High dose radiation induced meningioma.

Radiation therapy has played an important integral part in the management of various intracranial rumours. However, radiation has been implicated in the development of intracranial tumours. We describe three cases of radiation-induced meningiomas following high dose cranial irradiation. All these patients developed tumours within the previous radiation field and satisfied the criteria used for the definition of radiation-induced neoplasm. The interval between the irradiation and the onset of meningioma was significantly less in the younger patient. All the cases had several unique features of radiation-induced meningioma including features of atypical meningioma. Two patients developed multiple site meningiomas and one patient developed early recurrence of the tumour. This report confirms that patients exposed to cranial irradiation are at lifelong risk of developing radiation-induced tumours such as meningiomas. Hence these patients require long-term clinical and radiological surveillance to detect occurrence as early as possible.