Predictors of Functional Outcome after Spinal Ependymoma Resection

Spinal ependymomas are among the most common intramedullary neoplasms in both adults and children. While surgical resection is the golden treatment standard, the role chemotherapy and radiotherapy have in patients with spinal ependymomas remains unclear. The aim of this study is to determine the predictors of functional outcome following spinal ependymoma resection to single out patients that may require adjuvant therapy.

We conducted a retrospective study on patients that underwent spinal ependymoma resection in our institution in a 10-year period. Magnetic resonance imaging of the spine was used to set the diagnosis of an intradural/intramedullary neoplasm. All patients underwent either gross tumor resection or tumor mass reduction. Histological diagnosis and histopathological grading of spinal ependymoma were done for all collected samples. Patients' general and neurological examination were performed early after the surgery (within the 1^st week) and in a 6-month follow-up.

A total of 51 intradural and intramedullary ependymoma resection surgeries on 43 patients were performed. There were slightly more male patients (57%) and the average patient age was 41 years. About 76.5% of patients presented with a tumor affecting one vertebrae level, while 23.5% presented with tumors expanding over two or more spinal regions. Gross tumor resection was achieved in 80% of cases, while 25% of procedures were performed on a recurring ependymomas. Most of the tumors (57%) were classified as G2 histological grade, while 8% were anaplastic ependymomas. In 80% of cases, early postoperative patient status was either better or equivalent to the preoperative one, while in a 6-month follow-up, up to 60% of cases showed a significant improvement over the preoperative status. Different demographic and clinical parameters were not proven to be predictors of postsurgical patient outcome including age, gender, and initial neurological presentation. Interestingly, most tumor characteristics were also not associated with postoperative functional outcome (histological grade, number of vertebrae levels affected, whether it is a primary or recurrent tumor). Even the scope of surgical procedure did not affect the functional outcome. The spinal region affected by the tumor was proven to be a predictor of early postoperative outcome (ρ= 0.346, P = 0.033), with lumbar spine being associated with the best outcomes. As expected, the scope of the surgery and whether gross tumor resection or tumor mass reduction was performed were the only significant predictors of tumor recurrence (ρ= 0.391, P = 0.005).

Spinal ependymoma resection is an efficient procedure that improves the patient outcomes. Spinal region affected by the tumor is likely to be the most important predictor of functional outcome, while the procedure scope seems to be the most important predictor of tumor recurrence.