Clinical outcomes of radiotherapy for spinal cord ependymoma with adverse prognostic features: a single-center study

Purpose: This study evaluated the outcomes of radiotherapy (RT) for spinal ependymoma with adverse features, such as incomplete resection or disseminated disease. Methods: Twenty-five patients underwent RT for spinal cord ependymoma during 1991–2016. Twenty-four patients had gross disease on the pre-RT spinal magnetic resonance images. Six patients (24%) had disseminated disease. The World Health Organization grades were I (12 patients), II (12 patients), and III (1 patient). The RT fields were the tumor bed plus margin in 19 patients (76%), the entire craniospinal axis in 5 patients (20%), and the entire spinal canal with posterior cranial fossa in 1 patient (4%). The median RT dose was 50.4 Gy (range 44.0–59.4 Gy). Results: The median follow-up was 49 months (range 9–321 months), with 5-year overall and progression-free survival rates of 83.7% and 70.8%, respectively. Relative to patients with grade II/III ependymoma, patients with grade I ependymoma had higher 5-year rates of overall survival (100% vs. 69.4%, P =.088) and progression-free survival (100% vs. 42.3%, P =.02). Disease progression was observed in 4 patients who had grade II ependymoma, including 2 of 6 patients with disseminated disease and 2 of 19 patients with localized disease. Twelve patients (48%) exhibited improved neurological function. One patient who underwent craniospinal irradiation developed late hypopituitarism. No other RT-related late toxicities were observed. Conclusions: Favorable survival outcomes were achieved using RT for spinal ependymoma with adverse prognostic features. Thus, RT may be an effective treatment option when complete tumor removal cannot be achieved.