Notice: Users may be experiencing issues with displaying some pages on stanfordhealthcare.org. We are working closely with our technical teams to resolve the issue as quickly as possible. Thank you for your patience.
 

Learn about the flu shot, COVID-19 vaccine, and our masking policy »

Stanford Health Care

Microstructural injury to corpus callosum and intra-hemispheric white matter tracts correlate with attention and processing speed decline after brain radiation. International journal of radiation oncology, biology, physics Huynh-Le, M. P., Tibbs, M. D., Karunamuni, R. n., Tringale, K. R., Salans, M. n., Yip, A. n., Connor, M. n., Simon, A. B., Vitzthum, L. K., Reyes, A. n., Macari, A. C., Moiseenko, V. n., McDonald, C. R., Hattangadi-Gluth, J. A. 2021

Abstract

The corpus callosum (CC) and intra-hemispheric white matter tracts (IHWM) subserve critical aspects of attention and processing speed. We analyzed imaging biomarkers of microstructural injury within these regions and association with attention/processing speed decline post-radiotherapy in primary brain tumor patients.On a prospective clinical trial, 44 primary brain tumor patients underwent cognitive testing and MRI/diffusion-weighted imaging pre-radiotherapy, and 3-, 6-, and 12-months post-radiotherapy. CC (subregions; total) and IHWM tracts (left/right without CC; total) were autosegmented; tumor/tumor bed/edema were censored. Biomarkers included: volume changes (cc); mean diffusivity (MD, higher values indicate WM injury); fractional anisotropy (FA, lower values indicate WM injury). Reliable-change indices measured changes in attention (WAIS-IV digits-forward; D-KEFS-Trail-Making visual-scanning) and processing speed (WAIS-IV coding; D-KEFS-Trail-Making number-sequencing, letter-sequencing), accounting for practice effects. Linear mixed-effects models evaluated associations between 1) mean radiation dose and biomarkers (volume, MD, FA); 2) imaging biomarkers and neurocognitive performance. Statistics were corrected for multiple comparisons.Processing speed declined at 6 months (number-sequencing, letter-sequencing; p<0.04). Seizures and anti-epileptic drug therapy were associated with lower visual-scanning attention reliable-change indices at 6 months (p=0.039). Higher radiation dose correlated with smaller mid-anterior CC volume (p=0.023), lower FA in posterior CC, anterior CC, and total CC (all p<0.03), and higher MD in anterior CC (p=0.012). Smaller mid-anterior CC and left IHWM volume correlated with worse processing speed (coding, letter-sequencing, number-sequencing, all p<0.03). Higher FA in right, left, and total IHWM correlated with better coding scores (all p<0.01). Lower FA in total IHWM (p=0.009) was associated with worse visual-scanning attention scores. Higher FA in mid-posterior CC (p=0.029) correlated with better digits-forward attention scores.The CC demonstrated radiation dose-dependent atrophy and WM injury. Microstructural injury within the CC and IHWM was associated with attention/processing speed decline after radiotherapy. These areas represent possible avoidance regions for preservation of attention/processing speed.

View details for DOI 10.1016/j.ijrobp.2020.12.046

View details for PubMedID 33412257