The use of targeting mechanisms makes existing anti-cancer methodologies, such as radiation or toxic chemicals, work far more effectively and inflict less harm upon the patient. Via EurekAlert!: researchers used "a radiolabeled antibody to deliver targeted doses of radiation, followed by a stem cell transplant, to successfully treat a group of leukemia and pre-leukemia patients for whom there previously had been no other curative treatment options. All fifty-eight patients, with a median age of 63 and all with advanced acute myeloid leukemia or high-risk myelodysplastic syndrome - a pre-leukemic condition - saw their blood cancers go into remission. ... The key to success in this study was use of a radiolabeled antibody that has therapeutic iodine 131 attached and is designed to target leukemic bloods cells that carry a marker on the surface of the cell known as CD45. ... Delivered intravenously, the radiation looks for the CD45 antigen receptor on the surface of blood cells. This approach results in a two- to four-fold increase in the amount of radiation that reaches cancerous cells as compared to standard external beam radiation, which also radiates normal surrounding organs and tissue. The more radiation that can be applied, the more cancer cells will be killed in preparation for donor stem cells to take over the diseased immune system and kill off the remaining cancer cells." The survival rate after 3 years is around a third - somewhat better than the expected zero for existing options.