Ependymomas of the filum terminale: The role of surgery and radiotherapy

BACKGROUND: Ependymomas of the filum terminale (EFT) form a specific and relatively uncommon subtype of spinal cord ependymomas. Most series in the literature are small, spanning a large time period. Up to date no consensus has been reached about the optimal treatment of these lesions. Some authors promote postoperative radiotherapy for all cases, others advocate postoperative radiotherapy only when a subtotal resection is performed or when metastasis are apparent. METHODS: We performed a retrospective analysis of 22 patients with an EFT (mean age at diagnosis of 35.6 years). RESULTS: In all patients (9/22) with lesions smaller than 4.5 cm no metastases were present and a complete resection could be obtained. No adjuvant radiotherapy was performed and at latest follow they had an excellent outcome. In our series, these initial tumor characteristics were more important regarding prognosis than either histology or treatment-related factors. For the larger tumors, total resection was obtained less frequently, more dissemination was diagnosed and a worse outcome was scored. Radiotherapy if indicated did lead to an acceptable disease control. CONCLUSION: In every case of EFT, an individual treatment protocol has to be outlined, but if an EFT is relatively small and can be resected completely, we would advocate to withhold radiotherapy.