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Table L5: Radionuclide Data
Published in W. P. M. Mayles, A. E. Nahum, J.-C. Rosenwald, Handbook of Radiotherapy Physics, 2021
W. P. M. Mayles, A. E. Nahum, J.-C. Rosenwald
In lead, for radiation protection purposes broad beam attenuation values (i.e. half-value or tenth-value thicknesses – see Table 60.2) might be more appropriate. When shielding beta emitters it is better to use a low atomic number material (e.g. PMMA, also called perspex or lucite) close to the source, as lead will produce bremsstrahlung photons which will be more penetrating than the original beta particles, so the range in PMMA has been provided.
External Beam Radiotherapy and Brachytherapy
Published in Karl H. Pang, Nadir I. Osman, James W.F. Catto, Christopher R. Chapple, Basic Urological Sciences, 2021
Sophia C. Kamran, Jason A. Efstathiou
The radioactive decay of an atomic nucleus results in:Alpha radiation: emission of alpha particles (two protons, two neutrons).Beta radiation: emission of beta particles.beta− = electronsbeta+ = protonsGamma radiation: emission of electromagnetic energy (photon).
Kill or Cure
Published in Alan Perkins, Life and Death Rays, 2021
Some atoms with an excess of neutrons may attempt to reach stability by converting a neutron into a proton with the emission of an electron. The electron is called a beta-minus particle, the minus indicating that the particle is negatively charged. If the number of protons in the nucleus is too large for the nucleus to be stable, it may move to a more stable state by converting a proton into a neutron with the emission of a positively charged electron which is called a beta-plus particle or positron. The Italian physicist, Enrico Fermi, showed that these positively charged electrons were in fact antimatter that does not exist for very long, as they rapidly combine with a normal electron in a reaction called annihilation. This gives rise to the emission of two gamma rays that are emitted travelling in opposite directions. This process is used in modern-day medical imaging, in a technique known as PET scanning (positron emission tomography). Beta particles can travel many centimetres through air but are absorbed by small thicknesses of light materials such as aluminium, glass or acrylic plastics.
The potential of PSMA-targeted alpha therapy in the management of prostate cancer
Published in Expert Review of Anticancer Therapy, 2020
Luca Filippi, Agostino Chiaravalloti, Orazio Schillaci, Oreste Bagni
The alpha emission consists of a positively charged particle, identical to the naked helium-4 (4He) nucleus, formed by two protons and two neutrons bound together, having an extremely greater mass as compared to that of beta particles. Alpha particle is monoenergetic, with emission ranging between 5 and 9 MeV and presents a linear track of 50–100 micron, which entails an almost exclusive radiation delivery to the target and the strictly neighboring cells [12]. Alpha particles are classified as high linear energy transfer (LET) radiation and represent effective ionizing agents. The main advantage of utilizing alpha radiations consists in their capability of inducing effects independently from the oxygenation status of the cell. It is well known that hypoxic tumors are three-fold less sensitive to radiations than well-oxygenated tissues, since low LET radiations mainly produce deoxyribonucleic acid (DNA) damages through water hydrolysis and free radical formation. On the contrary, this ‘oxygen effect’ is of minor relevance for high LET radiations, such as alpha particles.
Radiation therapy techniques in the treatment of skin cancer: an overview of the current status and outlook
Published in Journal of Dermatological Treatment, 2019
Ali Pashazadeh, Axel Boese, Michael Friebe
Recently, a new form of radiotherapy as a treatment for the BCC and SCC has been introduced. This treatment is the superficial radiotherapy of skin tumors using beta-emitting isotopes (35,36). Internal application of the beta-emitting isotopes, however, is not a new concept, and it has a long successful history in therapeutic nuclear medicine. A good example of this claim is radioiodine therapy of thyroid disease whereby beta-emitter I-131 is administered to the patients. Recently, beta-emitting isotopes have started to be used in skin cancer therapy as an external source of radiation in topical application. Short penetration range of beta particles in tissue, typically from 5 to 10 mm, is an interesting feature of beta-emitting isotopes for use in irradiating the superficial skin lesions.
Decontamination of rat and human skin experimentally contaminated with 99mTc, 201Tl and 131I radionuclides using “Dermadecon” – a skin decontamination kit: an efficacy study
Published in Cutaneous and Ocular Toxicology, 2018
Dhruv Kumar Nishad, Supriya Bhalla, Kushagra Khanna, Braj Gaurav Sharma, Harish Singh Rawat, Gaurav Mittal, Aseem Bhatnagar
Radioactive material releases alpha, beta and gamma radiations. Alpha particles, consisting of protons (2) and neutrons (2), are an ionizing type of radiation with low capacity to penetrate living tissue (less than 0.1 mm)3. Beta particles are electrons or positrons that are less ionizing, but have more penetrating power (up to a few millimeters). Beta radiation travels only a short distance in tissue, depending on its energy and could be a substantial source of dose to skin. Gamma rays are sparsely ionizing electromagnetic radiation that penetrates the living tissue, typically generating fast electrons that deposit energy resulting in tissue damage. The health hazards resulting from radionuclides that emit these types of particles largely occur after internal deposition4 exposures to gamma radiation will affect skin as a result of external contamination and possible secondary internal (systemic) uptake of radionuclide. The acceptable levels of radionuclide particle contamination should be averaged over 10−2 m2 in the case of skin generally, or over 3 × 10−2 m−2 in the case of hands5. The stratum corneum functions as a reservoir for radionuclide and as a medium for percutaneous absorption. The rapidly growing germinativum layer of epidermal cells is predominantly susceptible to engrossed energy of beta and gamma emissions6.