View source for Radionuclide therapy

{{Short description|Type of radiation therapy}}
{{EngvarB|date = February 2019}}
{{Infobox medical intervention |
  Name        = Radionuclide therapy |
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  ICD9        = {{ICD9proc|92.28}} |
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'''Radionuclide therapy''' ('''RNT''', also known as '''unsealed source radiotherapy''' or '''molecular radiotherapy''') uses [[radioactivity|radioactive]] substances called [[radiopharmaceutical]]s to treat medical conditions, particularly [[cancer]]. These are introduced into the body by various means ([[Injection (medicine)|injection]] or [[Eating|ingestion]] are the two most commonplace) and localise to specific locations, [[Organ (anatomy)|organs]] or tissues depending on their properties and administration routes. This includes anything from a simple compound such as [[sodium iodide]] that locates to the [[thyroid]] via trapping the iodide ion, to complex biopharmaceuticals such as recombinant antibodies which are attached to radionuclides and seek out specific [[antigens]] on cell surfaces.<ref>{{cite journal|last1=Buscombe|first1=J.|last2=Navalkissoor|first2=S.|title=Molecular radiotherapy|journal=Clinical Medicine|date=1 August 2012|volume=12|issue=4|pages=381–386|doi=10.7861/clinmedicine.12-4-381|pmid=22930888|pmc=4952132|doi-access=free}}</ref><ref>{{cite journal |last1=Volkert |first1=Wynn A. |last2=Hoffman |first2=Timothy J. |title=Therapeutic Radiopharmaceuticals |journal=Chemical Reviews |volume=99 |issue=9 |year=1999 |pages=2269–2292 |doi=10.1021/cr9804386 |pmid=11749482}}</ref>

This is a type of targeted therapy which uses the physical, chemical and biological properties of the radiopharmaceutical to target areas of the body for radiation treatment.<ref name="1.">{{cite book|last1=Nicol|first1=Alice|last2=Waddington|first2=Wendy|title=Dosimetry for radionuclide therapy|date=2011|publisher=Institute of Physics and Engineering in Medicine|location=York|isbn=978-1-903613-46-7}}</ref> The related diagnostic modality of [[nuclear medicine]] employs the same principles but uses different types or quantities of radiopharmaceuticals in order to [[Functional imaging|image]] or analyse functional systems within the patient.

RNT contrasts with sealed-source therapy ([[brachytherapy]]) where the radionuclide remains in a capsule or metal wire during treatment and needs to be physically placed precisely at the treatment position.<ref>{{cite book|editor1-first=Elizabeth A|editor1-last=Martin|editor2-first=Tanya A|editor2-last=McFerran|title=A dictionary of nursing|date=2014|publisher=Oxford University Press|location=Oxford|isbn=978-0-19-966637-9|edition=6th|doi=10.1093/acref/9780199666379.001.0001}}</ref>

When the radionuclides are [[ligands]] (such as with [[Lutathera]] and [[Pluvicto]]), the technique is also known as '''radioligand therapy'''.
<ref>[https://www.cnbc.com/2023/02/11/radioligand-cancer-therapy-forces-manufacturers-to-race-the-clock.html Radioligand therapy, a 'game-changer' for cancer treatment, forces manufacturers to race against a ticking clock]</ref>

==Clinical use==
===Thyroid conditions===
{{see also|Iodine-131#Medical use}}
[[Iodine-131]] (<sup>131</sup>I) is the most common RNT worldwide and uses the simple compound [[sodium iodide]] with a radioactive isotope of [[iodine]]. The patient (human or animal) may ingest an oral solid or liquid amount or receive an intravenous injection of a solution of the compound. The iodide ion is selectively taken up by the [[thyroid]] gland. Both benign conditions like [[thyrotoxicosis]] and certain malignant conditions like [[papillary thyroid cancer]] can be treated with the radiation emitted by [[radioiodine]].<ref>{{cite journal|last1=Silberstein|first1=E. B.|last2=Alavi|first2=A.|last3=Balon|first3=H. R.|last4=Clarke|first4=S. E. M.|last5=Divgi|first5=C.|last6=Gelfand|first6=M. J.|last7=Goldsmith|first7=S. J.|last8=Jadvar|first8=H.|last9=Marcus|first9=C. S.|last10=Martin|first10=W. H.|last11=Parker|first11=J. A.|last12=Royal|first12=H. D.|last13=Sarkar|first13=S. D.|last14=Stabin|first14=M.|last15=Waxman|first15=A. D.|title=The SNMMI Practice Guideline for Therapy of Thyroid Disease with 131I 3.0|journal=Journal of Nuclear Medicine|date=11 July 2012|volume=53|issue=10|pages=1633–1651|doi=10.2967/jnumed.112.105148|pmid=22787108|doi-access=free}}</ref> Iodine-131 produces [[beta particle|beta]] and [[gamma ray|gamma]] radiation. The beta radiation released damages both normal thyroid tissue and any thyroid cancer that behaves like normal thyroid in taking up iodine, so providing the therapeutic effect, whilst most of the gamma radiation escapes the patient's body.<ref>{{cite book|last1=IAEA|title=Manual on therapeutic uses of iodine-131|date=1996|publisher=[[International Atomic Energy Agency]]|location=Vienna|page=7|url=http://www.iaea.org/inis/collection/NCLCollectionStore/_Public/28/027/28027984.pdf}}</ref>

