Introduction: Awake craniotomy with electrocortical and subcortical mapping (AC) has become the mainstay of surgical treatment of supratentorial low-grade gliomas in eloquent areas, but not as much for glioblastomas. This retrospective controlled-matched study aims to determine whether AC increases gross total resections (GTR) and decreases neurological morbidity in glioblastoma patients as compared to resection under general anesthaesia (GA, conventional).
Methods: Thirty-seven patients with glioblastoma undergoing AC were 1:3 controlled-matched with one hundred eleven patients undergoing GA for glioblastoma resection. The two groups were matched for age; gender; preoperative Karnofsky Performance Score (KPS); preoperative tumor volume; tumor location; and type of adjuvant treatment. Primary outcomes were extent of resection and the rate of postoperative complications. The secondary outcome was overall postoperative survival.
Results: After matching, there were no significant differences in clinical variables between groups. Extent of resection was significantly higher in the AC group: mean extent of resection in the AC group was 94.89% (SD=10.57) as compared to 70.30% (SD=28.37) in the GA group (p=0.0001). Furthermore, the mean rate of late minor postoperative complications in the AC group (0.03; SD=-0.16) was significantly lower than in the GA group (0.15; SD=0.39) (p=0.05). Overall postoperative survival did not differ between groups (p=0.297).
Conclusions: These findings suggest that resection of glioblastoma using AC is associated with significantly greater extent of resection and less late minor postoperative complications as compared with craniotomy under GA. These data suggest that in patients with glioblastoma near eloquent areas AC should be implemented in standard treatment. A prospective randomized study is therefore warranted.
Patient Care: More than 50% of GBMs are located in speech, motor or sensor areas. Tumor resection in these areas comes with a high risk of postoperative morbidity. The surgeon cannot identify these eloquent areas during resections under general anesthesia (GA). Therefore, when resecting GBMs in these areas, they are usually not operated as aggressive as possible, with negative consequences for survival and quality of life (QoL).
A surgical technique optimizing resection of the brain tumor in eloquent areas but preventing neurological deficits is necessary to improve survival and maintain QoL in these patients. Many studies have shown that AC greatly increases resection percentage while preserving QoL in low-grade glioma (LGG). Though, only very few studies have reported the use of AC in GBM. The evidence from these studies is currently lacking the quality to substantiate the use of AC as standard treatment in GBM: the investigated groups are very small, mixed with II and –III tumors and lacking robust statistical analyses to correct for co-factors. Our study advances these studies by investigating a big group of GBM patients, all proven WHO IV tumors, and matching patients operated with the AC technique with those operated under GA. The results yielded are therefore much more reliable and lay the foundation for further (prospective) research regarding the use of AC in GBM surgery.
Learning Objectives: By the conclusion of this section, participants should be able to:
1) Describe the added value of AC in glioblastoma surgery
2) Discuss for which specific patients AC should be implemented as standard care
3) Discuss which next steps should be taken for further research