Topic
Linear energy transfer
About: Linear energy transfer is a research topic. Over the lifetime, 1233 publications have been published within this topic receiving 25692 citations. The topic is also known as: restricted linear collision stopping power.
Papers published on a yearly basis
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Papers
TL;DR: 3D radiation dose distribution in polymer gel dosimeters may be imaged using magnetic resonance imaging (MRI), optical-computerized tomography (optical-CT), x-ray CT or ultrasound, and clinical dosimetry applications of polymer gel Dosimetry are presented.
Abstract: Polymer gel dosimeters are fabricated from radiation sensitive chemicals which, upon irradiation, polymerize as a function of the absorbed radiation dose. These gel dosimeters, with the capacity to uniquely record the radiation dose distribution in three-dimensions (3D), have specific advantages when compared to one-dimensional dosimeters, such as ion chambers, and two-dimensional dosimeters, such as film. These advantages are particularly significant in dosimetry situations where steep dose gradients exist such as in intensity-modulated radiation therapy (IMRT) and stereotactic radiosurgery. Polymer gel dosimeters also have specific advantages for brachytherapy dosimetry. Potential dosimetry applications include those for low-energy x-rays, high-linear energy transfer (LET) and proton therapy, radionuclide and boron capture neutron therapy dosimetries. These 3D dosimeters are radiologically soft-tissue equivalent with properties that may be modified depending on the application. The 3D radiation dose distribution in polymer gel dosimeters may be imaged using magnetic resonance imaging (MRI), optical-computerized tomography (optical-CT), x-ray CT or ultrasound. The fundamental science underpinning polymer gel dosimetry is reviewed along with the various evaluation techniques. Clinical dosimetry applications of polymer gel dosimetry are also presented.
891 citations
TL;DR: The results of experiments with mono-energetic charged particles, whereby narrow distributions of linear energy transfer (LET) are obtained, show that the OER decreases with increasing LET from about 2·6 at a LET∞ of 5·6 kev/μ of unit density tissue to a value of 2·05 at 61 kev /μ.
Abstract: SummaryOxygen-enhancement ratios (OER) have been determined for the inhibition of clone-formation by cultured cells of human origin irradiated with α-particles and deuterons of different energies, fast neutrons and 250 kvp x-rays. The results of experiments with mono-energetic charged particles, whereby narrow distributions of linear energy transfer (LET) are obtained, show that the OER decreases with increasing LET from about 2·6 at a LET∞ of 5·6 kev/μ of unit density tissue to a value of 2·05 at 61 kev/μ, followed by a more rapid decrease to 1·0 at 165 kev/μ. With fast neutrons, produced by bombarding Be with 16 mev deuterons, an OER of 1·6 was obtained and with 250 kvp x-rays the OER was 2·7.The relation between the relative biological effectiveness (RBE), the OER and the LET is discussed.
270 citations
TL;DR: An equation based on the MK model gives the dependence of the relative biological effectiveness in the limit of zero dose (RBE1) on the linear energy transfer (LET) and an equation that portrays the ratio of the sensitivity of a pair of cell types as a function of LET is presented.
Abstract: Hawkins, R. B. A Microdosimetric-Kinetic Model for the Effect of Non-Poisson Distribution of Lethal Lesions on the Variation of RBE with LET. Radiat. Res. 160, 61–69 (2003). The microdosimetric-kinetic (MK) model for cell killing by ionizing radiation is summarized. An equation based on the MK model is presented which gives the dependence of the relative biological effectiveness in the limit of zero dose (RBE1) on the linear energy transfer (LET). The relationship coincides with the linear relationship of RBE1 and LET observed for low LET, which is characteristic of a Poisson distribution of lethal lesions among the irradiated cells. It incorporates the effect of deviation from the Poisson distribution at higher LET. This causes RBE1 to be less than indicated by extrapolation of the linear relationship to higher LET, and to pass through a maximum in the range of LET of 50 to 200 keV per micrometer. The relationship is compared with several experimental studies from the literature. It is shown to ...
266 citations
TL;DR: By accounting for the α/β ratio of photons, clearer trends between RBE and LET of protons were found, and the results suggest that late responding tissues are more sensitive to LET changes than early responding tissues and most tumors.
Abstract: Background. The biological effects of particles are often expressed in relation to that of photons through the concept of relative biological effectiveness, RBE. In proton radiotherapy, a constant RBE of 1.1 is usually assumed. However, there is experimental evidence that RBE depends on various factors. The aim of this study is to develop a model to predict the RBE based on linear energy transfer (LET), dose, and the tissue specific parameter α/β of the linear-quadratic model for the reference radiation. Moreover, the model should capture the basic features of the RBE using a minimum of assumptions, each supported by experimental data. Material and methods. The α and β parameters for protons were studied with respect to their dependence on LET. An RBE model was proposed where the dependence of LET is affected by the (α/β)phot ratio of photons. Published cell survival data with a range of well-defined LETs and cell types were selected for model evaluation rendering a total of 10 cell lines and 24 R...
253 citations
TL;DR: Examination of frequencies and molecular spectrum of S1- mutants induced in human-hamster hybrid (A(L) cells by either a single or an exact number of alpha particles provides direct evidence that a single a particle traversing a nucleus will have a high probability of resulting in a mutation and highlight the need for radiation protection at low doses.
Abstract: One of the main uncertainties in risk estimation for environmental radon exposure using lung cancer data from underground miners is the extrapolation from high- to low-dose exposure where multiple traversal is extremely rare. The biological effects of a single alpha particle are currently unknown. Using the recently available microbeam source at the Radiological Research Accelerator Facility at Columbia University, we examined the frequencies and molecular spectrum of S1- mutants induced in human-hamster hybrid (A(L)) cells by either a single or an exact number of alpha particles. Exponentially growing cells were stained briefly with a nontoxic concentration of Hoechst dye for image analysis, and the location of individual cells was computer-monitored. The nucleus of each cell was irradiated with either 1,2,4, or 8 alpha particles at a linear energy transfer of 90 keV/microm consistent with the energy spectrum of domestic radon exposure. Although single-particle traversal was only slightly cytotoxic to A(L) cells (survival fraction approximately 0.82), it was highly mutagenic, and the induced mutant fraction averaged 110 mutants per 10(5) survivors. In addition, both toxicity and mutant induction were dose-dependent. Multiplex PCR analysis of mutant DNA showed that the proportion of mutants with multilocus deletions increased with the number of particle traversals. These data provide direct evidence that a single a particle traversing a nucleus will have a high probability of resulting in a mutation and highlight the need for radiation protection at low doses.
241 citations
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Performance Metrics
| Year | Papers |
|---|---|
| 2025 | 20 |
| 2024 | 53 |
| 2023 | 54 |
| 2022 | 151 |
| 2021 | 35 |
| 2020 | 36 |