Radiation-induced gliomas.

Radiation-induced gliomas represent a relatively rare but an extensively published entity in the neuro-oncologic literature. Extensive retrospective cohort data in pediatric populations after therapeutic intracranial radiation show an increased risk in glioma incidence that is both patient age- and radiation dose/volume-dependent. Data in adults are more limited but show heightened risk in certain groups exposed to radiation. In both populations, there is no statistically increased risk associated with routine exposure to diagnostic radiation. At the molecular level, there are conflicting data concerning whether distinct genetic differences between radiation-induced gliomas and their spontaneously occurring counterparts exist. Clinically, there is understandable reluctance on the part of clinicians to re-treat patients owing to concern for cumulative neurotoxicity. However, available data suggest that aggressive intervention can lead to improved outcomes in patients with radiation-induced gliomas.