedge factor
The Siemens Virtual Wedge factor (VWF: Siemens Medical Solutions, Malvern, PA) may drift significantly because of an increase in output as the dose rate declines. This variation in output is caused by sample and hold boards in the dosimetry circuit that become defective because of radiation damage....
Autores principales: | , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
John Wiley and Sons Inc.
2008
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5721535/ https://www.ncbi.nlm.nih.gov/pubmed/18449167 http://dx.doi.org/10.1120/jacmp.v9i1.2784 |
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author | Zhu, X. Ronald Gillin, Michael T. |
author_facet | Zhu, X. Ronald Gillin, Michael T. |
author_sort | Zhu, X. Ronald |
collection | PubMed |
description | The Siemens Virtual Wedge factor (VWF: Siemens Medical Solutions, Malvern, PA) may drift significantly because of an increase in output as the dose rate declines. This variation in output is caused by sample and hold boards in the dosimetry circuit that become defective because of radiation damage. Here, we present a simple model based on the principle of Virtual Wedge operation and the measured output variation with dose rate to quantitatively describe VWF drift as a function of field size and wedge angle. Our results support the recommendation that VWF be measured for large field sizes (for example, [Formula: see text] cm) and large wedge angles (for example, 60 degrees) as a part of routine quality assurance. PACS numbers: 87.55.Qr, 87.55.N‐ |
format | Online Article Text |
id | pubmed-5721535 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2008 |
publisher | John Wiley and Sons Inc. |
record_format | MEDLINE/PubMed |
spelling | pubmed-57215352018-04-02 Effect of output variation with dose rate on the Virtual Wedge factor Zhu, X. Ronald Gillin, Michael T. J Appl Clin Med Phys Radiation Oncology Physics The Siemens Virtual Wedge factor (VWF: Siemens Medical Solutions, Malvern, PA) may drift significantly because of an increase in output as the dose rate declines. This variation in output is caused by sample and hold boards in the dosimetry circuit that become defective because of radiation damage. Here, we present a simple model based on the principle of Virtual Wedge operation and the measured output variation with dose rate to quantitatively describe VWF drift as a function of field size and wedge angle. Our results support the recommendation that VWF be measured for large field sizes (for example, [Formula: see text] cm) and large wedge angles (for example, 60 degrees) as a part of routine quality assurance. PACS numbers: 87.55.Qr, 87.55.N‐ John Wiley and Sons Inc. 2008-01-28 /pmc/articles/PMC5721535/ /pubmed/18449167 http://dx.doi.org/10.1120/jacmp.v9i1.2784 Text en © 2008 The Authors. This is an open access article under the terms of the Creative Commons Attribution (http://creativecommons.org/licenses/by/3.0/) License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. |
spellingShingle | Radiation Oncology Physics Zhu, X. Ronald Gillin, Michael T. Effect of output variation with dose rate on the Virtual Wedge factor |
title | Effect of output variation with dose rate on the Virtual Wedge factor |
title_full | Effect of output variation with dose rate on the Virtual Wedge factor |
title_fullStr | Effect of output variation with dose rate on the Virtual Wedge factor |
title_full_unstemmed | Effect of output variation with dose rate on the Virtual Wedge factor |
title_short | Effect of output variation with dose rate on the Virtual Wedge factor |
title_sort | effect of output variation with dose rate on the virtual wedge factor |
topic | Radiation Oncology Physics |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5721535/ https://www.ncbi.nlm.nih.gov/pubmed/18449167 http://dx.doi.org/10.1120/jacmp.v9i1.2784 |
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