Hybrid phosphorescence and fluorescence native spectroscopy for breast cancer detection

Abstract

Fluorescence and phosphorescence measurements are performed on normal and malignant ex vivo human breast tissues using UV LED and xenon lamp excitation. Tryptophan (trp) phosphorescence intensity is higher in both normal glandular and adipose tissue when compared to malignant tissue. An algorithm based on the ratio of trp fluorescence intensity at 345 nm to phosphorescence intensity at 500 nm is successfully used to separate normal from malignant tissue types. Normal specimens consistently exhibited a low / 345 // 500 ratio ( < 10), while for malignant specimens, the / 345 // 500 ratio is consistently high ( > 15). The ratio analysis correlates well with histopa-thology. Intensity ratio maps with a spatial resolution of 0.5 mm are generated in which local regions of malignancy could be identified. © 2007 Society of Photo-Optical /instrumentation Engineers.