The study of blue LED to induce fluorescence spectroscopy and fluorescence imaging for oral carcinoma detection

Abstract

Fluorescence spectroscopy and fluorescence imaging diagnosis of malignant lesions provides us with a new method to diagnose diseases in precancerous stage. Early diagnosis of disease has significant importance in cancer treatment, because most cancers can be cured well in precancerous, especially when the diffusion of cancer is limited in a restricted region. In this study, Golden hamster models were applied to 5% 9, 10 dimethyl-1, 2-benzanthracene (DMBA) to induce hamster buccal cheek pouch carcinoma three times a week. Rose Bengal, which has been used in clinican for years and avoids visible side-effect to human was chosen as photosensitizer. 405 nm blue LED was used to induce the fluorescence of photosensitizer. After topical application of photosensitizer, characteristic red emission fluorescence peak was observed around 600nm. Similar, normal oral cavity has special luminescence around 480nm. Fluorescence spectroscopy technology is based on analysing emission peaks of photosensitizer in the areas of oral carcinoma, moreover, red-to-green (I_R/I_G) intensity ratio is also applied as a diagnostic algorithm. A CCD which is connected with a computer is used to take pictures at carcinoma areas through different filters. Fluorescence images from normal hamster buccal cheek pouch are compared with those from carcinogen-induced models of carcinoma, and morphological differences between normal and lesion tissue can be distinguished. The pictures are analyzed by Matlab and shown on the screen of computer. This paper demonstrates that Rose Bengal could be used as photosensitizer to detect oral carcinoma, and blue LED as excitation source could not only have a good effect to diagnose oral carcinoma, but also decrease cost greatly.