Which nuclide is used to investigate human thyroid

Longer-term NorthStar is considering a non-reactor approach. In , NorthStar Medical Radioisotopes signed an agreement with Westinghouse to investigate production of Mo in nuclear power reactors using its Incore Instrumentation System. It is aiming to set up a 44, m 2 radioisotope production facility in Columbia, Missouri. The NRC approved the plans in May However, Nordion withdrew from the project in April citing delays and cost overruns that had increased the project's commercial risk.

An earlier proposal for Mo production involving an innovative reactor and separation technology has lapsed. They planned to use Aqueous Homogeneous Reactor AHR technology with LEU in small kW units where the fuel is mixed with the moderator and the U forms both the fuel and the irradiation target.

As fission proceeds the solution is circulated through an extraction facility to remove the fission products with Mo and then back into the reactor vessel, which is at low temperature and pressure. In mid Los Alamos National Laboratory announced that it had recovered Mo from low-enriched sulphate reactor fuel in solution, raising the prospect of this process becoming associated with commercial reprocessing plants as at La Hague in France.

JSC Isotope was founded in and incorporated in Brazil is a major export market. Its product portfolio includes more than 60 radioisotopes produced in cyclotrons, nuclear reactors by irradiation of targets, or recovered from spent nuclear fuel, as well as hundreds of types of ionizing radiation sources and compounds tagged with radioactive isotopes. It has more than 10, scientific and industrial customers for industrial isotopes in Russia.

The Karpov Institute gets some supply from Leningrad nuclear power plant. Australia's Opal reactor has the capacity to produce half the world supply of Mo, and with the ANSTO Nuclear Medicine Project will be able to supply at least one-quarter of world demand from Tcm or Mo can also be produced in small quantities from cyclotrons and accelerators, in a cyclotron by bombarding a Mo target with a proton beam to produce Tcm directly, or in a linear accelerator to generate Mo by bombarding an Mo target with high-energy X-rays.

It is generally considered that non-reactor methods of producing large quantities of useful Tc are some years away.

At present the cost is at least three times and up to ten times that of the reactor route, and Mo is available only from Russia. If Tc is produced directly in a cyclotron, it needs to be used quickly, and the co-product isotopes are a problem. An LEU target solution is irradiated with low-energy neutrons in a subcritical assembly — not a nuclear reactor.

The neutrons are generated through a beam-target fusion reaction caused by accelerating deuterium ions into tritium gas, using a particle accelerator. SHINE is an acronym for 'subcritical hybrid intense neutron emitter'. Construction at Janesville, Wisconsin commenced in August on 'Building One' and in May on the main production facility, which would eventually be capable of producing over one-third of global Mo demand. A hour test run of Phoenix's high-flux neutron generator was in June Its Cassiopeia plant at Janesville is to produce , doses of Lu per year from At Lansing in Michigan, Niowave is using a superconducting electron linear accelerator to produce isotopes from fission of low-enriched uranium.

It reports production of Mo, I, Sr and Xe among many others. Cobalt has mostly come from Candu power reactors by irradiation of Co in special rods for up to three years or five in RBMK , and production is being expanded.

Most of this Co is used for sterilization, with high-specific-activity Co for cancer treatment. Much of the Co is supplied through Nordion.

The process will use Areva NP's patent-pending method of producing radioisotopes using a heavy water nuclear power plant. Orano Med built a small plant at Bessines-sur-Gartempe in France to provide Pb from irradiated thorium, and this came online in It was extended with a fivefold increase in capacity in A second plant has been built at Plano in Texas, operating from , and a new industrial-scale plant is planned for Caen in France. Ra is a natural decay product of Th, and indirectly, of Th Some iodine is produced at Leningrad nuclear power plant from tellurium oxide, using irradiation channels in the RBMK reactors.

A contract with the Karpov Institute of Physical Chemistry provides for delivery of 2. In Rosatom announced the establishment of a radiopharmaceutical production plant at the Institute of Reactor Materials IRM , which had started with lutetium, producing 24 TBq of it in Ci. The IRM will also produce iodine and iridium, and its products will be distributed through Isotop. Urenco Stable Isotopes at Almelo uses centrifuge technology to produce by centrifuge enrichment a variety of stable isotopes for medical applications.

