ABSTRACT
Almost since the discovery of radioactivity by Henri Becquerel and Pierre and Marie Curie just before the turn of the 20th century, the potential curative effects of radiation, particularly for cancer, have been known. In the 1940s, Saul Hertz, John Lawrence, and Samuel Seidlin introduced the medical use of internally administered radioactivity which, together with the diagnostic uses of radiopharmaceuticals, has led to the current field of theranostics. This chapter reviews the discovery of X-rays and radioactivity as well as the advances leading to the artificial production of radionuclides and the early developments of their use in therapeutic medicine. The path is described from these early advances to the rapidly changing modern era of radionuclide therapy and theranostics in which we find ourselves today.
