Lutetium-177 is a powerful radioisotope that has been used in targeted cancer therapy. It is a beta-emitting isotope that can be used to deliver radiation directly to cancer cells, while
From Wikipedia
Lutetium is a chemical element; it has symbol Lu and atomic number 71. It is a silvery white metal, which resists corrosion in dry air, but not in moist air. Lutetium is the last element in the lanthanide series, and it is traditionally counted among the rare earth elements; it can also be classified as the first element of the sixth-period transition metals.