Table 5.
Linear mixed-effects model results of imaging biomarkers of injury (volume, FA, and MD) as predictors of attention raw scores.
| Attention |
|||||||
|---|---|---|---|---|---|---|---|
| WAIS Digits Forward | D-KEFS-TM Visual Scanning | ||||||
| Region | Biomarker | Estimate (β)* | Standard Error | P Value | Estimate (β) | Standard Error | P Value |
| Total CC | Volume | −0.027 | 0.419 | .949 | −2.101 | −1.890 | .268 |
| FA | 0.042 | 0.046 | .367 | −0.021 | 0.196 | .918 | |
| MD | −1.192 | 2.690 | .662 | 1.584 | 8.836 | .858 | |
| Posterior CC | Volume | −0.343 | 1.230 | .786 | −3.330 | 5.570 | .552 |
| FA | 0.009 | 0.029 | .768 | −0.028 | 0.121 | .819 | |
| MD | −1.382 | 2.715 | .611 | 3.724 | 9.052 | .683 | |
| Mid-Posterior CC | Volume | 0.896 | 2.330 | .701 | −5.880 | 10.100 | .562 |
| FA | 0.078 | 0.035 | .029† | −0.013 | 0.155 | .936 | |
| MD | −2.446 | 2.413 | .328 | 3.516 | 8.302 | .673 | |
| Central CC | Volume | 0.377 | 2.470 | .879 | −9.860 | 10.900 | .375 |
| FA | 0.045 | 0.038 | .241 | −0.048 | 0.171 | .783 | |
| MD | −2.522 | 2.461 | .311 | 4.891 | 8.644 | .572 | |
| Mid-Anterior CC | Volume | −1.230 | 2.520 | .627 | −13.200 | 10.900 | .229 |
| FA | 0.035 | 0.034 | .308 | −0.012 | 0.163 | .943 | |
| MD | −2.454 | 2.093 | .243 | 4.198 | 7.430 | .574 | |
| Anterior CC | Volume | 0.179 | 1.340 | .900 | −11.300 | 5.860 | .062 |
| FA | 0.011 | 0.035 | .766 | −0.013 | 0.147 | .928 | |
| MD | 0.753 | 1.744 | .670 | −2.117 | 6.509 | .745 | |
| Total IHWM | Volume | −0.002 | 0.013 | .906 | 0.018 | 0.055 | .748 |
| FA | 0.085 | 0.127 | .505 | −1.411 | 0.510 | .009† | |
| MD | −1.657 | 3.732 | .660 | 12.190 | 11.473 | .292 | |
| Right IHWM | Volume | −0.024 | 0.039 | .532 | 0.158 | 0.163 | .335 |
| FA | −0.012 | 0.131 | .927 | −1.162 | 0.529 | .035 | |
| MD | −1.033 | 3.835 | .789 | 14.078 | 11.629 | .230 | |
| Left IHWM | Volume | 0.026 | 0.038 | .512 | −0.052 | 0.170 | .758 |
| FA | 0.085 | 0.129 | .525 | −1.162 | 0.528 | .040 | |
| MD | −1.851 | 3.706 | .623 | 9.424 | 11.375 | .412 | |
Abbreviations: CC = corpus callosum; D-KEFS-TM = Delis-Kaplan Executive Function System Trail Making; FA = fractional anisotropy; IHWM = intrahemispheric white matter tracts; MD = mean diffusivity; ROI = region of interest; RT = radiation therapy; WAIS-IV = Weschler Adult Intelligence Scale IV.
Note: Attention was measured via the WAIS Digits Forward and the D-KEFS Trail Making Visual Scanning tests. Models for each region of interest (ROI) and imaging parameter were created and analyzed independently. All volume models control for percentage of ROI censored. Significant results (P < .05) are shown in bold.
β estimate units are points/(mo*cm3) for volume; points/mo for FA, and points/(mo*μm2/ms) for MD.
Results that remained significant after corrections for multiple comparisons.