Related Experiment Video
Updated: Sep 3, 2025
10:33
Advanced Diffusion Imaging in The Hippocampus of Rats with Mild Traumatic Brain Injury
Published on: August 14, 2019
8.6K
Effects of Hippocampal Sparing Radiotherapy on Brain Microstructure-A Diffusion Tensor Imaging Analysis
Johannes G Dinkel1, Godehard Lahmer2, Angelika Mennecke1
1Neuroradiologisches Institut des Universitätsklinikums Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), 91054 Erlangen, Germany.
Brain Sciences
|July 27, 2022
Summary
Hippocampal-sparing radiotherapy (HSR) may alter brain microstructure differently than conventional methods. Diffusion Tensor Imaging (DTI) revealed complex changes in white matter and hippocampus following radiation, with some differences observed between HSR and conventional treatment groups.
Area of Science:
- Neuroimaging
- Radiation Oncology
- Neuroscience
Background:
- Cognitive side effects are a concern after cranial radiotherapy.
- Hippocampal-sparing radiotherapy (HSR) aims to mitigate these effects.
- Diffusion Tensor Imaging (DTI) can detect microstructural brain changes post-irradiation, but findings are sometimes conflicting.
Purpose of the Study:
- To investigate the effects of radiation on white matter and hippocampal microstructure using DTI.
- To evaluate if HSR can mitigate these radiation-induced microstructural changes.
- To correlate radiation dose with observed microstructural alterations.
Main Methods:
- Prospective randomized controlled trial involving 35 tumor patients comparing conventional radiotherapy with HSR.
- Diffusion Tensor Imaging (DTI) performed pre-radiotherapy and at multiple time points up to 30 months post-treatment.
- Analysis of Fractional Anisotropy (FA), Mean Diffusivity (MD), Axial Diffusivity (AD), and Radial Diffusivity (RD) in the hippocampus, temporal lobe, frontal lobe white matter, and corpus callosum using linear mixed models.
Main Results:
- Overall, radiation led to decreased FA and increased RD in the corpus callosum, decreased AD in the temporal lobe, and complex changes in hippocampal microstructure (increased FA, AD, MD, and RD over time).
- Higher radiation dose correlated positively with increased hippocampal FA.
- Significant differences in hippocampal microstructure (specifically higher ADCA) were observed between HSR and conventional radiotherapy groups by 6 months post-treatment.
Conclusions:
- Radiation induces complex, time-dependent microstructural changes in the brain, not fully explained by conventional DTI models.
- Hippocampal microstructure appears to be affected differently by HSR compared to conventional radiotherapy, suggesting potential differential impacts on cognitive function.
- Further research is needed to fully understand the pathophysiological implications of these observed microstructural changes and the long-term effects of HSR.
