SURG-01. LITT FOR IN-FIELD RECURRENCE OF BRAIN METASTASIS AFTER STEREOTACTIC RADIOSURGERY: OUTCOMES AND MECHANISMS OF DEATH

INTRODUCTION: Brain metastasis (BM) affects up to one-third of adults with cancer and carries a historically bleak prognosis. Thanks to advances in stereotactic radiosurgery (SRS), patients can live longer, and fewer succumb to their intracranial disease. However, rates of in-field recurrence after SRS range from 10–25%, either as true tumor re-growth or radiation necrosis (RN). In this setting, repeat SRS is not recommended and craniotomy may not be feasible or desired by the patient. Laser interstitial thermal therapy (LITT) is an emerging option with promising outcomes. In this study, we investigated outcomes and determined the mechanisms of death among patients with BM who underwent LITT for in-field recurrence after SRS. METHODS: Single institution retrospective review of patients with BM who underwent LITT for in-field recurrence after SRS. RESULTS: Between 2010–2018, seventy (70) patients with BM underwent LITT for in-field recurrence after SRS. At the time of review, 51/70 (72.9%) patients died, 16/70 (22.9%) were alive, and the status of 3/70 (4.3%) was undetermined. Among those who died, death was neurologic in 17/51 (33.3%), non-neurologic in 21/51 (41.2%), and undetermined in 13/51 (25.5%). Median survival after LITT for patients who died from neurologic and non-neurologic causes were 8.9 and 14.3 months, respectively. Mechanisms of neurologic death included progressive intracranial metastatic disease in eight patients and progressive RN in two. Mechanisms of non-neurologic death were nearly all related to progression of primary or systemic disease. CONCLUSIONS: For patients with BM who develop in-field recurrence after SRS, LITT is a viable alternative to craniotomy and can attenuate the neurological burden of this devastating disease. Among our patient population, very few died as the result of intracranial progression. Future studies that investigate which factors predispose patients to intracranial progression despite LITT will further improve its efficacy and ultimately improve the lives of cancer patients.