Yttrium-90 (90 Y ) is a radioisotope of
yttrium.[2] Yttrium-90 has found a wide range of uses in
radiation therapy to treat some forms of
cancer.[3]
Decay
90 Y undergoes beta particles emissions/decay (
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.
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.[7][8] Yttrium-90 is also directly produced by neutron activation of natural yttrium targets (Yttrium is mononuclidic in 89Y) in a nuclear research reactor.
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.[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]
^Chinol M, Hnatowich DJ (September 1987). "Generator-produced yttrium-90 for radioimmunotherapy". Journal of Nuclear Medicine. 28 (9): 1465–70.
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PMID3625298.