What is Cobalt 60 radiation therapy?
In modern day radiation therapy, a synthetic radioisotope of cobalt is used to emit rays for radiation therapy. Cobalt-60 is more stable and safer than the other past used radioactive elements. Because of this, cobalt-60 is now used in most radiation therapy to help treat cancer patients. Figure 5.
What is Cobalt 60 used for?
Cobalt-60 is used in a process called industrial radiography, to inspect metal parts and welds for defects. Beams of radiation are aimed at the object to be checked from a sealed source of Co-60. Radiographic film on the opposite side of the source is exposed when it is struck by radiation passing through the objects being tested.
What is the half life of Cobalt 60?
cobalt-60, radioactive isotope of cobalt used in industry and medicine. Cobalt-60 is the longest-lived isotope of cobalt, with a half-life of 5.27 years. It is produced by irradiating the stable isotope cobalt-59 with neutrons in a nuclear reactor.
Is Cobalt 60 radioactive?
The commonly used sources of radiation are cobalt-60, a radioactive element emitting γ-rays, or an accelerator producing a beam of electrons. Cobalt-60 is produced by neutron bombardment of stable cobalt in a nuclear reactor.
How cobalt-60 is used in the treatment of cancer?
Cobalt therapy is the medical use of gamma rays from the radioisotope cobalt-60 to treat conditions such as cancer. Beginning in the 1950s, cobalt-60 was widely used in external beam radiotherapy (teletherapy) machines, which produced a beam of gamma rays which was directed into the patient's body to kill tumor tissue.
How is cobalt-60 obtained for use in radiation treatment?
Cobalt-60 is produced by neutron bombardment of stable cobalt in a nuclear reactor. Small nickel-plated slugs of the radioactive metal are loaded into a sealed alloy cylinder typically 10 × 450 mm and doubly encapsulated in a corrosion-resistant steel pencil.
Is cobalt used in medicine?
Cobalt-60 is widely used as a medical and industrial source of radiation. Medical use consists primarily of cancer radiotherapy.
Is cobalt-60 used to treat brain tumor?
For many brain cancers, Cobalt-60 therapy is one of the most precise and advanced forms of radiation treatment available. Gamma Knife radiosurgery is a type of radiation therapy used to treat tumours and other abnormalities in the brain.
What element is used in radiotherapy?
Because of this, radioactive iodine (also called radioiodine or iodine-131) can be used to destroy the thyroid gland and thyroid cancer with little effect on the rest of the body. This treatment is often used after thyroid cancer surgery to destroy any thyroid cells left behind.
What is used for radiotherapy?
Radiation therapy is a type of cancer treatment that uses beams of intense energy to kill cancer cells. Radiation therapy most often uses X-rays, but protons or other types of energy also can be used.
What is cobalt used for?
Cobalt is often mixed with metals such as iron or nickel to make alloys (mixture of metals). These alloys are used for parts in gas turbine aircraft engines; corrosion resistant alloys; high-speed, heavy-duty, high-temperature cutting tools and dies; and in magnets and magnetic recording media.
Is cobalt-60 still used?
Cobalt Sources Cobalt-60 is used as a radiation source in many common industrial applications, such as in leveling devices and thickness gauges. It is also used for radiation therapy in hospitals. Accidental exposures may occur as the result of loss or improper disposal of medical and industrial radiation sources.
Which isotope is used in the treatment of goitre?
characteristics of iodine …exceptionally useful radioactive isotope is iodine-131, which has a half-life of eight days. It is employed in medicine to monitor thyroid gland functioning, to treat goitre and thyroid cancer, and to locate tumours of the brain and of the liver.
Which element isotope is used for treatment of leukemia?
A radioactive form of the element phosphorus. It is used in the laboratory to label DNA and proteins. It has also been used to treat a blood disorder called polycythemia vera and certain types of leukemia, but it is not commonly used anymore.
How much cobalt-60 is in a Gamma Knife?
