EPN-29: THE ROLE OF RADIOTHERAPY IN PEDIATRIC EPENDYMOMAS - BEYOND ADJUVANT TREATMENT

BACKGROUND: Ependymomas are the third most common tumor diagnosed in children. Our aim is to report extended follow-up of children with ependymoma submitted to radiotherapy. METHODS: We have retrospectively analyzed all ependymoma diagnosed children in our unit submitted to Radiotherapy between January 1988 and October 2015. Overall survival and event-free survival was obtained by Kaplan-Meier survival estimates. RESULTS: We obtained a total of 35 patients submitted to radiotherapy. All patients had surgery as previous treatment, with complete resection in 24 patients (69%) and partial resection in 11 patients (31%). Median prescribed dose was 54Gy (50 to 59.4Gy) to tumor bed. Median time of follow-up was 7 years (0.6 to 27 years), 11 (31%) patients had local recurrence and 4 (11%) had distant recurrence. The median overall survival was 6.5 years. The 5 years overall survival was of 81.2% (IC 95%: 68.6 - 96.1 %) and the 5 years event-free survival of 53.1% (IC 95%: 38.8 - 74.1%). From the patients with recurrent disease, 6 patients were submitted to re-irradiation. The median prescribe dose was 54Gy to tumor boost. These selected patients had a median overall survival of 1 year after re-irradiation treatment (1-year OS: 57% - IC 95%: 30 - 100%). CONCLUSIONS: Postoperative irradiation is the standard adjuvant therapy after resection of ependymoma due to its improvement in local control as well as in overall survival. Re-irradiation is an option for recurrent patients although durability of disease control and long-term effects require further follow-up and the establishment of guidelines.