Supratentorial low-grade glioma is a heterogeneous group of brain tumours, accounting for roughly 10–15% of all adult primary intracranial tumours.Because of the relatively slow growth rate of low-grade gliomas, a long expected survival is not unreasonable. Surgical resection or observation alone is the mainstay of treatment. Where the tumours involve critical functional regions of the brain, complete removal would be dangerous and is not feasible. Even with grossly total removal, the infiltrative feature of gliomas often leaves behind some microscopic tumours. The microscopic residual tumours might increase the incidence of local relapse and allow adjuvant therapy to play a role in the management of low-grade gliomas.