RO-23RECURRENT EPENDYMOMA A CHALLENGING THERAPY: RE-IRRADIATION PROLONGS SURVIVAL IN FAILURE OF RADICAL RESECTION

RO-23. RECURRENT EPENDYMOMA A CHALLENGING THERAPY: RE-IRRADIATION PROLONGS SURVIVAL IN FAILURE OF RADICAL RESECTION Stephan Tippelt1,RuthMikasch1,Monika Warmuth-Metz5,Torsten Pietsch7, Robert Kwiechien3, Andreas Faldum3, Stefan Rutkowski2, Katja Von Hoff2, Martin Mynarek2, Udo Bode4, Nele Siegler1, Gudrun Fleischhack1, and Rolf-Dieter Kortmann6; University Hospital Essen, Pediatric Hematology and Oncology, Essen, Germany; University Hospital Hamburg, Pediatric Hematology and Oncology, Hamburg, Germany; University Munster, Institute of Biostatistics and Clinical Research, Munster, Germany; University of Bonn, Childrens Hospital, Pediatric Hematology and Oncology, Bonn, Germany; University of Wuerzburg, Neuroradiology, Wurzburg, Germany; University of Leipzig, Department of Radiotherapy and Radioonkology, Leipzig, Germany; University of Bonn, Medical Center, Institute of Neuropathology, Bonn, Germany INTRODUCTION: In pediatric patients with ependymoma the 10-year overall survival (OS) rate is 64% with poor 5-year OS rates of only 42-55% in infancy. Beside maximal radical resection local radiotherapy is standard of care; chemotherapy is controversially discussed. In recurrence treatment options are rare. Re-resection with maximal radical intense is indicated in local relapses. In unresectable or metastatic disease longterm prognosis is fatal. Merchant et al. and others showed prolonged OS rates after re-irradiation even in metastatic disease. PATIENTS AND METHODS: From 55 patients of the German HIT2000 and HIT-REZ study cohort with recurrent ependymomaswhoreceivedre-irradiationdataasage; stageofdisease; time and extent of surgery; time, dose and volume of radiotherapy; time and kind of chemotherapy at primary diagnosis and relapse; date and disease state at last follow up and causes of death were analyzed. OS time was estimated based on Kaplan–Meier-analysis and compared to a cohort of 40 patients without re-irradiation. RESULTS: The 55 patients (74% male) with a median age at primary diagnosis/first recurrence of 5.4/8.4 years showed metastatic disease at recurrence in 47% and a median time to first progression of 22 months. Median OS after first relapse was 31 (CI 21-41) months with 5-year-OS rate of 33%. In comparison to the cohort without re-irradiation significant better 5-year-OS rate was observed in patients with residual tumor at time of re-irradiation (40 vs. 8%). CONCLUSION: Re-irradiation can lead to prolonged survival if radical surgery is impossible and is highly recommended in these cases. Neuro-Oncology 18:iii159–iii164, 2016. doi:10.1093/neuonc/now082.23 #The Author(s) 2016. Published by Oxford University Press on behalf of the Society for Neuro-Oncology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.