Multi-modality point spectroscopy: Interests, development and application to in vivo diagnosis of bladder and skin cancers

Combining autofluorescence (AF) and Diffuse Reflectance (DR) spectroscopies is supposed to improve diagnosispsila accuracy of early stages of cancer (as well as precancerous stages) which is of great clinical importance. For the present study, we developed a bimodal instrumentation combining spatially resolved AF and DR spectroscopies, and evaluated its ability to distinguish between healthy, inflammatory and early stages of cancers in vivo. In order to get such tissue types, we used 2 animal models: a rat bladder orthotopic cancer model and a mice UV-irradiated skin model. The first study shows that combining AF and DR improves both sensitivity and specificity of the diagnosis compared to one modality used alone: Se = 67% (DR alone), 72% (AF alone) increases up to 78% when combining the two modalities. Preliminary results of the second study reveal that some spectroscopic criteria may help quantitative histological analysis in making the difference between acute and precancerous hyperplasia.