Peritumoral edema correlates with mutational burden in meningiomas

Meningiomas are the most common primary central nervous system tumor. Emerging data supports that higher mutational burden portends worse clinical outcomes in meningiomas. However, there is a lack of imaging biomarkers that are associated with tumor genomics in meningiomas. We performed next-generation targeted sequencing in a cohort of 75 primary meningiomas and assessed preoperative imaging for tumor volume and peritumoral brain edema (PTBE). An Edema Index was calculated. Meningiomas that were high grade (WHO grade II or grade III) had significantly larger tumor volume and were more likely to present with PTBE. Moreover, PTBE was associated with brain invasion on histopathology and reduced overall survival. There was a direct association between Edema Index and mutational burden. For every one increase in Edema Index, the number of single nucleotide variants increased by 1.09-fold (95% CI: 1.02, 1.2) (P = 0.01). These data support that Edema Index may serve as a novel imaging biomarker that can inform underlying mutational burden in patients with meningiomas.