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Introduction
Published in Debbie Peet, Emma Chung, Practical Medical Physics, 2021
Debbie Peet, Emma Chung, Jasdip Mangat, Joanne Cowe
In Nuclear Medicine, Clinical Scientists are experts in working with radioactive materials. They usually take the lead in managing nuclear medicine equipment and services, and sometimes also support the preparation, control and administration of radiopharmaceuticals. Physicists working in Nuclear Medicine are also called on to perform calculations and simulations modelling radioactive decay. Nuclear medicine imaging is sometimes also called molecular imaging, as this technique makes it possible to “tag” specific molecules to observe functional changes. Single-photon emission CT (SPECT) and positron emission tomography (PET) are nuclear medicine techniques that provide metabolic and functional information (Chapter 5).
Radiation injuries
Published in Jan de Boer, Marcel Dubouloz, Handbook of Disaster Medicine, 2020
Yves Jouchoux, Christophe Boyer
The α and ß radiations have strong ionising power, but their track in air is short: a few centimetres for alpha radiation and a few metres for beta radiation. In water, these distances are reduced to a few micrometres and a few millimetres. They have little power to enter into matter and therefore are not very dangerous as ‘external sources’ of irradiation (external contamination). The hazard they pose is much greater in the case of internal irradiation that occurs when radioactive material is ingested because of this same ionising power (internal contamination). The track length grows as the energy of the radiation increases.
Radiation Therapy and Radiation Safety in Medicine
Published in Suzanne Amador Kane, Boris A. Gelman, Introduction to Physics in Modern Medicine, 2020
Suzanne Amador Kane, Boris A. Gelman
Unfortunately, defining the radiation equivalent of a drug dose is more complicated than just stating, for example, the amount of radioactive material administered for a gamma camera scan or during a radiation therapy treatment. The real quantity of interest must describe how much radiation the body is subjected to, how much of it is absorbed by the body, and what physiological effects result. In addition, the ordinary measures of a drug's toxicity do not suffice for describing radiation's effects. Extremely high exposures can quickly cause tissue damage, illness, or death, but many of the risks of radiation (such as an increased risk of cancer) do not manifest themselves for years. Because of these complexities, it is helpful to define several quantities, each of which is useful in quantifying radiation exposures in medical applications.
Early initiation of insulin attenuates histological and functional changes in the liver of streptozotocin-induced diabetic rats using 99mTc-sulfur colloid functional imaging
Published in Journal of Receptors and Signal Transduction, 2022
Fatma J. Al-Saeedi, Salah Kh. Al-Waheeb, Peramaiyan Rajendran, Khalid M. Khan, Moudhi Sadan
In nuclear medicine, functional imaging can be done using radioactive materials labeled with chemical compounds that specifically and biologically localized into certain organ such as liver for example. The technetium-99m-labeled sulfur colloid (99mTc-SC) can image the function of the phagocytic RES of the liver. 99mTc-SC is a significance tracer since it can be used to delineate the overall organ size, detect early changes in the liver function in the patients who do not show obvious clinical abnormalities such as in liver cirrhosis, determine the presence of focal lesions, assess the degree of hepatocellular dysfunction in the diffuse fatty liver disease, and it can be used to detect the function of phagocytic RES in the liver, which we will use in this study. 99mTc-SC is a particulate radiopharmaceutical, with particle diameters on the order of 100 to 1000 nm. 99mTc-SC is a gamma-emitting colloid used in scintillation scanning of the RES. After intravenous injection, these particles are rapidly phagocytized by RES, the Kupffer cells of the liver (85%) and the macrophages of the spleen (10%) and bone marrow (5%). Detection and localization of phagocytized gamma ray-emitting colloid is done with a gamma-ray scintillation camera [17–21].
mRNA and small RNA gene expression changes in peripheral blood to detect internal Ra-223 exposure
Published in International Journal of Radiation Biology, 2022
Patrick Ostheim, Matthias Miederer, Mathias Schreckenberger, Tim Nestler, Manuela A. Hoffmann, Michael Lassmann, Uta Eberlein, Vahe Barsegian, Alexis Rump, Mattháus Majewski, Matthias Port, Michael Abend
In such an RDD scenario, exposure of hundreds or thousands of people may occur. Besides mechanical trauma and direct irradiation, a much larger number of people may be externally contaminated by radioactive material with the concomitant danger of radionuclide incorporation and internal contamination (Rump et al. 2018). Acute radiation syndrome would be unexpected from radionuclide(s) incorporation, except in special cases such as the Litvinenko poisoning (Harrison et al. 2017). However, irradiation accompanied by internal contamination may cause long-term stochastic health effects (e.g. cancer). As an initial therapy, decorporation agents to eliminate internal radionuclides can be administered, and thus absorbed dose can be reduced and the adverse health effects minimized. Therapeutic efficacy decreases if therapy with decorporation agents is initiated too late and in most cases the time window is hours to several days in order to achieve acceptable results. This also depends on the types of radionuclides, the physicochemical properties and the metabolic pathway (Rump et al. 2016, 2017). Considering limited doses of decorporation antidotes in a nuclear mass casualty event, exposed individuals needing urgent treatment must be prioritized (Chaudhry 2008; Rump et al. 2018). Radiation dose from physical dosimetry (like measurements by monitoring portals) are thought to be sufficient for sensitive and high throughput triage in gamma-radionuclide exposure situations, but fall short for inhalation, ingestion or absorption routes.
Educational dialogue on public perception of nuclear radiation
Published in International Journal of Radiation Biology, 2022
Varsha Hande, Karthik Prathaban, M. Prakash Hande
Multiple field visits were arranged to demonstrate how nuclear radiation is used in various fields, as well as the safe disposal of radioactive material. Field visits were conducted at:The TRIGA PUSPATI (RTP) nuclear research reactor operated by the Malaysian Nuclear Energy (Agensi Nuklear Malaysia) as well as the neighboring radioactive waste management facility (unfortunately visit was not possible in 2020 due to Covid-19 restrictions). (Figures 3 and 4). The Sinagama Cobalt-60 food and medical devices irradiation facility operated by the Malaysian Institute of Nuclear Technology Research (MINTEC)Imaging and radiation therapy facilities within radiation oncology divisions at the National University Hospital (Figures 5 and 6) and the National Cancer Center Singapore.