Related Experiment Video
Updated: May 22, 2026
08:34
Proton Therapy Delivery and Its Clinical Application in Select Solid Tumor Malignancies
Published on: February 6, 2019
Exploring (57)Co as a new isotope for brachytherapy applications
Shirin A Enger1, Hans Lundqvist, Michel D'Amours
1Département de Radio-Oncologie, Centre Hospitalier Universitaire de Québec, Québec, Canada. shirin@enger.se
Medical Physics
|May 8, 2012
Summary
Cobalt-57 (57Co) shows promise as a brachytherapy source, offering a more uniform dose distribution than Iridium-192 (192Ir) due to its low-energy photon emissions. This radionuclide also requires less shielding.
Area of Science:
- Medical Physics
- Radiation Oncology
- Nuclear Medicine
Background:
- The use of radionuclides in brachytherapy is crucial for targeted cancer treatment.
- Cobalt-57 (57Co) possesses characteristics, including suitable half-life and photon emission, making it a potential candidate for brachytherapy sources.
- Current brachytherapy sources like Iridium-192 (192Ir) and Iodine-125 (125I) have established roles but also limitations.
Purpose of the Study:
- To evaluate the dosimetric properties of a hypothetical Cobalt-57 (57Co) brachytherapy source.
- To compare the performance of (57)Co with established brachytherapy sources, specifically (192)Ir and (125)I.
- To assess the potential advantages of (57)Co for brachytherapy applications.
Main Methods:
- Monte Carlo (MC) simulations using Geant4 code (version 9.4) were employed to model a hypothetical (57)Co brachytherapy source.
- The radial dose function, g(r), and anisotropy function, F(r,θ), were calculated according to the TG-43U1 formalism.
- Simulated data for (57)Co were compared with established data for (192)Ir and (125)I.
Main Results:
- The simulated (57)Co source emits photons with a mean energy of 123 keV in water after passing through encapsulation materials.
- An increasing radial dose function, g(r), was observed for (57)Co, attributed to the multiple scattering of low-energy photons.
- The dose distribution from (57)Co was found to be more uniform compared to (192)Ir.
Conclusions:
- Cobalt-57 (57Co) presents significant advantages over Iridium-192 (192Ir) for brachytherapy, notably its low-energy gamma emissions without electron contamination.
- (57)Co exhibits a more uniform dose distribution than (192)Ir due to its scattering characteristics.
- (57)Co demonstrates comparable anisotropy to (192)Ir and requires less shielding, enhancing its practical utility.
Related Concept Videos
01:28Isotopes and Radioisotopes
In the early 1900s, English chemist Frederick Soddy realized that an element could have atoms with different masses that were chemically indistinguishable. These different types are called isotopes — atoms of the same element that differ in mass. Isotopes differ in mass because they have different numbers of neutrons but are chemically identical because they have the same number of protons. Soddy was awarded the Nobel Prize in Chemistry in 1921 for this discovery.
An isotope containing more...
An isotope containing more...
01:29Positron Emission Tomography
Positron emission tomography (PET) is a medical imaging technique involving radiopharmaceuticals — substances that emit short-lived radiation. Although the first PET scanner was introduced in 1961, it took 15 more years before radiopharmaceuticals were combined with the technique and revolutionized its potential.
One of the main requirements of a PET scan is a positron-emitting radioisotope, which is produced in a cyclotron and then attached to a substance used by the part of the body being...
One of the main requirements of a PET scan is a positron-emitting radioisotope, which is produced in a cyclotron and then attached to a substance used by the part of the body being...
03:20Nuclear Transmutation
Nuclear transmutation is the conversion of one nuclide into another. It can occur by the radioactive decay of a nucleus, or the reaction of a nucleus with another particle. The first manmade nucleus was produced in Ernest Rutherford’s laboratory in 1919 by a transmutation reaction, the bombardment of one type of nuclei with other nuclei or with neutrons. Rutherford bombarded nitrogen-14 atoms with high-speed α particles from a natural radioactive isotope of radium and observed protons being...
01:17Radiation: Applications
The average temperature of Earth is the subject of much current discussion. Earth is in radiative contact with both the Sun and dark space; it receives almost all its energy from the radiation of the Sun and reflects some of it into outer space. Dark space is very cold, about 3 K, so Earth radiates energy into it. For instance, heat transfer occurs from soil and grasses, the rate of which can be so rapid that frost can occur on clear summer evenings, even in warm latitudes.
The average...
The average...
01:12Isotopes
Elements have a set number of protons that determines their atomic number (Z). For example, all atoms with eight protons are oxygen; however, the number of neutrons can vary for atoms of the same element. The sum of the number of protons and the number of neutrons is the mass number (A). Atoms with the same atomic number but different mass numbers are called isotopes. Elements can have multiple isotopes, for example, carbon-12, carbon-13, and carbon-14.
An element's atomic mass, or weight, is a...
An element's atomic mass, or weight, is a...
03:23Types of Radioactivity
The most common types of radioactivity are α decay, β decay, γ decay, neutron emission, and electron capture.
Alpha (α) decay is the emission of an α particle from the nucleus. For example, polonium-210 undergoes α decay:
Alpha (α) decay is the emission of an α particle from the nucleus. For example, polonium-210 undergoes α decay: