Protoporphyrin IX (PPIX), a metabolic product of 5-aminolevulinic acid (5-ALA) accumulating specifically in tumor tissue, shows fluorescence on exposure to excitation light having a peak wavelength of 405 ± 1 nm (laser spectrum overlaps that of ultraviolet light), and thus it allows detection of small amounts of tumor.1–3 We applied this fluorescence chemonavigation technique, which has been used in cerebral glioma surgery,2,3 to a case of spinal ependymoma.
This 19-year-old man presented with nuchal pain. Magnetic resonance imaging revealed a homogeneously enhancing intramedullary C4–5 spinal tumor (not shown); the tumor was then removed. One
LohCSVernonDIMacRobertAJBedwellJBownSGBrownSB: Endogenous porphyrin distribution induced by 5-aminolaevulinic acid in the tissue layers of the gastrointestinal tract. J Photochem Photobiol B20:47–541993
StummerWNovotnyASteppHGoetzCBiseKReulenHJ: Fluorescence-guided resection of glioblastoma multiforme by using 5-aminolevulinic acid-induced porphyrins: a prospective study in 52 consecutive patients. J Neurosurg93:1003–10132000
UtsukiSOkaHSatoSSuzukiSShimizuSTanakaS: Possibility of using laser spectroscopy for the intraoperative detection of nonfluorescing brain tumors and the boundaries of brain tumor infiltrates. Technical note. J Neurosurg104:618–6202006