Innv-19. language activation areas and pathways integrity assessment following glioma resection and subsequent radiation treatment

Abstract BACKGROUND It is a well-established practice to perform brain-mapping scans of patients diagnosed with dominant frontal/temporal lesions to evaluate their language activation areas (LAAs) and pathways prior to surgical intervention. Dependent on the pathology, brain functional regions and their associated pathways may be exposed to post-operative radiation as part of the patient's treatment protocol. The post-radiation detrimental effect on cognition is well-known, however, the effect of surgical resection and subsequent radiation on LAAs and pathways' integrity is not well studied. Here, the impact of surgical resection and radiation on LAAs and pathways integrity is examined. METHODS 8 patients that underwent surgical resection to frontal/temporal lesion located at their dominant hemisphere followed by radiation treatment with at least two brain-mapping scans in Sheba Medical Center between the years 2012 to 2021 were collected. Location of functional LAAs (such as Broca's and Wernicke’s areas) as well as that of structural fiber tracts (such as the arcuate fasciculus) were determined. Volumetric and tumor geometry data was measured and documented. Laterality index of activation and Fractional Anisotropy (FA) quantitative values were calculated and compared from the baseline scan to the post-treatments scan for each patient. RESULTS Patients’ demographics analysis showed that their median age-at-diagnosis was 41 years (range, 4-64). The median overall survival was 89 months (range, 19-130) and the median follow-up duration was 80 months (range, 16-129). Radiation mean dose was 57Gy (range 40.05-60) and Planning treatment volume was 315ml (range 123.3-456.5) Notably, the mean laterality index of LAAs was also affected by intervention (p=0.044). Additionally, the arcuate fasciculus’ FA values differed in the post-interventions scan compared to the pre-interventions scan CONCLUSION surgical resection and radiation treatment may cause changes in the lateralization of the LAAs that may represent an attempt to compensate for a significant brain injury.