The efficacy of stereotactic radiosurgery in the management of intracranial ependymoma

Objective: A retrospective analysis was performed to determine the outcome of patients with intracranial ependymoma treated with stereotactic radiosurgery (SRS). Methods: Nine ependymoma patients have been treated with SRS (four with linear accelerator and five with Gamma Knife) since 1990. Two patients had WHO grade III tumors, and the remaining seven had WHO grade II tumors. Eight of nine patients received external beam radiation therapy at some point prior to radiosurgery to a total median dose of 54 Gy. The radiosurgery dose ranged from 14 to 20 Gy. Results: The median follow-up was 28 months. The median age of patients at diagnosis was 35 years. Four patients developed progressive disease following radiosurgery, and two patients have died of progressive disease. The 3-year relapse-free survival was 55.6%. The 3-year overall survival was 71.1%. Patients treated with radiosurgery as a component of initial treatment (generally as a boost following external beam) had an improved relapse-free survival (100%) compared to those treated with radiosurgery to salvage an external beam local failure (20%). Conclusion: SRS is an effective treatment for intracranial ependymoma. Further clinical trials are warranted incorporating radiosurgery as a component of initial management in selected ependymoma patients.