Neurosurgeons have been performing fluorescence-guided brain tumor removal as part of FDA clinical trials testing the safety and efficacy of the drug 5-ALA since 2011. The drug, which is clinically approved for use in Europe, causes brain tumors to fluoresce. Glioma cells selectively uptake the drug, which contains the natural fluorophore protoporphyrin IX (PpIX). Once metabolized, PpIX fluorescence causes the tumor cells to glow red when viewed under a blue light operative microscope. This allows neurosurgeons to differentiate in real-time tumor cells from healthy cells during surgical resection of gliomas. However, current fluorescent imaging techniques can only identify high-grade gliomas.
Researchers at Emory University and Georgia Tech have developed a spectroscopic device that is extremely sensitive to PpIX fluorescence in vivo, thus enabling the identification of low-grade gliomas from healthy tissue. The hand-held spectroscopic device contains both the light source and detector, which are specifically tuned to the excitation and emission wavelengths of PpIX. Researchers tested the device on animal xenografts and human brain tumor specimens and found the device is “at least 3 orders of magnitude more sensitive than current surgical microscopes,” and enables the “detection of as few as 1000 tumor cells.” MRI and histological staining correlated with the fluorescent cells, indicating the device identified only tumor cells. The ultrasensitive device opens the possibility for surgeons to remove low-grade gliomas with the help of fluorescence-guided surgery.
Study in Analytical Chemistry: Intraoperative Spectroscopy with Ultrahigh Sensitivity for Image-Guided Surgery of Malignant Brain Tumors…
More on 5-ALA from Emory Healthcare: Clinical Trial Tests Investigational New Drug for Malignant Brain Tumors…
