Working memory and processing speed among pediatric brain tumor patients treated with photon or proton beam radiation therapy

Improved medical technology has enabled many pediatric patients with brain tumors to live longer and enjoy a better quality of life. Medical advances, such as proton beam radiation therapy (PBRT), spares more healthy tissue than traditional radiation (RT) and is thought to result in fewer cognitive late effects. However, PBRT is more expensive, and questions remain whether the cost is justified in terms of short- and long-term health improvements. This study aimed to determine whether working memory and processing speed differed across time in pediatric brain tumor patients treated with RT(n = 17) or PBRT (n = 22). The acute neurocognitive effects of RT and PBRT were examined by comparing neuropsychological test performance on the WISC-IV at treatment initiation (Time 1) and approximately 2-years post-treatment initiation (Time 2). Statistical analysis showed that regardless of treatment type, working memory and processing speed decreased over time. Further, results revealed that gender and age, but not tumor location, impacted working memory scores. Decline in processing speed was not associated with any of these medical or demographic variables. Despite the small sample size and limited power, results support the importance of comprehensive evaluations in this population, which may lead to better educational and vocational outcomes.