Predictive Clinical and Imaging Factors for Conservative versus Operative Management of Spinal Schwannomas and Meningiomas: A Retrospective Study

Introduction The paucity of research concerning the conservative management of spinal cord and cauda equina schwannomas and meningiomas complicates the determination of surgical necessity and its optimal timing. This study aimed to elucidate the clinical and imaging characteristics of schwannomas and meningiomas in the thoracolumbar and lumbar spine that support long-term conservative management strategies. Methods A retrospective case series of 159 patients with magnetic resonance imaging-confirmed schwannomas or meningiomas was conducted. Patients were categorized into operative (n=125) and conservative (n=34) groups based on whether surgery was performed within one year of diagnosis. Tumor characteristics, clinical symptoms, and imaging data were systematically analyzed. Tumor occupancy was modeled using an ellipsoidal formula to estimate spinal canal involvement. A receiver operating characteristic curve analysis determined the optimal cutoff for predicting treatment decisions. Multivariate logistic regression was employed to identify factors influencing treatment choice. Results Tumor occupancy emerged as a critical determinant, with a cutoff of 0.42 predicting treatment choice with a sensitivity of 0.79 and a specificity of 0.89 (area under the curve=0.87). Logistic regression analysis revealed significant associations for tumor occupancy (adjusted odds ratio [OR]=9.6×10-5; 95% confidence interval [CI]=6.2×10−7-5.3×10−3; p<0.001), presence of numbness or leg pain (OR=0.022; 95% CI=9.8×10−4-0.18; p=0.002), and male gender (OR=0.19; 95% CI=0.038-0.83; p=0.037). No significant associations were observed for age, decreased manual muscle testing, or imaging heterogeneity. Conclusions Prolonged conservative management is feasible for female patients who do not have leg pain or numbness and tumors with low occupancy. A tumor occupancy threshold of 0.42 may serve as a valuable clinical indicator to guide treatment decisions, promoting individualized, symptom-driven management strategies tailored to patient characteristics.