yttrium-90

{{SimpleNuclide|yttrium|90}} undergoes beta particles emissions/decay (β⁻ decay) to zirconium-90 with a half-life of 64.1 hours{{cite web |title=Y-90 Handling Precautions |work=Berkeley Lab |url=http://www2.lbl.gov/ehs/html/pdf/yttrium90.pdf |archive-url=https://web.archive.org/web/20180115001840/http://www2.lbl.gov/ehs/html/pdf/yttrium90.pdf |archive-date=15 January 2018 |access-date=2015-07-15}} and a decay energy of 2.28 MeV with an average beta energy of 0.9336 MeV.{{cite web |title=Live Chart of Nuclides |url=https://www-nds.iaea.org/relnsd/NdsEnsdf/QueryForm.html |publisher=International Atomic Energy Agency |date=2009 |access-date=2020-06-02}} It also produces 0.01% 1.7 MeV{{cite conference | vauthors = Rault E, Vandenberghe S, Staelens S, Lemahieu T |title=Optimization of Yttrium-90 Bremsstrahlung Imaging with Monte Carlo Simulations |conference=4th European Conference of the International Federation for Medical and Biological Engineering |volume=22 |pages=500–504 |year=2009 |url= https://books.google.com/books?id=83RUrYCMXOgC&pg=PA500 |access-date=21 October 2013 |publisher=Springer |location=Berlin, Heidelberg|isbn=9783540892083}} photons during its decay process to the 0⁺ state of ⁹⁰Zr, followed by pair production.{{cite journal| doi = 10.3390/atoms1010002| title = Emission of β+ Particles Via Internal Pair Production in the 0+ – 0+ Transition of 90Zr: Historical Background and Current Applications in Nuclear Medicine Imaging| year = 2013| last1 = d'Arienzo| first1 = Marco| journal = Atoms| volume = 1| issue = 1| pages = 2–12| bibcode = 2013Atoms...1....2D| doi-access = free| s2cid = 17248197| citeseerx = 10.1.1.361.5234}} 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.{{cite journal | vauthors = Chinol M, Hnatowich DJ | title = Generator-produced yttrium-90 for radioimmunotherapy | journal = Journal of Nuclear Medicine | volume = 28 | issue = 9 | pages = 1465–70 | date = September 1987 | pmid = 3625298 | citeseerx = 10.1.1.543.5481 }}{{cite web |url= http://radioisotopes.pnnl.gov/yttrium-90.stm |title=PNNL: Isotope Sciences Program - Yttrium-90 Production |date=February 2012 |publisher=PNNL |access-date=2012-10-23}} Yttrium-90 is also directly produced by neutron activation of natural yttrium targets (Yttrium is mononuclidic in ⁸⁹Y) in a nuclear research reactor.

