INTRACRANIAL EPENDYMOMA LONG-TERM OUTCOME, PATTERNS OF FAILURE

We analyzed 31 patients with intracranial ependymoma, all verified by secondary neuropathology review. There were 12 patients with ependymomas and 19 patients with anaplastic ependymoma by the WHO classification. Eight patients received craniospinal irradiation, 22 patients received cranial irradiation alone, and one patient was treated with chemotherapy alone. The median follow-up time was 11 years. The 5- and 10-year progression-free survivals (PFS) were 60% and 48%. Those with anaplastic tumors had a decreased 10 year PFS over those with low grade lesions: 26% vs. 55% (p = 0.02). Delivering spinal irradiation in addition to cranial irradiation did not improve outcome. There were relapses in 16 patients. All patients relapsed at the primary intracranial sites with no spinal failures. Patients treated with whole brain irradiation had decreased 10 year PFS over those treated with local fields: 19% vs. 64% (p = 0.006). Those patients treated to greater-than-or-equal-to 50 Gy had an improved long-term PFS (p = 0.04). Multivariate analysis was undertaken with the following variables: extent of cranial irradiation, pathology, anatomic site of ependymoma, cranial irradiation dose, extent of surgery, and whether spinal irradiation was given. With PFS as the endpoint, only extent of cranial irradiation (favoring local fields) and pathology (favoring low grade ependymoma) were significant prognosticators. We conclude that carefully outlined local field irradiation is the therapy of choice, and elective spinal irradiation is of questionable benefit.