Abstract
PURPOSE: To identify risk factors associated with incomplete neurological recovery in pediatric patients with infratentorial ependymoma treated with postoperative conformal radiation therapy (CRT). METHODS: The study included 68 patients (median age +/- standard deviation of 2.6 +/- 3.8 years) who were followed for 5 years after receiving CRT (54-59.4 Gy) and were assessed for function of cranial nerves V to VII and IX to XII, motor weakness, and dysmetria. The mean (+/- standard deviation) brainstem dose was 5,487 (+/-464) cGy. Patients were divided into four groups representing those with normal baseline and follow-up, those with abnormal baseline and full recovery, those with abnormal baseline and partial or no recovery, and those with progressive deficits at 12 (n = 62 patients), 24 (n = 57 patients), and 60 (n = 50 patients) months. Grouping was correlated with clinical and treatment factors. RESULTS: Risk factors (overall risk [OR], p value) associated with incomplete recovery included gender (male vs. female, OR = 3.97, p = 0.036) and gross tumor volume (GTV) (OR/ml = 1.23, p = 0.005) at 12 months, the number of resections (>1 vs. 1; OR = 23.7, p = 0.003) and patient age (OR/year = 0.77, p = 0.029) at 24 months, and cerebrospinal fluid (CSF) shunting (Yes vs. No; OR = 21.9, p = 0.001) and GTV volume (OR/ml = 1.18, p = 0.008) at 60 months. An increase in GTV correlated with an increase in the number of resections (p = 0.001) and CSF shunting (p = 0.035); the number of resections correlated with CSF shunting (p < 0.0001), and male patients were more likely to undergo multiple tumor resections (p = 0.003). Age correlated with brainstem volume (p < 0.0001). There were no differences in outcome based on the absolute or relative volume of the brainstem that received more than 54 Gy. CONCLUSIONS: Incomplete recovery of brainstem function after CRT for infratentorial ependymoma is related to surgical morbidity and the volume and the extent of tumor.