External beam radiotherapy for head and neck cancers is associated with increased variability in retinal vascular oxygenation.
Radiation retinopathy is a possible post-treatment complication of radiation therapy. The pathophysiologic mechanism is hypothesized to be microvascular in origin, but evidence is limited. In an effort to study retinal oxygenation in these patients, we herein evaluate the repeatability and variabili...
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doaj-ce9ef29032684bd38b90911d03bef4c72020-11-24T20:45:37ZengPublic Library of Science (PLoS)PLoS ONE1932-62032013-01-0188e6965710.1371/journal.pone.0069657External beam radiotherapy for head and neck cancers is associated with increased variability in retinal vascular oxygenation.Daniel S HigginsonAlok SahgalMichael V LawrenceSarah MoyerMihaela StefanescuAdam K WillsonBahjat QaqishAdam ZanationLawrence B MarksSeema GargBhishamjit S CheraRadiation retinopathy is a possible post-treatment complication of radiation therapy. The pathophysiologic mechanism is hypothesized to be microvascular in origin, but evidence is limited. In an effort to study retinal oxygenation in these patients, we herein evaluate the repeatability and variability of retinal oximetry measurements in subjects who had previously received radiation and make comparisons to a cohort of unirradiated subjects.Using retinal oximetry, a non-invasive imaging modality, we performed in vivo measurements of arteriole (SaO2) and venule SO2 (SvO2) in subjects (n = 9, 18 retinas) who had received incidental radiation to their retinas (≥ 45 Gy to one retina) and in healthy subjects (n = 20, 40 retinas). A total of 1367 SO2 observations on 593 vessels in 29 persons were analyzed to assess three sources of variance in vessel SO2: 1) variance in repeated measurements of the same vessel ("repeatability"), 2) variance in different vessels within the same subject ("within-subject variability"), and 3) variance between subjects ("between-subject variability").Retinal oximetry measurements were highly repeatable in both irradiated patients and unirradiated subjects. The within-subject variability of SvO2 and SaO2 measurements constituted the highest component of variance in both groups and was significantly higher in venules vs. arterioles (relative effect size 1.8, p<0.001) and in irradiated subjects vs. unirradiated subjects (relative effect size 1.6, p<0.001).Retinal oximetry is a highly repeatable technology and can be reliably used to study vascular oxygenation in irradiated subjects. Different vessels within the same subject exhibit a high degree of variability, suggesting that pooled analyses of multiple vessels are most likely to be informative of regional retinal oxygenation. Finally, irradiated subjects exhibited significantly higher within-subject variability in SO2 measurements, suggesting that radiation may cause regional alterations in retinal oxygen delivery and/or metabolism.http://europepmc.org/articles/PMC3735567?pdf=render |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Daniel S Higginson Alok Sahgal Michael V Lawrence Sarah Moyer Mihaela Stefanescu Adam K Willson Bahjat Qaqish Adam Zanation Lawrence B Marks Seema Garg Bhishamjit S Chera |
spellingShingle |
Daniel S Higginson Alok Sahgal Michael V Lawrence Sarah Moyer Mihaela Stefanescu Adam K Willson Bahjat Qaqish Adam Zanation Lawrence B Marks Seema Garg Bhishamjit S Chera External beam radiotherapy for head and neck cancers is associated with increased variability in retinal vascular oxygenation. PLoS ONE |
author_facet |
Daniel S Higginson Alok Sahgal Michael V Lawrence Sarah Moyer Mihaela Stefanescu Adam K Willson Bahjat Qaqish Adam Zanation Lawrence B Marks Seema Garg Bhishamjit S Chera |
author_sort |
Daniel S Higginson |
title |
External beam radiotherapy for head and neck cancers is associated with increased variability in retinal vascular oxygenation. |
title_short |
External beam radiotherapy for head and neck cancers is associated with increased variability in retinal vascular oxygenation. |
title_full |
External beam radiotherapy for head and neck cancers is associated with increased variability in retinal vascular oxygenation. |
title_fullStr |
External beam radiotherapy for head and neck cancers is associated with increased variability in retinal vascular oxygenation. |
title_full_unstemmed |
External beam radiotherapy for head and neck cancers is associated with increased variability in retinal vascular oxygenation. |
title_sort |
external beam radiotherapy for head and neck cancers is associated with increased variability in retinal vascular oxygenation. |
publisher |
Public Library of Science (PLoS) |
series |
PLoS ONE |
issn |
1932-6203 |
publishDate |
2013-01-01 |
description |
Radiation retinopathy is a possible post-treatment complication of radiation therapy. The pathophysiologic mechanism is hypothesized to be microvascular in origin, but evidence is limited. In an effort to study retinal oxygenation in these patients, we herein evaluate the repeatability and variability of retinal oximetry measurements in subjects who had previously received radiation and make comparisons to a cohort of unirradiated subjects.Using retinal oximetry, a non-invasive imaging modality, we performed in vivo measurements of arteriole (SaO2) and venule SO2 (SvO2) in subjects (n = 9, 18 retinas) who had received incidental radiation to their retinas (≥ 45 Gy to one retina) and in healthy subjects (n = 20, 40 retinas). A total of 1367 SO2 observations on 593 vessels in 29 persons were analyzed to assess three sources of variance in vessel SO2: 1) variance in repeated measurements of the same vessel ("repeatability"), 2) variance in different vessels within the same subject ("within-subject variability"), and 3) variance between subjects ("between-subject variability").Retinal oximetry measurements were highly repeatable in both irradiated patients and unirradiated subjects. The within-subject variability of SvO2 and SaO2 measurements constituted the highest component of variance in both groups and was significantly higher in venules vs. arterioles (relative effect size 1.8, p<0.001) and in irradiated subjects vs. unirradiated subjects (relative effect size 1.6, p<0.001).Retinal oximetry is a highly repeatable technology and can be reliably used to study vascular oxygenation in irradiated subjects. Different vessels within the same subject exhibit a high degree of variability, suggesting that pooled analyses of multiple vessels are most likely to be informative of regional retinal oxygenation. Finally, irradiated subjects exhibited significantly higher within-subject variability in SO2 measurements, suggesting that radiation may cause regional alterations in retinal oxygen delivery and/or metabolism. |
url |
http://europepmc.org/articles/PMC3735567?pdf=render |
work_keys_str_mv |
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