Malignant tumors are one of the serious public health problems that threaten the survival time of human beings. They are prone to metastasis to distant organs and the central nervous system is one of the common target organs. As it is difficult for chemotherapeutics, targeted drugs and other macromolecules to pass through the blood brain barrier (BBB), local radiation therapy is often used for treating intracranial primary or metastatic tumors. However, whether it is whole brain radiation therapy (WBRT) or stereotactic body radiation therapy (SBRT), the choice of radiation dose is limited by the side effects of radiation therapy on the surrounding normal brain tissues. Radiation-induced brain injury (RBI) can further develop into radiation necrosis (RN) in the late stage. Bevacizumab is often effective against RBI by antagonizing vascular endothelial growth factor (VEGF), but it still cannot completely reverse RN. Emerging treatment options such as human pluripotent stem-cell transplantation have made it possible to reverse the process of RN.