For malignant gliomas ((grade III and IV) such as glioblastoma, mesenchymal astrocytoma and mesenchymal oligodendroglioma, radiotherapy should be given as early as possible after good blood and liver and kidney functions and good healing of the incision after surgery, usually within 2 weeks after surgery. Some family members and patients worry that radiotherapy will affect the recovery of the body after the surgery when the body has just undergone a blow. This worry is superfluous. First of all, the latest radiotherapy is conformal intensity modulated radiotherapy, the radiation area is only 3cm outside the tumor area, which has very little effect on the body; in addition, the tumor cells hidden in the brain tissue will proliferate quickly after surgery, so if radiotherapy is not given as soon as possible, the tumor will recur soon. If some patients do not hurry up the treatment, the tumor will return to the preoperative size in less than a month after surgery. Therefore, some patients and family members with good intentions may not necessarily do a good thing, but delay the best time for patient treatment and affect the efficacy, and even need to operate again soon to remove the tumor, so that the patient will experience the risk of secondary surgery and suffer more pain that is not necessary. The US NCCN guidelines recommend a total radiation dose of 60 Gy for malignant glioma, divided into 1.8-2 Gy/dose. For patients >70 years of age who require assistance in living, the radiation dose can be reduced: 40Gy divided into 15 sessions or 50Gy divided into 28 sessions. Whole brain radiotherapy and gamma knife radiotherapy are not recommended.