ABSTRACT
In the United States, the incidence rate of malignant brain tumors was 7.3 per 100,000 persons per year during 2004–2008 according to the National Cancer Institute. This chapter introduces Time-resolved fluorescence spectroscopy (TRFS), which has already demonstrated strong potentials in characterizing brain tumors from previous outcomes. TRFS measures dynamic fluorescence signals such as fluorescence lifetime, in addition to fluorescence spectrum. Technologies using minimally invasive optical techniques, called optical biopsies, have been developed for intraoperative diagnosis in a number of applications. In principle, the optical biopsy modalities that provide endogenous biochemical and morphological features are preferred in intraoperative applications over those that rely on exogenous contrast agents. TRFS is considered a more robust tool for optical biopsy, as the fluorescence lifetime is independent of the emission and quantum yield, but is sensitive to changes in the tumor microenvironment.