A new cascade commissioned in is designed to produce multiple isotopes, including those of cadmium, germanium, iridium, molybdenum, selenium, tellurium, titanium, tungsten, xenon and zinc. Many radioisotopes are made in nuclear reactors, some in cyclotrons. Generally neutron-rich ones and those resulting from nuclear fission need to be made in reactors; neutron-depleted ones such as PET radionuclides are made in cyclotrons with energy ranging from 9 to 19 MeV.

There are about 40 activation product radioisotopes and five fission product ones made in reactors. Bismuth half-life: 46 min : Used for targeted alpha therapy TAT , especially cancers, as it has a high energy 8. Chromium 28 d : Used to label red blood cells for monitoring, and to quantify gastro-intestinal protein loss or bleeding.

Cobalt 5. High-specific-activity HSA Co is used for brain cancer treatment. Dysprosium 2 h : Used as an aggregated hydroxide for synovectomy treatment of arthritis.

Holmium 26 h : Being developed for diagnosis and treatment of liver tumours. Administered as microspheres. Iodine 60 d : Used in cancer brachytherapy prostate and brain , also diagnostically to evaluate the filtration rate of kidneys and to diagnose deep vein thrombosis in the leg. It is also widely used in radioimmuno-assays to show the presence of hormones in tiny quantities.

A strong gamma emitter, but used for beta therapy. Iridium 74 d : Supplied in wire form for use as an internal radiotherapy source for cancer treatment used then removed , e. Strong beta emitter for high dose-rate brachytherapy. Lead Used especially for melanoma, breast cancer and ovarian cancer. Demand is increasing. Used in peptide receptor radionuclide therapy PRRT. Lutetium 6. Its half-life is long enough to allow sophisticated preparation for use.

It is usually produced by neutron activation of natural or enriched lutetium targets or indirectly by neutron irradiation of Yb Palladium 17 d : Used to make brachytherapy permanent implant seeds for early stage prostate cancer. Emits soft x-rays. Phosphorus 14 d : Used in the treatment of polycythemia vera excess red blood cells. Beta emitter. Potassium 12 h : Used for the determination of exchangeable potassium in coronary blood flow. Rhenium 3. Beta emitter with weak gamma for imaging.

Samarium 47 h : Sm is very effective in relieving the pain of secondary cancers lodged in the bone, sold as Quadramet.

Also very effective for prostate and breast cancer. Scandium 4. It is produced by irradiating calcium to produce Ca which decays to Sc Selenium d : Used in the form of seleno-methionine to study the production of digestive enzymes. Technetiumm 6 h : Used in to image the skeleton and heart muscle in particular, but also for brain, thyroid, lungs perfusion and ventilation , liver, spleen, kidney structure and filtration rate , gall bladder, bone marrow, salivary and lacrimal glands, heart blood pool, infection, and numerous specialized medical studies.

Produced from Mo in a generator. Pure beta emitter and of growing significance in therapy, especially liver cancer. Carbon, Nitrogen, Oxygen, Fluorine These are positron emitters used in PET for studying brain physiology and pathology, in particular for localizing epileptic focus, and in dementia, psychiatry, and neuropharmacology studies.

They also have a significant role in cardiology. F in FDG fluorodeoxyglucose has become very important in detection of cancers and the monitoring of progress in their treatment, using PET.

Cobalt d : Used as a marker to estimate organ size and for in-vitro diagnostic kits. Copper 13 h : Used to study genetic diseases affecting copper metabolism, such as Wilson's and Menke's diseases, for PET imaging of tumours, and also cancer therapy.

Fluorine min as FLT fluorothymidine , F-miso fluoromisonidazole , 18F-choline: It decays with positron emission, so used as tracer with PET, for imaging malignant tumours. Gallium 78 h : Used for tumour imaging and locating inflammatory lesions infections. Derived from germanium in a generator. Indium 2.

Also for locating blood clots, inflammation and rare cancers. Iodine 13 h : Increasingly used for diagnosis of thyroid function, it is a gamma emitter without the beta radiation of I Iodine 4. Also used to image the thyroid using PET. Kryptonm 13 sec from rubidium 4. Thallium 73 h : Used for diagnosis of coronary artery disease other heart conditions such as heart muscle death and for location of low-grade lymphomas. It is the most commonly used substitute for technetium in cardiac-stress tests.

