A surgical loupe system for observing protoporphyrin IX fluorescence in high-grade gliomas after administering 5-aminolevulinic acid

Background: We recently developed a surgical loupe system for observing the fluorescence emitted by protoporphyrin IX (PplX), a metabolite of 5-aminolevulinic acid. Methods: This system used a semiconductor laser as the excitation light source. A compact, transparent, and ultraviolet cut-off filter was mounted on an eyepiece lens, which did not require filter on-off manipulation. Results: Good quality protoporphyrin IX fluorescence was acquired using the surgical loupe system during glioblastoma resection, which was nearly identical to that acquired by fluorescent microscopy. In addition, surgeons can perform ordinary surgical procedures using this surgical loupe system under white light. Conclusion: This surgical loupe system enables the detection of PpIX fluorescence during resection of high-grade glioma. Further evaluations of this system are required to determine the extent of surgical resection before its practical application. (C) 2013 Elsevier B.V. All rights reserved.