General | |
---|---|
Symbol | 90Y |
Names | yttrium-90, 90Y, Y-90 |
Protons (Z) | 39 |
Neutrons (N) | 51 |
Nuclide data | |
Half-life (t1/2) | 64.60±0.43 h[1] |
Isotopes of yttrium Complete table of nuclides |
Yttrium-90 (90
Y
) is an isotope of yttrium.[2] Yttrium-90 has found a wide range of uses in radiation therapy to treat some forms of cancer.[3]
90
Y
undergoes β− decay to zirconium-90 with a half-life of 64.1 hours[3] and a decay energy of 2.28 MeV with an average beta energy of 0.9336 MeV.[4] It also produces 0.01% 1.7 MeV[5] photons during its decay process to the 0+ state of 90Zr, followed by pair production.[6] The interaction between emitted electrons and matter can lead to the emission of Bremsstrahlung radiation.
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.[7][8]
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.[9] 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.[10] The microspheres become lodged in blood vessels surrounding the tumor and the resulting radiation damages the nearby tissue.[11] Radioembolization with 90Y significantly prolongs time-to-progression (TTP) of HCC,[12] has a tolerable adverse event profile, and improves patient quality of life more than do similar therapies.[13] 90Y has also found uses in tumor diagnosis by imaging the Bremsstrahlung radiation released by the microspheres.[14] Positron emission tomography after radioembolization is also possible.[15]