6. Proton Beam Therapy For Patients With Intracranial Ependymoma Under 3 Years Old: Initial Clinical Outcomes

Abstract BACKGROUND Proton beam therapy (PBT) provides dosimetric benefits in sparing normal tissue when treating pediatric patients with brain tumors. We report the preliminary clinical outcomes of surgery and adjuvant PBT for patients under 3 years old diagnosed as intracranial ependymoma at our institute. METHODS This is a retrospective review of the medical records for 3 children with ependymoma in the fourth ventricle, diagnosed between March 2013 and September 2019. PBT was performed after tumor resection in all the patients. RESULTS Gross total resection was achieved in 2 males and 1 female patients with fourth ventricle WHO grade II to III ependymoma at 15, 18, and 37 months old. All the patients received adjuvant PBT (54.0 GyE/30 fractions) to the postoperative tumor bed under general anesthesia or sedation. PBT was acutely well tolerated, with mostly mild alopecia and skin reactions at the irradiated sites. At a median follow-up of 54 months (4–59 months) after irradiation, all the patients are alive without recurrence. No serious late adverse events were observed in any of the patients. CONCLUSION The number of patients in this study remains small for drawing any definite conclusion, however our preliminary results are still encouraging. Further studies of a large number of pediatric patients with long term follow-up are needed to more fully assess tumor control and late adverse events.