204 Laster Interstitial Thermal Therapy for Primary and Recurrent Meningioma: A Prospective and Retrospective Multi-institutional Study

INTRODUCTION: Meningiomas are a common central nervous system tumor, and a subset are aggressive lesions resistant to standard therapies. Laser interstitial thermal therapy (LITT) has been successfully applied to other brain tumors, but its role in meningioma treatment is understudied. METHODS: Eight United States-based hospitals enrolled patients with meningioma in the prospective multicenter registry and pooled additional retrospective enrollments for this cohort study. Demographics, procedural, safety, and outcomes data were collected and analyzed using standard statistical methods. RESULTS: Twenty adult patients (12 prospective, 8 retrospective) with LITT-targeted meningiomas were accrued. Patients underwent LITT for primary (6 patients) and recurrent tumors (14 patients, ranging from 1st to 12th recurrence). Twenty percent of patients (4/20) had exhausted all other treatment options. Median length of follow-up was 1.3 years. One-third of primary (2/6) and one-half of recurrent meningiomas (7/14) recurred during follow-up. Of those with grading information, grade 2 meningiomas were most common (9/18), followed by Grade 1(5/18), and Grade 3 (4/18). Sixty percent (60%) of patients (12/20) had convexity meningiomas treated with LITT. 2 patients (10%) had post-procedural complications, of which one resolved. One-year estimated local control (LC), progression-free survival, and overall survival were 55.3%, 48.4%, and 86.3%, respectively. In the 10 patients who had 91% ablative coverage, 1-year estimated LC was 64.8%. High grade (Grades 2 and 3) patients (n = 13) treated with LITT had a 1-year LC of 46.3%. CONCLUSIONS: This cohort represents the largest series of patients with meningioma undergoing LITT and supports the safety of the procedure in this tumor type. LITT can offer a much-needed treatment option, especially for those with multiply recurrent meningiomas and where heavy pretreatment limits remaining treatment options. LITT should be considered in the armamentarium of treatment options for meningiomas.