Fluorescein Sodium Use during Spinal Ependymoma Resection

Abstract

Spinal ependymomas (SEs) are common adult intramedullary tumors; however, determining the absolute boundary between the tumor and the tumor residual may be difficult. We assessed outcomes following the use of fluorescein sodium (FS) during surgical removal of SEs. We performed a retrospective analysis of 112 patients with SEs who were treated at Beijing Tsinghua Changgung Hospital between December 2014 and December 2016. Each patient received intravenous FS (3-4 mg/kg) to determine the SE boundaries during surgery. Tumor removal efficiencies and tumor residuals were assessed using magnetic resonance imaging (MRI) at 10 days and 3 months after surgical recovery; McCormick's spinal function classification was also performed at the 3-month follow-up. The complete tumor removal rate was 92% (103/112). Ninetyfour patients underwent tumor removal under fluorescent light, which provided distinctive tumor fluorescence. Tumor removal under white light was performed in 18 patients; fluorescent images were invisible or indistinctive in these 18 patients. At the 3-month follow-up, sensory function (85.8% (91/106)) and movement (84.3% (86/102)) were improved in patients with pre-surgical dysfunction; urination and defecation functions were improved in 66.7% (16/24). The McCormick spinal cord functional classifications, at the 3-month follow-up, showed significant differences in the percentages of patients with disease classified to each grade (I-IV), compared with preoperative classifications (each, P < 0.05). There was no MRI evidence of tumor relapse or residuals at the 3-month follow-up. FS use during the surgical treatment of SE enables complete tumor removal and detection of tumor residuals.