SURG-28. Long-term brainstem tumor control using MRI-guided laser interstitial thermal therapy

Abstract Brainstem tumors remain a surgical challenge due to their deep, difficult to access, and functionally critical neuroanatomical location. There is a high risk of morbidity with surgical resection and safe gross total resection is often unachievable. MRI-guided laser interstitial therapy (MRgLITT) provides a potential minimally invasive surgical option. There are few reports of MRgLITT for brainstem tumors, and none report on long-term outcomes. This case series is the first to present long-term outcomes in patients with brainstem tumors treated with MRgLITT. A retrospective review of patients undergoing MRgLITT for brainstem tumors at Atrium Health Wake Forest Baptist Hospital was conducted. Demographic data, clinical course, surgical technique, pathology, imaging, and treatment response were collected from the electronic medical record. Two female patients underwent MRgLITT for brainstem tumors. One patient had a pilocytic astrocytoma (WHO grade I). The other had an anaplastic ependymoma (WHO grade III). The pilocytic astrocytoma was a very large cystic tumor located in the pons; the anaplastic ependymoma was in the dorsal midbrain. Both patients had significant pre-operative symptoms including diplopia, intractable nausea, weakness and paresthesias. Each patients’ symptoms improved or resolved following surgery. Neither patient experienced a significant complication or post-operative deficit. The patient with anaplastic ependymoma underwent post-operative fractionated radiation. Both patients have completed 10 years of postoperative follow up without radiographic evidence of tumor recurrence. This series demonstrates two patients treated with MRgLITT for primary brainstem tumors who have long term progression-free survival. MRgLITT can be a viable surgical option for carefully selected patients with brainstem tumors and can confer long term tumor control with a favorable side effect profile.