Re-irradiation of locally recurrent pediatric intracranial ependymoma: Experience of the French society of children's cancer.

Purpose: This study aimed to evaluate retrospectively the clinical results of re-irradiation for children with a locally recurrent brain ependymoma.

Methods: 33 full-dose re-irradiations were delivered to 31 children with a recurrent brain ependymoma after a standard treatment. Each child was followed up with clinical and MRI examinations. We evaluated overall survival, local recurrence free-survival and short term toxicity according to CTCAE 4.0 scale.

Results: With a median follow-up of 37 months (range, 0 to 107), median local recurrence free-survival was 31 months (range, 2 to 63) and median overall survival was 34 months (range, 3 to 63). It was significantly higher in patients who underwent surgery first, compared with re-irradiation only. Cumulated dosimetric data were available for 22 patients. On average, maximal BED to brain stem was 106,2 Gy (±35,4) for infratentorial re-irradiation. No acute toxicity grade >2 was reported and 1 case of brain radionecrosis treated successfully with steroids was reported after radiosurgery.

Conclusion: Local recurrence of brain ependymoma can be treated with full-dose re-irradiation, which can be hypofractionated with an acceptable short term toxicity in spite of high total doses delivered to OARs, especially brain stem.