Radiation Therapy Is used to control malignant disease. when a tumor cannot be removed surgically. local nodal metastasis is present. prophylactically to prevent leukemic infiltration to the brain or spinal cord. Palliative irradiation is frequently used to relieve symptoms of metastatic disease,especially when it has spread to brain,bone,or soft tissue.Radiation Therapy ◼ Is used to control malignant disease. ◼ when a tumor cannot be removed surgically. ◼ local nodal metastasis is present. ◼ prophylactically to prevent leukemic infiltration to the brain or spinal cord. ◼ Palliative irradiation is frequently used to relieve symptoms of metastatic disease, especially when it has spread to brain, bone, or soft tissue