Predictive Evolution Factors of Incidentally Discovered Suspected Low-Grade Gliomas: Results from a Consecutive Series of 101 Patients

Abstract

BACKGROUND: Incidentally discovered suspected diffuse low-grade gliomas (LGGs) on brain imaging pose a challenge to neurosurgeons. Modern surgical series of LGGs favor early prophylactic surgery with a maximal extent of resection. However, some nonevolutive lesions may mimic LGGs on magnetic resonance imaging (MRI). OBJECTIVE: To determine objective criteria to advocate surgical resection of an incidentally discovered suspected LGG based upon MRI findings. METHODS: The prospective cohort of patients referred to our institution for an incidental finding suggestive of LGG was retrospectively reviewed. Stable lesions underwent systematic serial MRI follow-up, while evolutive lesions underwent prophylactic surgery under awake conditions. Initial clinico-radiological features were compared between stable and evolutive lesions in order to determine predictive criteria of further evolution. RESULTS: Among 101 patients referred for surgical resection of incidentally discovered suspected LGG in our center, 19 patients (18.8%) had nonevolutive MRI lesions after a mean follow-up of 46.9 ± 34.9 mo. Insular topography (P =. 003), higher mean volume at discovery (19.2 vs 5.2 cm3, P