Fluorescence-guided Surgery for Low- and High-grade Gliomas

Study Summary

Gliomas are the most common primary brain tumor, yet remain a challenge to effectively treat. Mounting evidence suggests that survival improves with greater tumor removal, yet being able do a complete removal can be difficult due to the tumor's infiltrating nature. 5-aminolevulinic acid (5-ALA) is a natural compound that, when patients take it by mouth 3 hours before surgery, is selectively taken up by glioma cells and causes a red/pink fluorescence (glow) under a blue light that allows tumor margins to be seen during the course of surgery. While this compound is used as a standard-of-care agent in Europe, it remains under testing by the Food and Drug Administration (FDA). A recent clinical trial in Germany, however, has demonstrated a significant improvement in the rate of complete resection for certain brain tumors (65% vs. 34%). The Barrow 5-ALA Intraoperative Confocal (BALANCE) Trial will measure the effect of 5-ALA on the amount of glioma tumor removal. To improve the usefulness of 5-ALA, a new special microscope fitted with a blue light, will be used to magnify microscopic fluorescence at the tumor margins. The investigators' hypothesis is that 5-ALA fluorescence with the use of the special microscope during surgery will greatly lower the amount of tumor left behind.

Primary Outcome

Volumetric analysis of MRI contrast T1-weighted images (for low grade gliomas) will be compared to the preoperative sequences to calculate the volume of residual disease. Slice-by-slice assessment of pre- and postoperative tumor volume will be quantified by sequentially measuring the area of tumor on each slice and then integrating the combined measurements. This methodology has been previously reported (Sanai et al., Journal of Neurosurgery, 2010; Sanai et al, The New England Journal of Medicin

Interventions

• DRUG 5-Aminolevulinic acid (ALA)
• DRUG Placebo - ascorbic acid