The investigators use a monopolar stimulator to determine and retain the tumor margin within 5mm in the sensitive area which is posterior superior longitudinal fasciculus or posterior arcuate fasciculus.

The investigators use bipolar stimulator according to the current standard surgery plan. After the positive points are identified, those points would be retained to avoiding language function impairment after the tumor resection.

Randomly select 30 participants to implement new surgical plan, which is using a monopolar stimulator to determine positive function sites and save tumors within 5 mm of the posterior superior longitudinal fasciculus/arcuate fasciculus

The ratio of language function recovery in patients with new surgical plan would higher than those receive traditional surgical plan. The main tool is to use Western Aphasia Battery (WAB) language evaluation form to record each patient's language ability in 4-7days after surgery and every other 3 months. The executive function and attention would also be evaluated by cognitive assessment (MoCA) and Mini-Mental State Exam (MMSE). Each patient's scores and reponse time would be used to compare the differences between two surgical plans.

The new surgical plan preserves the language function to improve the quality of life, in order to influence the patient's length of life after surgery. Hence, the overall survival days of patients in two surgical plans would be compared by recording patients' date of death from any cause.