Gamma Knife radiosurgery in a cohort of neurofibromatosis type 2-associated and sporadic pediatric meningiomas and schwannomas.

Objective: Pediatric intracranial tumors present a unique spectrum of pathology and their own challenges. However, little data are available on the use of Gamma Knife radiosurgery (GKRS) in their management. Therefore, the authors aimed to present their experience with GKRS in treating pediatric tumors, focusing on the impact of associated neurofibromatosis (NF) on the outcomes.

Methods: This retrospective review assimilated data of patients ≤ 18 years old who underwent GKRS between January 2013 and December 2021 for tumors. Outcomes were compared among tumors associated with NF and those that were not.

Results: Twenty-six patients were treated for 40 tumors, with a mean patient age of 15.4 ± 1.7 years. Thirteen patients were diagnosed with NF type 2 (NF2). The most frequent tumor was schwannoma (75%), followed by meningioma (25%). The mean dose delivered was 12.8 ± 2.2 Gy. After a mean follow-up of 51 months, all tumors regressed or remained stable. Regression of tumor occurred significantly more frequently among non-NF2-associated meningiomas and schwannomas (11/11, 100%) compared with 20 (68.9%) of 29 NF2-associated meningiomas and schwannomas (p = 0.036), with a significantly greater decrease in tumor volume (21.7% [IQR 14.8%-62.1%] vs 10.5% [IQR 3.4%-14.6%]; p < 0.001).

Conclusions: GKRS appears to be effective in achieving tumor control in meningiomas and schwannomas in the pediatric population. Although tumor regression occurs less frequently in patients with NF2, outcomes are largely favorable, with a low rate of acute and delayed complications.