skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Brain necrosis after fractionated radiation therapy: Is the halftime for repair longer than we thought?

Abstract

Purpose: To derive a radiobiological model that enables the estimation of brain necrosis and spinal cord myelopathy rates for a variety of fractionation schemes, and to compare repair effects between brain and spinal cord. Methods: Sigmoidal dose response relationships for brain radiation necrosis and spinal cord myelopathy are derived from clinical data using nonlinear regression. Three different repair models are considered and the repair halftimes are included as regression parameters. Results: For radiation necrosis, a repair halftime of 38.1 (range 6.9-76) h is found with monoexponential repair, while for spinal cord myelopathy, a repair halftime of 4.1 (range 0-8) h is found. The best-fit alpha beta ratio is 0.96 (range 0.24-1.73)Conclusions: A radiobiological model that includes repair corrections can describe the clinical data for a variety of fraction sizes, fractionation schedules, and total doses. Modeling suggests a relatively long repair halftime for brain necrosis. This study suggests that the repair halftime for late radiation effects in the brain may be longer than is currently thought. If confirmed in future studies, this may lead to a re-evaluation of radiation fractionation schedules for some CNS diseases, particularly for those diseases where fractionated stereotactic radiation therapy is used.

Authors:
 [1]
  1. Department of Human Oncology, University of Wisconsin-Madison, School of Medicine and Public Health, 600 Highland Avenue, Madison, Wisconsin 53792 (United States)
Publication Date:
OSTI Identifier:
22099092
Resource Type:
Journal Article
Journal Name:
Medical Physics
Additional Journal Information:
Journal Volume: 39; Journal Issue: 11; Other Information: (c) 2012 American Association of Physicists in Medicine; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0094-2405
Country of Publication:
United States
Language:
English
Subject:
62 RADIOLOGY AND NUCLEAR MEDICINE; 60 APPLIED LIFE SCIENCES; BETA RATIO; BIOLOGICAL REPAIR; BRAIN; DELAYED RADIATION EFFECTS; DOSE-RESPONSE RELATIONSHIPS; FRACTIONATION; HALF-LIFE; NECROSIS; RADIATION DOSES; RADIOTHERAPY; REGRESSION ANALYSIS; SCHEDULES; SIMULATION; SPINAL CORD

Citation Formats

Bender, Edward T. Brain necrosis after fractionated radiation therapy: Is the halftime for repair longer than we thought?. United States: N. p., 2012. Web. doi:10.1118/1.4762562.
Bender, Edward T. Brain necrosis after fractionated radiation therapy: Is the halftime for repair longer than we thought?. United States. doi:10.1118/1.4762562.
Bender, Edward T. Thu . "Brain necrosis after fractionated radiation therapy: Is the halftime for repair longer than we thought?". United States. doi:10.1118/1.4762562.
@article{osti_22099092,
title = {Brain necrosis after fractionated radiation therapy: Is the halftime for repair longer than we thought?},
author = {Bender, Edward T.},
abstractNote = {Purpose: To derive a radiobiological model that enables the estimation of brain necrosis and spinal cord myelopathy rates for a variety of fractionation schemes, and to compare repair effects between brain and spinal cord. Methods: Sigmoidal dose response relationships for brain radiation necrosis and spinal cord myelopathy are derived from clinical data using nonlinear regression. Three different repair models are considered and the repair halftimes are included as regression parameters. Results: For radiation necrosis, a repair halftime of 38.1 (range 6.9-76) h is found with monoexponential repair, while for spinal cord myelopathy, a repair halftime of 4.1 (range 0-8) h is found. The best-fit alpha beta ratio is 0.96 (range 0.24-1.73)Conclusions: A radiobiological model that includes repair corrections can describe the clinical data for a variety of fraction sizes, fractionation schedules, and total doses. Modeling suggests a relatively long repair halftime for brain necrosis. This study suggests that the repair halftime for late radiation effects in the brain may be longer than is currently thought. If confirmed in future studies, this may lead to a re-evaluation of radiation fractionation schedules for some CNS diseases, particularly for those diseases where fractionated stereotactic radiation therapy is used.},
doi = {10.1118/1.4762562},
journal = {Medical Physics},
issn = {0094-2405},
number = 11,
volume = 39,
place = {United States},
year = {2012},
month = {11}
}