SURG-43. Outcome of differing surgical techniques in the management of subcortical glioblastomas

Surgical management of subcortical glioblastomas (sub-glioblastoma), defined by an epicenter more than 2 cm from the cortex, poses challenges due to proximity to critical neuroanatomy. This study evaluated outcomes of patients treated with stereotactic needle biopsy (SNB), SNB plus laser interstitial thermal therapy (SNB+LITT), surgical resection (SR) with intent for gross total resection, and planned subtotal resection followed by LITT (STR+LITT). Clinical data from 78 consecutive isocitrate dehydrogenase wild-type sub-glioblastoma patients treated between 2017 and 2025 were analyzed. Resection or ablation was classified as gross-total (GT), near-total (NT, >90%), or subtotal (ST, <90%). A total of 23, 22, 18, and 15 patients underwent SNB, SNB+LITT, SR, and STR+LITT, respectively. Tumors in the biopsy-based groups (SNB and SNB+LITT) were smaller than those in resective groups (SR and STR+LITT; 1.81±0.38 vs. 3.76±0.74 cm, p<0.001). Surgical morbidity was similar between SNB and SNB+LITT (~10%), but SNB+LITT was associated with longer median overall survival (mOS) compared to SNB alone (211 vs. 197 days, p=0.015). Among resective approaches, extent of resection or ablation did not significantly differ (p=0.33), but STR+LITT had a lower rate of transient or permanent postoperative deficits than SR (6.7% vs. 44%, p=0.021). mOS was similar for SR and STR+LITT (199 vs. 286 days). No significant differences were observed in hospital stay duration or 30-day readmission across all groups. Importantly, the presence of postoperative motor deficits was associated with worse survival outcomes (mOS 115 vs. 212.5 days, p=0.029). In conclusion, STR+LITT is a safe and effective alternative to gross total resection, offering reduced neurological risk with comparable survival, while SNB+LITT confers a survival advantage over SNB alone. Postoperative motor deficits remain a strong predictor of poor prognosis.