PeopleÂ touched by a brain tumor — patients,Â their families or friends — may have heard of the drug Gliolan or 5-ALA, which is taken up preferentially byÂ tumor cells and makes them fluorescent. The idea behind it is straightforward: if the neurosurgeon can seeÂ the tumor’s boundaries better during surgery, he or she can excise it more thoroughly and accurately.
5-ALA is approved for use in Europe but is still undergoing evaluation by the U.S. FDA. A team at Emory was the first to test this drug in the United States.Â [Note:Â A similar approach, based on protease activation of a fluorescent probe, was reportedÂ last week in Science Translational Medicine.]
Biomedical engineer Shuming Nie and colleagues recently described their development of a hand-held spectroscopic deviceÂ for viewing fluorescent brain tumors. This presents aÂ contrast withÂ the current tool, a surgical microscope — see figure.
Nie’s team testedÂ their technologyÂ on specimens obtained from cancer surgeries.Â Their paper in Analytical Chemistry reports:
The results indicate that intraoperative spectroscopy is at least 3 orders of magnitude more sensitive than the current surgical microscopes, allowing ultrasensitive detection of as few as 1000 tumor cells.
Based on this work, Nie reportsÂ plans to conduct a clinical trial nextÂ year with neurosurgeon colleagues at Emory and Mount Sinai. Studies using standard surgical microscopes will continue.
Nie and his team have also been developingÂ a similar tool for viewing lung tumors, made fluorescent with a green dye.Â Nie is a consultant for Spectropath, an Atlanta-based company that is seeking to develop this technology as a commercial product.