Gliomas are common primary tumors in the brain and can be classified into four grades according to WHO pathological grading criteria. Although grade 1 gliomas can be cured by surgical resection, grade 2, 3, and 4 gliomas are prone to recurrence after surgical resection alone, especially for high-grade glioblastomas, where recurrence is almost inevitable even after surgery with adjuvant radiotherapy and electric field therapy. And recurrence of glioma often means tumor progression, with low-grade grade II gliomas progressing in about 5-15 years and the highest grade glioblastoma having a median survival of only about 15 months. Although there are traditional radiotherapy and chemotherapy as well as newer techniques and drugs such as tumor electric field therapy, immunotherapy, and small molecule targeted therapy used in the treatment of glioma, the best treatment for glioma requires first removing as much of the tumor as possible. For low-grade grade II gliomas, the more complete the resection, the more it can delay the chance of malignant progression and transformation of the tumor, thus prolonging the patient’s survival time. For most high-grade gliomas with significant enhancement on MRI, resection of 98% or more of the enhancement can significantly prolong survival. Therefore, for glioma, the more complete the resection of the tumor, the more it can delay the recurrence of the tumor and the better the treatment outcome, while ensuring patient safety and function. The recurrence of glioma has factors such as distant infiltration of glioma cells along nerve fibers, clonal evolution of glioma cells, and glioma stem cells. Infiltration of glioma cells along nerve fibers means that tumor cells can extend far in brain tissue just like tree roots. Therefore, tumor cells can still be present in the periphery of the glioma tumor, and at the furthest point, glioma tumor cells can even be found in the contralateral brain tissue. This suggests that complete resection of only the enhanced part of high-grade glioma or the part of low-grade glioma with abnormal signal on MRI may still have tumor residue and cause recurrence and progression of glioma, therefore, the concept of extended resection of glioma is proposed, hoping to resect more “completely” than the original one. The concept of extended glioma resection has been proposed to allow for more “complete” resection of gliomas. In low grade II gliomas, extended resection or complete resection of the main body of the tumor can delay the time to recurrence, reduce the rate of malignant transformation of the tumor, and possibly avoid unnecessary radiotherapy compared with incomplete resection of the main body of the tumor. For grade III or IV high-grade glioma, extended resection of the enhanced main body of the tumor and the surrounding edematous tissue can prolong the survival time of some glioma patients. However, the tumor is surrounded by brain tissues, and these structures and tissues cannot be resected in an unlimited extent, because this will inevitably affect the important functions of brain tissues, and even have the risk of fatalities. Therefore, the expanded resection of glioma is an expanded resection within a certain range. Previously, the expanded resection of glioma means from the enhanced part to within the FLAIR part on MRI, later expanded to include the whole FLAIR part, and now it means beyond the FLAIR part until close to the functional brain area. Although expanded glioma resection has been shown to delay tumor recurrence and prolong survival time in some glioma patients, expanded glioma resection is not useful for all glioma patients, for example, for high-grade grade III and IV gliomas, expanded resection does not prolong survival time for IDH wild-type gliomas, although it can prolong survival time for IDH mutated tumors. time. Therefore, for each individual glioma, an experienced neurosurgeon will consider and weigh the benefits and harms of securing patient safety and function against the maximum extent of tumor resection for each individual glioma and adopt the best surgical resection plan based on the location and grade of the tumor and the patient’s physical condition.