NCOG-19. TUMOR INVASION INFLUENCES ON COGNITIVE FUNCTION IN RIGHT CEREBRAL HEMISPHERIC GLIOBLASTOMAS

Glioblastoma cells broadly infiltrate into surrounding brain parenchyma. In this study, we investigated the influence of tumor invasion on cognitive function in glioblastomas, using diffusion tensor imaging (DTI) .

Participants were 32 patients with right hemispheric glioblastoma who underwent surgery in Kanazawa University Hospital (mean age, 61.8 years). We evaluated the differences in p-map and q-map, which represent diffusion isotropy and anisotropy with the patients' preoperative DTI. The patients were divided into two groups: less-invasive and highly-invasive types. Following clinical and demographic factors were collected retrospectively: age, sex, volume of enhanced lesion, tumor location, and methylation status of MGMT promoter. Several kinds of cognitive functions mediated by right cerebral hemisphere were assessed preoperatively. All these factors were compared between two groups. Moreover, voxel-based lesion symptom (VLSM) analyses were performed to investigate brain regions relate to decline of cognitive function by tumor invasion.

All clinical and demographic factors were not significantly different between two groups. Tumor cells significantly infiltrated to insula and basal ganglia in highly-invasive group. Verbal fluency, executive function, attention, and social cognition were impaired in highly-invasive group (p=0.0067, 0.036, 0.0064, and 0.030, respectively). Score of verbal fluency and social cognition were significantly lower when tumor infiltrated to the medial frontal region including cingulate cortex, and deep part of posterior middle and inferior frontal gyrus. Invasion to the sagittal stratum influenced on deterioration of attention and executive function.

The present study revealed that tumor invasion extending beyond the enhanced lesion causes deterioration of cognitive functions such as verbal fluency, executive function, attention, and social cognition in right hemispheric glioblastoma.