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Hypoxia imaging and radiotherapy: bridging the resolution gap
Oxygen distribution is a major determinant of treatment success in radiotherapy, with well-oxygenated tumour regions responding by up to a factor of three relative to anoxic volumes. Conversely, tumour hypoxia is associated with treatment resistance and negative prognosis. Tumour oxygenation is high...
Autores principales: | , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
The British Institute of Radiology.
2017
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5603947/ https://www.ncbi.nlm.nih.gov/pubmed/28540739 http://dx.doi.org/10.1259/bjr.20160939 |
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author | Grimes, David Robert Warren, Daniel R Warren, Samantha |
author_facet | Grimes, David Robert Warren, Daniel R Warren, Samantha |
author_sort | Grimes, David Robert |
collection | PubMed |
description | Oxygen distribution is a major determinant of treatment success in radiotherapy, with well-oxygenated tumour regions responding by up to a factor of three relative to anoxic volumes. Conversely, tumour hypoxia is associated with treatment resistance and negative prognosis. Tumour oxygenation is highly heterogeneous and difficult to measure directly. The recent advent of functional hypoxia imaging modalities such as fluorine-18 fluoromisonidazole positron emission tomography have shown promise in non-invasively determining regions of low oxygen tension. This raises the prospect of selectively increasing dose to hypoxic subvolumes, a concept known as dose painting. Yet while this is a promising approach, oxygen-mediated radioresistance is inherently a multiscale problem, and there are still a number of substantial challenges that must be overcome if hypoxia dose painting is to be successfully implemented. Current imaging modalities are limited by the physics of such systems to have resolutions in the millimetre regime, whereas oxygen distribution varies over a micron scale, and treatment delivery is typically modulated on a centimetre scale. In this review, we examine the mechanistic basis and implications of the radiobiological oxygen effect, the factors influencing microscopic heterogeneity in tumour oxygenation and the consequent challenges in the interpretation of clinical hypoxia imaging (in particular fluorine-18 fluoromisonidazole positron emission tomography). We also discuss dose-painting approaches and outline challenges that must be addressed to improve this treatment paradigm. |
format | Online Article Text |
id | pubmed-5603947 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2017 |
publisher | The British Institute of Radiology. |
record_format | MEDLINE/PubMed |
spelling | pubmed-56039472017-09-26 Hypoxia imaging and radiotherapy: bridging the resolution gap Grimes, David Robert Warren, Daniel R Warren, Samantha Br J Radiol Review Article Oxygen distribution is a major determinant of treatment success in radiotherapy, with well-oxygenated tumour regions responding by up to a factor of three relative to anoxic volumes. Conversely, tumour hypoxia is associated with treatment resistance and negative prognosis. Tumour oxygenation is highly heterogeneous and difficult to measure directly. The recent advent of functional hypoxia imaging modalities such as fluorine-18 fluoromisonidazole positron emission tomography have shown promise in non-invasively determining regions of low oxygen tension. This raises the prospect of selectively increasing dose to hypoxic subvolumes, a concept known as dose painting. Yet while this is a promising approach, oxygen-mediated radioresistance is inherently a multiscale problem, and there are still a number of substantial challenges that must be overcome if hypoxia dose painting is to be successfully implemented. Current imaging modalities are limited by the physics of such systems to have resolutions in the millimetre regime, whereas oxygen distribution varies over a micron scale, and treatment delivery is typically modulated on a centimetre scale. In this review, we examine the mechanistic basis and implications of the radiobiological oxygen effect, the factors influencing microscopic heterogeneity in tumour oxygenation and the consequent challenges in the interpretation of clinical hypoxia imaging (in particular fluorine-18 fluoromisonidazole positron emission tomography). We also discuss dose-painting approaches and outline challenges that must be addressed to improve this treatment paradigm. The British Institute of Radiology. 2017-08 2017-07-28 /pmc/articles/PMC5603947/ /pubmed/28540739 http://dx.doi.org/10.1259/bjr.20160939 Text en © 2017 The Authors. Published by the British Institute of Radiology This is an Open Access article distributed under the terms of the Creative Commons Attribution 4.0 Unported License http://creativecommons.org/licenses/by/4.0/, which permits unrestricted use, distribution and reproduction in any medium, provided the original author and source are credited. |
spellingShingle | Review Article Grimes, David Robert Warren, Daniel R Warren, Samantha Hypoxia imaging and radiotherapy: bridging the resolution gap |
title | Hypoxia imaging and radiotherapy: bridging the resolution gap |
title_full | Hypoxia imaging and radiotherapy: bridging the resolution gap |
title_fullStr | Hypoxia imaging and radiotherapy: bridging the resolution gap |
title_full_unstemmed | Hypoxia imaging and radiotherapy: bridging the resolution gap |
title_short | Hypoxia imaging and radiotherapy: bridging the resolution gap |
title_sort | hypoxia imaging and radiotherapy: bridging the resolution gap |
topic | Review Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5603947/ https://www.ncbi.nlm.nih.gov/pubmed/28540739 http://dx.doi.org/10.1259/bjr.20160939 |
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