Spacial Profiling of Recurrent and High-grade Meningioma

Introduction: High-grade meningioma (WHO grade II-III) distinguish themselves from low-grade meningiomas with a specifically high incidence in tumor recurrence/progression after microsurgical resection. Differences in distribution of high-grade meningioma (e.g. higher incidence in males compared to females), and anatomical prevelance (e.g. lower frequency in the skull base) have been described in the past. This study aims to analyze the special distribution of high-grade and recurrent meningioma in a voxel-based approach.

Methods: This is a retrospective cohort study. Pre-operative magnetic resonance imaging of histologically confirmed meningioma was automatically normalized. The meningioma was segmented using an automated segmentation algorithm. Using these patient-specific volumes of interest - a voxel-based morphometry is performed to link significant voxels to clinical parameters and outcome. Extent of resection was classified in Simpson Grades.

Results: N=538 patients were included in this study with 23% high-grade meningioma in this cohort. Histopathological high-grade meningioma distinct themselves from lower grade meningioma in their pattern of spatial distribution with a significant accumulation in voxels in the frontal, temporal, central and parietal convexity. Low-grade meningioma occurred significantly more often in the skull base, posterior fossa and occipital convexity. The rate of tumor recurrence/progression in high-grade meningioma was significantly higher (27% versus 8%) – even though the extent of resection was also significantly higher in high-grade meningioma due to their less common prevalence in the skull base. The significant in voxels of tumor recurrence was accumulated in the convexity of the central and parietal region. The highest density of tumor recurrences in low grade meningioma occurred in the medial skull base.

Conclusion : This voxel-based analysis reveals special differences in distribution of high-grade meningioma compared to low grade meningioma (convexity versus skull base). More importantly, it distinguishes a difference in anatomical pattern of recurrence depending on the meningioma type (low and high grade meningioma).