The Gamma Knife Unit The Gamma Knife contains 192- 201 cobalt-60 sources of approximately 30 curies each, placed in a circular array in a heavily shielded unit. The unit directs gamma radiation very precisely to a target point.
How do doctors do chemotherapy?
Chemotherapy is most often given as an infusion into a vein (intravenously). The drugs can be given by inserting a tube with a needle into a vein in your arm or into a device in a vein in your chest. Chemotherapy pills. Some chemotherapy drugs can be taken in pill or capsule form.
What products is cobalt found in?
Cobalt is an essential raw material for superalloy, cemented carbide, diamond tool, batteries, anticorrosive and magnetic materials. It is widely applied in fields including aerospace, electronic appliances, machinery manufacturing, automobiles, chemical industry, agriculture, ceramics, etc.
Do we need cobalt in our diet?
You should be able to get all the cobalt you need from your daily diet. Cobalt is a major part of the structure of vitamin B12. Therefore, if you get enough vitamin B12, you will also get enough cobalt. Adults need about 0.0015mg (1.5 micrograms) of vitamin B12 a day.
What foods are high in cobalt?
Some of the dietary sources that are abundant in cobalt include red meat, milk, fish, cabbage, figs and turnips.
Do we need cobalt?
Cobalt is an important component in lithium-ion batteries because it maximizes energy density and extends battery life.
What is cobalt 60?
cobalt processing: Cobalt-60. A radioactive form of cobalt, cobalt-60, prepared by exposing cobalt to the radiations of an atomic pile, is useful in industry and medical... The Editors of Encyclopaedia Britannica This article was most recently revised and updated by Erik Gregersen, Senior Editor. History at your fingertips.
What is the longest-lived isotope of cobalt?
Cobalt-60, radioactive isotope of cobalt used in industry and medicine. Cobalt-60 is the longest-lived isotope of cobalt, with a half-life of 5.27 years. It is produced by irradiating the stable isotope cobalt-59 with neutrons in a nuclear reactor.
What is cobalt 60 used for?
Industrial cobalt-60 irradiators are primarily used for food or phytosanitary applications and medical device sterilization. They operate in either continuous or, less commonly, in a large batch mode, and products to be irradiated come in pallets or tote boxes.
How does the radiation output of a cobalt 60 machine work?
The radiation output of a cobalt-60 machine depends on the shape and sizeof the source as well as upon the amount of radioactive isotope that it contains . Usually the source is cylindrical in shape, its length being about the same as its diameter. In order to reduce geometric penumbra to a minimum the source diameter must be kept as small as possible (see Chapter XXXV ). This reduces the amount of radioactive material in the source unless the length is correspondingly increased. Unfortunately, this solution is not acceptable, for even if the volume of radioactive material were kept constant the radiation output would not, because radiation coming from the back of the source would be increasingly attenuated, as the source length increased, by the source material in front of it (often known as ‘self-attenuation’). Therefore the source is seldom more than 2 cm. long and has about the same diameter. This is considerably greater than the 6-mm. focal spot of the linear accelerator, or the even smaller focal spot of the betatron. With the cobalt-60 unit, therefore, there is inevitably a much greater geometric penumbra, which constitutes something of a disadvantage compared with the X-ray machines.
Why does cobalt leak?
Sealed cobalt sources may leak as a result of electrolytic action between the cobalt and the container. The result is often a soluble cobalt salt, which creeps and spreads. This is best decontaminated with a detergent or an ethylenediamine tetraacetic acid solution, followed by treatment with mineral acids.
What is the most common radioisotope of cobalt?
The most common radioisotope of cobalt is cobalt-60, which is a beta and gamma emitter. Metallic cobalt-60 is commonly used in sealed gamma sources. Particles of cobalt dust adhering to small articles are readily removed by ultrasonic cleaners or by dipping the article in a dilute solution of nitric, hydrochloric, or sulfuric acid.
What is a large industrial irradiator?
Large industrial irradiators (greater than 1 MCi) are almost exclusively used for medical device sterilization as they can deliver high doses required for medical products (25–50 kGy) at high speed. If needed, they can also be used for food or phytosanitary applications with a split source rack.
