[Radiation-induced meningiomas: analysis of 33 cases].

The latency period is shorter after radiotherapy (median 22 years compared to 52 years after X-ray epilation). Incidence of atypical and malignant meningiomas directly correlates with irradiation dose. Approximately equal incidence of radiation-induced meningiomas after X-ray epilation in women and men can indicate other mechanisms of development of these tumors in comparison with spontaneous ones. Radiotherapy is followed by occurrence of meningiomas within the irradiated area. These tumors are usually single. In case of X-ray epilation, the tumors may be localized anywhere within the intracranial space (convexital and/or parasagittal localization in 77% of cases). Multiple neoplasms occur in 42% of cases. Refusal of head X-ray epilation for the treatment of a ringworm for the last 50 years may be followed by reduced incidence of radiation-induced meningiomas, especially multiple ones. However, extended indications for radiotherapy of various brain diseases can result an increase of the incidence of meningiomas within the irradiated area.