Comparative study of tumor hypoxia by diffuse optical spectroscopy and immunohistochemistry in two tumor models.

The capabilities of diffuse optical spectroscopy for noninvasive assessing of oxygen status in experimental tumors have been demonstrated. Specific features of the distribution of total hemoglobin, oxygenated hemoglobin, deoxygenated hemoglobin, and blood-oxygen saturation were shown on two tumor models having different histological structure and functional characteristics. The results obtained by the optical technique were verified by immunohistochemical study of tissue samples marked with exogenous marker of hypoxia--pimonidazole.