Relationships between language lateralization and CC dti metrics, tumor grade and tumors distance to language-eloquent-areas in glial neoplasms

PURPOSE: To search relationships between language lateralization and CC DTI metrics, tumor grade and tumors distance to language-eloquent-areas in glial neoplasms. MATERIALS AND METHODS: Total 42 patients with glial neoplasm were enrolled. Their fmri performed for language lateralization and DTI with 64-direction were retrospectively evaluated. Fiber tracking method was used for tractography of CC. Three groups were formed based on language lateralization (left, right and bilateral). We investigatedrelationships between these 3 groups and CC DTI metrics, grade of glial masses and tumors distance to language-eloquent-areas (nearby or remote) and relationship between grade of glial masses and CC DTI metrics.Kruskal Wallis, Mann-Whitney-U and Chi-square tests were used (p ≤ 0, 05). 26 of 42 patients had left hemispheric mass. All above tests were repeated for left hemispheric masses. RESULTS: Patients with left lateralized had highest CC tract number. In glial masses, language bilaterality was more common than normal population. Bilaterality in low grade tumors was found to be higher than high grade. In tumors nearby the language-eloquent-areas, bilaterality was more common.No relationship between tumor grades and CC DTI metrics was found. Similar distributions were observed for left hemispheric masses. CONCLUSION: Higher bilaterality in language dominancyin glial masses comparing the normal population and in tumors nearby language eloquent areassupport interhemispheric reorganization and plasticity. In low grade tumors with a longer life-span, bilaterality was higher than high grade, explaining interhemispheric reorganization and plasticity. Highest CC tract number in left lateralized group suggest intact CC integrity with limited hemispheric destruction.