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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...

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Autores principales: Komiyama, Riho, Ohira, Shingo, Kanayama, Naoyuki, Karino, Tsukasa, Washio, Hayate, Ueda, Yoshihiro, Miyazaki, Masayoshi, Teshima, Teruki
Formato: Online Artículo Texto
Lenguaje:English
Publicado: John Wiley and Sons Inc. 2019
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.
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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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