View source for Strontium-89

{{Short description|Isotope of strontium}}
{{Infobox isotope
 | alternate_names =
 | symbol =Sr
 | mass_number =89
 | mass =
 | num_neutrons =51
 | num_protons =38
 | abundance = [[Synthetic radioisotope|syn]]
 | halflife = {{val|50.56|u=days}}<ref name="nubase">{{NUBASE2020}}</ref>
 | image =
 | decay_product = yttrium-89
 | decay_symbol =Y
 | decay_mass =89
 | decay_mode1 =[[Beta decay]]
 | decay_energy1 =1.501<ref name="nndc">{{NNDC}}</ref>
 | decay_mode2 =
 | decay_energy2 =
 | decay_mode3 =
 | decay_energy3 =
 | decay_mode4 =
 | decay_energy4 =
 | parent =
 | parent_symbol =
 | parent_mass =
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}}

'''Strontium-89''' ({{SimpleNuclide|strontium|89}}) is a [[radioisotope|radioactive isotope]] of [[strontium]]  with a [[half-life]] of 50.56 days.<ref name="nubase" /> It undergoes [[beta decay|β<sup>−</sup> decay]] (with practically no gamma rays) into [[yttrium-89]].<ref name="nndc" /> Strontium-89 has application in medicine. It is also a [[fission product]], but is produced technically by [[neutron capture]] on ordinary strontium.<ref>[https://www.isotopes.gov/Ensuring-steady-supply-of-strontium-89]</ref>

== History ==
Strontium-89 was first synthesized in 1937 by D. W. Stewart et al. at the [[University of Michigan]]; it was synthesized via irradiation of stable strontium (the <sup>88</sup>Sr isotope) with [[deuteron]]s.<ref name=discovery>{{cite journal |title=Discovery of rubidium, strontium, molybdenum, and rhodium isotopes |last1=Parker |first1=A. M. |last2=Thoennessen |first2=M. |journal=Atomic Data and Nuclear Data Tables |date=2012 |volume=98 |issue=4 |pages=812–831 |doi=10.1016/j.adt.2012.06.001 |arxiv=1102.2388|bibcode=2012ADNDT..98..812P }}</ref> Biological properties and applications of strontium-89 were studied for the first time by Belgian scientist [[Charles Pecher]].<ref>{{Cite journal |last=Pecher |first=Charles |date=1941 |title=Biological Investigations with Radioactive Calcium and Strontium |journal=Proceedings of the Society for Experimental Biology and Medicine |language=en |volume=46 |issue=1 |pages=86–91 |doi=10.3181/00379727-46-11899 |s2cid=88173163 |issn=0037-9727 }}</ref><ref name=":2">{{Cite book |title=Biological investigations with radioactive calcium and strontium; preliminary report on the use of radioactive strontium in the treatment of metastatic bone cancer |last=Pecher |first=Charles |date=1942 |publisher=University of California Publications in Pharmacology |volume=2 |pages=117–150 |language=en |oclc=7837554 }}</ref> Pecher filed a patent in May 1941 for the synthesis of strontium-89 and [[yttrium-86]] using cyclotrons, and described the therapeutic use of strontium.<ref>{{Cite patent|country=US|number=2302470|title=Material and method for radiography|status=|pubdate=1941-05-14|gdate=|invent1=Pecher|inventor1-first=Charles}}</ref>

==Physiological effects and medical use==
[[File:Metastron (Strontium-89), GE Healthcare.jpg|thumb|Metastron, a preparation of strontium-89 [[Strontium chloride|chloride]] made by [[GE Healthcare]] and used for purposes such as prostate cancer treatment.<ref name="Strontium 89 (Metastron) treatment">{{cite web|title=Strontium 89 (Metastron) treatment|url=http://www.uhb.nhs.uk/metastron-treatment.htm|website=QEH Birmingham|publisher=NHS|access-date=23 November 2015}}</ref>]]
Strontium belongs to the same periodic family as [[calcium]] ([[alkaline earth metal]]s), and is metabolised in a similar fashion, preferentially targeting metabolically active regions of the bone. <sup>89</sup>Sr is an artificial radioisotope used in the treatment of osseous (bony) [[metastases]] of [[bone cancer]].<ref name="HalperinPerez2008">{{cite book|last1=Halperin|first1=Edward C.|last2=Perez|first2=Carlos A.|last3=Brady|first3=Luther W.|title=Perez and Brady's principles and practice of radiation oncology|url=https://books.google.com/books?id=NyeE6-aKnSYC&pg=PA1997|access-date=19 July 2011|year=2008|publisher=Lippincott Williams & Wilkins|isbn=978-0-7817-6369-1|pages=1997–}}</ref><ref name="BaumanCharette2005">{{cite journal|last1=Bauman|first1=Glenn|last2=Charette|first2=Manya|last3=Reid|first3=Robert|last4=Sathya|first4=Jinka|title=Radiopharmaceuticals for the palliation of painful bone metastases—a systematic review|journal=Radiotherapy and Oncology|volume=75|issue=3|year=2005|pages=258.E1–258.E13|issn=0167-8140|doi=10.1016/j.radonc.2005.03.003|pmid=16299924}}</ref>

In circumstances where cancer patients have widespread and painful bony metastases, the administration of <sup>89</sup>Sr results in the delivery of [[beta particle]]s directly to the area of bony problem, where calcium turnover is greatest.<ref name="MertensFilipczak1998">{{cite journal|last1=Mertens|first1=W. C.|last2=Filipczak|first2=L. A.|last3=Ben-Josef|first3=E.|last4=Davis|first4=L. P.|last5=Porter|first5=A. T.|title=Systemic bone-seeking radionuclides for palliation of painful osseous metastases: current concepts|journal=CA: A Cancer Journal for Clinicians|volume=48|issue=6|year=1998|pages=361–374|issn=0007-9235|doi=10.3322/canjclin.48.6.361|pmid=9838899|doi-access=free}}</ref> Consequently, intravenous or intracavity administration of <sup>89</sup>Sr may be helpful in the palliation of painful bony metastases, as it allows radiation to be targeted at metastatic lesions, inducing [[apoptosis]] of cells, membrane and protein damage. Subsequently, bone pain resulting from [[cytokine]] release at the site of lesions, bone-associated nerve compression and stretching of the [[periosteum]] may be reduced. Treatment with <sup>89</sup>Sr has been particularly effective in patients with hormonally-resistant [[prostate cancer]], often leading to a decreased requirement for [[opioid analgesic]]s, an increase in time until further radiation is needed, and a decrease in tumour markers.

==See also==
* [[Isotopes of strontium]]
* [[Alpharadin]], radium-223 with similar clinical use

==References==
{{Reflist}}

{{Radiation oncology}}
{{Therapeutic radiopharmaceuticals}}

[[Category:Isotopes of strontium|Strontium-089]]
[[Category:Medical isotopes]]