gms | German Medical Science

Objective: Microsurgical resection of spinal ependymomas is associated with considerable risk of postoperative neurological deterioration. Several factors were reported to be related to the risk of postoperative outcome. We aimed at developing a risk score for the prediction of functional outcome after microsurgery for spinal ependymoma.

Methods: All patients who underwent surgical resection of spinal ependymoma in our institution between 1990 and 2015 were eligible for this study. Different preoperative and early postoperative parameters were collected for the score construction. The study endpoint was the risk of functional dependence at 6 months after surgery defined as the modified McCormick Scale. Clinically relevant cutoffs were defined using the receiver operating characteristics analysis.

Results: Of 131 individuals (mean age: 45.6 [±16.7] years; 64 [48.9%] females) included in the final analysis, 38 cases (29%) showed poor outcome at 6 months after surgery. Based on the results of the univariate analysis, preoperative MMS, subtotal tumor resection, cranial tumor level on the spinal cord, tumor extension, intramedullary location, and WHO grading were included in the multivariate analysis. The final risk score consisted of the following independent predictors of poor outcome: preoperative MMS >1 (1 point), proximal tumor level at Th 10 and higher (1 point), and tumor extending over ≥3 vertebrae (1 point). The constructed score (0-3 points; Score for OUtcome Risk in Spinal Ependymoma [SOURSE]) showed high diagnostic accuracy for the prediction of functional dependency at 6 months after surgery (area under the curve [AUC]=0.883), which was superior as compared to preoperative MMS (AUC=0.798) and KPS (AUC=0.794). In particular, the patients scoring 0, 1, 2 and 3 points of the score showed poor outcome in 0%, 12.9%, 54.6% and 76.2% of the cases respectively.

Conclusion: The presented SOURSE score based on preoperative neurologic condition, tumor location and extension showed a high predictive value for early prognostication of postoperative outcome in patients undergoing microsurgery for spinal ependymoma. We recommend external validation of the proposed outcome score.