Fluorescent spectroscopic assessment before and after radiation treatment in oral cavity cancer and its clinical correlation.

Abstract

Biochemical changes in irradiated malignant tissue lead to altered autofluorophores status which should be different for cancerous tissue (residual/recurrence) and irradiated normal tissue. If this irradiated tissue is examined through fluorescent spectroscopy, we can find the spectroscopic changes occurring after the completion of treatment which can be helpful in evaluating treatment response. Punch biopsy sample was examined through fluorescent spectroscopy in oral cavity cancer patients before and after definitive radiation treatment. The change in spectroscopic pattern before and after radiation treatment was recorded and assessed. Final analysis was done in 36 samples. In irradiated tissue, it has been observed that there was increase in the intensity of collagen fluorescence. It was found that the Half width half maximum (HWHM) is more in case of preirradiated sample. The decrease in the HWHM in case of irradiated sample shows the decrease in the number of cells (cell density as compared to that in preirradiated sample). These spectral findings are well-explained pathophysiologically and clinically as amount of collagen are increased in irradiated tissues due to loss of cancerous cells and regeneration of collagen cross-links (fibrosis) and reproduction of normal tissue as a response to radiation treatment. After thorough study in a large number of samples, we may be able in the future to grade the alteration in fluorescence of collagen obtained after radiation treatment in terms of complete, partial, or no response.