Regional variation in brain white matter diffusion index changes following chemoradiotherapy: a prospective study...

Area of Science:

• Neuroimaging
• Radiotherapy Research
• White Matter Integrity

Background:

• Radiation therapy can cause neurocognitive impairment.
• Understanding white matter's response to radiation is crucial.
• Regional variations in white matter response are poorly understood.

Purpose of the Study:

• To investigate regional differences in brain white matter changes after chemoradiotherapy using diffusion tensor imaging (DTI).
• To assess the impact of radiation on specific white matter structures.

Main Methods:

• Diffusion tensor imaging (DTI) was performed on 14 patients before, during, and after chemoradiotherapy.
• Measured diffusion indices included fractional anisotropy (FA), radial diffusivity (RD), and axial diffusivity (AD).
• Tract-based spatial statistics identified significant voxel-wise changes in diffusion indices across 14 white matter structures.

Main Results:

• Significant decreases in FA and increases in RD were observed in all white matter structures.
• The fornix, cingula, and corpus callosum exhibited the most substantial changes (20-50%).
• The inferior cingula showed a significantly greater mean FA decrease compared to most other structures.

Conclusions:

• Brain white matter structures demonstrate heterogeneous responses to chemoradiotherapy.
• DTI-detectable changes, particularly demyelination in the cingula and fornix, are linked to neurocognitive impairment.
• DTI may serve as a predictive biomarker for adverse effects of brain chemoradiotherapy.