Impact of radiation dose on neurocognitive function and quality of life in long-term survivors of childhood brain tumour

Abstract

Background and purpose: Children treated with radiotherapy (RT) for a brain tumour often exhibit neurocognitive impairment and report lower quality of life (QoL) later in life. The aim of this nationwide cross-sectional cohort study was to explore the impact of RT dose to brain organs at risk (OARs) on neurocognition and QoL in long-term survivors of childhood brain tumours. Patient/material and methods: A total of 132 survivors of childhood brain tumours, diagnosed from 2001 to 2017 in Denmark, underwent neurocognitive tests and QoL questionnaires at least 5-years post-diagnosis. Neurocognitive assessments were complete and available for 86 patients (61 no-RT/25 RT), and QoL scores for 107 (79 no-RT/28 RT). Mann Whitney U-tests were used to compare scores between no-RT and RT groups. For scores impacted by RT, OAR-specific robust linear regressions were performed to evaluate RT dose effects while adjusting for potential confounders. Results: Clinically significant overall cognitive impairment was observed for 55% of the neurocognitive sub-cohort, with younger age at treatment time as a significant risk factor, while hydrocephalus status had no impact. There were no statistically significant differences on neurocognitive tests between the RT and no-RT group. However, patients treated with RT had significantly lower scores on the physical and social functioning QoL domains, with mean dose to the pituitary gland and left hippocampus, respectively, as significant predictors. Interpretation: This cross-sectional study indicates that RT dose-effects, particularly in the pituitary gland and left hippocampus, might contribute to reduced QoL in survivors of childhood brain tumours.