PT-01 * THE IMPACT OF INITIAL RADIATION IN INFANTS AND THE RE-IRRADIATION OF RECURRENT DISEASE ON THE SURVIVAL OF EPENDYMOMA PATIENTS AT THE HOSPITAL FOR SICK CHILDREN, TORONTO

Abstract

BACKGROUND: Two significant changes in the management of ependymoma have taken place since 1990 at The Hospital for Sick Children, Toronto; the up-front irradiation of infants and the re-irradiation of recurrent disease. This study retrospectively reviews the impact of these changes on survival. METHODS: A retrospective case note analysis of children treated for ependymoma between 1990 and 2014 was undertaken. Survival was determined using the Kaplan Meier method. RESULTS: 76 ependymoma patients were identified with a median age of 4.58 years (0.42-17.6) including 31 infants < 3 years old (median age 1.51 years (0.42-2.97)). 45 (59.2%) were male and 31 (40.8%) were female. The majority (56 (73.7%)) were grade III histology and most (56 (73.7%)) were located within the posterior fossa. The median progression free survival (PFS) and overall survival (OS) was 41 months (95% CI 20.4-61.7) and 116 months (95% CI 63.5-169.4) respectively. 5 year PFS and OS were 43.3% and 59.3% respectively. 21 infants received up-front radiation and 10 received chemotherapy only. 5 year PFS and OS were significantly higher in irradiated compared to non-irradiated infants (PFS: 52.9% versus 0% (p = 0.000002), OS: 74.6% versus 30.0% (p = 0.004)). 38 patients recurred of which 26 were previously irradiated.19 patients received re-irradiation on recurrence whereas 7 did not. 5 year OS was significantly higher in the re-irradiated patients at 71.8% compared to 0% in the non re-irradiated patients (p = 0.00007). Both management strategies were consistently implemented from 2004. Patients treated pre (n = 34) and post (n = 42) 2004 showed a significant improvement in 5 year PFS from 33.4% to 53.3% (p = 0.037) and OS from 51.2% to 79.2% (p = 0.02). CONCLUSIONS: Both radiation of infants as the initial management of ependymoma and re-irradiation of recurrent ependymoma significantly improve survival. Implementing these treatment strategies has resulted in significant improvement in progression free and overall survival for ependymoma patients.