Whether a patient with brain tumor needs further radiotherapy and chemotherapy after surgical resection needs to be considered and judged by a combination of factors. First of all, the pathological diagnosis of the tumor. The traditional pathological diagnosis of tumor includes two elements: the type of tumor and the grade of tumor. The common types of brain tumors include glioma, meningioma, etc.; the grade of tumor, that is, the malignancy degree of tumor. For example, for glioma, there are 4 grades, while for meningioma, there are 3 grades. The lower the grade, the better the patient’s prognosis; the higher the grade, the more malignant the tumor is, and the worse the patient’s prognosis. Generally speaking, low-grade, benign tumors tend to have clearer borders with brain tissue, so experienced surgeons are able to remove them completely and therefore do not require follow-up radiotherapy and chemotherapy after surgery. On the other hand, high-grade, malignant brain tumors often have unclear borders with brain tissues, which are difficult to be removed completely by surgery, and often have tumor residues that need further radiotherapy and chemotherapy for control. Secondly, the degree of surgical resection should be considered. The more complete the surgical resection is, the less tumor remains, and the need for postoperative radiotherapy and chemotherapy will be lower. However, the majority of brain tumors are malignant gliomas. Gliomas grow in the brain just like the roots of a tree grow into the earth, without clear boundaries. Therefore, surgery is difficult to perform complete resection at the cellular level. On the other hand, there is the site of tumor growth. The brain is the most important organ (one of them) in the human body. There are some tumors that grow in some important functional areas of the brain, such as the central region (controlling movement and sensation). Therefore, it is important to consider not only the extent of tumor removal during surgery, but also the protection of the patient’s function, thus ensuring the patient’s quality of life after surgery. These two factors, to a large extent, can limit the complete resection of the tumor. Finally, there is also the consideration of the patient’s condition. Some brain tumor patients, who are in poor physical condition, if radiotherapy and chemotherapy are forced, it will not only destroy the patient’s own physical condition (immune system), but also will not help to ensure the patient’s quality of life. In conclusion, whether a brain tumor patient needs radiotherapy or chemotherapy is an individualized judgment that takes into account the nature of the tumor, the extent of surgical resection and the patient’s physical condition.