Noninvasive fluorescence excitation spectroscopy for the diagnosis of oral neoplasiain vivo

Abstract

Fluorescence excitation spectroscopy (FES) is an emerging approach to cancer detection. The goal of this pilot study is to evaluate the diagnostic potential of FES technique for the detection and characterization of normal and cancerous oral lesions in vivo. Fluorescence excitation (FE) spectra from oral mucosa were recorded in the spectral range of 340 to 600 nm at 635 nm emission using a fiberoptic probe spectrofluorometer to obtain spectra from the buccal mucosa of 30 sites of 15 healthy volunteers and 15 sites of 10 cancerous patients. Significant FE spectral differences were observed between normal and well differentiated squamous cell carcinoma (WDSCC) oral lesions. The FE spectra of healthy volunteers consists of a broad emission band around 440 to 470 nm, whereas in WDSCC lesions, a new primary peak was seen at 410 nm with secondary peaks observed at 505, 540, and 580 nm due to the accumulation of porphyrins in oral lesions. The FE spectral bands of the WDSCC lesions resemble the typical absorption spectra of a porphyrin. Three potential ratios (I410/I505, I410/I540, and I410/I580) were calculated from the FE spectra and used as input variables for a stepwise linear discriminant analysis (SLDA) for normal and WDSCC groups. Leave-one-out (LOO) method of cross-validation was performed to check the reliability on spectral data for tissue characterization. The diagnostic sensitivity and specificity were determined for normal and WDSCC lesions from the scatter plot of the discriminant function scores. It was observed that diagnostic algorithm based on discriminant function scores obtained by SLDA-LOO method was able to distinguish WDSCC from normal lesions with a sensitivity of 100% and specificity of 100%. Results of the pilot study demonstrate that the FE spectral changes due to porphyrin have a good diagnostic potential; therefore, porphyrin can be used as a native tumor marker.

Native fluorescence spectroscopic characterization of DMBA induced carcinogenesis in mice skin for the early detection of tissue transformation

“…compared with the other bands. This finding is consistent with the previous work by Ebenezar et al, who found out that similar soret and Q-bands were observed in WDSCC of buccal mucosa of oral cancerous patients at 635 nm emission by fluorescence excitation spectroscopy in vivo 27. Further, this observed spectral signature of the WDSCC lesions resembles the typical absorption spectra of the porphyrin molecule, it indicates that higher amount of porphyrins synthesized in WDSCC lesions than other transformation conditions.…”

The Outline of Prognosis and New Advances in Diagnosis of Oral Squamous Cell Carcinoma (OSCC): Review of the Literature

“…As well, tumour-specific enzymes are about to be specifically targeted by fluorescent markers "smart probes" in order to improve both sensitivity and specificity [54][55][56]. Ebenezar stated that the diagnostic algorithm based on discriminant function scores obtained by fluorescence excitation spectroscopy (FES) method was able to distinguish welldifferentiated squamous cell carcinoma from normal lesions with a sensitivity of 100% and specificity of 100% [57].…”

Current concepts and future of noninvasive procedures for diagnosing oral squamous cell carcinoma - a systematic review

“…Leunig et al studied 58 patients with suspected cancer of the oral cavity by measuring emission spectra of 5-ALA-induced PPIX fluorescence and reported a specificity of 60% and sensitivity of 99% after pathologic evaluation of biopsy specimens [ 114 ]. Ebenezar et al reported that a diagnostic algorithm based on discriminant function scores obtained by fluorescence excitation spectroscopy distinguished well-differentiated SCC from normal lesions with a sensitivity of 100% and specificity of 100% [ 115 ].…”