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Ion therapy is an emerging technique used for the treatment of solid cancers. The monitoring of the dose delivered during such treatments and the on-line knowledge of the Bragg Peak (BP) position is still a matter of research. This paper reviews the current understanding of which radiation is produced during the interaction of the beam with the patient, the corresponding techniques developed to detect it and the level of understanding of the conversion between the emission spectra and the dose profile. It also performs a comparison between the different approaches.

The prediction of fading for the glow peaks relevant to dosimetry of iodised salt has been made using the values of the trapping parameters, namely the thermal activation energy (E), frequency factor (s) and the order of kinetic (b). This theoretical prediction has been checked with experimentally observed glow curves recorded after storage period of 2, 5, 10, 165, 375 and 790 days at room temperature (~21°C). Excellent agreement has been observed between the experimental and theoretical glow curves. This has been possible because of reliable retrieval of the trapping parameters by the use of Computerised Glow Curve Deconvolution (CGCD) as well as state-of-art of data acquisition system. The concept developed in the present paper in principle may be applied to any TLD.

Graphene has been considered one of the most important materials for many applications due to its unique electronic structure, physical and chemical properties. Graphite flakes are the main source of graphene oxide which can be transformed to graphene after reduction. The effect of irradiation on graphene oxide has been rarely studied, only few studies dealing with the irradiation of graphene oxide with gamma radiation were reported. The effect of irradiation of graphene oxide with gamma ray doses (low linear energy transfer) has been previously studied. It was found that there are no changes in the crystalline structure of graphene oxide after irradiation. Graphene oxide was prepared by modified Hummer’s method. The scanning electron microscopy image of the obtained sample suggests the presence of both single and multilayer graphene oxide sheets. The structural measurements for the graphene oxide samples with high linear energy transfers were carried out after irradiations with different doses of alpha particle (9.30–479.90 Gy). The effect of irradiation on oxygen functional groups of graphene oxide was followed by Fourier transforms infra-red spectrometer. Moreover, the irradiation effect on the lamellar space of graphene oxide layers was measured by X-ray diffraction. It was found that the d-spacing of graphene oxide was decreased after alpha particles irradiation with different doses. The effect of irradiation on dielectric constant and conductivity of graphene oxide samples was measured in the frequency range (200 Hz–1.00 MHz). The dielectric measurements show less dependence on irradiation doses. The graphene oxide sample can be used as radiation dosimeter for $\alpha$-particles in the range of the low irradiation doses.

Nowadays, the pacific use of ionizing radiation has attracted a great deal of attention in medicine, as well as in radiodiagnostic, and radiotherapy. However to avoid unnecessary irradiations to the healthy tissue, a strict quality control is required. This has led to the development of a new dosimeter equivalent to the tissue that could be highly suitable for the radiation dosimetry. The borate of magnesium with its low effective atomic number (Z_eff), is considered equivalent to the human-tissue. For this reason, in this work, we present the results obtained of the thermoluminescent characterization of this material. The test that was carried out includes the lower detection limit, sensitivity, reproducibility of the TL measurement, stability of information (fading), and TL response as a function of the delivered dose and energy response, which are recommended by the International Commission on Radiological Units and Measurements (ICRU) and International Commission on Radiological Protection (ICRP). Two different concentrations of Dy activator were used i.e. 1.25 (batch A) and 1.5 (batch B) mol%. Meanwhile, the Na activator was 0.5 mol% in both cases. The results show that this new thermoluminescent material is adequate for radiation dosimetry in different medical applications.

Carbon dioxide (CO₂) angiography represents an important technique to overcome most clinical problems related to the use of iodine contrast medium. The recent technologic advancements in the fields of gas injection and image reconstructions made CO₂ angiography a very efficient method for clinical evaluation of peripheral cardiovascular system. Despite that, some challenges are still open and a better knowledge of the biomechanical behavior of CO₂ and its interactions with blood flowing into the vessels is necessary to optimize this technology and to expand its field of application. This paper presents a quick overview about biomechanical behavior of carbon dioxide during injection, suggesting possible optimization tricks to make CO₂ angiography procedures more effective to improve imaging and reduce the patients’ radiological dose. Particular attention has been also paid to 3D imaging techniques, which can certainly be opened to the use of carbon dioxide.

The history and technology of medical linacs are reviewed, focusing on machine requirements for radiotherapy. Configurations used in modern machines are described and operational aspects of a gantry-style linac system are illustrated with reference to the state of the art. Aspects of structure design, modeling and testing are discussed.

