SURG-32. Spinal Cord Ependymomas: Surgical Techniques, Instrumentation Needs, and Outcomes– A Single Center Experience

Abstract BACKGROUND The cornerstone of spinal cord ependymoma (SPE) treatment is maximal safe resection, with gross total resection (GTR) often curative. However, no consensus exists regarding the role of adjuvant radiation therapy or posterior instrumentation. This study aimed to assess oncological outcomes in SPE and identify secondary predictors related to extent of resection (EOR), adjuvant radiation therapy and the need for spinal instrumentation METHODS We retrospectively reviewed patients who underwent surgery for SPE between 1992 and 2024, excluding myxopapillary ependymomas, subependymomas, tumors with intracranial extension, and cases with <3 months of follow-up. Primary outcomes were progression-free survival (PFS) and overall survival (OS), analyzed using Kaplan–Meier curves and Cox regression. Secondary analyses evaluated predictors of EOR and instrumentation using Firth-penalized logistic regression. Clinical, radiological, and intraoperative factors were assessed. A p-value <0.05 was considered significant. RESULTS We included 105 patients; mean age was 44.6 years, and 83.8% underwent GTR. Median PFS and OS were 59 and 61 months, respectively. Age >60, WHO grade 3 pathology, and subtotal resection (STR) were independent predictors of worse PFS. OS was independently associated with postoperative KPS >70 and GTR, and negatively associated with age >60. STR was significantly associated with a single polar cyst and prior radiation, while marginalization >180° on MRI favored GTR. STR showed no association with WHO grade, syrinx, or contrast-enhancement pattern. Instrumentation was associated with tumors at junctional segments but not with multilevel laminectomy. At two years, 92.4% of patients maintained Frankel grade D or E. CONCLUSIONS In SPE, GTR and postoperative KPS >70 are strong predictors of improved survival. Older age, STR, and WHO grade 3 are associated with worse PFS. Prior radiation impairs resectability. Preoperative MRI and intraoperative ultrasound (iUS) are valuable tools for optimizing surgical planning and outcomes.