LOCL-10 EVOLUTION OF FUNCTIONAL OUTCOMES AFTER LASER INTERSTITIAL THERMAL THERAPY (LITT) VERSUS RESECTION IN THE TREATMENT OF LESIONS IN OR NEAR THE PRIMARY MOTOR CORTEX

Laser interstitial thermal therapy (LITT) has become increasingly common, particularly in the treatment of progressive lesions after stereotactic radiosurgery for brain metastases. Previous work has illustrated the sensitivity to its use near critical structures, including the corticospinal white matter tracts. A single-surgeon retrospective study was performed of patients who underwent LITT or open resection for lesions located in or near the primary motor cortex, with functional outcomes graded relative to pre-treatment symptoms at 30, 90, and 180 days. Forty patients met inclusion criteria, with median age 64 years (57-72), and estimated baseline KPS 80 (80-90). Nineteen (47.5%) received LITT and 21 (42.5%) resections with intra-operative motor mapping. LITT patients trended towards smaller maximum diameters (2.1 cm vs 2.8 cm, p<0.01), with shorter ICU (0 vs 1 day, p<0.01) and hospital stays (1 vs. 2 days, p<0.01). At 30 days after treatment, 88.9% of resected patients had stable or improved symptoms compared to 35.3% of the LITT cohort (p<0.01). At 90 days, the difference was 87.5% to 50% (p=0.04), and at 180 days 100% to 85.7% (p=0.3684). When separated by new vs. progressive lesions, steroid responsiveness, and lesion histology, similar though not statistically significant trends were identified. In summary, LITT and resection provided similar functional outcomes in the treatment of lesions in or near the primary motor cortex for patients who survived at least 180 days post-treatment. Patients who received resection tended to have better functional outcomes in the nearer term. These differences are likely due to transient, expected post-LITT edema that subsides with time.