Outcomes After Reirradiation for Recurrent Pediatric Intracranial Ependymoma

Outcomes After Reirradiation for Recurrent Pediatric Intracranial Ependymoma
This is a retrospective review of 101 children aged up to 21 years treated with repeat irradiation for recurrent ependymoma. In the setting of disease recurrence, traditional dogma is that re-irradiation can lead to toxicity. In this study, the efficacy and safety of re-irradiation for patients with recurrent ependymoma was evaluated.
Retrospective review of patients treated between 1985 and 2017. Patients with localized, intracranial ependymoma treated with surgery followed by focal irradiation were included. Patients with recurrence were treated with repeat surgery, followed by either focal repeat irradiation (for those with local recurrence) or craniospinal irradiation followed by focal boost RT (for those with any distant recurrence).
For the entire cohort, 5-year overall survival (OS) was 57% and 5-year freedom-from-progression (FFP) was 37%. Patients with distant-only failure and treated with CSI had the best outcomes, with 5-year OS and FFP of 76% and 49%, respectively.
In a multivariable analysis, male sex and anaplastic recurrence were negative prognostic factors for both OS and FFP. Again, those with distant-only failure treated with CSI had the best outcomes, with a hazard ratio (HR) of 0.4 (versus local failure treated with focal RT).Gain of chromosome 1q was associated with poorer survival in the subgroup of patients with distant failure after first RT (HR 3.5). Administering CSI as part of re-irradiation reduces distant-only failures.10-year cumulative incidence of grade ≥3 radiation necrosis was low, at 7.9%.
This was a retrospective study and represents a lower level of evidence as compared with a prospective study. The study had some patients who received CSI for locally recurrent ependymoma. It is unclear why CSI was given for some cases and not for others.
Association of histological grade with outcome in this study may be a proxy for underlying molecular biology. Although the authors had relatively complete data on chromosome 1q gain and C11orf95-RELA fusion, they did not have methylation data to determine if these patients had Group A or B ependymomas.
Retrospective study showed re-irradiation of children with recurrent ependymoma is effective without severe toxicity, particularly those with distant failures who received CSI. Further evaluation of re-irradiation will be done in upcoming prospective studies. (St. Jude re-irradiation study for ependymoma in progress (ClinicalTrials.gov identifier NCT02125786)