SURG-14. Laser Ablation for Brain Metastases: Risk Factors for Neurologic Complication

INTRODUCTION: Laser interstitial thermal therapy (LITT) is a routinely used in treatment of recurrent brain metastases following SRS or open craniotomy. While considered safer than craniotomy, patients do experience neurologic decline following LITT. Identifying which patients are at risk for neurologic deterioration can help better advise patients on the most appropriate treatment options for their tumor. OBJECTIVE: The objective of the present study was to assess the frequency and identify risk factors for neurologic decline following LITT. METHODS: Data was gathered on patients who underwent LITT for ablation of metastatic brain tumors at our institution between 2014–2019. These cases were analyzed retrospectively and data was collected on patient demographics, tumor characteristics, procedural details, and post-operative complications and outcomes. Pre-operative neurologic function was compared to neurologic status at the 6–12 week post-op visit. RESULTS: 16 patients underwent LITT of a total of 18 metastatic lesions during the study time period and were included in the analysis. 7/16 patients demonstrated reduced KPS or worse neurologic function at 6–12 week follow up. 4 patients (25%) demonstrated neurologic deficits that were attributable to the laser ablation procedure, and each of these 4 patients had lesions in eloquent areas. Comparatively, none of the other 12 patients analyzed had eloquent lesions (p = 0.002). The presence of a pre-op neurologic deficit was not predictive of worsening neurologic function following LITT (p = 0.35). Average lesion size in patients who experienced neurologic deficit was 5.69cm(3) compared to 3.15cm(3) in those that did not (p = 0.1). CONCLUSION: Our complications rate is similar to other published case series (15–44%). LITT, while better tolerated than standard craniotomy, can lead to neurologic decline in patients with brain metastases regardless of lesion size or pre-operative functional status. Eloquence is a significant predictor of neurologic complications following laser ablation.