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.

QOL-08. Visual memory and potential clinical risk factors in long-term survivors of a childhood brain tumor

A brain tumor treatment has previously been associated with long-term neurocognitive sequelae. However, clinical profiles differ between certain patient subgroups. We investigated the impact of tumor location, radiotherapy (RT), and age at diagnosis in childhood brain tumor survivors on long-term cognitive outcomes. Adult survivors (n=32) of pediatric brain tumors (n=11 infratentorial, n=21 supratentorial; 14 astrocytomas, 3 craniopharyngiomas, 2 ependymomas, 2 germinomas, 1 hemangioblastomas, 4 medulloblastomas, 6 nervus opticus gliomas) participated in this neuropsychological study (n=11 RT) (16.8-35.1 years old, >2years after treatment, mean age at diagnosis = 9.2 years, 50% male). An extensive neurocognitive test battery was used to assess intelligence scales (n=5), verbal and visual memory (n=2), and language (n=3). In order to investigate the effects of tumor location (infra- versus supratentorial), RT (yes vs. no), and age at diagnosis on the cognitive scores, a multivariate ANCOVA model was tested including the main effects and interaction between age and RT. Of all included scales, only visual memory was significantly associated with the risk factors. More specifically, patients who received RT (F=10.3, p=.004) and were younger at diagnosis (F=6.9, p=.014) scored worse on this task. Furthermore, the interaction effect between these factors was also significant (F=8.8, p=.006). These findings suggest that younger patients could be more vulnerable to the radiotoxic effects to visual memory outcomes. Tumor location (supra- vs. infratentorial) was not significantly associated with any outcome. In this study, only visual memory appeared to be associated with the risk factors of interest. Both radiotherapy and age at radiotherapy, as well as their interaction, could be risk factors for altered neurodevelopmental patterns of brain areas associated with visual memory.