A large single-center study shows that insular gliomas-tumors in one of the brain's most challenging regions-can be safely removed with a transcortical approach guided by cortical and subcortical stimulation mapping.
Analyzing 502 resections in 394 patients over 25 years, researchers found that persistent motor or language deficits occurred in fewer than 4% of newly diagnosed low-grade cases. Transient deficits were more common, but overall complication rates remained under 3%.
For newly diagnosed grade 2 insular gliomas, survival improved when residual tumor volume was less than 2.7 cm³. In IDH wildtype glioblastoma, removing more than 88.6% of the enhancing tumor also led to better progression-free and overall survival. Crucially, new permanent limb weakness was tied to worse survival, highlighting the importance of functional preservation.
The study concludes that maximum safe resection with mapping offers a strong balance between aggressive tumor removal and neurologic protection.