Clinical and Neuroimaging Features of Magnetic Resonance−Guided Stereotactic Laser Ablation for Newly Diagnosed and Recurrent Pediatric Brain Tumors: A Single Institutional Series

Abstract

We describe our single-institutional experience with magnetic resonance-guided stereotactic laser ablation (SLA) for the treatment of newly diagnosed and recurrent pediatric brain tumors. Eighteen consecutive ablation procedures were performed in 17 patients from March 2016-April 2020. Patient demographics, indications, procedures, neuroimaging features, and outcomes were reviewed retrospectively. Seventeen patients (mean age of 11.4 years, 11 boys, 6 girls) underwent SLA with a mean follow-up of 24 months (range: 3-45 months). Tumor histologies included pilocytic astrocytoma (n= 5), ganglioglioma (n= 3), low-grade glioma not otherwise specified (n= 4), glioblastoma (n= 2), meningioma (n= 1), medulloblastoma (n= 1), andmetastatic malignant peripheral nerve sheath tumor (n= 1). SLA was first-line therapy in 10 patients. Mean procedure duration including anesthesia time was 328 minutes (range: 244-529 minutes), and mean postoperative length of stay was 1.5 days (range 1-5 days). The complication rate was 29%, which included 3 patients who experienced postoperative motor changes, which resolved within several weeks of surgery, 1 patient with self-limited intraoperative bradycardia and hypotension, and 1 patient who died postoperatively due to intracranial hemorrhage from a distant lesion. Twelve of 17 patients had a neuroimaging response after SLA (4 complete responses, 8 partial responses, 1 stable disease). Percentage of tumor shrinkage from baseline ranged from 33%-100% (mean 75%). Patients with low-grade glioma exhibited the best responses to SLA (range 3%-100% decrease; mean 90%; 36% complete response rate). SLA is a minimally invasive modality for the treatment of newly diagnosed and recurrent low-grade pediatric brain tumors. Low-grade glioma exhibited the best responses. Identification of ideal candidates for SLA, mitigation of perioperative complications, and demonstration of long-term outcomes need to be better defined in a clinical trial setting.