Factors associated with neurological recovery of brainstem function following postoperative conformal radiation therapy for infratentorial ependymoma.
OBJECTIVE
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.
Merchant
Thomas E
TE
Department of Radiological Sciences, St. Jude Children's Research Hospital, Memphis, Tennessee 38105-3678, USA. thomas.merchant@stjude.org
Chitti
Ramana M
RM
Li
Chenghong
C
Xiong
Xiaoping
X
Sanford
Robert A
RA
Khan
Raja B
RB
D001933:Brain Stem / Q000503:physiopathology / Q000528:radiation effects*; D002557:Cerebrospinal Fluid Shunts; D002675:Child, Preschool; D018572:Disease-Free Survival; D004806:Ependymoma / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015192:Infratentorial Neoplasms / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery; D008297:Male; D011183:Postoperative Complications / Q000209:etiology / Q000503:physiopathology; D011446:Prospective Studies; D011836:Radiation Tolerance; D020266:Radiotherapy, Conformal; D020127:Recovery of Function / Q000502:physiology / Q000528:radiation effects*; D012044:Regression Analysis; D012086:Reoperation; D012307:Risk Factors; D012737:Sex Factors; D047368:Tumor Burden