In this study, large-area (6-cm diameter) Teflon polytetrafluoroethylene (PTFE) discs of different thicknesses (0.2-, 0.5- and 1 -mm) were negatively and positively charged by using the “modified single point-to-plane corona poling rotating system”. The effects of some crucial parameters of the PTFE disc as well as the modified corona poling rotating system on the PTFE surface potential uniformity such as: (a) PTFE disc thickness, (b) PTFE disc polarity and (c) needle-to-PTFE disc distance were successfully reported. Accordingly, closer needle-to-PTFE disc distance, positive charging mode and thinner PTFE disc provided a better PTFE surface potential uniformity. However, the effects of PTFE charge polarity and needle distance on the electrostatic charge potential uniformity were much more remarkable in comparison with the effects of PTFE thickness. Additionally, the surface potential distribution profiles of charged PTFE discs were totally flat and independent of the PTFE thickness at 5- and 13-mm needle distances for the negative and positive charging modes, respectively. At the optimized charging conditions, large-area PTFE electret disc (0.5-mm-thick) with positive uniform surface charge potential especially at the edges up to $\sim$ 1.8kV with stability up to 77 days studied was produced by applying a new multiple heat treatment protocol to the PTFE disc for radon dosimetry. As also observed in this study, the sensitivity of PTFE electret dosimeters to a defined radon gas concentration increases as the PTFE thickness increases. Meanwhile, 0.5-mm-thick PTFE electret disc produced was selected to be used as a high quality electret dosimeter with acceptable and superior parameters for different applications in particular medium-term radiation dosimetry in both low and high dose rate ionizing radiation fields.

The Selective Production of Exotic Species (SPES) facility, now under construction at Legnaro National Laboratories of INFN, is a second-generation accelerator for the production of neutron-rich ion beams. The radioactive nuclear species are produced by fission of a ${}^{\mathrm{\text{238}}}$U target, on which a 200$\mu$A primary proton beam of 40MeV energy impinges. Materials and components constituting the Target and Ion Source assembly and the Front-End supporting structure are subjected to serious radioactive damage due to intense neutron and photon fields present under operating conditions. In the framework of the SPES project, experimental campaigns aimed at testing the radiation hardness of critical materials and components of potential use in the construction were started. Irradiations were conducted in a reactor mixed field of neutrons and photons in order to reproduce, as close as possible, the actual environmental service conditions. Results obtained for different types of elastomeric materials used for construction of vacuum O-rings, as well as preliminary results obtained for lubricating oils and greases, are presented. Materials under consideration are both conventional ones as well as materials specifically developed for applications in the presence of ionizing radiation. The latter materials were previously tested mainly in gamma radiation fields.

Innovating dosimetric materials, which includes design and development of new dosimetric materials based on rare earth oxides, is challenging. Yttrium oxide (Y${}_{\mathrm{\text{2}}}$O${}_{\mathrm{\text{3}}})$ is one of the most important sesquioxides and presents crystal characteristics that enable doping with rare earth ions, making it a promising material for radiation dosimetry. This paper reports on the development and measurement of Electron Paramagnetic Resonance (EPR) signal response for Y${}_{\mathrm{\text{1.98}}}$Eu${}_{\mathrm{\text{0.02}}}$O${}_{\mathrm{\text{3}}}$micro rods that have undergone facile low-pressure hydrothermal synthesis and bio-prototyping. As- synthesized powders with narrow sub-micrometer particle size distribution with d${}_{\mathrm{\text{50}}}$ of 584 nm exhibited a reactive surface, which led to the formation of stable aqueous suspensions by controlling the surface charge density of particles through alkaline pH adjustment. Ceramic samples with dense microstructure were formed by sintering at 1600 ${}^{\text{o}}$C for 4h at ambient atmosphere. Y${}_{\mathrm{\text{1.98}}}$Eu${}_{\mathrm{\text{0.02}}}$O${}_{\mathrm{\text{3}}}$micro rods were irradiated using a ${}^{\mathrm{\text{60}}}$Co source with doses from 1 to 100 kGy, and EPR spectra were measured at room temperature in X-band microwave frequencies. Sintered samples exhibited linearity of the main EPR signal response from 10 Gy to 10 kGy. Supralinearity was observed for higher doses, which is possibly ascribed to formation of more defects. Using europium as a dopant enhanced the EPR signal of yttrium rods remarkably, due to 4f–4f transitions of the Eu${}^{\mathrm{\text{3+}}}$ ion. These innovative findings make europium-doped yttrium oxide a promising material for radiation dosimetry.

Recent results in the field of film dosimetry demonstrated that the Green–Saunders equation, a solution of the logistic equation describing phenomena of kinetics of chemical reactions, is the absolute calibration function for all radiochromic film types. Taking advantage of the new opto-electronics-based radiochromic film reading method, which allows real-time measurements of the spectral response of radiochromic films, we confirm that the film darkening is ruled by the Green–Saunders equation independently both from the reading instrument or the choice of the observable used for the calibration. In order to demonstrate it, we exposed an XR-QA2 Gafchromic film to ⁹⁰Sr/⁹⁰Y beta rays up to 1400 mGy. Film spectra are recorded in real-time. The calibration is performed by means of two analytic methods: evaluation of the integral under the curves from 500 nm to 645 nm and evaluation of the intensity at 570, 600 and 643 nm. Experimental data fit to the Green–Saunders equation for both methods.

