MULTIMODAL (5-ALA, TRACTOGRAPHY AND ULTRASOUND GUIDED) AWAKE CRANIOTOMY FOR GLIOBLASTOMA: MAXIMISING SAFE SURGICAL RESECTION

Abstract AIMS Maximising the extent of surgical resection of glioblastoma is a key prognostic factor for survival. This must be balanced against avoiding neurological deficit, which may delay or preclude adjuvant treatments. This is a particular challenge in eloquent tumours. Optimal surgical adjuncts to enable maximal resection of glioblastomas in eloquent brain regions, remain unclear. We present the first series assessing the safety and efficacy of multimodality image-guided, awake resection of IDH-wildtype glioblastoma, combining 5-aminolevulinic acid (5-ALA), diffusion tractography (DTI) and intraoperative ultrasound (USS). METHOD We present a single centre retrospective series of 175 patients undergoing awake craniotomy for primary resection of glioblastomas, between January 2014 and January 2023. Awake craniotomy was considered if tumours were in or adjacent to eloquent areas. Key outcomes assessed included post-operative neurological complications (classified into transient, if persisting <3 months and completely resolved, or permanent if persisting >3 months), extent of resection (EOR) and overall survival (OS). RESULTS 175 patients (103M:72F) were included, with a mean age of 58.2 years. All cases used neuronavigation, whilst 5- ALA and DTI were used in 98.9% and 97.1% of patients respectively. Intraoperative USS was used 88/175 (50.3%). Gross total resection (>98%) was achieved in 101/175 patients (64.7%). 83/175 patients (47.4%) experienced a post-operative neurological deficit, which was temporary in 84.3% (70/83) of cases. When transient deficits occurred, these were most often speech related (49/70). Subgroup analysis found left temporal tumours were highest risk for transient dysphasia (59.2%), followed by left frontal (21.7%) and left parietal (16.0%). The median percentage EOR with USS was 100%, whilst without USS was 97.8% (Wilcox, p=0.0004). CONCLUSION Patients should be counselled about the high risk of transient neurological complications following awake surgery, particularly speech deficit. Multimodal image-guided surgery can maximise the extent of safe resection for glioblastoma.