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.{{cite journal | vauthors = Tong AK, Kao YH, Too CW, Chin KF, Ng DC, Chow PK | title = Yttrium-90 hepatic radioembolization: clinical review and current techniques in interventional radiology and personalized dosimetry | journal = The British Journal of Radiology | volume = 89 | issue = 1062 | pages = 20150943 | date = June 2016 | pmid = 26943239 | pmc = 5258157 | doi = 10.1259/bjr.20150943 }} Trans-arterial radioembolization is a procedure performed by interventional radiologists, in which ⁹⁰Ymicrospheres are injected into the arteries supplying the tumor.{{cite journal | vauthors = Kallini JR, Gabr A, Salem R, Lewandowski RJ | title = Transarterial Radioembolization with Yttrium-90 for the Treatment of Hepatocellular Carcinoma | journal = Advances in Therapy | volume = 33 | issue = 5 | pages = 699–714 | date = May 2016 | pmid = 27039186 | pmc = 4882351 | doi = 10.1007/s12325-016-0324-7 | df = mdy}} The microspheres come in two forms: resin, in which ⁹⁰Y is bound to the surface, and glass, in which ⁹⁰Y is directly incorporated into the microsphere during production.{{Cite journal |last1=Semaan |first1=Sahar |last2=Makkar |first2=Jasnit |last3=Lewis |first3=Sara |last4=Chatterji |first4=Manjil |last5=Kim |first5=Edward |last6=Taouli |first6=Bachir |date=November 2017 |title=Imaging of Hepatocellular Carcinoma Response After 90Y Radioembolization |url=https://ajronline.org/doi/10.2214/AJR.17.17993 |journal=American Journal of Roentgenology |volume=209 |issue=5 |pages=W263–W276 |doi=10.2214/AJR.17.17993 |pmid=29072955 |issn=0361-803X}} Once injected, the microspheres become lodged in blood vessels surrounding the tumor and the resulting radiation damages the nearby tissue.{{Cite web|url=https://www.ccalliance.org/blog/patient-support/understanding-sir-spheres-y-90-resin-microspheres|title=Understanding SIR-Spheres Y-90 Resin Microspheres|website=Colorectal Cancer Alliance|date=23 October 2015 |language=en|access-date=2019-10-21}} The distribution of the microspheres is dependent on several factors, including catheter tip positioning, distance to branching vessels, rate of injection, properties of particles, like size and density, and variability in tumor perfusion. Radioembolization with ⁹⁰Y significantly prolongs time-to-progression (TTP) of HCC,{{cite journal | vauthors = Salem R, Gordon AC, Mouli S, Hickey R, Kallini J, Gabr A, Mulcahy MF, Baker T, Abecassis M, Miller FH, Yaghmai V, Sato K, Desai K, Thornburg B, Benson AB, Rademaker A, Ganger D, Kulik L, Lewandowski RJ | display-authors = 6 | title = Y90 Radioembolization Significantly Prolongs Time to Progression Compared With Chemoembolization in Patients With Hepatocellular Carcinoma | journal = Gastroenterology | volume = 151 | issue = 6 | pages = 1155–1163.e2 | date = December 2016 | pmid = 27575820 | pmc = 5124387 | doi = 10.1053/j.gastro.2016.08.029}} has a tolerable adverse event profile, and improves patient quality of life more than do similar therapies.{{cite journal | vauthors = Salem R, Gilbertsen M, Butt Z, Memon K, Vouche M, Hickey R, Baker T, Abecassis MM, Atassi R, Riaz A, Cella D, Burns JL, Ganger D, Benson AB, Mulcahy MF, Kulik L, Lewandowski R | display-authors = 6 | title = Increased quality of life among hepatocellular carcinoma patients treated with radioembolization, compared with chemoembolization | journal = Clinical Gastroenterology and Hepatology | volume = 11 | issue = 10 | pages = 1358–1365.e1 | date = October 2013 | pmid = 23644386 | doi = 10.1016/j.cgh.2013.04.028 | doi-access = free }} ⁹⁰Y has also found uses in tumor diagnosis by imaging the Bremsstrahlung radiation released by the microspheres.{{cite journal | vauthors = Wright CL, Zhang J, Tweedle MF, Knopp MV, Hall NC | title = Theranostic Imaging of Yttrium-90 | journal = BioMed Research International | volume = 2015 | pages = 481279 | date = 2015-04-22 | pmid = 26106608 | pmc = 4464848 | doi = 10.1155/2015/481279 | doi-access = free }} Positron emission tomography after radioembolization is also possible.{{cite journal| pmc=3726297| year=2013| last1=Kao| first1=Y. H.| last2=Steinberg| first2=J. D.| last3=Tay| first3=Y. S.| last4=Lim| first4=G. K.| last5=Yan| first5=J.| last6=Townsend| first6=D. W.| last7=Takano| first7=A.| last8=Burgmans| first8=M. C.| last9=Irani| first9=F. G.| last10=Teo| first10=T. K.| last11=Yeow| first11=T. N.| last12=Gogna| first12=A.| last13=Lo| first13=R. H.| last14=Tay| first14=K. H.| last15=Tan| first15=B. S.| last16=Chow| first16=P. K.| last17=Satchithanantham| first17=S.| last18=Tan| first18=A. E.| last19=Ng| first19=D. C.| last20=Goh| first20=A. S.| title=Post-radioembolization yttrium-90 PET/CT - part 1: Diagnostic reporting| journal=EJNMMI Research| volume=3| issue=1| page=56| doi=10.1186/2191-219X-3-56| pmid=23883566| doi-access=free}}

Following treatment with ⁹⁰Y, imaging is performed to evaluate ⁹⁰Y delivery and absorption to evaluate coverage of target regions and involvement of normal tissue. This is typically performed using Bremsstrahlung imaging with single-photon emission computed tomography CT (SPECT/CT), or using ⁹⁰Y position imaging with positron emission tomography CT (PET/CT).

As ⁹⁰Y undergoes beta decay, broad spectrum bremsstrahlung radiation is emitted and is detectable with standard gamma cameras or SPECT.{{Cite journal |last1=Rice |first1=Mitchell |last2=Krosin |first2=Matthew |last3=Haste |first3=Paul |date=October 2021 |title=Post Yttrium-90 Imaging |journal=Seminars in Interventional Radiology |volume=38 |issue=4 |pages=460–465 |doi=10.1055/s-0041-1735569 |issn=0739-9529 |pmc=8497086 |pmid=34629714}}{{Cite journal |last1=Tong |first1=Aaron K. T. |last2=Kao |first2=Yung Hsiang |last3=Too |first3=Chow Wei |last4=Chin |first4=Kenneth F. W. |last5=Ng |first5=David C. E. |last6=Chow |first6=Pierce K. H. |date=June 2016 |title=Yttrium-90 hepatic radioembolization: clinical review and current techniques in interventional radiology and personalized dosimetry |journal=The British Journal of Radiology |volume=89 |issue=1062 |pages=20150943 |doi=10.1259/bjr.20150943 |issn=1748-880X |pmc=5258157 |pmid=26943239}} These modalities provide information about radioactive uptake of ⁹⁰Y, however, there is poor spatial information. Consequently, it is challenging to delineate anatomy and thereby evaluate tumor and normal tissue uptake. This led to the development of SPECT/CT, which combines the functional information of SPECT with the spatial information of CT to allow for more accurate ⁹⁰Y localization.

PET/CT and PET/MRI have superior spatial resolution compared to SPECT/CT because PET detects positron pairs produced from the decay of emitted positrons, negating the requirement for a physical collimator. This allows for better assessment of microsphere distribution and dose absorption. However, both PET/CT and PET/MRI are less widely available and more costly.

• Radionuclide therapy
• Selective internal radiation therapy

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Category:Isotopes of yttrium

Category:Medical isotopes