Lead Pb-207

**Semantic type:** Element, Ion, or Isotope

**Definition:** A stable isotope of lead (Pb) and the final non-radioactive product of radioactive decay in the actinium series (uranium-235) or plutonium cascade (plutonium-239), which both include the daughter radionuclide radium-223 (Ra-223). As Ra-223 is used to treat metastatic bone disease and Ra-223 decays to the stable isotope Pb-207, the concentration of Pb-207 found in bone metastases may be used to estimate the amount of Ra-223 that accumulated in the bone during treatment.

**Synonyms:** - Lead 207 - Lead Pb 207 - Lead-207 - Pb-207 - Pb207