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Author Seibert, Tyler M. ♦ Karunamuni, Roshan ♦ Bartsch, Hauke ♦ Kaifi, Samar ♦ Krishnan, Anitha Priya ♦ Dalia, Yoseph ♦ Burkeen, Jeffrey ♦ Murzin, Vyacheslav ♦ Moiseenko, Vitali ♦ Kuperman, Joshua ♦ White, Nathan S. ♦ Brewer, James B. ♦ Farid, Nikdokht ♦ McDonald, Carrie R. ♦ Hattangadi-Gluth, Jona A.
Source United States Department of Energy Office of Scientific and Technical Information
Content type Text
Language English
Subject Keyword RADIOLOGY AND NUCLEAR MEDICINE ♦ ATROPHY ♦ BIOLOGICAL MARKERS ♦ BIOMEDICAL RADIOGRAPHY ♦ CLINICAL TRIALS ♦ COMPUTER CODES ♦ GY RANGE 01-10 ♦ GY RANGE 10-100 ♦ HIPPOCAMPUS ♦ IMAGES ♦ IN VIVO ♦ MULTIVARIATE ANALYSIS ♦ NEOPLASMS ♦ NMR IMAGING ♦ PATIENTS ♦ RADIATION DOSES ♦ RADIATION EFFECTS ♦ RADIOTHERAPY
Abstract Purpose: After radiation therapy (RT) to the brain, patients often experience memory impairment, which may be partially mediated by damage to the hippocampus. Hippocampal sparing in RT planning is the subject of recent and ongoing clinical trials. Calculating appropriate hippocampal dose constraints would be improved by efficient in vivo measurements of hippocampal damage. In this study we sought to determine whether brain RT was associated with dose-dependent hippocampal atrophy. Methods and Materials: Hippocampal volume was measured with magnetic resonance imaging (MRI) in 52 patients who underwent fractionated, partial brain RT for primary brain tumors. Study patients had high-resolution, 3-dimensional volumetric MRI before and 1 year after RT. Images were processed using software with clearance from the US Food and Drug Administration and Conformité Européene marking for automated measurement of hippocampal volume. Automated results were inspected visually for accuracy. Tumor and surgical changes were censored. Mean hippocampal dose was tested for correlation with hippocampal atrophy 1 year after RT. Average hippocampal volume change was also calculated for hippocampi receiving high (>40 Gy) or low (<10 Gy) mean RT dose. A multivariate analysis was conducted with linear mixed-effects modeling to evaluate other potential predictors of hippocampal volume change, including patient (random effect), age, hemisphere, sex, seizure history, and baseline volume. Statistical significance was evaluated at α = 0.05. Results: Mean hippocampal dose was significantly correlated with hippocampal volume loss (r=−0.24, P=.03). Mean hippocampal volume was significantly reduced 1 year after high-dose RT (mean −6%, P=.009) but not after low-dose RT. In multivariate analysis, both RT dose and patient age were significant predictors of hippocampal atrophy (P<.01). Conclusions: The hippocampus demonstrates radiation dose–dependent atrophy after treatment for brain tumors. Quantitative MRI is a noninvasive imaging technique capable of measuring radiation effects on intracranial structures. This technique could be investigated as a potential biomarker for development of reliable dose constraints for improved cognitive outcomes.
ISSN 03603016
Educational Use Research
Learning Resource Type Article
Publisher Date 2017-02-01
Publisher Place United States
Journal International Journal of Radiation Oncology, Biology and Physics
Volume Number 97
Issue Number 2


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