Quantitative Analysis of the Effect of Stereotactic Radiosurgery for Postoperative Residual Cervical Dumbbell Tumors: A Multicenter Retrospective Cohort Study

Abstract

Objective: Stereotactic radiosurgery (SRS) has been performed for spinal tumors. However, the quantitative effect of SRS on postoperative residual cervical dumbbell tumors remains unknown. This study aimed to quantitatively evaluate the efficacy of SRS for treating postoperative residual cervical dumbbell tumors. Methods: We retrospectively reviewed cases of postoperative residual cervical dumbbell tumors from 1995 to 2020 in 2 tertiary institutions. Residual tumors underwent SRS (SRS group) or were observed with clinical and magnetic resonance imaging (MRI) follow-up (observation group). Tumor regrowth rates were compared between the SRS and observation groups. Additionally, risk factors for tumor regrowth were analyzed. Results: A total of 28 cervical dumbbell tumors were incompletely resected. Eight patients were in the SRS group, and 20 in the observation group. The mean regrowth rate was not significantly lower (p = 0.784) in the SRS group (0.18 ± 0.29 mm/mo) than in the observation group (0.33 ± 0.40 mm/mo). In the multivariable Cox regression analysis, SRS was not a significant variable (hazard ratio [HR], 0.57; 95% confidence interval [CI], 0.18–1.79; p = 0.336). Conclusion: SRS did not significantly decrease the tumor regrowth rate in our study. We believe that achieving maximal resection during the initial operation is more important than postoperative adjuvant SRS. © 2024 by the Korean Spinal Neurosurgery Society.