How thick is cobalt?
The radioactive cobalt in the source is in the form of thin disks (each about 2.5 mm. thick), as shown in the diagram, or, increasingly nowadays, of tiny cobalt cylinders each about 1 mm. long and 1 mm. in diameter. The latter are ‘packed by vigorous agitation of the capsule’.
Can X-rays be used for sterilisation?
In principle, X-rays may also be used for sterilisation. For example, high- energy electrons produced by an accelerator could be used to produce high- energy photons (e.g., X-rays produced by bombarding a tungsten target).
When was the first cobalt 60 treatment?
The first patient to be treated with cobalt-60 radiation was treated on October 27, 1951, at the War Memorial Children's Hospital in London, Ontario. In 1961 cobalt therapy was expected to replace X-ray radiotherapy. In 1966, Walt Disney 's lung cancer was treated with this procedure, but could not prevent his death.
What is the activity of Cobalt-60?
Cobalt-60, produced by neutron irradiation of ordinary cobalt metal in a reactor, is a high activity gamma ray emitter, emitting 1.17 and 1.33 MeV gamma rays with an activity of 44 TBq /g (about 1100 Ci /g).
What is cobalt therapy?
Specialty. oncology. [ edit on Wikidata] Cobalt therapy is the medical use of gamma rays from the radioisotope cobalt-60 to treat conditions such as cancer. Beginning in the 1950s, cobalt-60 was widely used in external beam radiotherapy (teletherapy) machines, which produced a beam of gamma rays which was directed into the patient's body ...
Why were cobalt machines used in radiotherapy?
Because these "cobalt machines" were expensive and required specialist support, they were often housed in cobalt units. Cobalt therapy was a revolutionary advance in radiotherapy in the post-World War II period but is now being replaced by other technologies such as linear accelerators.
How much energy does cobalt 60 have?
As used in radiotherapy, cobalt units produce stable, dichromatic beams of 1.17 and 1.33 MeV, resulting in an average beam energy of 1.25 MeV. The cobalt-60 isotope has a half-life of 5.3 years so the cobalt-60 needs to be replaced occasionally.
What was the only radiation source used for teletherapy?
Before the development of medical linear accelerators in the 1970s, the only artificial radiation source used for teletherapy was the x-ray tube. Researchers found ordinary x-ray tubes, which used voltages of 50-150 keV, could treat superficial tumors, but did not have the energy to reach tumors deep in the body.
Where was the Cobalt 60 made?
Two cobalt-60 apparatuses were then built, one in Saskatoon in the cancer wing of the University of Saskatchewan and the other in London, Ontario. Dr. Johns collected depth-dose data at the University of Saskatchewan which would later become the world standard.
What is the purpose of cobalt 60?
The cobalt-60 system is designed to deliver radiation in the shape of a sphere. To cover irregularly shaped tumors, several of these radiation spheres have to be used. If a metastasis is pear-shaped, for example, then two different sized spheres must be used to mimic the shape of the tumor.
What is the Cobalt 60 system?
The cobalt-60 system is designed to deliver radiation in the shape of a sphere. To cover irregularly shaped tumors, several of these radiation spheres are combined to best mimic the tumor’s shape.
How does Cobalt 60 work?
Cobalt-60 systems, like the Gamma Knife, deliver radiation beams through 192 circular pinholes in a fixed helmet worn by the patient. The pinhole radiation meets at the tumor site, delivering a high dose, while the surrounding healthy tissue and critical brain structures receive minimal radiation. These systems offer treatment options with proven effectiveness and high precision and for decades were the only dedicated radiosurgery systems for the treatment of brain metastases.
Why is Cobalt 60 used in radiation?
Because of it’s high activity and simple gamma spectrum, it is used in the calibration of radiation detectors. Today it is also used in some MRI guided external beam therapy systems Cobalt-60 is able to generate an MV beam without strongly influencing a magnetic field. Cobalt-60 decay scheme.
What is 60 Co?
