384 BOLD Asynchrony Reveals Tumor Burden in IDH-Wildtype Gliomas

INTRODUCTION: IDH-wildtype gliomas are aggressive, highly invasive, and invariably fatal. Maximal safe resection of tumors is the primary goal in glioma surgery, as it has been associated with improved survival and better outcomes. However, there is no clinically accepted method for identifying the extent of tumor burden in these neoplasms. This uncertainty poses a challenge for clinicians who must balance tumor removal with the sparing of healthy brain. METHODS: Forty stereotactically-localized biopsies were obtained during open surgical resection from twenty treatment-naÏve patients with IDH-wildtype gliomas who received standard-of-care preoperative imaging as well as echo-planar resting-state BOLD fMRI. Signal intensity for BOLD asynchrony and standard-of-care imaging was compared to cell counts of total cellularity (H&E), tumor density (Sox2), cellular proliferation (Ki67), and neuronal density (NeuN), for each corresponding sample. RESULTS: BOLD asynchrony was directly related to tumor density as well as cellular proliferation and inversely related to neuronal density. Peritumoral regions that appeared normal on standard-of-care imaging but with elevated BOLD asynchrony showed elevated tumor burden on histology. CONCLUSIONS: BOLD asynchrony is a novel imaging technique that can elucidate tumor burden that is not observable on standard-of-care imaging. Including BOLD asynchrony in preoperative planning can provide more accurate margins for tumor resection, which may improve patient outcomes and overall survival.