Time-resolved fluorescence spectroscopy of human brain tumors

Fluorescence spectroscopy of the endogenous emission of brain tumors has been researched as a potentiallyimportant method for the intraoperative localization of brain tumor margins. In this study, we investigate theuse of time-resolved laser-induced fluorescence spectroscopy (TR-LIFS) for demarcation of primary braintumors by studying the time-resolved spectra of gliomas of different histologic grades. Time-resolvedfluorescence (3 ns, 337 nm excitation) from excised human brain tumor show differences between the time-resolved emission of malignant glioma and normal brain tissue (gray and white matter). Our findings suggestthat brain tumors can be differentiated from normal brain tissue based upon unique time-resolvedfluorescence signature. Keywords: Time-Resolved Laser Induced Fluorescence, brain tumor, glioma, spectroscopy.1. INTRODUCTIONDespite aggressive treatment including surgical resection, irradiation and chemotherapy, the median survivalof patients diagnosed with malignant gliomas is less than 12 months [1,2]. Surgical resection alone offers asurvival benefit, particularly when a complete resection can be achieved. Considerable evidence suggeststhat both survival and quality of life depend on the amount of tumor removed at surgery; a better prognosisoccurs when maximal surgical resection is achieved.The degree to which a complete resection can be carried out is limited in the brain by a number of factorsunique to the central nervous system. Primary brain tumors are infiltrating in nature, and the margins of thetumor are often indistinct. The goal at surgery is to remove as much of the tumor as safely possible withoutextending the resection into the normal adjacent brain [3]. Current imaging technologies to detect cancer inthe central nervous system fails to accurately detect the extent of infiltrating glial tumor [4,5]. Because