There is evidence that fluorescent tissue signal extends farther than tissue highlighted in Gad T1 sequence MRI.
To study whether the presence of residual fluorescent tissue after surgery carries a different prognosis for glioblastoma (GBM) with complete resection confirmed by MRI.
A retrospective review in our center found 118 consecutive patients with high-grade GBMs operated on with 5-aminolevulinic acid. 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 (OS) and neurological complication rate. Multivariate analysis included potential relevant factors: age, Karnofsky Performance Scale, O-methylguanine methyltransferase methylation promoter status, tumor eloquent location, preoperative tumor volume, and adjuvant therapy.
The median OS was 27.0 months in patients with nonresidual fluorescence (n = 25) and 17.5 months for the group with residual fluorescence (n = 27) (P = .015). The influence of residual fluorescence was maintained in multivariate analysis with all covariables, hazard ratio = 2.5 (P = .041). The neurological complication rate was 18.5% in patients with nonresidual fluorescence and 8% for the group with residual fluorescence (P = .267).
GBM patients with CRET in early MRI and no fluorescent residual tissue had longer overall survival than patients with CRET and residual fluorescent tissue.