A therapy unit installed at the Oak Ridge hospital in 1955 used a source of radioactive cesium-137 to kill diseased tissue, allowing maximum dose of radiation to the cancerous area and minimizing effects to healthy tissue elsewhere. The hospital, one of the nation’s early centers for nuclear medicine, is being stripped of its identity and may be gone altogether in a couple of years. The U.S. Department of Energy plans to declare the property «excess» and transfer it to Methodist Medical Center of Oak Ridge in 2005. (AP Photo/ Oak Ridge Associated Universities) 2003.