Hironobu Yasui1,2, Shingo Matsumoto1, Jeeva P. Munasinghe3, Nallathamby Devasahayam1, Sankaran Subramanian1, James B. Mitchell1, Murali C. Krishna1
1National Cancer Institute, Bethesda, MD, United States; 2Hokkaido University, Hokkaido, Japan; 3National Institute of Neurological Disorder and Stroke
Structural and functional abnormality of blood vessels within malignant tumors influences delivery of oxygen, a key radio-sensitizer, resulting in two different types of hypoxia. Chronic hypoxia is attributed to large diffusion distances between tumor microvessels and longitudinal oxygen gradient, whereas acute hypoxia is though to be the result of transient vascular occlusion and fluctuation in red blood cell flux. Electron paramagnetic resonance (EPR) imaging is a sensitive method to non-invasively map tissue oxygenation distribution. To investigate the fluctuation of tumor oxygen concentration, dynamic 3D EPR oxygen imaging was applied to two different types of tumor bearing in mouse.