Targeted radiotherapy of small tumors, micrometastases, and single cancer cells can all benefit from radionuclides that produce  Auger electrons in the subcellular range. Radionuclides differ in terms of the type of radiation they emit, as well as their radiobiological efficacy and range of action, allowing for tumor type selection. Also, it has either found an application or shown potential in solving lymphoma, breast, prostate, colon, thyroid, lung, and brain cancer types, as well as in bone pain palliation.