Radioisotopes in Medicine Updated October Nuclear medicine uses radiation to provide diagnostic information about the functioning of a person's specific organs, or to treat them. Diagnostic procedures using radioisotopes are now routine.

Radiotherapy can be used to treat some medical conditions, especially cancer, using radiation to weaken or destroy particular targeted cells. Sterilization of medical equipment is also an important use of radioisotopes. Nuclear medicine diagnosis, nuclear imaging Radioisotopes are an essential part of medical diagnostic procedures.

Diagnositic radiopharmaceuticals Every organ in our bodies acts differently from a chemical point of view. These are: It has a half-life of six hours which is long enough to examine metabolic processes yet short enough to minimize the radiation dose to the patient. It decays by an 'isomeric' process, which involves the emitting of gamma rays and low energy electrons.

Since there is no high-energy beta emission the radiation dose to the patient is low. The low-energy gamma rays it emits easily escape the human body and are accurately detected by a gamma camera. The chemistry of technetium is so versatile it can form tracers by being incorporated into a range of biologically-active substances that ensure it concentrates in the tissue or organ of interest. Nuclear medicine is the medical specialty that employs radiopharmaceuticals, which has presented itself as a tremendously useful ally for medicine assisting in various diagnoses and treatments, especially for cancer.

The general objective of this work is to identify the main radionuclides and metal complexes currently used as radiopharmaceuticals. The main metal complexes used as radiopharmaceuticals are compounds of technetium 99m Tc like sodium pertechnetate and methylenediphosphonate MDP- 99m Tc and other compounds of indium In , thallium Tl , gallium 67 Ga, 68 Ga , iodine I and I , chromium 51 Cr , sulphur 35 S , phosphorus 32 P , fluorine as fluorodeoxyglucose, 18 F-FDG and sodium fluorine, Na 18 F , which are widely used in the nuclear medicine for diagnosis by imaging.

They have been of great importance for the early diagnosis of numerous diseases, mainly cancer. Currently, technetium compounds are the majority of radiopharmaceuticals used in all countries. In Brazil, Institute of Energy and Nuclear Research IPEN is one of the most important distributors of radiopharmaceuticals, producing, importing and distributing them to clinics and hospitals over the country. Keywords: radionuclide, nuclear medicine, diagnosis, radiopharmaceutical. In nuclear medicine, radiopharmaceuticals are used in diagnostic imaging and radiotherapy, being of utmost importance for medicine in general to assist in diagnoses of organs and treatments of pathological conditions, especially cancer.

In the imaging modality, radiopharmaceuticals are administered via oral, intravenous, or by inhalation to enable visualization with their radioactive tracers of various organs, such as kidneys, lungs, thyroid and heart functions, bone metabolism and blood circulation. In therapeutic modality, aiming to treat cancer or over functioning thyroid gland, a high dose of radiation is delivered through specific radiopharmaceuticals targeting the diseased organ 1. Radiopharmaceuticals generally consist of two components, a radioactive element radionuclide , that permits external scan, linked to a non-radioactive element, a biologically active molecule, drug or cell red and white blood cells labeled with a radionuclide, for example that acts as a carrier or ligand, responsible for conducting the radionuclide to a specific organ 2.

Diagnostic radiopharmaceuticals have no pharmacological effects and their administration is not associated with relevant clinical side effects. Its clinical use, however, carries the inherent risk of exposure to radiation and possible contamination during radiopharmaceutical formulation, since most radiopharmaceuticals are administered intravenously 3. The most notable difference between normal medicines and radiopharmaceuticals is that the former has therapeutic effect while the latter does not.

Besides that, radiopharmaceuticals have a short half-life, because of their rapid decay. For this reason, radiopharmaceuticals must be prepared immediately before their administration.

The preparation and use of radiopharmaceuticals with safety and expertise are therefore vital for operator and patient protection 3. Understanding the mechanism of interaction between the radioactive elements and the different molecules, drugs, cells and organs it is necessary for the development of more efficient imaging or therapeutic radiopharmaceuticals 4.

