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Applicability of the linear–quadratic model to single and fractionated radiotherapy schedules: an experimental study

The aim of this study was to examine the applicability of the linear-quadratic (LQ) model to single and fractionated irradiation in EMT6 cells. First, the α/β ratio of the cells was determined from single-dose experiments, and a biologically effective dose (BED) for 20 Gy in 10 fractions (fr) was ca...

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Autores principales: Miyakawa, Akifumi, Shibamoto, Yuta, Otsuka, Shinya, Iwata, Hiromitsu
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Oxford University Press 2014
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4014161/
https://www.ncbi.nlm.nih.gov/pubmed/24351457
http://dx.doi.org/10.1093/jrr/rrt138
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author Miyakawa, Akifumi
Shibamoto, Yuta
Otsuka, Shinya
Iwata, Hiromitsu
author_facet Miyakawa, Akifumi
Shibamoto, Yuta
Otsuka, Shinya
Iwata, Hiromitsu
author_sort Miyakawa, Akifumi
collection PubMed
description The aim of this study was to examine the applicability of the linear-quadratic (LQ) model to single and fractionated irradiation in EMT6 cells. First, the α/β ratio of the cells was determined from single-dose experiments, and a biologically effective dose (BED) for 20 Gy in 10 fractions (fr) was calculated. Fractional doses yielding the same BED were calculated for 1-, 2-, 3-, 4-, 5-, 7-, 15- and 20-fraction irradiation using LQ formalism, and then irradiation with these schedules was actually given. Cell survival was determined by a standard colony assay. Differences in cell survival between pairs of groups were compared by t-test. The α/β ratio of the cells was 3.18 Gy, and 20 Gy in 10 fr corresponded to a BED(3.18) of 32.6 Gy. The effects of 7-, 15- and 20-fraction irradiation with a BED(3.18) of 32.6 Gy were similar to those of the 10-fraction irradiation, while the effects of 1- to 5-fraction irradiation were lower. In this cell line, the LQ model was considered applicable to 7- to 20-fraction irradiation or doses per fraction of 2.57 Gy or smaller. The LQ model might be applicable in the dose range below the α/β ratio.
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spelling pubmed-40141612014-05-12 Applicability of the linear–quadratic model to single and fractionated radiotherapy schedules: an experimental study Miyakawa, Akifumi Shibamoto, Yuta Otsuka, Shinya Iwata, Hiromitsu J Radiat Res Biology The aim of this study was to examine the applicability of the linear-quadratic (LQ) model to single and fractionated irradiation in EMT6 cells. First, the α/β ratio of the cells was determined from single-dose experiments, and a biologically effective dose (BED) for 20 Gy in 10 fractions (fr) was calculated. Fractional doses yielding the same BED were calculated for 1-, 2-, 3-, 4-, 5-, 7-, 15- and 20-fraction irradiation using LQ formalism, and then irradiation with these schedules was actually given. Cell survival was determined by a standard colony assay. Differences in cell survival between pairs of groups were compared by t-test. The α/β ratio of the cells was 3.18 Gy, and 20 Gy in 10 fr corresponded to a BED(3.18) of 32.6 Gy. The effects of 7-, 15- and 20-fraction irradiation with a BED(3.18) of 32.6 Gy were similar to those of the 10-fraction irradiation, while the effects of 1- to 5-fraction irradiation were lower. In this cell line, the LQ model was considered applicable to 7- to 20-fraction irradiation or doses per fraction of 2.57 Gy or smaller. The LQ model might be applicable in the dose range below the α/β ratio. Oxford University Press 2014-05 2013-12-17 /pmc/articles/PMC4014161/ /pubmed/24351457 http://dx.doi.org/10.1093/jrr/rrt138 Text en © The Author 2013. Published by Oxford University Press on behalf of The Japan Radiation Research Society and Japanese Society for Radiation Oncology. http://creativecommons.org/licenses/by/3.0/ This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited.
spellingShingle Biology
Miyakawa, Akifumi
Shibamoto, Yuta
Otsuka, Shinya
Iwata, Hiromitsu
Applicability of the linear–quadratic model to single and fractionated radiotherapy schedules: an experimental study
title Applicability of the linear–quadratic model to single and fractionated radiotherapy schedules: an experimental study
title_full Applicability of the linear–quadratic model to single and fractionated radiotherapy schedules: an experimental study
title_fullStr Applicability of the linear–quadratic model to single and fractionated radiotherapy schedules: an experimental study
title_full_unstemmed Applicability of the linear–quadratic model to single and fractionated radiotherapy schedules: an experimental study
title_short Applicability of the linear–quadratic model to single and fractionated radiotherapy schedules: an experimental study
title_sort applicability of the linear–quadratic model to single and fractionated radiotherapy schedules: an experimental study
topic Biology
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4014161/
https://www.ncbi.nlm.nih.gov/pubmed/24351457
http://dx.doi.org/10.1093/jrr/rrt138
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