Superior verbal learning and memory in pediatric brain tumor survivors treated with proton versus photon radiotherapy.

Abstract

Objective: Radiotherapy for pediatric brain tumor has been associated with late cognitive effects. Compared to conventional photon radiotherapy (XRT), proton radiotherapy (PRT) delivers lower doses of radiation to healthy brain tissue. PRT has been associated with improved long-term cognitive outcomes compared to XRT. However, there is limited research comparing the effects of XRT and PRT on verbal memory. Method: Survivors of pediatric brain tumor treated with either XRT (n = 29) or PRT (n = 51) completed neuropsychological testing >1 year following radiotherapy. Performance on neuropsychological measures was compared between treatment groups using analysis of covariance. Chi-squared tests of independence were used to compare the frequency of encoding, retrieval, and intact memory profiles between treatment groups. Associations between memory performance and other neurobehavioral measures were examined using Pearson correlation. Results: Overall, patients receiving PRT demonstrated superior verbal learning and recall compared to those treated with XRT. Encoding and retrieval deficits were more common in the XRT group than the PRT group, with encoding problems being most prevalent. The PRT group was more likely to engage in semantic clustering strategies, which predicted better encoding and retrieval. Encoding ability was associated with higher intellectual and adaptive functioning, and fewer parent-reported concerns about day-to-day attention and cognitive regulation. Conclusion: Results suggest that PRT is associated with verbal memory sparing, driven by effective encoding and use of learning strategies. Future work may help to clarify underlying neural mechanisms associated with verbal memory decline, which will better inform treatment approaches. This document is copyrighted by the American Psychological Association or one of its allied publishers.This article is intended solely for the personal use of the individual user and is not to be disseminated broadly.Lisa E. Mash https://orcid.org/0000-0002-3425-8646 Lisa S. Kahalley received funding from Grant R01CA221197 and R01CA187202 from the Division of Cancer Prevention, National Cancer Institute. The authors have no conflict of interest to disclose.Data and analysis code for this study are available upon request. This study was not preregistered.Lisa E. Mash played lead role in conceptualization, formal analysis, methodology, software, writing of original draft and writing of review and editing. Lisa S. Kahalley played lead role in funding acquisition and equal role in conceptualization, data curation, formal analysis, investigation, methodology, project administration, resources, supervision, writing of original draft and writing of review and editing. M. Fatih Okcu played supporting role in conceptualization, data curation, investigation, methodology, project administration, resources and writing of review and editing. David R. Grosshans played supporting role in conceptualization, data curation, investigation, methodology, project administration, resources...

White matter connectivity and social functioning in survivors of pediatric brain tumor

“…Generally, higher radiation therapy (RT) dose and volume are related to greater white matter injury, with initial evidence that proton RT reduces white matter disruption compared to photon RT [22]. Neurosurgery and chemotherapy also confer risk for white matter abnormalities but to a lesser degree than RT [23]. These factors impair myelination and alter the balance between gray and white matter [10].…”