Intracranial meningiomas following irradiation--a growing problem?

Area of Science:

• Neuro-oncology
• Radiation oncology
• Pathology

Background:

• High-dose irradiation for intracranial tumors is a known risk factor for secondary neoplasms.
• Meningiomas are the most common primary tumors of the central nervous system, with a subset arising after radiation exposure.

Purpose of the Study:

• To investigate the clinical and pathological characteristics of meningiomas that develop after high-dose cranial irradiation.
• To compare radiation-induced meningiomas with spontaneous meningiomas and review existing literature on radiation-induced meningiomas.

Main Methods:

• Retrospective analysis of 10 cases of post-irradiation meningiomas.
• Comparison of clinical and pathological features with 262 spontaneous meningiomas from the same institution.
• Literature review of 69 previously reported radiation-induced meningiomas and 119 low-dose radiation-induced cases.

Main Results:

• Post-irradiation meningiomas represented 3.7% of all meningiomas treated.
• Malignant histological features and tumor multiplicity were significantly more common in radiation-induced meningiomas (p < 0.01).
• Increased long-term survival after radiotherapy may contribute to a rising incidence of post-irradiation meningiomas.

Conclusions:

• High-dose irradiation for brain tumors increases the risk of developing secondary meningiomas.
• Radiation-induced meningiomas exhibit distinct pathological characteristics, including higher rates of malignancy and multiplicity.
• Improved survival rates for primary brain tumors may lead to an increased occurrence of these secondary tumors.