Most of the iodine not taken up by thyroid tissue is [[excretion|excreted]] through the [[kidney]]s into the [[urine]]. After radioiodine treatment the urine will be radioactive or 'hot', and the patients themselves will also emit [[gamma radiation]]. Depending on the amount of radioactivity administered, it can take several days for the radioactivity to reduce to the point where the patient does not pose a [[radiation protection|radiation hazard]] to bystanders. Patients are often treated as [[inpatient]]s and there are international guidelines, as well as legislation in many countries, which govern the point at which they may return home.<ref>{{cite book|last1=IAEA|last2=ICRP|title=Release of patients after radionuclide therapy|date=2009|publisher=[[International Atomic Energy Agency]]|location=Vienna, Austria|isbn=978-92-0-108909-0|url=http://www-pub.iaea.org/books/iaeabooks/8179/Release-of-Patients-After-Radionuclide-Therapy}}</ref>

===Bone metastasis===
{{see also|Targeted alpha-particle therapy}}
[[Radium-223]] chloride, [[strontium-89]] chloride and [[samarium-153]] [[EDTMP]] are used to treat [[Bone metastasis|secondary cancer]] in the bones.<ref>{{cite journal|last1=Den|first1=RB|last2=Doyle|first2=LA|last3=Knudsen|first3=KE|title=Practical guide to the use of radium 223 dichloride.|journal=The Canadian Journal of Urology|date=April 2014|volume=21|issue=2 Supp 1|pages=70–6|pmid=24775727}}</ref><ref>{{cite journal|last1=Lutz|first1=Stephen|last2=Berk|first2=Lawrence|last3=Chang|first3=Eric|last4=Chow|first4=Edward|last5=Hahn|first5=Carol|last6=Hoskin|first6=Peter|last7=Howell|first7=David|last8=Konski|first8=Andre|last9=Kachnic|first9=Lisa|last10=Lo|first10=Simon|last11=Sahgal|first11=Arjun|last12=Silverman|first12=Larry|last13=von Gunten|first13=Charles|last14=Mendel|first14=Ehud|last15=Vassil|first15=Andrew|last16=Bruner|author-link16=Deborah Watkins Bruner|first16=Deborah Watkins|last17=Hartsell|first17=William|title=Palliative Radiotherapy for Bone Metastases: An ASTRO Evidence-Based Guideline|journal=International Journal of Radiation Oncology, Biology, Physics|date=March 2011|volume=79|issue=4|pages=965–976|doi=10.1016/j.ijrobp.2010.11.026|pmid=21277118|doi-access=free}}</ref> [[Radium]] and [[strontium]] mimic calcium in the body.<ref>{{cite journal|last1=Goyal|first1=Jatinder|last2=Antonarakis|first2=Emmanuel S.|title=Bone-targeting radiopharmaceuticals for the treatment of prostate cancer with bone metastases|journal=Cancer Letters|date=October 2012|volume=323|issue=2|pages=135–146|doi=10.1016/j.canlet.2012.04.001|pmc=4124611|pmid=22521546}}</ref> [[Samarium]] is bound to tetraphosphate [[EDTMP]], phosphates are taken up by [[osteoblast]]ic (bone forming) repairs that occur adjacent to some metastatic lesions.<ref>{{cite journal|last1=Serafini|first1=AN|title=Samarium Sm-153 lexidronam for the palliation of bone pain associated with metastases.|journal=Cancer|date=15 June 2000|volume=88|issue=12 Suppl|pages=2934–9|doi=10.1002/1097-0142(20000615)88:12+<2934::AID-CNCR9>3.0.CO;2-S|pmid=10898337|s2cid=45863868 }}</ref>

