Fluorescein sodium in the surgical treatment of recurrent glioblastoma multiforme.

BACKGROUND: Glioblastoma multiforme (GBM) is the most common primary brain tumor and has a high recurrence rate. Maximizing the extent of resection (EOR) in recurrent GBM has proved to be the cornerstone of neurosurgical re-treatment. The development of surgical microscopes fitted with fluorescein-specific filters has facilitated fluorescein-guided microsurgery and the identification of tumor tissue. Use of fluorescein sodium (FL) in primary high-grade glioma resection has shown promising results. Here, we present our experience with FL and the dedicated surgical microscope filter YELLOW 560 nm in 106 patients with recurrent GBM.

METHODS: 106 patients with recurrent GBM were included (53 women, 53 men, mean age 53 years). 5 mg/kg bodyweight of FL had been intravenously injected approximately 45 min. before craniotomy. A YELLOW 560 nm filter (Pentero 900, ZEISS Meditec, Germany) was used for microsurgical tumor resection and resection control. Surgical reports were reviewed regarding the degree of fluorescent staining. Postoperative MRIs were examined within 48 hours after surgery regarding the extent of resection and postoperative courses regarding neurological outcome, complications, and any adverse events.

RESULTS: Bright fluorescent staining was present in all patients, which markedly enhanced tumor visibility and was deemed helpful for tumor resection. 17 patients (16%) showed residual tumor tissue on the postoperative MRI. Thus, gross-total resection (GTR) had been achieved in 89 (84%) of patients. No adverse events were registered postoperatively.

CONCLUSIONS: FL and YE560 are a readily available method for fluorescence-guided tumor resection, similar to contrast enhancement in T1-weighted MRI. FL may improve resection in recurrent GBM with minimal risk, and tumor margins are clearly visualized. FL and the YELLOW 560 nm filter are safe and feasible tools for safe maximal resection of recurrent glioblastoma.