Cognitive Predictors of Social Adjustment in Pediatric Brain Tumor
Survivors Treated with Photon versus Proton Radiation Therapy
Abstract
Background: Pediatric brain tumor survivors are at risk for poor social
outcomes. It remains unknown whether cognitive sparing with proton
radiotherapy (PRT) supports better social outcomes relative to photon
radiotherapy (XRT). We hypothesized that survivors treated with PRT
would outperform those treated with XRT on measures of cognitive and
social outcomes. Further, we hypothesized that cognitive performance
would predict survivor social outcomes. Procedure: Survivors who
underwent PRT (n=38) or XRT (n=20) participated in a neurocognitive
evaluation >1 year post-radiotherapy. Group differences in
cognitive and social functioning were assessed using ANCOVA. Regression
analyses examined predictors of peer relations and social skills.
Results: Age at evaluation, radiation dose, tumor diameter, and sex did
not differ between groups (all p>0.05). However, XRT
participants were younger at diagnosis (XRT M=5.0 years, PRT M=7.6
years) and further out from radiotherapy (XRT M=8.7 years, PRT M=4.6
years). The XRT group performed worse than the PRT group on measures of
processing speed (p=0.01) and verbal memory (p<0.01); however,
social outcomes did not differ by radiation type. The proportion of
survivors with impairment in peer relations and social skills exceeded
expectation (2(1)=38.67, p<0.001; 2(1)=5.63,
p<0.05), and verbal memory approached significance as a unique
predictor of peer relations (t=-2.01, p=0.05). Total tumor RT dose
significantly predicted social skills (t=-2.23, p<0.05).
Conclusions: Regardless of radiation modality, survivors are at risk for
social challenges, with one-quarter being socially excluded or
undervalued. Deficits in verbal memory may place survivors at particular
risk. Results support monitoring of cognitive and social functioning
throughout survivorship.