The Effect of Initial Treatment Modality on Oncological Outcomes in Children with Ependymoma.

Aim: To evaluate the oncological outcomes and the prognostic factors for children with ependymoma who receive radiotherapy (RT) ± chemotherapy after surgery.

Material and methods: The medical records of 71 children with ependymoma who received RT between 2001 and 2022 were retrospectively evaluated. Survival outcomes and prognostic factors were analyzed using log-rank and cox-regression tests. SPSS v24.0 was utilized for statistical analyses.

Results: Gross total resection (GTR) was achieved in 37 (52%) patients. Craniospinal fluid (CSF) seeding was observed in 8 (11%) patients at the time of diagnosis. The median RT dose was 54 Gy (42-60 Gy). The median time from surgery to the first RT was 2.4 months (1-109 months). The median follow-up time was 65.9 months (2.5-242.8 months), and 5-y overall survival, progression-free survival (PFS), and local recurrence-free survival (LRFS) were 74%, 39%, and 46%, respectively. Recurrence was observed in 41 (58%) patients. Among patients who initiated treatment with chemotherapy, 5-y PFS and LRFS were higher in patients who received RT at the time of diagnosis than those who received RT at the progression (23% vs. 0%, p < 0.001 and 39% vs 0%, p < 0.001). In multivariate analysis, increased time from surgery to radiotherapy was found to be a poor prognostic factor for PFS.

Conclusion: Young age, less than GTR, large residual tumor volume, initiation of treatment with chemotherapy after surgery, and increased time from surgery to radiotherapy may deteriorate survival. RT should not be delayed until progression, even in young patients receiving chemotherapy.