P03.18.A LESION MAPPING FOR PATIENTS WITH IDH MUTATED GLIOMAS

Abstract BACKGROUND Studies on brain and functional involvement with lower-grade gliomas (LGG) are typically restricted to predefined functionalities of interest, rather than data-driven. The brain functionality at risk has implications in surgical planning, cognitive testing, rehabilitation focus, and strategies such as supramarginal resection. We provide the mIDH LGG involvement with cortical and network parcellations. MATERIAL AND METHODS Populational lesion involvement (0-1) was quantified for the patients by overlaying tumor distribution with normative atlases of cortical areas, white matter tracts and resting-state functional networks. The structures with highest involvement were reviewed for functionality and established neuropsychological and intraoperative testing. RESULTS We included 284 patients with mIDH LGG. Preliminary results showed the three most common cortical areas, white matter tracts and functional networks respectively: Cingulum (population-involvement: 0.72), Frontal Operculum (0.64), Insula (0.60); Uncinate Fasciculus (0.60), Frontal Aslant Tract (0.54), Inferior Fronto-Occipital Fasciculus (0.40); Salient/Ventral Attention Network (0.36), Default Mode Network (0.26) and Frontoparietal Network (0.25). In patient-based-involvement, 60% of the patients showed at least one of these nine structures involved with the tumor by at least 20% of the structure’s total size. The involved functionality was emotional, social, language, speech, sensory and motor processing, executive functioning, working memory and ability to reflect and mentalize. CONCLUSION The most common brain areas and functions at risk are provided for patients with mIDH LGG. Validated clinical testing was lacking for a large part of the frequently involved functions. Efforts should be directed to establish and validate tests for emotional, social and sensory processing and ability to reflect and mentalize.