Radiation therapy has been a cornerstone of cancer management for many decades 
and is an integral part of the multi-modality care of patients with brain 
tumors. The known serious side effects of radiation therapy on the head or 
central nervous system are uncommon and include radiation necrosis, 
microangiopathy, and progressive leukencephalopathy. In addition, there have 
been descriptions of radiation-induced tumors including sarcomas, gliomas, 
lymphomas, and carcinomas of the thyroid. Patients who have received radiation 
therapy of the head or face may rarely develop radiation-induced tumors, a 
majority of which are meningiomas, followed by radiation-induced gliomas (RIGs) 
and sarcomas. The increased risk of RIGs is well described in both the pediatric 
and adult populations and after the use of both therapeutic and diagnostic 
radiations. The incidence of RIGs is estimated at approximately 0.5-2.7% at a 
latent period of approximately 15 years. The risk appears to be dependent on 
patient age at treatment, as well as radiation dose and treatment volume 
considerations. The scope of this review focuses on the etiology, clinical 
features, and management of RIGs as they relate to previous radiation therapy.