LG-14HOW IMPORTANT ARE TUMOUR SITE AND TREATMENT FOR NEUROCOGNITIVE IMPAIRMENT IN LOW GRADE GLIOMA PATIENTS? NEUROPSYCHOLOGICAL RESULTS FROM THE SIOP-LGG-2004 STUDY

Abstract

OBJECTIVE: The proportionate impact of tumour and treatment on neuropsychological impairment in pediatric low-grade-glioma(LGG) patients is not resolved. We report Results of the German “basic neuropsychological diagnostic” tool∗, measuring primary cognitive abilities in LGG-patients from the German and Swiss SIOP-LGG-2004-cohort, regarding treatment and tumour localisation. PATIENTS AND Methods: Patients diagnosed with LGG 4 years of age were examined 2 and 5 years after diagnosis (n = 213-249; depending on investigated dimensions). Tumour sites were supratentorial-hemispheric (18%), supratentorial-midline (32%), infratentorial (50%). Interventions (non-NF1) were observation/surgery-only (71%), chemotherapy (CT, 13%), and radiotherapy (RT, 16%). Median age at start of treatment was9.0 years forRT-and 4.8 years for CT-patients. Since patients with NF1 proved to have impaired overall neurocognitive performance at diagnosis, they were excluded from further analysis. Results: Impairments were statistically noticeable in non-NF1-patients with hemispheric tumours for tasks requiring higher cognitive functions (verbal short-term-memory), and with infratentorial tumours for fine motor skills, (p =.005-.026). No specific impairments were found for supratentorialmidline locations. No noticeable differences in Results were found between observation-, CT-and RT-patients, possibly reflecting the effect of ageassignment and delayed impact of RT-effects. Conclusion: First analyses of our cohort had shown significant neuropsychological impairments for all domains in all LGG patients. Expanding our Results, initial hydrocephalus and presence of NF1 remain strongest predictors for general neuropsychologicalimpairment, while tumour-site impactsuponspecific skills. Further studies should focus upon the role of age at start of treatment and length of time after treatment as predictor for neurocognitive decline in radiotherapy-patients.