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Volumetric modulated arc therapy treatment planning based on virtual monochromatic images for head and neck cancer: effect of the contrast‐enhanced agent on dose distribution
Virtual monochromatic images (VMIs) at a lower energy level can improve image quality but the computed tomography (CT) number of iodine contained in the contrast‐enhanced agent is dramatically increased. We assessed the effect of the use of contrast‐enhanced agent on the dose distributions in volume...
Autores principales: | , , , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
John Wiley and Sons Inc.
2019
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6839366/ https://www.ncbi.nlm.nih.gov/pubmed/31633869 http://dx.doi.org/10.1002/acm2.12752 |
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author | Komiyama, Riho Ohira, Shingo Kanayama, Naoyuki Karino, Tsukasa Washio, Hayate Ueda, Yoshihiro Miyazaki, Masayoshi Teshima, Teruki |
author_facet | Komiyama, Riho Ohira, Shingo Kanayama, Naoyuki Karino, Tsukasa Washio, Hayate Ueda, Yoshihiro Miyazaki, Masayoshi Teshima, Teruki |
author_sort | Komiyama, Riho |
collection | PubMed |
description | Virtual monochromatic images (VMIs) at a lower energy level can improve image quality but the computed tomography (CT) number of iodine contained in the contrast‐enhanced agent is dramatically increased. We assessed the effect of the use of contrast‐enhanced agent on the dose distributions in volumetric modulated arc therapy (VMAT) planning for head and neck cancer (HNC). Based on the VMIs at 40 keV (VMI(40keV)), 60 keV(VMI(60keV)), and 77 keV (VMI(77keV)) of a tissue characterization phantom, lookup tables (LUTs) were created. VMAT plans were generated for 15 HNC patients based on contrast‐enhanced‐ (CE‐) VMIs at 40‐, 60‐, and 77 keV using the corresponding LUTs, and the doses were recalculated based on the noncontrast‐enhanced‐ (nCE‐) VMIs. For all structures, the difference in CT numbers owing to the contrast‐enhanced agent was prominent as the energy level of the VMI decreased, and the mean differences in CT number between CE‐ and nCE‐VMI was the largest for the clinical target volume (CTV) (125.3, 55.9, and 33.1 HU for VMI(40keV), VMI(60keV), and VMI(77keV,) respectively). The mean difference of the dosimetric parameters (D(99%), D(50%), D(1%), D(mean), and D(0.1cc)) for CTV and OARs was <1% in the treatment plans based on all VMIs. The maximum difference was observed for CTV in VMI(40keV) (2.4%), VMI(60keV) (1.9%), and VMI(77keV) (1.5%) plans. The effect of the contrast‐enhanced agent was larger in the VMAT plans based on the VMI at a lower energy level for HNC patients. This effect is not desirable in a treatment planning procedure. |
format | Online Article Text |
id | pubmed-6839366 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2019 |
publisher | John Wiley and Sons Inc. |
record_format | MEDLINE/PubMed |
spelling | pubmed-68393662019-11-14 Volumetric modulated arc therapy treatment planning based on virtual monochromatic images for head and neck cancer: effect of the contrast‐enhanced agent on dose distribution Komiyama, Riho Ohira, Shingo Kanayama, Naoyuki Karino, Tsukasa Washio, Hayate Ueda, Yoshihiro Miyazaki, Masayoshi Teshima, Teruki J Appl Clin Med Phys Radiation Oncology Physics Virtual monochromatic images (VMIs) at a lower energy level can improve image quality but the computed tomography (CT) number of iodine contained in the contrast‐enhanced agent is dramatically increased. We assessed the effect of the use of contrast‐enhanced agent on the dose distributions in volumetric modulated arc therapy (VMAT) planning for head and neck cancer (HNC). Based on the VMIs at 40 keV (VMI(40keV)), 60 keV(VMI(60keV)), and 77 keV (VMI(77keV)) of a tissue characterization phantom, lookup tables (LUTs) were created. VMAT plans were generated for 15 HNC patients based on contrast‐enhanced‐ (CE‐) VMIs at 40‐, 60‐, and 77 keV using the corresponding LUTs, and the doses were recalculated based on the noncontrast‐enhanced‐ (nCE‐) VMIs. For all structures, the difference in CT numbers owing to the contrast‐enhanced agent was prominent as the energy level of the VMI decreased, and the mean differences in CT number between CE‐ and nCE‐VMI was the largest for the clinical target volume (CTV) (125.3, 55.9, and 33.1 HU for VMI(40keV), VMI(60keV), and VMI(77keV,) respectively). The mean difference of the dosimetric parameters (D(99%), D(50%), D(1%), D(mean), and D(0.1cc)) for CTV and OARs was <1% in the treatment plans based on all VMIs. The maximum difference was observed for CTV in VMI(40keV) (2.4%), VMI(60keV) (1.9%), and VMI(77keV) (1.5%) plans. The effect of the contrast‐enhanced agent was larger in the VMAT plans based on the VMI at a lower energy level for HNC patients. This effect is not desirable in a treatment planning procedure. John Wiley and Sons Inc. 2019-10-21 /pmc/articles/PMC6839366/ /pubmed/31633869 http://dx.doi.org/10.1002/acm2.12752 Text en © 2019 The Authors. Journal of Applied Clinical Medical Physics published by Wiley Periodicals, Inc. on behalf of American Association of Physicists in Medicine. This is an open access article under the terms of the http://creativecommons.org/licenses/by/4.0/ License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. |
spellingShingle | Radiation Oncology Physics Komiyama, Riho Ohira, Shingo Kanayama, Naoyuki Karino, Tsukasa Washio, Hayate Ueda, Yoshihiro Miyazaki, Masayoshi Teshima, Teruki Volumetric modulated arc therapy treatment planning based on virtual monochromatic images for head and neck cancer: effect of the contrast‐enhanced agent on dose distribution |
title | Volumetric modulated arc therapy treatment planning based on virtual monochromatic images for head and neck cancer: effect of the contrast‐enhanced agent on dose distribution |
title_full | Volumetric modulated arc therapy treatment planning based on virtual monochromatic images for head and neck cancer: effect of the contrast‐enhanced agent on dose distribution |
title_fullStr | Volumetric modulated arc therapy treatment planning based on virtual monochromatic images for head and neck cancer: effect of the contrast‐enhanced agent on dose distribution |
title_full_unstemmed | Volumetric modulated arc therapy treatment planning based on virtual monochromatic images for head and neck cancer: effect of the contrast‐enhanced agent on dose distribution |
title_short | Volumetric modulated arc therapy treatment planning based on virtual monochromatic images for head and neck cancer: effect of the contrast‐enhanced agent on dose distribution |
title_sort | volumetric modulated arc therapy treatment planning based on virtual monochromatic images for head and neck cancer: effect of the contrast‐enhanced agent on dose distribution |
topic | Radiation Oncology Physics |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6839366/ https://www.ncbi.nlm.nih.gov/pubmed/31633869 http://dx.doi.org/10.1002/acm2.12752 |
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