Lutetium-177

Naturally occurring lutetium (₇₁Lu) is composed of one stable isotope ¹⁷⁵Lu (97.41% natural abundance) and one long-lived radioisotope, ¹⁷⁶Lu with a half-life of 3.78 × 10¹⁰ years (2.59% natural abundance). Thirty-five 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 (t_1/2 160.4 days), ^174mLu (t_1/2 142 days) and ^178mLu (t_1/2 23.1 minutes).

The isotopes of lutetium range in mass number from 149 to 184. The primary decay mode before the most abundant stable isotope, ¹⁷⁵Lu, is electron capture (with some alpha and positron emission), and the primary mode after is beta emission. The primary decay products before ¹⁷⁵Lu are isotopes of ytterbium and the primary products after are isotopes of hafnium. All isotopes of lutetium are either radioactive or, in the case of ¹⁷⁵Lu, observationally stable, meaning that ¹⁷⁵Lu is predicted to be radioactive but no actual decay has been observed.

List of isotopes

Lutetium-177

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.

• Isotope masses from:
  • Audi, Georges; Bersillon, Olivier; Blachot, Jean; Wapstra, Aaldert Hendrik (2003), "The NUBASE evaluation of nuclear and decay properties", Nuclear Physics A, 729: 3–128, Bibcode:2003NuPhA.729....3A, doi:10.1016/j.nuclphysa.2003.11.001
• Isotopic compositions and standard atomic masses from:
  • de Laeter, John Robert; Böhlke, John Karl; De Bièvre, Paul; Hidaka, Hiroshi; Peiser, H. Steffen; Rosman, Kevin J. R.; Taylor, Philip D. P. (2003). "Atomic weights of the elements. Review 2000 (IUPAC Technical Report)". Pure and Applied Chemistry. 75 (6): 683–800. doi:10.1351/pac200375060683.
  • Wieser, Michael E. (2006). "Atomic weights of the elements 2005 (IUPAC Technical Report)". Pure and Applied Chemistry. 78 (11): 2051–2066. doi:10.1351/pac200678112051.
• "News & Notices: Standard Atomic Weights Revised". International Union of Pure and Applied Chemistry. 19 October 2005.
• Half-life, spin, and isomer data selected from the following sources.
  • Audi, Georges; Bersillon, Olivier; Blachot, Jean; Wapstra, Aaldert Hendrik (2003), "The NUBASE evaluation of nuclear and decay properties", Nuclear Physics A, 729: 3–128, Bibcode:2003NuPhA.729....3A, doi:10.1016/j.nuclphysa.2003.11.001
  • National Nuclear Data Center. "NuDat 2.x database". Brookhaven National Laboratory.
  • Holden, Norman E. (2004). "11. Table of the Isotopes". In Lide, David R. (ed.). CRC Handbook of Chemistry and Physics (85th ed.). Boca Raton, Florida: CRC Press. ISBN 978-0-8493-0485-9.