If the tumor has infiltrated and there is no obvious border between the tumor and brain tissue, it is difficult to remove all of the tumor except for the small tumor in the early stage and located in the appropriate area. Surgical treatment of glioma The principle of surgical treatment of glioma is to remove the tumor as much as possible while preserving the neurological function. If the tumor is small in the early stage, all the tumors should be removed. For shallow tumors, cortical incision should be made around the tumor, and for white matter tumors, cortical incision should be made avoiding important functional areas. When separating the tumor, it should be done at a certain distance from the tumor and within the normal brain tissue, not close to the tumor. Especially for more benign tumors such as astrocytoma and oligodendroglioma in the frontal or anterior temporal lobes or cerebellar hemispheres, better results can be obtained. For larger tumors located in the frontal or anterior temporal lobes, lobectomy can be performed to remove them together with the tumor. In the frontal lobe, the posterior margin of the incision should be at least 2 cm in front of the anterior central gyrus, in the dominant hemisphere and avoiding the motor speech center. In the temporal lobe, the posterior margin should be before the inferior anastomotic vein and avoid damage to the lateral fissure. If the frontal or temporal lobe tumors are too extensive to be removed, the frontal pole or frontal pole can be removed as much as possible for internal decompression, which can also prolong the recurrence time. If the tumor involves more than two lobes of the cerebral hemisphere, but does not invade the basal ganglia, thalamus or the contralateral side, hemispherectomy can be performed. If the tumor is located in motor and speech area without obvious hemiparesis and aphasia, attention should be paid to maintain the neurological function to remove the tumor appropriately to avoid serious sequelae. Sub-temporal muscle or debridement decompression can be performed at the same time. Or, decompression can be performed after biopsy only. If the thalamus tumor compresses and obstructs the third ventricle, shunt can be performed, otherwise decompression can also be performed. Ventricular tumor can be removed from the non-important functional area to enter the ventricle according to the location of the tumor, so as to remove the tumor and relieve the ventricular obstruction. Care should be taken to avoid damaging the hypothalamus or brainstem adjacent to the tumor to prevent danger. Except for small nodular or cystic tumors, brain stem tumors can be resected, and those with increased intracranial pressure can be shunted. If the tumor is difficult to be resected, shunt can also be performed. For those who are in critical condition, dehydration medication should be given to the supratentorial tumor first, and the diagnosis should be confirmed by examination as soon as possible, and then surgery should be performed immediately. Posterior cranial fossa tumors can be treated by ventricular drainage first, and then surgery after 2~3 days when the condition improves and stabilizes. The radiation sources used for external irradiation are high-voltage x-ray therapy machine, gamma knife, electron gas pedal and so on. The latter two are high-energy rays with strong penetrating power, low skin dose, low bone absorption and low bypass scattering. The gas pedal, on the other hand, concentrates the dose at the expected depth, beyond which the dose drops sharply, and protects the normal brain tissue behind the lesion. Radiation therapy is recommended as early as possible after the recovery of general condition after surgery. Radiation therapy for glioma is generally given at a dose of 5,000-6,000 cGy for glioma and is completed within 5-6 weeks. For those with high sensitivity to radiation therapy in large irradiation fields, such as medulloblastoma, 4000-5000 cGy can be given. The sensitivity of various types of gliomas to radiation therapy varies. It is generally considered that poorly differentiated tumors are more sensitive than well differentiated ones. Medulloblastoma is the most sensitive to radiotherapy, followed by ventriculoblastoma. Glioblastoma multiforme is only moderately sensitive, and astrocytoma, oligodendroglioma, and pineal cell tumor are even worse. For medulloblastoma and ventricular meningioma, whole spinal canal irradiation should be included because they are easily disseminated with cerebrospinal fluid. Chemotherapy for glioma Chemotherapeutic drugs with high lipolytic properties that cross the blood-brain barrier are suitable for cerebral gliomas. In astrocytoma grade III-IV, the blood-brain barrier is destroyed due to edema, allowing water-soluble large molecules to pass through, so some people think that the selection of drugs can be expanded to many water-soluble molecules. However, in fact, the blood-brain barrier is not severely damaged in the peritumor area where proliferating cells are dense. Therefore, it is still appropriate to select drugs mainly with fat-soluble molecules.