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The ratio of weight loss to planning target volume significantly impacts setup errors in nasopharyngeal cancer patients undergoing helical tomotherapy with daily megavoltage computed tomography

BACKGROUND: Changes in head and neck anatomy during radiation therapy (RT) produce setup uncertainties of nasopharyngeal cancer (NPC) irradiation. We retrospectively analyzed image guidance data to identify clinical predictors of setup errors. PATIENTS AND METHODS: The data of 217 NPC patients under...

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Autores principales: Hou, Wei-Hsien, Wang, Chun-Wei, Tsai, Chiao-Ling, Hsu, Feng-Ming, Cheng, Jason Chia-Hsien
Formato: Online Artículo Texto
Lenguaje:English
Publicado: De Gruyter 2016
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5120582/
https://www.ncbi.nlm.nih.gov/pubmed/27904451
http://dx.doi.org/10.1515/raon-2016-0047
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author Hou, Wei-Hsien
Wang, Chun-Wei
Tsai, Chiao-Ling
Hsu, Feng-Ming
Cheng, Jason Chia-Hsien
author_facet Hou, Wei-Hsien
Wang, Chun-Wei
Tsai, Chiao-Ling
Hsu, Feng-Ming
Cheng, Jason Chia-Hsien
author_sort Hou, Wei-Hsien
collection PubMed
description BACKGROUND: Changes in head and neck anatomy during radiation therapy (RT) produce setup uncertainties of nasopharyngeal cancer (NPC) irradiation. We retrospectively analyzed image guidance data to identify clinical predictors of setup errors. PATIENTS AND METHODS: The data of 217 NPC patients undergoing definitive RT on a helical tomotherapy (HT) unit were analyzed. Factors including tumor stage, body mass index, weight loss, and planning target volume (PTV) were assessed as predictors of daily megavoltage computed tomography (MVCT) setup displacements, which were automatically registered using software. RESULTS: Mean daily setup displacements (in mm) were 1.2 ± 0.6, 1.8 ± 0.8, 3.4 ± 1.4 in the medial-lateral (ML), superior-inferior (SI), and anterior-posterior (AP) directions, respectively. Mean weight loss was 4.6 ± 3.3 kg (6.8 ± 4.9%). Patients with weight loss > 5% had significantly larger setup displacements in the AP (3.6 ± 1.5 vs. 2.9 ± 1.1 mm, p < 0.001) and SI (1.6 ± 0.7 vs. 1.9 ± 0.9 mm, p = 0.01) direction, but not in the ML direction (p = 0.279). The AP setup error increased 0.06 mm (y = 0.055x + 2.927, x: percentage of weight loss/PTV, y: AP displacement) per one percent increase in weight loss normalized to PTV. CONCLUSIONS: Patients with weight loss > 5% and smaller PTVs, possibly because of small body frame or neck girth, were more likely to have increased setup errors in the AP direction.
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spelling pubmed-51205822016-12-01 The ratio of weight loss to planning target volume significantly impacts setup errors in nasopharyngeal cancer patients undergoing helical tomotherapy with daily megavoltage computed tomography Hou, Wei-Hsien Wang, Chun-Wei Tsai, Chiao-Ling Hsu, Feng-Ming Cheng, Jason Chia-Hsien Radiol Oncol Research Article BACKGROUND: Changes in head and neck anatomy during radiation therapy (RT) produce setup uncertainties of nasopharyngeal cancer (NPC) irradiation. We retrospectively analyzed image guidance data to identify clinical predictors of setup errors. PATIENTS AND METHODS: The data of 217 NPC patients undergoing definitive RT on a helical tomotherapy (HT) unit were analyzed. Factors including tumor stage, body mass index, weight loss, and planning target volume (PTV) were assessed as predictors of daily megavoltage computed tomography (MVCT) setup displacements, which were automatically registered using software. RESULTS: Mean daily setup displacements (in mm) were 1.2 ± 0.6, 1.8 ± 0.8, 3.4 ± 1.4 in the medial-lateral (ML), superior-inferior (SI), and anterior-posterior (AP) directions, respectively. Mean weight loss was 4.6 ± 3.3 kg (6.8 ± 4.9%). Patients with weight loss > 5% had significantly larger setup displacements in the AP (3.6 ± 1.5 vs. 2.9 ± 1.1 mm, p < 0.001) and SI (1.6 ± 0.7 vs. 1.9 ± 0.9 mm, p = 0.01) direction, but not in the ML direction (p = 0.279). The AP setup error increased 0.06 mm (y = 0.055x + 2.927, x: percentage of weight loss/PTV, y: AP displacement) per one percent increase in weight loss normalized to PTV. CONCLUSIONS: Patients with weight loss > 5% and smaller PTVs, possibly because of small body frame or neck girth, were more likely to have increased setup errors in the AP direction. De Gruyter 2016-09-08 /pmc/articles/PMC5120582/ /pubmed/27904451 http://dx.doi.org/10.1515/raon-2016-0047 Text en © 2016 Radiol Oncol
spellingShingle Research Article
Hou, Wei-Hsien
Wang, Chun-Wei
Tsai, Chiao-Ling
Hsu, Feng-Ming
Cheng, Jason Chia-Hsien
The ratio of weight loss to planning target volume significantly impacts setup errors in nasopharyngeal cancer patients undergoing helical tomotherapy with daily megavoltage computed tomography
title The ratio of weight loss to planning target volume significantly impacts setup errors in nasopharyngeal cancer patients undergoing helical tomotherapy with daily megavoltage computed tomography
title_full The ratio of weight loss to planning target volume significantly impacts setup errors in nasopharyngeal cancer patients undergoing helical tomotherapy with daily megavoltage computed tomography
title_fullStr The ratio of weight loss to planning target volume significantly impacts setup errors in nasopharyngeal cancer patients undergoing helical tomotherapy with daily megavoltage computed tomography
title_full_unstemmed The ratio of weight loss to planning target volume significantly impacts setup errors in nasopharyngeal cancer patients undergoing helical tomotherapy with daily megavoltage computed tomography
title_short The ratio of weight loss to planning target volume significantly impacts setup errors in nasopharyngeal cancer patients undergoing helical tomotherapy with daily megavoltage computed tomography
title_sort ratio of weight loss to planning target volume significantly impacts setup errors in nasopharyngeal cancer patients undergoing helical tomotherapy with daily megavoltage computed tomography
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5120582/
https://www.ncbi.nlm.nih.gov/pubmed/27904451
http://dx.doi.org/10.1515/raon-2016-0047
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