===Bone marrow conditions===
[[beta particle|Beta]] emitting [[phosphorus-32]] (<sup>32</sup>P), as sodium phosphate, is used to treat [[myeloproliferative disease|overactive]] [[bone marrow]], in which it is otherwise naturally metabolised.<ref>{{cite journal|last1=Tennvall|first1=Jan|last2=Brans|first2=Boudewijn|title=EANM procedure guideline for 32P phosphate treatment of myeloproliferative diseases|journal=European Journal of Nuclear Medicine and Molecular Imaging|date=30 March 2007|volume=34|issue=8|pages=1324–1327|doi=10.1007/s00259-007-0407-4|pmid=17396258|s2cid=21759615}}</ref><ref>{{cite book|last1=Raj|first1=Gurdeep|title=Advanced Inorganic Chemistry Vol 1|publisher=Krishna Prakashan Media|isbn=978-81-87224-03-7|page=497|url=https://books.google.com/books?id=0uwDTrxyaB8C&pg=PA497|language=en}}</ref><ref>{{cite book|last1=Gropper|first1=Sareen S.|last2=Smith|first2=Jack L.|title=Advanced Nutrition and Human Metabolism|publisher=Cengage Learning|isbn=978-1-133-10405-6|page=432|url=https://books.google.com/books?id=3R0Yeu79jfQC&pg=PA432|language=en|date=2012-06-01}}</ref>

===Joint inflammation===
====Yttrium-90 colloid====
An [[yttrium-90]] (<sup>90</sup>Y) [[colloid]]al suspension is used for [[radiosynovectomy]] in the [[knee]] joint.<ref>{{cite journal|last1=Siegel|first1=Michael E.|last2=Siegel|first2=Herrick J.|last3=Luck|first3=James V.|title=Radiosynovectomy's clinical applications and cost effectiveness: A review|journal=Seminars in Nuclear Medicine|date=October 1997|volume=27|issue=4|pages=364–371|doi=10.1016/S0001-2998(97)80009-8|pmid=9364646}}</ref>

===Liver tumours===
====Yttrium-90 spheres====
{{main|Selective internal radiation therapy}}
<sup>90</sup>Y in the form of a [[resin]] or glass spheres can be used to treat primary and metastatic liver cancers.<ref>{{cite journal|last1=Allen|first1=Theresa M.|title=Ligand-targeted therapeutics in anticancer therapy|journal=Nature Reviews Cancer|date=October 2002|volume=2|issue=10|pages=750–763|doi=10.1038/nrc903|pmid=12360278|s2cid=21014917}}</ref>

===Neuroendocrine tumours===
====Iodine-131 mIBG====
<sup>131</sup>I-mIBG ([[metaiodobenzylguanidine]]) is used for the treatment of [[phaeochromocytoma]] and [[neuroblastoma]].<ref>{{cite journal|last1=Sharp|first1=Susan E.|last2=Trout|first2=Andrew T.|last3=Weiss|first3=Brian D.|last4=Gelfand|first4=Michael J.|title=MIBG in Neuroblastoma Diagnostic Imaging and Therapy|journal=RadioGraphics|date=January 2016|volume=36|issue=1|pages=258–278|doi=10.1148/rg.2016150099|pmid=26761540|doi-access=}}</ref>

====Lutetium-177====
{{see also|Peptide receptor radionuclide therapy}}
<sup>177</sup>Lu is bound with a [[DOTA (chelator)|DOTA]] [[chelator]] to target [[neuroendocrine tumours]].<ref>{{cite journal |last1=Maqsood |first1=Muhammad Haisum |last2=Tameez Ud Din |first2=Asim |last3=Khan |first3=Ameer H |title=Neuroendocrine Tumor Therapy with Lutetium-177: A Literature Review |journal=Cureus |date=30 January 2019 |volume=11 |issue=1 |article-number=e3986 |doi=10.7759/cureus.3986 |pmid=30972265 |pmc=6443107|doi-access=free}}</ref>

==Experimental antibody based methods==

At the [[Institute for Transuranium Elements]] (ITU) work is being done on alpha-immunotherapy, this is an experimental method where antibodies bearing [[alpha radiation|alpha]] isotopes are used. [[Bismuth-213]] is one of the isotopes which has been used. This is made by the alpha decay of [[actinium-225]]. The generation of one short-lived isotope from longer lived isotope is a useful method of providing a portable supply of a short-lived isotope. This is similar to the generation of [[technetium-99m]] by a [[technetium generator]]. The actinium-225 is made by the irradiation of [[radium-226]] with a [[cyclotron]].<ref>{{cite journal|last1=Morgenstern|first1=Alfred|last2=Bruchertseifer|first2=Frank|last3=Apostolidis|first3=Christos|title=Bismuth-213 and Actinium-225 – Generator Performance and Evolving Therapeutic Applications of Two Generator-Derived Alpha-Emitting Radioisotopes|journal=Current Radiopharmaceuticals|date=1 June 2012|volume=5|issue=3|pages=221–227|doi=10.2174/1874471011205030221|pmid=22642390}}</ref>

== References ==
{{reflist|30em}}

{{Radiation oncology}}
{{Radiopharmaceuticals}}

[[Category:Radiation therapy]]
[[Category:Nuclear medicine]]