An old drug could be a new tool for doctors working to improve radiation therapy by increasing oxygen in tumors. Low levels of oxygen in cancer cells (hypoxia) can negatively impact the efficacy of radiation. In response to this longtime problem, Ohio State researchers screened thousands of drugs in hopes of finding therapies that could reduce oxygen consumption in tumors. The best of the bunch &mdash; isolated from the poppy plant but not an opium-like substance &mdash; was first discovered 150 years ago. Researchers are now putting the old drug to new use in a clinical trial that could one day lead to better radiation treatments for a number of cancers. &ldquo;It could be used for any tumor that has hypoxia in it, which is why it's so important to be able to identify that first &mdash; to say that this patient with this tumor would benefit from the drug,&rdquo; Nicholas Denko, MD, PhD, says.