Introduction: Stereotactic radiosurgery (SRS) is a potentially important option for patients with intracranial ependymoma. We analyzed the outcomes of intracranial ependymoma patients who underwent SRS as a part of multimodality management.
Methods: Four participating centers of the International Gamma Knife Research Foundation (IGKRF) identified 74 patients who underwent SRS for 95 intracranial ependymomas. The median patient age was 21 years (range, 1.8-80). All patients had previous surgical resection of their ependymomas, 64 had previous fractionated radiation therapy, and 26 had previous chemotherapy. Forty-three patients had low-grade ependymomas (53 tumors) and 31 patients had high-grade ependymomas (42 tumors). The median radiosurgery target volume was 3.7 cc (range, 0.03-36.8) and the median margin dose was 15 Gy (range, 10-22).
Results: At a median follow-up of 23 months after SRS (range, 3.3-220), 37 patients died. The overall survival after SRS was 77% at 1 year, 60% at 2 years, 52% at 3 years, and 45% at 5 years. The progression-free survival after SRS was 75% at 1 year, 65% at 2 years, 53% at 3 years, and 47% at 5 years. Factors associated with better PFS included low-grade ependymoma (p=0.021) and higher margin dose (p=0.013). The distant tumor relapse rate after SRS was 17% at 1 year, 26% at 2 years, 37% at 3 years, and 40% at 50 years. Symptomatic adverse radiation effects developed in 9 patients (12%).
Conclusions: SRS provides another management option for patients with intracranial ependymomas that have failed surgery and radiation therapy.
Patient Care: This research provides further insight into the use of stereotactic radiosurgery for patients with intracranial ependymomas.
Learning Objectives: By the conclusion of this session, participants should understand risks and benefits of stereotactic radiosurgery for intracranial ependymomas.