copper-64

{{see also|Isotopes of copper}}

{{sup|64}}Cu has a half-life of 12.7 hours and decays 17.9% by positron emission to nickel-64, 39.0% by beta decay to zinc-64, 43.1% by electron capture to {{sup|64}}Ni, and 0.475% gamma radiation/internal conversion. These emissions are 0.579 MeV, 0.653 MeV and 1.35 MeV for beta minus, positron, and gamma respectively.{{cite book|last1=Bé|first1=M.-M|last2=Chisté|first2=V|last3=Dulieu|first3=C|last4=Mougeot|first4=X|last5=Chechev|first5=V|last6=Kuzmenko|first6=N|last7=Kondev|first7=F|last8=Luca|first8=A|last9=Galán|first9=M|last10=Nichols|first10=A L|last11=Lee|first11=K B|last12=Arinc|first12=A|last13=Pearce|first13=A|last14=Huang|first14=X|last15=Wang|first15=B|editor1-last=Bé|editor1-first=M.-M|title=Table of radionuclides (Volume 6)|date=2006|publisher=BIPM|location=Sèvres|isbn=978-92-822-2242-3|page=13|url=http://www.bipm.org/en/publications/scientific-output/monographie-ri-5.html|chapter=Cu-64|chapter-url=http://www.nucleide.org/DDEP_WG/Nuclides/Cu-64_tables.pdf}}

Copper-64 can be produced by several different reactions with the most common methods using either a reactor or a particle accelerator. Thermal neutrons can produce {{sup|64}}Cu in low specific activity (the number of decays per second per amount of substance) and low yield through the {{sup|63}}Cu(n,γ){{sup|64}}Cu reaction. At the University of Missouri Research Reactor Center (MURR) {{sup|64}}Cu was produced using high-energy neutrons via the {{sup|64}}Zn(n,p){{sup|64}}Cu nuclear reaction in high specific activity but low yield. Using a biomedical cyclotron the {{sup|64}}Ni(p,n){{sup|64}}Cu nuclear reaction can produce large quantities of the nuclide with high specific activity.{{cite book |last1=Welch |first1=Michael |title=Handbook of Radiopharmaceuticals : radiochemistry and applications |last2=Redvanly |first2=Carol S. |date=2003 |publisher=Wiley |isbn=9780471495604 |location=New York |doi=10.1002/0470846380 |s2cid=94079329}}

As a positron emitter, {{sup|64}}Cu has been used to produce experimental and clinical radiopharmaceuticals for the imaging of a range of conditions. Its beta emissions also raise the possibility of therapeutic applications. Compared to typical PET radionuclides it has a relatively long half-life, which can be advantageous for therapy, and for imaging certain physiological processes.{{cite book |last1=IAEA |title=Cyclotron Produced Radionuclides: Emerging Positron Emitters for Medical Applications: 64Cu and 124I |date=2016 |publisher=International Atomic Energy Agency |location=Vienna |isbn=978-92-0-109615-9 |url=https://www.iaea.org/publications/10791/cyclotron-produced-radionuclides-emerging-positron-emitters-for-medical-applications-64cu-and-124i |language=en}}{{cite journal |last1=Gutfilen |first1=Bianca |last2=Souza |first2=Sergio AL |last3=Valentini |first3=Gianluca |title=Copper-64: a real theranostic agent |journal=Drug Design, Development and Therapy |date=2 October 2018 |volume=12 |pages=3235–3245 |doi=10.2147/DDDT.S170879 |pmid=30323557 |pmc=6173185|doi-access=free}}{{cite journal |last1=Zhou |first1=Yeye |last2=Li |first2=Jihui |last3=Xu |first3=Xin |last4=Zhao |first4=Man |last5=Zhang |first5=Bin |last6=Deng |first6=Shengming |last7=Wu |first7=Yiwei |title=64 Cu-based Radiopharmaceuticals in Molecular Imaging |journal=Technology in Cancer Research & Treatment |date=1 January 2019 |volume=18 |pages=153303381983075 |doi=10.1177/1533033819830758 |pmid=30764737 |pmc=6378420|doi-access=free}}

Experimental preclinical work has shown that {{sup|64}}Cu linked to methanephosphonate functional groups has potential as a bone imaging agent.{{cite journal|last1=Sun|first1=Xiankai|last2=Wuest|first2=Melinda|last3=Kovacs|first3=Zoltan|last4=Sherry|first4=Dean|last5=Motekaitis|first5=Ramunas|last6=Wang|first6=Zheng|last7=Martell|first7=Arthur|last8=Welch|first8=Michael|last9=Anderson|first9=Carolyn|title=In vivo behavior of copper-64-labeled methanephosphonate tetraaza macrocyclic ligands|journal=Journal of Biological Inorganic Chemistry|date=1 January 2003|volume=8|issue=1–2|pages=217–225|doi=10.1007/s00775-002-0408-5|pmid=12459917|s2cid=22225650}}

