Intraoperative MRI in pediatric brain tumor surgery: an 18-year single-center experience

To describe our single-center experience with intraoperative MRI (iMRI)-guided pediatric brain tumor surgery over 18 years and to evaluate how often iMRI changed intraoperative management, together with short-term safety and functional outcomes.

We performed a retrospective observational study of consecutive patients aged 18 years or younger who underwent iMRI-guided intracranial tumor resection between 2007 and 2024. Demographic data, tumor characteristics, imaging studies, operative records, and postoperative follow-up were reviewed. Extent of resection was defined using the final intraoperative MRI and the first postoperative MRI during the index hospitalization. Because of the absence of a contemporaneous non-iMRI control group and the heterogeneity of tumor entities, analyses were descriptive.

A total of 156 pediatric patients (median age 8 years) were included. The most common histologies were pilocytic astrocytoma (46/156, 30%) and craniopharyngioma (20/156, 13%). Overall, gross-total resection (GTR) was achieved in 118/156 cases (76%). iMRI identified residual tumor judged safely resectable in 36/156 procedures (23%), resulting in additional resection and conversion from subtotal resection to GTR in 30 cases. No adverse events were attributable to the iMRI workflow. Overall perioperative complications included one intraoperative hemorrhage unrelated to iMRI and one transient wound-healing disorder. At approximately 6 months, functional status was improved in 16 patients (10.3%), stable in 139 (89.1%), and worsened in 1 (0.6%).

In this retrospective single-center experience, iMRI primarily served as a resection-control tool that identified residual tumor and prompted further resection in a meaningful subset of pediatric brain tumor procedures. The present data support its usefulness as an adjunct in selected cases, but they do not establish superiority over surgery performed without iMRI.