Measuring oral inflammation in vivo with diffuse reflectance spectroscopy

Inflammation of the oral epithelium has been shown to provide a promotional environment for evolving cancer cells. This has led to chemoprevention trials exploring the effectiveness of various anti-inflammatory drugs. These trials require quantitative assessment of epithelial inflammation which are traditionally provided by punch biopsy. To reduce patient discomfort and morbidity, we have developed a non-invasive alternative using diffuse reflectance spectroscopy. Though any optical system has the potential for probing near-surface structures, traditional methods of accounting for scattering of photons are generally invalid for typical epithelial thicknesses. We have developed a theory that is valid in this regime and our Monte Carlo simulations and phantom models of a two layered structure have validated our approach. We use a differential measure with accurate sensitivity to small changes in layer scattering coefficients. Preliminary results from this work are encouraging and further development is planned to enable quantification of epithelial thickness in vivo.