In , Henri Becquerel used uranium salts on photographic plates, which resulted in marked radiographs without the presence of light. In , Marie and Pierre Curie were the first to suggest radium for treatment of cancer. In , Ernest Lawrence built the first cyclotron, equipment that accelerated alpha particles, such as protons, deuterons, or helium ions, with the aim of penetrating the nucleus to produce stable and radioactive isotopes.

In , Ernest Lawrence and Milton Livingstone, with their invention of the cyclotron, allowed the artificial production of new radioactive elements, but the quantities were very small. The medical use of radionuclides began during World War II with the Oak Ridge reactor in the United States, initiating the production of radionuclides in global scale. Hal Anger, in , developed the image-scintillation chamber, which did not require the movement of the detector.

It had a higher geometric resolution, and it was possible to obtain different projections of the same distribution of the radiopharmaceutical. However, computers were not yet capable of acquiring the information and transforming it into images. So, the information was sent to the cathode ray tube for it to be recorded on photographic plates or films. The modern scintillation cameras used nowadays are the Anger camera type 7.

Nuclear Medicine only had a diagnostic power when Paul Harper and his group introduced the 99m Tc radionuclide as a marker. This radionuclide decays by isometric transition emitting photon with energy of keV, gamma-type radiation and physical half-life of about 6 hours, which allows studies with reasonable intervals.

The first radiopharmaceuticals were commercialized in The radioactive elements, thus classified, may have highly energetic unstable nuclides due to the excess of energy, which stabilizes by the emission of particles or electromagnetic radiation or charged particles during radioactive decay.

In this context, there are three types of radiation: alpha, beta minus and gamma 1 , 2. Radiation propagates at a certain speed and contains energy with electric and magnetic charges that can be generated by natural sources or by artificial devices, such as a cyclotron.

Ionizing radiation is generated from the energy emitted by an unstable nucleus in artificial form or by a cyclotron 5. Radiopharmaceuticals may be divided in two distinct groups: one that includes radionuclides with radioactive decay period half life less than 2 h, and other that includes radionuclides with half life higher than 2 h 9.

Nuclear medicine cameras are proper for identifying radioactive particles. The type of radiation emitted defines the type of camera: SPECT cameras are used to detect nuclides that decay through direct emission of single gamma rays, and PET cameras are able to detect the pair of gamma rays emitted after a decay of positron Diagnostic techniques in nuclear medicine use radioactive tracers that emit gamma radiation from within the body.

The camera constructs an image from the points where the radiation is emitted. It can determine whether thyroid cancer has spread by detecting where the iodine is absorbed. The procedure is typically performed after thyroid surgery and ablation, or removal.

It can identify pieces of the thyroid that remain after surgery. Thyroid scans are usually performed on an outpatient basis in the nuclear medicine department of a hospital. They can be administered by a nuclear medicine technologist. Your endocrinologist may or may not be there during the procedure.

The technologist will tip your head back so that your neck is extended. The process takes about 30 minutes. An RAIU is performed 6 to 24 hours after taking the radionuclide.

The technologist will place a probe over your thyroid gland, where it will measure the radioactivity present. This test takes several minutes. This allows your doctor to determine the amount of thyroid hormone produced between the two tests. Scans of your body will be taken from the front and the back while you lie very still. This can be uncomfortable for some people. After your thyroid scan, you must contact your physician for instructions on how to resume taking your thyroid medication.

The radioactive iodine in your body is passed when you urinate. You may be advised to drink extra fluids and empty your bladder often to flush out the radionuclide. You may need to be careful to protect others from potential exposure to the material.

To do this, your doctor may advise you to flush twice after using the toilet for up to 48 hours after the test. Your exposure to radiation will be minimal and within the acceptable ranges for diagnostic exams. There are no known long-term complications of having a nuclear medicine procedure. Allergic reactions to the radionuclide material are extremely rare. The effects are mild when they occur. You may experience mild pain and redness at the injection site for a short time if you receive an injection of the radionuclide.

Discuss how they should be used before and during the test. You may have to discontinue thyroid medication from four to six weeks before your scan. Some heart medications and any medicine containing iodine also may require adjustments. For any thyroid scan, you may be asked to avoid certain foods that contain iodine for about a week before your procedure. A few days before your procedure, your doctor may request a blood test to confirm that your thyroid function is still abnormal.

Thyroid scans are used as secondary diagnostic tools to other tests, such as blood work.