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Translation of Radiopharmaceuticals
Published in Michael Ljungberg, Handbook of Nuclear Medicine and Molecular Imaging for Physicists, 2022
Pedro Fragoso Costa, Latifa Rbah-Vidal, An Aerts, Fijs W.B. van Leeuwen, Margret Schottelius
Perhaps the most widely known example of translational research in medicine, where basic experimental and theoretical discoveries are implemented into benefiting humanity, comes from the physics discipline [1]. Particle acceleration as a means to create x rays, Röntgen’s discovery in 1895, has had a profound impact on modern medicine and continues to benefit millions of patients worldwide. Since then, many other basic research breakthroughs have entered the healthcare domain.
Medical and Biological Applications of Low Energy Accelerators
Published in Vlado Valković, Low Energy Particle Accelerator-Based Technologies and Their Applications, 2022
For example, ProBeam® 360° Proton Therapy System (made by Varian, A Siemens Healthineers Company) offers uncompromised clinical capabilities with ultra-high dose rates, a 360° gantry and exceptional precision, all within a 30% smaller footprint. The evolution of radiotherapy has pushed dose rates higher, and proton therapy is now leading this trend. The ProBeam 360° System features the most powerful particle accelerator available to treat cancer. High dose rates are used today to reduce treatment time, manage motion, and can improve treatment plan quality and conformity. We expect next-generation proton therapy to employ even higher and ultra-high dose rates.
ABC: Accelerators, Beams, and Charges
Published in Rob Appleby, Graeme Burt, James Clarke, Hywel Owen, The Science and Technology of Particle Accelerators, 2020
Rob Appleby, Graeme Burt, James Clarke, Hywel Owen
A charged particle may be accelerated to large velocities such that its kinetic energy becomes comparable to or much greater than its rest energy; the effects of relativity must then be taken into account, and this is the case for nearly all the situations encountered in particle accelerator science. The behaviour under the conditions for special relativity will however suffice rather than any effects due to general relativity.
Surface Modification of lactose carrier particles using a fluid bed coater to improve fine particle fraction for dry powder inhalers
Published in Pharmaceutical Development and Technology, 2023
Qin Qin Gong, Justin Yong Soon Tay, Natalia Veronica, Jian Xu, Paul Wan Sia Heng, Yong Ping Zhang, Celine Valeria Liew
During inhalation, the carrier particles leaving the device will mostly be deposited at the back of the throat while the drug particles detach themselves from the carrier particles. After detachment, the drug particles will be conveyed to the lower airways with the inspiratory airflow (Islam et al. 2004). The extent of drug detachment will ultimately determine the performance of the DPI. Drug detachment from carrier particles is primarily governed by two mechanisms, flow stream (fluid forces) and impact (mechanical forces) (Voss and Finlay 2002; de Boer et al. 2003). Separation of drug particles from carrier particles by flow stream mainly involves aerodynamic lift and drag due to air turbulence. In contrast, drug separation from carrier particles by impact is related to a sudden change in particle acceleration or velocity due to collisions, generating a separation force. With an increase in the surface roughness of the carrier particles, drug particles may be shielded by the undulating edges on the carrier particles, and the drug detachment depends more on the mechanical forces of separation where other factors influencing drug-carrier adhesive forces (Donovan and Smyth 2010) such as van der Waals forces, electrostatic forces and capillary forces may also play their roles. The magnitude of these forces is affected by the physicochemical properties of both the carrier and the drug particles, such as the surface properties, contact surface area and environmental conditions (Buckton 1997; Young and Price 2004).
Dosimetry study on Auger electron-emitting nuclear medicine radioisotopes in micrometer and nanometer scales using Geant4-DNA simulation
Published in International Journal of Radiation Biology, 2020
Seifi Moradi Mahdi, Shirani Bidabadi Babak
The results show that on a single-cell scale, each radioisotope transmits more dose than 131I (the exception is only in three configurations N ← Cy, N → CS and C → CS for 99Tc) and, on the other hand, they transmit small amounts of dose to healthy cells adjacent to the cancerous cell (up to 2.5%). These diagnostic radioisotopes have a good half-life and easier access to them. For example, access to therapeutic 211At radioisotope is limited due to the need for an alpha particle accelerator with moderate energy to produce it. Another 211At problem, its daughter, is 110Po, which emits alpha particles with a half-life of 138.4 days. Also, due to the proper energy of the Auger electrons and the internal conversion electrons of these diagnostic radioisotopes, they can also be used in cluster irradiation of cancer cells.
Focus small to find big – the microbeam story
Published in International Journal of Radiation Biology, 2018
The first application of the microbeam by Zirkle back in 1950s was to look at the role of radiation during mitosis (Zirkle and Bloom 1953). With modern microbeam settings and an advanced imaging system, spatiotemporal analysis of DNA damage repair can be studied with a live imaging system. Using a charged particle accelerator, Tobias et al. (2010) visualized the kinetics of repair-related proteins being recruited to DNA damage sites after irradiation. Fast recruited proteins like DNA-PK or XRCC1 or slower recruited proteins like 53BP1 or MDC1 were classified by microbeam microscopy, and this classification helped to establish the hierarchical organization of damage recognition and subsequent repair events. Due to the subnuclear dose deposition by the microbeam and the development of fluorescent protein tags, the accumulation of different repair proteins to DNA damage sites and their mobility can be efficiently analyzed. With the combination of microbeam and fluorescence tagged proteins, roles of proteins involved in various biological processes can be analyzed in a real-time manner.