Management of Pediatric Myxopapillary Ependymoma: The Role of Adjuvant Radiation

Abstract

Myxopapillary ependymoma (MPE) is a distinct entity most frequently presenting in the lumbosacral region of the spinal cord. This tumor is rare in children with the majority of publications and treatment recommendations based on adult patients. The primary treatment of choice is gross total resection (GTR) with no clearly defined role for adjuvant radiation therapy. Published reports suggest that children with MPE present with a more aggressive disease course with higher rates of both local failure and distant metastasis. The goal of this study is to assess the role of adjuvant radiation therapy (RT) in pediatric myxopapillary ependymoma. Sixteen pediatric patients with histologically confirmed myxopapillary ependymoma seen at Johns Hopkins Hospital between November 1984 and December 2010 were retrospectively reviewed. Fifteen boys and one girl with a median age of 16.5 years (range 12 - 21 years) were initially identified of whom fifteen patients were evaluable. Descriptive statistics were used for analysis. All patients received surgery as the initial treatment modality. Five patients received surgery alone and 10 patients received RT given as either adjuvant therapy or as salvage at the time of recurrence. The median total dose of radiation was 50.4 Gy (range 48.6 - 54 Gy) delivered to the involved field. After a median follow up of 8.4 years (range 0.3 - 26.2 years), all patients in this study were alive with stable disease. 50% of patients receiving surgery alone were progression-free at 5 years compared to 66.7% receiving RT. Patients treated with surgery alone had a median progression-free survival (PFS) of 3.5 years compared to patients treated with adjuvant RT who had a median PFS of 8.8 years. Specifically, patients treated with GTR had a median PFS of 4 years compared to a median PFS of 7.1 years in patients treated with GTR and RT. Of the patients receiving surgery alone, 43% developed local recurrence. In contrast, no patient who received adjuvant RT failed locally. Two patients treated with RT experienced grade 2 toxicity and four reported grade 1 toxicity. No late toxicity was reported at last follow-up. Neurologic symptoms either improved or remained stable following surgery and/or radiation in all patients. The results of this study demonstrate that adjuvant RT can improve local control and progression free survival compared to GTR alone. Adjuvant RT should be considered following surgical resection in pediatric patients with myxopapillary ependymoma.