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Introduction
Published in Debbie Peet, Emma Chung, Practical Medical Physics, 2021
Debbie Peet, Emma Chung, Jasdip Mangat, Joanne Cowe
From the early days of hospital care and the inception of the NHS in 1948, the field of Medical Physics has driven advances in technology and aided innovations in healthcare. In 1901, the first Nobel Prize for Physics was awarded to Wilhelm Roentgen for his discovery of X-rays in 1895. Roentgen found that passing X-rays through human tissue revealed the structure of the bones (Figure 1.1). The increasing reliance of doctors on diagnostic X-ray imaging then paved the way for the development of X-ray computed tomography (CT) and further innovations including magnetic resonance imaging (MRI) and ultrasound. Today, high-energy X-rays generated by linear accelerators are also applied to radiotherapy treatment of cancer.
Radiation Dose and Exposure Indicators
Published in Ken Holmes, Marcus Elkington, Phil Harris, Clark's Essential Physics in Imaging for Radiographers, 2021
To determine the dose in Sieverts from the dose in Grays, simply multiply by the WR. This is obviously a simplification. The WR approximates what otherwise would be a very complicated calculation. The values for WR change periodically as new research refines the risks associated with radiation exposure.
Oncology
Published in Roy Palmer, Diana Wetherill, Medicine for Lawyers, 2020
Among the general public radiotherapy is the least understood modality for the management of cancers. Although the taking of X-rays is understood for diagnosis, treatment with radiation conjures up similes with the atomic bomb, nuclear war and the induction of leukaemia. Radiotherapy has been used to treat cancer almost since the discovery of X-rays by Roentgen in 1895 and there have been large numbers of technical and innovative advances during the course of the development of current standards. Radiotherapy treatment is prescribed and planned by the clinical oncologist with the help of a team of medical physicists and the treatment is given daily by radiographers. The most frequently prescribed type of radiotherapy is external beam radiotherapy given by linear accelerators. These large and expensive machines are present in all cancer centres in the UK and therefore access to state of the art machinery should not be denied to anyone.
The role of small GTPase Rac1 in ionizing radiation-induced testicular damage
Published in International Journal of Radiation Biology, 2022
Yasar Aysun Manisaligil, Mukaddes Gumustekin, Serap Cilaker Micili, Cemre Ural, Zahide Cavdar, Gizem Sisman, Aysegul Yurt
Rats were exposed to low, medium and high doses of radiation corresponding to 0.02 Gy, 0.1 Gy and 5 Gy respectively. A digital Roentgen device (Philips Tele Diagnost, Amsterdam, Netherlands) operating in Department of Radiology, Dokuz Eylul University, was used for low dose exposures. A linear accelerator (Siemens Primus, Erlangen, Germany) available in Dokuz Eylul University Radiation Oncology Department was used for medium and high dose exposures. Following a series of measurements taken with an ionization chamber (RTI, Model R100, Mölndal, Sweden), low dose set up was achieved with a tube potential of 133 kV, tube current of 300 mA and exposure time of 0.5 s to give 0.02 Gy. Medium and high dose exposures were achieved by using 6 MV photon beams with a dose rate of 300 Monitor Units (MU)/min. Irradiation setups with 10 MU and 500 MU were used to provide 0.1 Gy and 5 Gy radiation doses, respectively. Each rat was kept in a 13x18x10 cm plastic container through which X-rays can penetrate easily. The irradiation field was set to 13 × 18 cm2 at a skin to source distance (SSD) of 83 cm for all exposures (Said et al. 2019; Zhang et al. 2020).
Mass spectrometry-based phospholipid imaging: methods and findings
Published in Expert Review of Proteomics, 2020
Al Mamun, Ariful Islam, Fumihiro Eto, Tomohito Sato, Tomoaki Kahyo, Mitsutoshi Setou
In biology, imaging refers to the techniques used to visualize internal structure or biomolecules in tissues and cells of a living system, in two-dimensional (2D) or three-dimensional (3D) style without perturbing the structure. The history of imaging dates back to 1895 when Wilhelm Roentgen discovered X-ray. X-ray was originally used in medical imaging to create a 2D image of internal organs in an X-ray film [1]. With the advancement of computer vision and algorithms, several methods such as computed tomography [2], magnetic resonance imaging [3], positron emission tomography [4], and ultrasound [5] have been evolved to produce 2D as well as 3D image [6]. Besides anatomical imaging, those techniques play important role in molecular imaging where contrast agents are used for the noninvasive visualization, characterization, and measurement of the biological processes in the living system [6–8]. Discovery of electron microscope enabled the comprehensive visualization of cellular and subcellular ultrastructures [9]. Some other microscopy-based labeled molecular imaging techniques such as green fluorescent protein labeling [10], and immunohistochemistry [11] are used to visualize the distribution map of protein molecules in tissue as well as cell structure.
The influence of ketogenic therapy on the 5 R’s of radiobiology
Published in International Journal of Radiation Biology, 2019
Within only one year after their discovery by Wilhelm Conrad Röntgen in his laboratory in Würzburg in 1895, X-rays were applied to treat patients with cancer by pioneers such as Victor Despeignes in Lyon (Sgantzos et al. 2014; Foray 2016) and – possibly − Emil Grubbé in Chicago (Grubbé 1933). In 1995, celebrating ‘100 years of Röntgen rays’, an editorial in the journal Strahlentherapie und Onkologie by E. Scherer concluded with the prospect that besides further technical refinements, the future of radiotherapy (RT) would mainly lie in its combination with chemotherapy, targeted therapies, hyperthermia, radiosensitizers and radioprotectors (Scherer 1995). While nowadays the majority of cancer patients in developed countries will receive RT as an essential part of their treatment (Miller et al. 2016), the search for good tolerable adjunct treatment options that could widen the therapeutic window remains a challenge. This is exemplified by the disappointing efficacy of personalized targeted therapies that seem to benefit at best a small percentage of patients, yet come with exorbitant costs and additional risks of severe side effects (Prasad 2016).