Prognostic Value of Residual Fluorescent Tissue in Glioblastoma Patients After Gross Total Resection in 5-ALA Guided Surgery

Background
There is evidence in the literature that supports fluorescent tissue signal in fluorescence guided surgery (FGS) extends farther than tissue highlighted in T1Gd MRI, which is the standard to quantify the extent of resection (EOR).

Objective
To study whether the presence of residual fluorescent tissue after surgery carries a different prognosis for glioblastoma (GBM) cases with complete resection confirmed by MRI.

Methods
A retrospective review in our center found 118 consecutive patients with high-grade gliomas operated using 5-aminolevulinic acid (5-ALA) FGS. Within that series, the 52 patients with newly diagnosed GBM and complete resection of enhancing tumor (CRET) in early MRI were selected for analysis. We studied the influence of residual fluorescence in the surgical field on overall survival and neurological complication rate. Multivariate analysis included potential relevant factors: age, Karnofsky Performance Scale (KPS), MGMT methylation promoter status, tumor eloquent location, preoperative tumor volume, and adjuvant therapy.

Results
The median overall survival was 27.0 months (CI= 22.4-31.6) in patients with non-residual fluorescence (n=25) and 17.5 months (CI= 12.5-22.5) for the group with residual fluorescence (n=27) (p= 0.015). The influence of residual fluorescence was maintained in the multivariate analysis with all covariables, HR= 2.5 (p=0.041).

The neurological complication rate was 8% in patients with non-residual fluorescence and 18.5% for the group with residual fluorescence (p= 0.267).

Conclusion
GBM patients with CRET in early MRI and no fluorescent residual tissue had longer OS than patients with CRET and residual fluorescent tissue.

CITATION  Neurosurgery. DOI: 10.1227/NEU.0b013e31828c3974