Third Recurrent World Health Organization 1 Spinal Meningiomas: Case Series and Clinical Outcomes Following Surgery or Definitive Radiotherapy

Background: Spinal meningiomas (SMs) are rare, predominantly benign tumors that account for 1.2%–12.7% of all meningiomas. While surgical resection is the primary treatment, recurrence occurs in a subset of patients, necessitating subsequent therapies such as reoperation or definitive radiation therapy (RT). This study evaluates the outcomes of definitive RT versus third surgery for recurrent World Health Organization (WHO) grade 1 SM, focusing on progression-free survival (PFS) and treatment-related toxicities. Methods: A retrospective review of 48 patients with third progression of WHO grade 1 SM was conducted between 2008 and 2021. Inclusion criteria required prior second surgery and a confirmed pathology of WHO grade 1. Patients who received RT after earlier surgeries or whose pathology upgraded to WHO grade 2 or 3 were excluded. Data on demographics, tumor characteristics, surgical outcomes, and RT parameters were analyzed. PFS was assessed using Kaplan-Meier survival analysis, and treatment-related toxicities were recorded. Results: Of the 48 patients, 31 underwent third surgery and 17 received definitive RT (median dose: 54 Gy in 30 fractions). Median follow-up was 30 months. PFS at 36 months was comparable between surgery (77.4%) and RT (76.4%). Tumor size was larger in the surgery group (median 1.8 cm vs. 1 cm, P < 0.001). Neurological improvements were noted in 79.1% of surgery patients and 58.3% of RT patients. RT offered superior pain control, with no cases of radiation myelopathy observed. Conclusions: Definitive RT appears to be a feasible alternative to third surgery for recurrent SM in selected patients, providing comparable PFS and manageable toxicities. Larger prospective studies are needed to validate these findings and refine treatment approaches for recurrent SM.