Respiratory Challenges in Breast Cancer: Potential for Enhanced Diagnostics and Therapy PRINCIPAL INVESTIGATOR:

Current imaging modalities allow precise visualization of tumors but do not enable quantitative characterization of thetumor metabolic state. Such quantitative information would enhance our understanding of tumor progression andresponse to treatment, and to our overall understanding of tumor biology. To address this problem, we have developed awide-field functional imaging (WiFI) instrument which combines two optical imaging modalities, spatially modulatedimaging (MI) and laser speckle imaging (LSI). Our current WiFI imaging protocol consists of multispectral imaging inthe near infrared (650-980 nm) spectrum, over a wide (7 cm x 5 cm) field of view. Using MI, the spatially-resolvedreflectance of sinusoidal patterns projected onto the tissue is assessed, and optical properties of the tissue are estimatedusing a Monte Carlo model. From the spatial maps of local absorption and reduced scattering coefficients, tissuecomposition information is extracted in the form of oxy-, deoxy-, and total hemoglobin concentrations, and percentageof lipid and water. Using LSI, the reflectance of a 785 nm laser speckle pattern on the tissue is acquired and analyzed tocompute maps of blood perfusion in the tissue. Tissue metabolism state is estimated from the values of blood perfusion,volume and oxygenation state. We currently are employing the WiFI instrument to study tumor development in aBRCA1/p53 deficient mice breast tumor model. The animals are monitored with WiFI during hyperoxic respiratorychallenge. At present, four tumors have been measured with WiFI, and preliminary data suggest that tumor metabolicchanges during hyperoxic respiratory challenge can be determined.