Qol-24. Treatment- And Time-Related Impact on Long-Term Neurocognitive Outcomes in Adult Survivors of a Pediatric Brain Tumor

Abstract Treatment for pediatric brain tumors has been associated with the risk of developing long-term neurocognitive impairment. However, it is not well understood which neurocognitive profiles exist within this population. We investigated neurocognitive functioning (NF) in survivors in early adulthood and aimed to assess the impact of radiotherapy dose (RTD) and time since treatment (TxT) on NF. Forty-six survivors of pediatric brain tumors (mean age 23.99±4.71, mean age at diagnosis 9.29±4.54) performed an extensive neurocognitive test battery resulting in intelligence (n=5), memory (n=2), and language (n=3) scores. NF in long-term survivors was compared to sex-, age-, and education-matched controls, and between the different treatment strategies (surgery-only n=19, chemotherapy n=8, radiotherapy n=11, or chemo-radiotherapy n=8). Furthermore, relation between max-RTD (range 40.28 – 61.61 Gy) as well as TxT and NF was assessed. Three ANCOVA models were tested, and false discovery rate (FDR) was applied. For all scales and domain scores, survivors scored lower compared to controls. Scores were significant lower on full scale intelligence (pfdr 0.001), verbal comprehension (pfdr 0.001), working memory (pfdr= 0.003), perceptual reasoning (pfdr 0.001), processing speed (pfdr 0.001), spoken word comprehension (pfdr= 0.001), and semantic word generation (pfdr= 0.036) compared to controls. NF was not significantly different between the different treatments, nor did the association with max-RTD reach significance. TxT was associated with verbal comprehension and spoken word comprehension; albeit significance was not retained after FDR correction. In this study, the overall survivor cohort scored lower on multiple cognitive outcomes. More detailed analysis of various risk factors might further elucidate the different neurocognitive profiles for this population. Furthermore, more detailed analysis of RTD distributions and affected brain structures may provide greater insight on the impact of radiotherapy on NF.