Intracranial ependymomas: an analysis of prognostic factors and patterns of failure

From 1965 to 1997, 49 patients were diagnosed and treated for intracranial ependymoma at one institution. Tumor location was infratentorial in two thirds, and pathology was low grade in 38 patients (78%). Gross total resection of the primary tumor was achieved in 21 (43%). Thirty-six patients received adjuvant radiotherapy; the entire neuraxis was treated in 14, whole brain in 10, and local field only in 12. Median follow-up was 9.6 years (range, 2-33 years). The 5-, 10-, and 15-year overall survival rates were 71.4%, 63.5%, and 63.5% for craniospinal radiotherapy, 60.0%, 60.0%, and 40.0% for whole brain radiotherapy, and 80.8%, 64.6%, and 64.6% for local field radiotherapy (p = 0.88). The 5-, 10-, and 15-year local control rates were 60.3%, 54.4%, and 48.9%. The prognostic factors for a better local control rate were gross total resection (p = 0.021) and low grade histology (p = 0.031). Seventeen of 43 (39.5%) M0 patients did not respond to treatment; all had local failure and 4 also had a spinal relapse. Spinal relapse developed in 3 of 31 (10%) M0 patients who did not receive spinal radiotherapy, whereas 1 of 12 (8%) who had spinal radiotherapy did not respond to treatment in the spine. The results of this study indicate that local radiotherapy is sufficient for M0 patients with intracranial ependymoma.