Radiation therapy is used to treat a broad range of malignancies. The adoption of conformal treatment techniques such as intensity-modulated radiation therapy (IMRT) and image-guided radiation therapy (IGRT) has reduced the amount of radiation delivered to normal tissue surrounding the targeted tumor. However, the irradiated normal tissue toxicity still limits the dose that can be administered and contributes to treatment-related morbidity and decreased quality of life. Therefore, there is a need for therapeutic agents that selectively reduce radiation-induced normal tissue injury without reducing tumoricidal effectiveness, thereby increasing the therapeutic ratio of radiation therapy. Additionally, the use of these agents is expected to improve patients' quality of life through the reduction of treatment-related toxicities.
Over the past few years, the United States has increased efforts to develop countermeasures to protect people against the effects of radiological/nuclear terrorism. Agents administered after radiation exposure but before symptoms or organ toxicity occurs are called...