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Title: Differences in Brainstem Fiber Tract Response to Radiation: A Longitudinal Diffusion Tensor Imaging Study

Abstract

Purpose: To determine whether radiation-induced changes in white matter tracts are uniform across the brainstem. Methods and Materials: We analyzed serial diffusion tensor imaging data, acquired before radiation therapy and over 48 to 72 months of follow-up, from 42 pediatric patients (age 6-20 years) with medulloblastoma. FSL software (FMRIB, Oxford, UK) was used to calculate fractional anisotropy (FA) and axial, radial, and mean diffusivities. For a consistent identification of volumes of interest (VOIs), the parametric maps of each patient were transformed to a standard brain space (MNI152), on which we identified VOIs including corticospinal tract (CST), medial lemniscus (ML), transverse pontine fiber (TPF), and middle cerebellar peduncle (MCP) at the level of pons. Temporal changes of DTI parameters in VOIs were compared using a linear mixed effect model. Results: Radiation-induced white matter injury was marked by a decline in FA after treatment. The decline was often accompanied by decreased axial diffusivity, increased radial diffusivity, or both. This implied axonal damage and demyelination. We observed that the magnitude of the changes was not always uniform across substructures of the brainstem. Specifically, the changes in DTI parameters for TPF were more pronounced than in other regions (P<.001 for FA) despite similarities inmore » the distribution of dose. We did not find a significant difference among CST, ML, and MCP in these patients (P>.093 for all parameters). Conclusions: Changes in the structural integrity of white matter tracts, assessed by DTI, were not uniform across the brainstem after radiation therapy. These results support a role for tract-based assessment in radiation treatment planning and determination of brainstem tolerance.« less

Authors:
 [1];  [1]; ;  [2];  [3]; ;  [1]
  1. Department of Radiological Sciences, St. Jude Children's Research Hospital, Memphis, Tennessee (United States)
  2. Department of Biostatistics, St. Jude Children's Research Hospital, Memphis, Tennessee (United States)
  3. Department of Oncology, St. Jude Children's Research Hospital, Memphis, Tennessee (United States)
Publication Date:
OSTI Identifier:
22224474
Resource Type:
Journal Article
Journal Name:
International Journal of Radiation Oncology, Biology and Physics
Additional Journal Information:
Journal Volume: 86; Journal Issue: 2; Other Information: Copyright (c) 2013 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0360-3016
Country of Publication:
United States
Language:
English
Subject:
62 RADIOLOGY AND NUCLEAR MEDICINE; ANISOTROPY; BRAIN; COMPUTER CODES; INJURIES; PATIENTS; RADIATION DOSES; RADIOTHERAPY; TOLERANCE

Citation Formats

Uh, Jinsoo, Merchant, Thomas E., Li, Yimei, Feng, Tianshu, Gajjar, Amar, Ogg, Robert J., and Hua, Chiaho. Differences in Brainstem Fiber Tract Response to Radiation: A Longitudinal Diffusion Tensor Imaging Study. United States: N. p., 2013. Web. doi:10.1016/J.IJROBP.2013.01.028.
Uh, Jinsoo, Merchant, Thomas E., Li, Yimei, Feng, Tianshu, Gajjar, Amar, Ogg, Robert J., & Hua, Chiaho. Differences in Brainstem Fiber Tract Response to Radiation: A Longitudinal Diffusion Tensor Imaging Study. United States. https://doi.org/10.1016/J.IJROBP.2013.01.028
Uh, Jinsoo, Merchant, Thomas E., Li, Yimei, Feng, Tianshu, Gajjar, Amar, Ogg, Robert J., and Hua, Chiaho. 2013. "Differences in Brainstem Fiber Tract Response to Radiation: A Longitudinal Diffusion Tensor Imaging Study". United States. https://doi.org/10.1016/J.IJROBP.2013.01.028.
@article{osti_22224474,
title = {Differences in Brainstem Fiber Tract Response to Radiation: A Longitudinal Diffusion Tensor Imaging Study},
author = {Uh, Jinsoo and Merchant, Thomas E. and Li, Yimei and Feng, Tianshu and Gajjar, Amar and Ogg, Robert J. and Hua, Chiaho},
abstractNote = {Purpose: To determine whether radiation-induced changes in white matter tracts are uniform across the brainstem. Methods and Materials: We analyzed serial diffusion tensor imaging data, acquired before radiation therapy and over 48 to 72 months of follow-up, from 42 pediatric patients (age 6-20 years) with medulloblastoma. FSL software (FMRIB, Oxford, UK) was used to calculate fractional anisotropy (FA) and axial, radial, and mean diffusivities. For a consistent identification of volumes of interest (VOIs), the parametric maps of each patient were transformed to a standard brain space (MNI152), on which we identified VOIs including corticospinal tract (CST), medial lemniscus (ML), transverse pontine fiber (TPF), and middle cerebellar peduncle (MCP) at the level of pons. Temporal changes of DTI parameters in VOIs were compared using a linear mixed effect model. Results: Radiation-induced white matter injury was marked by a decline in FA after treatment. The decline was often accompanied by decreased axial diffusivity, increased radial diffusivity, or both. This implied axonal damage and demyelination. We observed that the magnitude of the changes was not always uniform across substructures of the brainstem. Specifically, the changes in DTI parameters for TPF were more pronounced than in other regions (P<.001 for FA) despite similarities in the distribution of dose. We did not find a significant difference among CST, ML, and MCP in these patients (P>.093 for all parameters). Conclusions: Changes in the structural integrity of white matter tracts, assessed by DTI, were not uniform across the brainstem after radiation therapy. These results support a role for tract-based assessment in radiation treatment planning and determination of brainstem tolerance.},
doi = {10.1016/J.IJROBP.2013.01.028},
url = {https://www.osti.gov/biblio/22224474}, journal = {International Journal of Radiation Oncology, Biology and Physics},
issn = {0360-3016},
number = 2,
volume = 86,
place = {United States},
year = {Sat Jun 01 00:00:00 EDT 2013},
month = {Sat Jun 01 00:00:00 EDT 2013}
}