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Application of Laser-Driven Beams for Radiobiological Experiments
Published in Paul R. Bolton, Katia Parodi, Jörg Schreiber, Applications of Laser-Driven Particle Acceleration, 2018
Anna A. Friedl, Thomas E. Schmid
Radiobiology is the science of the response of living systems to ionizing radiation. This comprises the identification and quantification of lesions in the DNA and other cellular structures induced by irradiation and the characterization of the complex response mechanisms that cells possess in order to deal with the damage induced. Elaborate mechanisms ascertain that lesions are detected, signal pathways are activated, lesions are repaired, and – if this is not possible – cells stop division and possibly enter a controlled form of cell death [Goldstein 2014]. Elucidation of these pathways and the factors and genes involved has contributed to our general understanding of cellular activities and facilitates the identification of pathogenic phenotypes associated with enhanced radiation sensitivity, as well as the estimation of radiation-associated risk. It is expected that this will, in the future, allow for the optimization of radiation therapy by the personalization of treatment concepts [Shah 2012, Boss 2014, Ree 2015].
Radiobiology and Hadron Therapy
Published in Manjit Dosanjh, Jacques Bernier, Advances in Particle Therapy, 2018
Eleanor A. Blakely, Manjit Dosanjh
Radiobiology is a scientific field that measures a large and diverse number of biological effects from exposures to different radiations from the electron magnetic spectrum at several levels of biological scale and organisation from submolecular to cells, tissues, whole organisms and even populations. Radiobiology can provide essential information regarding preclinical responses to radiation-based treatments for disease that can guide a physician’s selection of ionising radiation dose and treatment regime time-course. The medical field of radiotherapy for the treatment of cancer has significantly benefited from radiobiological evidence underlying the mechanisms involved in the clinical outcome. Radiobiology has been essential for the implementation of new treatment modalities involving radiation alone or in combination with chemotherapy and has uncovered inherent heterogeneities within tumour and normal tissues responses that have led to the realisation that personalised medicine for individual patients is likely critical to future medical care.
Nanotechnology-Mediated Radiation Therapy
Published in D. Sakthi Kumar, Aswathy Ravindran Girija, Bionanotechnology in Cancer, 2023
The high-energy X-rays or gamma rays, and charged particles emitting from radiation therapy target the most important sub-cellular molecule DNA to cause double-strand breaks, followed by the initiation of a chain of events to promote cell death via mitotic catastrophe, apoptosis, necrosis, and autophagy, thus dictate the central dogma of radiobiology [45]. The cell cycle is a tightly regulated process that is divided into two phases: interphase comprising (G1, S, and G2 phases) and mitosis. Cells exposed to radiation, undergo DNA damage, which is sensed by the two protein kinases ataxia-telangiectasia mutated (ATM) and ataxia-telangiectasia and Rad3-related protein (ATR) causing the arrest of the cell cycle and repairing the DNA damage. The double-strand DNA breaks are mainly repaired by non-homologous end joining (NHEJ) and homologous recombination (HR) pathways [44]. Mitotic catastrophe takes place when a cell loses its ability to complete mitosis, thus controlling the cells by triggering mitotic arrest and regulated cell death. Mitotic catastrophe in irradiated cells especially solid tumors is a delayed process taking around 2–6 days during which the cells might take several attempts to repair the damage and undergo cell divisions [46]. Though the exact mechanism of the initiation of mitotic catastrophe presents unclear answers requiring further investigation, nonetheless two different ideas have been proposed to shed light on this cellular event. The first idea proposed occurs as a result of DNA damage and dysfunctional cell cycle checkpoints. It is a well-established fact that tumors possess dysfunctional cell cycle checkpoints due to impaired p53 and aberrant apoptotic signaling pathways. The presence of mutated p53 leads to premature entry into the G2/M checkpoint that contains the unrepaired DNA, ultimately leading to cell death [47]. The second idea puts forward the concept of centrosome hyper amplification. Centrosomes are the microtubules organizing centers that facilitate the systematic chromosome segregation into daughter cells during mitosis. In the case of centrosome hyper amplification, it leads to the formation of multipolar mitotic spindle that promotes atypical chromosomal segregation, and the formation of abnormal giant cells with multiple nuclei culminating in cell death [48, 49].
Monte Carlo simulation for the interaction characteristics of gamma-rays with several tissues and water as a tissue substitute
Published in Radiation Effects and Defects in Solids, 2023
Urkiye Akar Tarim, Orhan Gurler, Latif Korkmaz
A certain material utilized to simulate a stated body tissue in terms of a group of physical specifics is designated as a tissue substitute. The group of selected physical characteristics will depend on the user’s utilization. In general, for choosing the most suitable material as a substitute for stated body tissue, two groups of physical properties complementary to each other are preferred to use as assessment criteria; these are declared as (a) the radiation interactions in the body tissue and (b) the dosimetric quantities at a concerned point in the body tissue (1). When using a tissue substitute in a phantom, care should be taken that the chosen material ideally has the same radiation absorption and scattering properties as the body tissue or organ of interest. This serves to simulate the modification caused by radiation absorption and scattering in relevant body tissues or organs. These phantoms constructed from tissue equivalent materials (i.e. various types of tissue substitutes) are especially used for the calibration of radiation detection systems, evaluation of imaging devices, testing new imaging methods and the enabling depth-dose measurements in medicine, radiation protection, and radiobiology (1, 2).
Absent, yet present? Moving with ‘Responsible Research and Innovation’ in radiation protection research
Published in Journal of Responsible Innovation, 2018
Michiel Van Oudheusden, Catrinel Turcanu, Susan Molyneux-Hodgson
Radiation protection (RP) is a subfield in nuclear science and technology where various scientific disciplines (e.g. radiobiology, epidemiology, dosimetry, radioecology) converge to enhance research for ‘[t]he protection of people from harmful effects of exposure to ionizing radiation and the means for achieving this’ (IAEA 2016). Significant milestones in its development include the establishment of the International Commission on Radiological Protection (ICRP) in 1928 and international legislation for the protection of workers (ILO 1960). Research in RP is burgeoning due, for example, to changing understandings of the health effects of low radiation doses; increasing use of ionizing radiation in medical applications; growing attention to decommissioning and environmental remediation projects; and ongoing issues related to nuclear accidents. European RP research is currently structured around five research ‘platforms’, under an overarching joint programme called CONCERT.1 These coordinated initiatives seek to address technical and societal challenges related to RP in an integrated manner.