General Radiation Biophysics and Biology
George W. Casarett in Radiation Histopathology, 2019
Alpha particles are relatively large particles (8000 times heavier than electrons) carrying a double positive charge. They are helium nuclei (two protons and two neutrons) lacking two electrons. Their velocity is much lower than that of electrons, they penetrate tissue very shallowly, a few hundred µm at most (depending on the tissue density), their tracks are straight, and the ionization density is greatest near the end of the track. Because of the shallow penetration, alpha radiation is relatively unimportant as an external source of radiation, but it is important as a radiation emitted from various radionuclides deposited within the body. Because of their low velocity and penetration and their double charge, alpha particles are very densely ionizing. In terms of linear energy transfer (LET) units (kev per µm of track length), the average value V for alpha particles would be about 100, as compared with 3.0 for orthovoltage X-rays and 0.3 for gamma rays.
External Beam Radiotherapy and Brachytherapy
Karl H. Pang, Nadir I. Osman, James W.F. Catto, Christopher R. Chapple in Basic Urological Sciences, 2021
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).
Radionuclide imaging
Damian Tolan, Rachel Hyland, Christopher Taylor, Arnold Cowen in Get Through, 2020
False – between 100 and 300 keV ideally.True – the dose from alpha radiation would be unacceptable. There are no alpha-emitting radionuclides that are used for imaging.True – to provide an image with good contrast.False – for detection of the primary gamma ray, a single gamma peak is preferred. All other photon energies detected can then be rejected as scatter.False – the radionuclide should concentrate in the organ of interest, giving a high critical organ uptake.
Modeling of dose and linear energy transfer homogeneity in cell nuclei exposed to alpha particles under various setup conditions
Published in International Journal of Radiation Biology, 2023
Adrianna Tartas, Mateusz Filipek, Marcin Pietrzak, Andrzej Wojcik, Beata Brzozowska
The high DNA damage complexity, the complicated dose distribution in exposed matter and uncertainties regarding the level of possible stochastic effects from exposure of cells to high LET radiation (Shuryak et al. 2017) make alpha particles an interesting focus of radiobiological studies. A number of alpha radiation exposure devices have been constructed for exposing cells to particles with strictly defined LET values (Roos and Kellerer 1989; Goodhead et al. 1991; Neti et al. 2004; Esposito et al. 2009). LET homogeneity is achieved by the use of collimators which block particles that would penetrate cell nuclei attached to a flat plate at angles different than 90∘. Although high LET homogeneity may be advantageous for studies on the mechanisms of alpha particle interaction with the DNA, cells irradiated under occupational, environmental and medical scenarios are always exposed to a mixed field of energies and, consequently, LET values of alpha particles. Mixed LET exposure scenarios can be reproduced under laboratory conditions by placing cells attached to a flat plate on an alpha source without a collimator. Here, two possibilities exist: cells grown on a Mylar foil are positioned on top of an alpha source, with alpha particles penetrating from below (bottom-up setups), or cells growing on a flat surface are covered by Mylar foil and the alpha source is placed on top with alpha particles penetrating from above (top-down setup). To our knowledge, no publication exists describing results of experiments with the bottom-up setup. The top-down setup was applied by Edwards et al. (1980) and Staaf et al. (2012).
Impact of radon and combinatory radon/carbon dioxide spa on pain and hypertension: Results from the explorative RAD-ON01 study
Published in Modern Rheumatology, 2019
Paul F. Rühle, Gerhart Klein, Tatiana Rung, Hong Tiep Phan, Claudia Fournier, Rainer Fietkau, Udo S. Gaipl, Benjamin Frey
Low dose radiation therapy has beneficial effects on patients suffering from chronic painful diseases of the musculoskeletal system [1–4]. Besides a local application of low doses of X-rays, which is used for annual treatment of 37,000 patients in Germany [5], a whole body irradiation with low doses of alpha radiation is performed in radon spas or galleries [3]. Although the alpha radiation which results from radon decay has high ionization energy, it has a very low penetration depth. Thus, it can be applied to whole body exposure and is advantageous for patients suffering from multiple painful joints and back pain. For both forms of therapy, an improvement of pain is described for about twelve months. But in contrast to application of X-rays, the radon therapy is committed to its natural occurrence and therefore tightly linked to health resorts [3].
Correlation between cytogenetic biomarkers obtained from DC and CBMN assays caused by low dose radon exposure in smokers
Published in International Journal of Radiation Biology, 2019
Radon and its decay products emit high LET alpha radiation. Half of the human annual background radiation exposure occurs because of the Radon-222 (Robertson et al. 2013). High doses of ionizing radiation causes detrimental effects in humans such as chromosomal damage (Ulsh et al. 2015), mutations (Vilenchik and Knudson 2006), carcinogenesis (Evrard et al. 2005; Krewski et al. 2006) etc. Data related to low dose ionizing radiation effects is limited and there is an increasing concern towards the risk of low dose exposure because of frequent flyer risks, screening tests for cancer, occupational exposure, manned space exploration etc. (ICRP 1999; Gilbert 2001). At present, risks of low dose exposure are derived by linear extrapolation from higher doses which might not truly reflect the low dose risk (Mitchel 2007; Matsumoto et al. 2009; Wheeler and John Bailer 2013; Desouky et al. 2015). Because of lack of understanding of the molecular consequences of low dose exposure, ambiguity exists on the risks of low dose in human beings (Kim et al. 2015).
Related Knowledge Centers
- Alpha Particle
- Antimony
- Atom
- Beta Decay
- Helium
- Radioactive Decay
- Thorium
- Atomic Nucleus
- Nickel
- Cluster Decay