20023 Purpose: To evaluate the delayed adverse changes in neuro-cognitive functions as well as white matter damage in radiated survivors of pediatric brain tumors. Methods: Forty two children (22 males) with primary brain tumors who were only treated with cranial radiation, were recruited. 28 patients were treated for low risk medulloblastoma, 10 patients for low grade astrocytoma, 3 patients for low grade ependymoma, and 1 patient for craniopharyngioma. Their ages ranged from 3 to 18 years (mean 10.3±3.98 years).They were subjected, initially just before radiotherapy and at follow-up 1–2 year after completion of cranial radiation, to serial clinical and neuropsychological assessments including Wechseler Intelligence Scale for Children, Vineland social maturity test, Benton Visual Memory Test, and Revised Behavior Problem Checklist. Magnetic resonance scans were also performed to detect the presence of white matter damage before radiotherapy and at follow up. Results: Initially, after surgery and before radiation, intelligence test scores were below normal scores for age and this was of high statistical significance (Total IQ: t= -3.02, P= 0.006). Visual memory test showed evidence of organicity in all cases. Social maturity showed a statistically significant decline as well (t= -2.11, P= 0.04). Follow-up after radiotherapy showed further decline with high statistical significance (Total IQ t= 3.228, P=0.003; visual memory t= 4.08, P= 0.001); An attentional problem has emerged (t= -6.12, P= 0.00). Both radiation dose and volume of radiation showed negative and statistically significant correlation with IQ. Age at diagnosis correlated positively and significantly with IQ ( r= 0.601, P=0.001). Multiple linear regression showed impaired neurocognitive function which was correlated with the degree of white matter damage. (standardized B= -0.577, P= 0.001) and young age at diagnosis (standardized B= -0.427, P= 0.014). Conclusions: Cranial radiation in pediatric brain tumors is associated with a decline in multiple neurocognitive functions including total IQ, visual memory, and attention; which are related to the toxic effect of cranial radiation on white matter of the brain especially in young age of childhood with high dose and whole cranial radiation. No significant financial relationships to disclose.
The relationship between working memory and cerebral white matter volume in survivors of childhood brain tumors treated with conformal radiation therapy
