Fluorescence spectroscopic study on malignant and premalignant oral mucosa of patients undergoing treatment: An observational prospective study.

BACKGROUND To evaluate the changes of oral mucosa in malignancy and pre-malignant oral conditions using fluorescence spectroscopy during various phases of treatment. MATERIAL AND METHODS The study involved patients of squamous cell carcinoma of the oral cavity and the premalignant lesions coming for the follow up/post-operative radiotherapy. The autofluorescence spectra were recorded in vivo using a Nitrogen laser based fluorimeter. Three sites of each patient were examined-right & the left buccal mucosa and the tongue. For a given pathology, spectra from all the individuals were grouped and mean spectra after different radiation cycles were compared. The quantitative analysis of the spectra involved extraction of diagnostically relevant spectral information through Maximum Representation and Discrimination Feature. RESULTS As different patients had different response to the radiation, it was difficult to visualize any particular trend with increased number of radiation cycles. However, for a given pathology and an individual, when mean spectra after different radiation cycles and surgery were compared, the observation was: Intensity of the 460 nm fluorescence band for each pathology was increased with the number of radiation cycle. That had indicated tissue was being reverted back to its grossly normal features. As 460 nm fluorescence spike was a standard spectra for normal mucosa. CONCLUSION The results strengthened the hypothesis that fluorescence spectroscopy has considerable potential for use as a tool to evaluate the response to treatment in oral malignancy. These spectra of radiotherapy and surgically treated patients can be used as standards for treated patients in further studies.