SURG-02. MAGNETIC RESONANCE-GUIDED HIGH-INTENSITY FOCUSED ULTRASOUND (MRGHIFU) FOR TREATMENT OF LOW GRADE GLIOMA IN A PEDIATRIC PATIENT

INTRODUCTION: Transcranial magnetic resonance-guided high-intensity focused ultrasound (MRgHIFU) has demonstrated efficacy in the treatment of adult essential tremor through targeted thermoablation visualized in real-time with MR thermography. The minimally invasive nature of MRgHIFU and lack of ionizing radiation makes it an appealing treatment modality for pediatric patients. There is limited data describing MRgHIFU for pediatric brain tumors. This case report describes the use of MRgHIFU to treat a low grade glioma in a pediatric patient. METHODS: A prospective, non-randomized, single-arm study enrolled patients 8-22 years old with benign intracranial tumors requiring intervention to be treated with the ExAblate 4000 System. Clinical and radiographic examinations were performed at the following intervals after treatment: 1 day, 14 days, 3 months, 6 months, and 1 year. RESULTS: One patient was treated with MRgHIFU in 2022. A 12 year-old female with headaches and Neurofibromatosis Type 1 (NF1) without prior medical or surgical treatment presented with a progressive enhancing lesion in the right parieto-occipital region. Stereotactic biopsy confirmed pathological diagnosis of a low-grade glioma. MRgHIFU was used to treat the lesion with 5 sonications ranging 600-800 watts resulting in immediate T2 and FLAIR changes. There were no complications or adverse events. MRI demonstrated slight volume reduction after one year. The patient scored herself a 7 on the Patient Global Impression of Change scale for considerable improvement. Her headaches improved and she participates actively in school and sports. CONCLUSION: MRgHIFU is an attractive alternative to open craniotomy and/or radiation for pediatric patients with benign brain tumors. In our experience with one patient, the use of MRgHIFU for treatment of a low-grade glioma demonstrated safety in addition to radiographic disease control at 1 year with favorable patient impression scores. Additional patient enrollment and extended follow-up time will be necessary to determine generalizability and therapeutic longevity.