Unsealed radionuclides

The objective of treatment with unsealed radionuclides, like that with sealed sources or beam therapy, is to administer to a target lesion, organ, or tissue sufficient radiation to achieve the desired therapeutic effect, while minimizing the radiation dose to the rest of the body, particularly the gonads and bone marrow. The concepts underlying such treatment are, however, in many respects fundamentally different from those of other forms of radiotherapy. The effects produced depend on a combination of the physical properties of the radionuclide and the way it is handled metabolically