Keita Saito1, Shingo Matsumoto1, Nallathamby Devasahayam1, Sankaran Subramanian1, Jeeva P. Munasinghe2, Vyomesh Patel3, Silvio Gutkind3, James B. Mitchell1, Murali C. Krishna1
1National Cancer Institute,
Effects of anti-tumor drug rapamycin on tumor oxygenation and angiogenesis in tumor bearing mice were investigated by using pulsed electron spin resonance imaging and magnetic resonance imaging. Blood volume in tumor region was significantly decreased after 2 days from beginning of the rapamycin treatment. Tumor oxygenation did not drastically change by rapamycin treatments, but pO2 level slightly increased and the ratio of hypoxic area to tumor region slightly decreased after 2 days rapamycin treatments. These results suggest that rapamycin can normalize blood volume and suppress depletion of oxygen in the tumor region.