Ytterbium has seven stable isotopes and two of them are used for medical and industrial purposes. Yb-168 is used for the production of Yb-169 and this radioisotope is used as a radiation source in gamma cameras. Yb-169 is also used in the medical field where it has been proposed as an alternative for I-125 and Pd-103 in the treatment of prostate cancer while it is also used for diagnostics in the gastrointestinal tract. Yb-176 can be used as a target for the production of carrier-free Lu-177 with a high specific activity. Yb-171 in an excited state has been proposed as an optical frequency standard, while the other Yb isotopes are used in various physics experiments.
