Radiation-induced cerebral meningiomas. Case reports.

Two cases are presented of meningiomas following external cranial irradiation in which several features clearly indicate a causal relationship between radiotherapy and tumour development. In one patient multiple recurred meningioma was diagnosed 30 years after low-dose X-ray treatment of Tinea capitis; in the other patient the meningioma was diagnosed approximately 18 years after high-dose radiation therapy for astrocytoma. The features distinguishing radiation-induced meningiomas from other meningiomas are reviewed. The use of radiation therapy only in those cases in which there is clear evidence that it will have beneficial effects and that these effects will outweigh the risks is emphasized.