{{see also|Copper (64Cu) oxodotreotide}}

Neuroendocrine tumors (NETs) are localised clinically using a range of DOTA based radiopharmaceuticals. For PET imaging these are typically Gallium-68 based. A commercial {{sup|64}}Cu-DOTA-TATE product has been FDA approved for localization of somatostatin receptor positive NETs since 2020.{{cite web |title=DETECTNET |url=http://www.accessdata.fda.gov/scripts/cder/daf/index.cfm?event=overview.process&varApplNo=213227 |archive-url=https://web.archive.org/web/20201127064452/https://www.accessdata.fda.gov/scripts/cder/daf/index.cfm?event=overview.process&varApplNo=213227 |url-status=dead |archive-date=November 27, 2020 |website=Drugs@FDA |publisher=Food and Drug Administration |access-date=25 April 2021}}{{cite journal |last1=Eychenne |first1=Romain |last2=Bouvry |first2=Christelle |last3=Bourgeois |first3=Mickael |last4=Loyer |first4=Pascal |last5=Benoist |first5=Eric |last6=Lepareur |first6=Nicolas |title=Overview of Radiolabeled Somatostatin Analogs for Cancer Imaging and Therapy |journal=Molecules |date=2 September 2020 |volume=25 |issue=17 |pages=4012 |doi=10.3390/molecules25174012 |pmid=32887456 |pmc=7504749|doi-access=free}}

The Bombesin peptide has been shown to be overexpressed in BB2 receptors in prostate cancer. CB-TE2A a stable chelation system for {{sup|64}}Cu was incorporated with Bombesin analogs for in vitro and in vivo studies of prostate cancer. PET-CT imagining studies showed that it underwent uptake into prostate tumor xenografts selectively with decreased uptake into non target tissues. Other preclinical studies have shown that by targeting the gastrin-releasing peptide receptor pancreatic and breast cancer can also be detected.{{cite journal|last1=Parry|first1=Jesse J.|last2=Andrews|first2=Rebecca|last3=Rogers|first3=Buck E.|title=MicroPET Imaging of Breast Cancer Using Radiolabeled Bombesin Analogs Targeting the Gastrin-releasing Peptide Receptor|journal=Breast Cancer Research and Treatment|date=13 July 2006|volume=101|issue=2|pages=175–183|doi=10.1007/s10549-006-9287-8|pmid=16838112|s2cid=25579379}}

Ethylglyoxal bis(thiosemicarbazone) (ETS) has potential utility as a PET radiopharmaceutical with the various isotopes of copper. {{sup|64}}Cu-ETS has been used for experimental preclinical myocardial, cerebral and tumor perfusion evaluations, with a linear relationship between the renal uptake and blood flow. Renal perfusion can also be evaluated with CT or MRI instead of PET, but with drawbacks: CT requires administration of potentially allergenic contrast agents. MRI avoids use of ionising radiation but is difficult to implement, and often suffers from motion artefacts. PET with {{sup|64}}Cu can offer quantitative measurements of renal perfusion.{{cite journal|last1=Green|first1=Mark A.|last2=Mathias|first2=Carla J.|last3=Willis|first3=Lynn R.|last4=Handa|first4=Rajash K.|last5=Lacy|first5=Jeffrey L.|last6=Miller|first6=Michael A.|last7=Hutchins|first7=Gary D.|title=Assessment of Cu-ETS2 as a PET radiopharmaceutical for evaluation of regional renal perfusion|journal=Nuclear Medicine and Biology|date=April 2007|volume=34|issue=3|pages=247–255|doi=10.1016/j.nucmedbio.2007.01.002|pmid=17383574}}{{cite book |last1=Welch |first1=Michael J. |last2=Redvanly |first2=Carol S. |title=Handbook of Radiopharmaceuticals: Radiochemistry and Applications |date=2003 |publisher=John Wiley & Sons |isbn=978-0-471-49560-4 |page=407 |url=https://books.google.com/books?id=WfyE31mvGIcC&pg=PA407 |language=en}}

Wilson disease is a rare condition in which copper is retained excessively in the body. Toxic levels of copper can lead to organ failure and premature death. {{sup|64}}Cu has been used experimentally to study whole body retention of copper in subjects with this disease. The technique can also separate heterozygous carriers and homozygous normals.{{cite journal |last1=Reed |first1=Emily |last2=Lutsenko |first2=Svetlana |last3=Bandmann |first3=Oliver |title=Animal models of Wilson disease |journal=Journal of Neurochemistry |date=2018 |volume=146 |issue=4 |pages=356–373 |doi=10.1111/jnc.14323 |pmid=29473169 |pmc=6107386|doi-access=free}}

Image:Copper-ATSM-3D-spacefill.png

{{sup|64}}Cu-ATSM (diacetyl-bis(N4-methylthiosemicarbazone)) has been shown to increase the survival time of tumor-bearing animals. Areas of low oxygen retention have been shown to be resistant to external beam radiotherapy because hypoxia reduces the lethal effects of ionizing radiation. {{sup|64}}Cu was believed to kill these cells because of its unique decay properties. In animal models having colorectal tumors with and without induced hypoxia, Cu-ATSM was preferentially taken up by hypoxic cells over normoxic cells. The results demonstrated that this compound increased survival of the tumor bearing hamsters compared with controls.{{cite journal|last1=Lewis|first1=J. S.|last2=Laforest|first2=R.|last3=Buettner|first3=T. L.|last4=Song|first4=S.-K.|last5=Fujibayashi|first5=Y.|last6=Connett|first6=J. M.|last7=Welch|first7=M. J.|title=Copper-64-diacetyl-bis(N4-methylthiosemicarbazone): An agent for radiotherapy|journal=Proceedings of the National Academy of Sciences|date=30 January 2001|volume=98|issue=3|pages=1206–1211|doi=10.1073/pnas.98.3.1206|pmc=14733|bibcode=2001PNAS...98.1206L|pmid=11158618|doi-access=free}}

• Nuclear medicine
• Radioactive tracer
• Radionuclide
• Radiopharmacology

{{Reflist}}

Category:Isotopes of copper

Category:Positron emitters

Category:Medical isotopes