RADT-08. THIRD RECURRENT WHO 1 SPINAL MENINGIOMAS. CASE SERIES AND CLINICAL OUTCOMES FOLLOWING SURGERY OR DEFINITIVE RADIOTHERAPY

Abstract INTRODUCTION Spinal meningiomas (SM) account for approximately 1.2–12.7% of all meningiomas and 25% of spinal cord tumors. Most are benign (WHO grade 1), but a small percentage are atypical (WHO grade 2) or anaplastic (WHO grade 3). These tumors are typically solitary and non-invasive with low recurrence rates post-surgery. This study aims to compare the efficacy of definitive radiotherapy (RT) versus third surgery for recurrent SM WHO grade 1, focusing on local control, progression-free survival (PFS), and toxicity. METHODS A retrospective review approved by the Institutional Review Board included patients diagnosed with recurrent SM WHO grade 1 who underwent second surgery between 2008-2020. Patients who received radiation after the first surgery or upgraded to WHO grade 2 or 3 were excluded. Data on demographics, tumor characteristics, surgical techniques, and radiation therapy details were analyzed using descriptive and inferential statistics. RESULTS The study included 48 cases of third progression SM WHO grade 1. The median age was 53 years, and 70.8% were female. Tumor locations were primarily thoracic (75%). There was no significant difference in PFS between the third surgery and RT groups, with 36-month PFS rates of 77.4% and 76.4%, respectively. RT-related toxicities were manageable, and neurological improvements were noted in both groups, with more pronounced improvements in the surgical group. RT showed better pain control outcomes. CONCLUSION Both definitive RT and third surgery are effective for managing recurrent SM WHO grade 1, with comparable PFS. RT is a viable alternative, especially for high-risk surgical patients, providing effective pain control and manageable toxicities. Further studies with larger cohorts and longer follow-ups are recommended to validate these findings and refine treatment protocols for recurrent SM, ultimately improving patient outcomes and quality of life.