Diagnosis of oral cancer by light-induced autofluorescence spectroscopy using double excitation wavelengths

A cancer diagnostic algorithm, light-induced autofluorescence spectroscopy using double excitation wavelengths, was employed for distinguishing betwee n cancerous and normal oral mucosa. For emission spectra at the shorter exc itation wavelengths (280, 290, and 300 nm), the ratio between the area unde r 325-335 nm and the area under 465-475 nm was calculated. In the same way, for emission spectra at the longer excitation wavelengths (320, 330, and 3 40 nm), the ratio between the area under 375-385 nm and the area under 465- 475 nm was calculated. Receiver operating characteristic curves were used t o evaluate the performance of algorithms using single and the double (by co mbining shorter and longer) excitation wavelengths. The results showed that better performance, up to sensitivity 81.25%, specificity 93.75%, and posi tive predictive value 92.86%, could be achieved by using the double excitat ion wavelengths. The present study can be useful as a basis for further inv estigation on in vivo autofluorescence measurement and analysis using doubl e excitation wavelength. (C) 1999 Elsevier Science Ltd. All rights reserved .