Cobalt-60 ( 60 Co) is a synthetic radioisotope that has been used in both external beam radiation therapy and brachytherapy. 60 Co decays via decay to an excited state of Nickel-60 which then emits two high energy (1.17MeV and 1.33MeV) gamma-rays. It is these energetic gamma rays which are primarily important for use in radiation therapy.
What is the best radionuclide for radiation therapy?
Cobalt-60 is the radionuclide of choice for nuclide based external beam radiation therapy. Compared to other radionuclides used for this purpose (Radium-226 and Cesium-137), 60 Co has a greater specific activity and a higher energy.
Is Cobalt 60 used in brachytherapy?
Cobalt-60 is was used in brachytherapy in the past but is rarely used today. Compared with Ir-192, Cobalt-60 is more expensive and requires a larger source size for the same dose rate but has the advantage of a longer half life.
Is cobalt 60 absorbed?
The particle emitted is absorbed by the cobalt metal and the sources encapsulation such that it doesn’t contribute meaningfully to the dose distribution. Cobalt 60 has been largely replaced by other Iridium-192 in high dose rate brachytherapy and by linear accelerators in external beam radiation therapy. Because of it’s high activity and simple ...
Introduction
In the mid-1950s, the rising demand for sterile single-use medical devices paved the way for the expansion of radiation processing and specifically gamma sterilization using cobalt-60. Over the ensuing decades, the industry has not only grown in size, but also in its diversity and sophistication.
Social and Industrial Contribution
The United States currently produces 50% of the medical devices manufactured globally. These products, including syringes, catheters, surgical gloves, bandages, drapes, gowns and hundred of others must meet strict FDA regulations for sterility, to protect against patient infection.
The Gamma Processing Industry
The worldwide installed base of cobalt-60 is approximately 260 million curies, contained in more than 160 large-scale gamma facilities. The United States has just over 50% of the total cobalt-60 installed base contained in 51 commercial irradiation facilities.
The How and Why of Cobalt-60
Cobalt-60 is type of ionizing radiation. Gamma rays from a source penetrate the targeted material and knock electrons from orbit. For sterilization applications this has the effect of disrupting DNA, which renders any microorganisms present nonviable.
Cobalt-60 Production
Placing non-radioactive, refined Cobalt-59 slugs or pellets into a nuclear reactor creates deliberately produced cobalt-60. Over time cobalt-59 absorbs a neutron to become cobalt-60. After removal from the reactor the cobalt-60 is double encapsulated in stainless steel sealed sources.
Summary
Cobalt-60 makes an important contribution to the health and well being of people, as well as providing significant economic benefit to many industries around the world.
What is the chemical name for cobalt 60?
Cobalt-60 – toxicity, side effects, diseases and environmental impacts. Cobalt-60 is a synthetic, radioactive isotope of cobalt, a hard, gray-blue metal. A by-product of nuclear reactor operations, cobalt-60 is formed when metal structures come into contact with neutron radiation. Cobalt-60, also known as co-60, ...
How does cobalt 60 affect the body?
Body systems affected by cobalt-60. Cobalt-60 that’s been ingested is usually eliminated through the excretion of feces. However, a small amount continues to remain in the body. This because the liver, kidneys and bones absorb small amounts of cobalt-60, in turn increasing the risk of cancer. This material has been shown to affect the brain as well.
What is the most common isotope of cobalt?
Cobalt-60, also known as co-60, is the most common cobalt isotope and can occur as a solid material or as a powder if the solid source has been damaged or ground up. The most frequent applications of cobalt-60 are industrial, namely in thickness gauges and leveling devices.
Does cobalt 60 cause radiation?
List of known side effects. Cobalt-60 decays through gamma radiation. As such, exposure to this material can result in a plethora of health complications. For example, contact with a large amount of Cobalt-60 has led to people experiencing skin burns or acute radiation sickness, a serious illness characterized by nausea, vomiting, fatigue, ...
Does cobalt 60 cause brain swelling?
All patients who have undergone radiation therapy have experienced varying degree s of cerebral edema, or brain swelling.
