Measurement of hemoglobin saturation in tumor microvasculature in preclinical models using hyperspectral imaging

Tumor hypoxia has been shown to be of prognostic value in several clinical trials involving radiation, chemotherapy, and surgery. Studies of tumor oxygenation at the microvascular and microregional levels can provide understanding of tumor oxygen transport on scales comparable to the diffusion distance of oxygen in tissue. To fully grasp the significance of blood oxygen delivery and hypoxia at the microvascular level, the spatial and temporal relationship of blood oxygenation data must be preserved and mapped. Using tumors grown in dorsal skin-fold window chamber models, hyperspectral imaging can provide spatial maps of blood oxygenation in terms of hemoglobin saturation at the microvascular level, and these measurements can be performed serially in the same animal in a non-invasive fashion with relative technical ease. A hyperspectral imaging system has been constructed to create image maps of hemoglobin saturation in microvasculature of tumors grown in dorsal skin-fold window chambers. Preliminary baseline studies of early tumor development using 4T1 mouse mammary carcinomas are currently being conducted with the system.