SURG-06. IMPACT OF LASER INTERSTITIAL THERMAL THERAPY VERSUS RESECTION FOR METASTASES ASSOCIATED WITH THE MOTOR CORTEX

Abstract BACKGROUND For brain metastases (BM), resection remains a mainstay for the upfront management of large, symptomatic lesions, while laser interstitial thermal therapy (LITT) has become a key treatment for radiographically progressive BM following stereotactic radiosurgery (SRS). Compared to LITT, resection-associated morbidity may delay systemic therapies. We evaluated functional outcomes for resection versus LITT to primary motor cortex (PMC)-associated metastases. METHODS Patients receiving resection or LITT for BM radiographically associated with the PMC from 2015-2023 were retrospectively reviewed. Demographic and survival data were collected, with patient Karnofsky Performance Status (KPS) or modified Rankin Scale (mRS) scores assessed out to 1-year by independent raters. RESULTS Forty-one patients underwent resection and 30 underwent LITT to a PMC-associated lesion. Median age was 67 (range 38 – 80) vs 65 (44 – 80) for resection vs LITT; median pre-operative KPS (70 vs 80, P = 0.1) or mRS (2 vs 2, P = 0.66) did not differ between groups. Lung was the most common primary (56.1% resections vs 56.7% LITTs). Resected lesions were of larger median diameter than LITT, 2.8 vs 1.9 cm, P = 0.0001. For resections, length of stay was longer, median 2 vs 1 day, P = 0.0002, and ICU use more frequent (75.6% versus 20.0%, P < 0.0001). At 1-month post-op, 66.7% of resection patients and 51.7% of LITT patients had stable or improved symptoms from pre-op, P = 0.21, with parity at 3-months (65.7% vs 62.9%) and therafter. Further, there was no significant decrement in KPS or mRS score out to a year for either intervention. CONCLUSIONS While there is a short-term increased risk of post-operative neurologic worsening due to LITT-associated edema, our data shows that, relative to resection, this is a transient and clinically limited phenomenon. With careful patient selection, LITT to lesions involving the PMC is feasible.