Yttrium-90

Yttrium-90 (⁹⁰
Y
) is an isotope of yttrium. Yttrium-90 has found a wide range of uses in radiation therapy to treat some forms of cancer.

Decay

⁹⁰
Y
undergoes β⁻ decay to zirconium-90 with a half-life of 64.1 hours and a decay energy of 2.28 MeV with an average beta energy of 0.9336 MeV. It also produces 0.01% 1.7 MeVphotons during its decay process to the 0⁺ state of ⁹⁰Zr, followed by pair production. The interaction between emitted electrons and matter can lead to the emission of Bremsstrahlung radiation.

Production

Yttrium-90 is produced by the nuclear decay of strontium-90 which has a half-life of nearly 29 years and is a fission product of uranium used in nuclear reactors. As the strontium-90 decays, chemical high-purity separation is used to isolate the yttrium-90 before precipitation.

Medical application

⁹⁰Y plays a significant role in the treatment of hepatocellular carcinoma (HCC), leukemia, and lymphoma, although it has the potential to treat a range of tumors. Trans-arterial radioembolization is a procedure performed by interventional radiologists in which microspheres are impregnated with ⁹⁰Y and injected into the arteries supplying the tumor. The microspheres become lodged in blood vessels surrounding the tumor and the resulting radiation damages the nearby tissue.Radioembolization with ⁹⁰Y significantly prolongs time-to-progression (TTP) of HCC, has a tolerable adverse event profile, and improves patient quality of life more than do similar therapies.⁹⁰Y has also found uses in tumor diagnosis by imaging the Bremsstrahlung radiation released by the microspheres.Positron emission tomography after radioembolization is also possible.

See also

• Isotopes of yttrium
• Unsealed source radiotherapy

External links

• CID {{{1}}} from PubChem