Naturally occurring lutetium (71Lu) is composed of one stable isotope175Lu (97.41% natural abundance) and one long-lived radioisotope, 176Lu with a half-life of 37 billion years (2.59% natural abundance). Forty radioisotopes have been characterized, with the most stable, besides 176Lu, being 174Lu with a half-life of 3.31 years, and 173Lu with a half-life of 1.37 years. All of the remaining radioactive isotopes have half-lives that are less than 9 days, and the majority of these have half-lives that are less than half an hour. This element also has 18 meta states, with the most stable being 177mLu (t1/2 160.4 days), 174mLu (t1/2 142 days) and 178mLu (t1/2 23.1 minutes).
Lutetium (177Lu) chloride, sold under the brand name Lumark among others, is used for radiolabeling other medicines, either as an anti-cancer therapy or for scintigraphy (medical radio-imaging). Its most common side effects are anaemia (low red blood cell counts), thrombocytopenia (low blood platelet counts), leucopenia (low white blood cell counts), lymphopenia (low levels of lymphocytes, a particular type of white blood cell), nausea (feeling sick), vomiting and mild and temporary hair loss.[8][9]
^Tarasov, O. B.; Gade, A.; Fukushima, K.; et al. (2024). "Observation of New Isotopes in the Fragmentation of 198Pt at FRIB". Physical Review Letters. 132 (072501). doi:10.1103/PhysRevLett.132.072501.
^"Lumark EPAR". European Medicines Agency. 17 September 2018. Retrieved 7 May 2020. Text was copied from this source for which copyright belongs to the European Medicines Agency. Reproduction is authorized provided the source is acknowledged.
^"EndolucinBeta EPAR". European Medicines Agency (EMA). 17 September 2018. Retrieved 7 May 2020. Text was copied from this source for which copyright belongs to the European Medicines Agency. Reproduction is authorized provided the source is acknowledged.