To estimate the respiration-induced dosimetric change at beam edge during a beam-on interval of radiotherapy, by the integration of a mathematical model for organ motion and a modeled beam profile. A method is proposed which incorporated the effects of intra-treatment organ motion due to breathing on the dosimetric change for the treatment of liver cancer. The basic algorithm was to assume the motion of infra-abdominal organs was predominantly in the superior-inferior (S-I) direction. The starting phase was defined as the mid-phase at exhale, to reproduce the same situation of computed tomography simulation for liver cancer. The S-I extent of motion was defined as 1.5cm. The period of a breathing cycle was defined as 4.2 seconds. The shape parameter of the respiratory model was defined as 3. The radiation dose of 100 cGy given with the rate of 300 MU/minute was designed for the model analysis. The position at the beam edge as a function of time could be parameterized for a 10cm x 10cm field with a setup of SAD 100cm. The dose profiles of both 6MV and 18MV photons were applied for the dosimetric calculation of the beam-edge point during the dynamic movement in a beam-on time interval of radiotherapy. The point doses at the superior beam edge for 6MV photons and18MV photons during a beam-one interval of 22.8 seconds were 73.5% and 77.2% of the isocenter dose, respectively. The point doses at the inferior beam edge for the two energies were 31.2% and 32.4%, respectively. There were 147-154% dose increase for superior beam edge and 62.4-64.8% dose decrease for inferior beam edge, as compared to the 50% isocenter dose with the static dose distribution. It is simple and feasible to use the mathematical model to estimate the dosimetric change of the intra-abdominal organ motion from respiration. The impact of respiration on the dosimetric difference deserves more attention in the prescription of radiation treatment. Further measurement of the exact organ motion during the real treatment is warranted to optimize the model.

Ultrafine particles (less than 100 nm in diameter) are encountered in ambient air and at the workplace. Normal background levels in the urban atmosphere for ultrafine particles are in the range 1−4 × 10⁴cm⁻³; however, their mass concentration is normally not greater than 2 μg m⁻³. At the workplace, ultrafine particles occur regularly in metal fumes and polymer fumes, both of which can induce acute inflammatory responses in the lung upon inhalation. Although ultrafine particles occurring at the workplace are not representative, and, therefore, are not relevant for urban atmospheric particles, their use in toxicological studies can give valuable information on principles of the toxicity of ultrafine particles. Studies in rats using ultrafine polymer fumes of polytetrafluoroethylene (PTFE) (count median diameter ca. 18 nm) showed that (i) they induced very high pulmonary toxicity and lethality in rats after 15 min of inhalation at 50 μg m⁻³; (ii) ageing of PTFE fumes resulted in agglomeration to larger particles and loss of toxicity; (iii) repeated pre-exposure for very short periods protected against the toxic and lethal effects of a subsequent 15 min exposure; (iv) rapid translocation of PTFE particles occurred to epithelial, interstitial and endothelial sites. Since one characteristic of urban ultrafine particles is their carbonaceous nature, exposure of rats to laboratory-generated ultrafine carbonaceous (elemental, and organic, carbon) particles was carried out at a concentration of ca. 100 μm⁻³ for 6 h. Modulating factors of responses were prior lowdose inhalation of endotoxin in order to mimic early respiratory tract infections, old age (22-month old rats versus 10-week old rats) and ozone co-exposure. Analysis of results showed that (i) ultrafine carbon particles can induce slight inflammatory responses; (ii) LPS priming and ozone co-exposure increase the responses to ultrafine carbon; (iii) the aged lung is at increased risk for ultrafine particle-induced oxidative stress. Other studies with ultrafine and fine TiO₂ showed that the same mass dose of ultrafine particles has a significantly greater inflammatory potential than fine particles. The increased surface area of ultrafine particles is apparently a most important determinant for their greater biological activity. In addition, the propensity of ultrafine particles to translocate may result in systemic distribution to extrapulmonary tissues.

This chapter describes the development of boron neutron capture therapy (BNCT) from several technical aspects, including the neutron source, dosimetry and the treatment process. The principle of BNCT to kill tumor cells is mainly based on the nuclear reaction between thermal neutrons and boron. The energy generated by this nuclear reaction will destroy the double helix structure of DNA in the nucleus, making it impossible to repair and causing apoptosis of the whole cell. While the boron drug is the protagonist, the development and application of neutron sources and nuclear-related technologies are also a crucial aspect. The differences between the two types of neutron source, reactor-based and accelerator-based, as well as the key components and related technologies of these neutron sources are discussed. Three typical BNCT facilities in the world are also introduced. An entire section is dedicated to dosimetry, as accurate dose assessment and calculation are the key to the success of BNCT. The chapter is completed by a step-by-step explanation of the treatment planning system and treatment process.

The history and technology of medical linacs are reviewed, focusing on machine requirements for radiotherapy. Configurations used in modern machines are described and operational aspects of a gantry-style linac system are illustrated with reference to the state of the art. Aspects of structure design, modeling and testing are discussed.