QOL-16. A 6-year longitudinal study of neurocognition in children treated for a brain tumor

Long-term neurocognitive difficulties in children treated for a brain tumor are well documented and known to be affected by treatment. However, longitudinal studies of these neurocognitive difficulties are scarce. In the present study, we investigated the impact of radiotherapy (RT) on the evolution of neurocognition between different consecutive time points after diagnosis, and throughout treatment and survivorship. This study included 69 children diagnosed with a brain tumor at the University Hospitals Leuven who completed a comprehensive neuropsychological test battery (intelligence, memory, visuomotor functioning, and QoL) on at least three consecutive time points (2-year interval). Of all patients, 40 completed the test battery at 4 time points. The first assessment was conducted at the earliest possible moment after diagnosis and before the start of any adjuvant therapy. Mean age at diagnosis and first assessment were 7.75 and 7.92 years, respectively. The most common diagnoses were pilocytic astrocytoma (n=33) and medulloblastoma (n=11). 29.0% of the children received local RT and 15.9% received craniospinal RT. A repeated measures analysis with cranial irradiation (no, focal, craniospinal) as between-subjects factor and age at diagnosis as covariate demonstrated a significant interaction effect between time and type of irradiation for both overall intelligence (p=0.007) and QoL (p=0.006) for children with three and four assessments. Children who received craniospinal irradiation demonstrated a significant decline in overall intelligence and a significant worsening of QoL. For the non-irradiated group, an improvement of QoL was observed. For processing speed, a significant time effect was found for children with three and four assessments (p<0.001), with a significant improvement for the overall group. The results of this longitudinal study demonstrated diverse longitudinal trajectories. Children who received craniospinal irradiation are most often confronted with intellectual decline and worsening of QoL.