Outcomes Following Proton Radiation for Pediatric Meningiomas

Pediatric meningiomas make up 2% of all pediatric central nervous system tumors and are distinct from adult meningiomas, often coinciding with neurofibromatosis-2 (NF2). However, there is limited useful outcome data regarding pediatric meningiomas treated with radiation therapy (RT).

We identified 18 pediatric patients with meningiomas treated at our institution between 2006 and 2024 with proton therapy (PT). All patients received a total dose of 50.4-59.4 Gy in 1.8 Gy/fraction daily, based on tumor grade. Nine patients had WHO Grade I meningiomas and nine had WHO Grade II meningiomas. Sixteen of 18 patients had gross disease at the time of RT. The male-to-female ratio was 1:1. Seven of 18 patients had an NF2 diagnosis. Kaplan-Meier statistical analysis was employed to estimate progression-free survival (PFS), local recurrence, and overall survival (OS) rates. We assessed toxicity during on-treatment visits and follow-ups based on severity and need for intervention.

Median follow-up was 8.5 years (range: 0.5-18 years). No patients were lost to follow-up. At 10 years, local control was 87%, PFS was 75%, and OS was 94%. One patient died from a radiation-associated second neoplasm, and one died from cerebral vasculopathy occurring in the high-dose region. Other notable radiation-related toxicities included hearing loss (n = 1), cataract formation (n = 1), and endocrinopathy (n = 2). No patients had progressive vision loss.

This study contributes to the limited data for children with meningioma requiring RT. Long-Term disease control was encouraging and aligned with adult meningioma data. Despite the use of PT, serious radiation toxicity was observed.