Chemoradiation impairs normal developmental cortical thinning in medulloblastoma

Area of Science:

• Neuroimaging
• Developmental Neuroscience
• Pediatric Oncology

Background:

• Temporal lobe radiation exposure in medulloblastoma (MB) treatment may cause neurocognitive deficits.
• Longitudinal cortical thickness changes can reflect neurodevelopmental processes like synaptic pruning.
• Comparing MB patients to juvenile pilocytic astrocytoma (JPA) patients offers insight into treatment effects versus natural development.

Purpose of the Study:

• To compare longitudinal changes in temporal lobe cortical thickness between MB and JPA patients.
• To investigate if treatment modality affects neurodevelopmental cortical changes.
• To test the hypothesis that developmental rates of cortical thickness differ between MB and JPA groups.

Main Methods:

• Retrospective cohort study analyzing high-resolution MRI scans.
• Measured longitudinal cortical thickness changes in bilateral temporal lobe substructures.
• Utilized a linear mixed effects model to assess group differences in developmental trajectories.

Main Results:

• Medulloblastoma patients exhibited increased temporal lobe cortical thickness (0.14 mm/year) compared to juvenile pilocytic astrocytoma patients (-0.018 mm/year).
• This divergence was most pronounced in the inferior temporal lobe substructures.
• Right temporal lobe changes mirrored these trends, albeit less significantly.

Conclusions:

• Medulloblastoma patients display abnormal cortical thickening, unlike the thinning seen in JPA patients and typical development.
• Chemoradiation may disrupt neurodevelopmental mechanisms, leading to altered cortical thickness.
• Longitudinal imaging analysis could serve as an early biomarker for neurocognitive outcomes.