gms | German Medical Science

Objective: Gross total resection (GTR) of glioblastomas (GBMs) can be facilitated by fluorescence-guided resection (FGR) and has been proven to be one of the most important determinants for PFS and OAS. GTR of GBM is usually impeded by eloquent localization. However, intraoperative functional monitoring could avoid or minimize resection-induced deficits (RID). We therefore report our experience with the combination of FGR aiming at GTR of eloquent located GBMs monitored by awake surgery with cortical and subcortical stimulation. Defined endpoints were grade of resection and functional outcome.

Methods: Patients with GBMs in eloquent localizations were treated with a combination of FGR and cortical and subcortical stimulation in an awake setting (sleep, awake, sleep). Functional outcome was determined by the evaluation of the NIH-score at the 1^st and 5^th postoperative day and then at 3-month intervals. The resection grade was evaluated by early postoperative MRI (< 72 h). Resection was defined as GTR (no contrast enhancement), subtotal (STR > 95%) and incomplete (ICR < 95%). PFS and OAS were evaluated by serial MRI every 3 months.

Results: Since 2007, 44 patients (32 left-, 12 right-sided) were subject to 52 procedures. In 4 patients, intraoperative monitoring was impeded by loss of compliance. An early postoperative deterioration was noticed in 26/48 cases. Importantly, in 18/26 cases a complete remission of RID was observed within 1 to 5 days after surgery, in 1 patient after 6 months. Four of the remaining 7 patients improved favorably (NIHs pre-op/post-op/discharge: 0-8-2,0-1-1,0-5-2,0-2-1). Three patients suffered from a persisting deterioration due to ischemic lesions. Early MRI documented a GTR in 24/48, a STR in 22/48 and ICR in 2/48 patients. Radiological follow-up with at least one MRI after 3 months was available in 30 patients. The present median follow-up is 12 months (range 2-30 months). A local recurrence was observed in 25 patients within 1.5-24 months. The median time to progression was 7 months. The current PFS and OAS at 6 and 12 months are 57% and 24% and 90% and 78% respectively.

Conclusions: Despite of the eloquent localization a high rate of GTR or STR was achieved. Interestingly, in the majority of patients, the high rate of RID's resolved within 5 days. Our study demonstrates that an aggressive surgical approach for GBMs in eloquent regions is feasible, if controlled by awake surgery. Due to the short observation time PFS and OAS cannot yet be interpreted, but compare favorably with current data.