The effects of nuclear explosions were documented in the survivors of the atomic bomb blasts, who had acute and chronic myelocytic leukemias. In the early part of the 20th century, radiologists who had frequent exposure to x-rays incurred a threefold to fourfold risk for development of leukemia. Both healthy tissue and tumors are affected by radiation. Some cells remain undamaged, some recover over time, and other cells die. Radiation therapy for malignancies, although one of the most common treatments for cancer, has been shown to lead to the development of secondary cancers ( American Cancer Society, 2006b ;Friedman & Constine, 2006 ; Ganz, 2001 ; Paulino, 2004 ).