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.