Energy dependent track structure parametrisations for protons and carbon ions based on nanometric simulations

Alexander, F.G.; Villagrasa, C.; Rabus, Hans; Wilkens, Jan J.

doi:10.1140/epjd/e2015-60206-5

Cited by 13 publications

(25 citation statements)

References 30 publications

(32 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In combination with a stopping power weighted method, the parametrization can be used to characterize the track structure of a mixed radiation field. 6,7 Conte et al were able to establish a relationship between nanodosimetric quantities and the coefficients of the linear-quadratic model. 8 The relative biological effectiveness can then be derived from the obtained linear-quadratic model parameters.…”

Section: Introductionmentioning

confidence: 99%

First measurements of ionization cluster‐size distributions with a compact nanodosimeter

Vasi

Schneider

2021

Medical Physics

View full text Add to dashboard Cite

A nanodosimeter is a type of detector which measures single ionizations in a small gaseous volume in order to obtain ionization cluster size probability distributions for characterization of radiation types. Working nanodosimeter detectors are usually bulky machines which require a lot of space. In this work, the authors present a compact ceramic nanodosimeter detector and report on first measurements of cluster size distributions of 5 MeV alpha particles. Methods: Single ionization measurements are achieved by applying a weak electric field to collect positive ions in a hole in a ceramic plate. Inside the ceramic plate, due to a strong electric field, the ions are accelerated and produce impact-ionizations. The resulting electron avalanche is detected in a read-out electrode. A Bayesian unfolding algorithm is then applied to the experimentally obtained cluster size distributions to reconstruct the true cluster size distributions. Results: Experimentally obtained cluster size distributions by the compact nanodosimeter detector are presented. The reconstructed cluster size distributions agreed well with Monte Carlo simulated cluster size distributions for small volumes (diameter = 2.5 nm). For larger volumes, discrepancies between the reconstructed cluster size distributions and cluster size distributions from Monte Carlo simulations were observed. Conclusions: For the first time, ionization cluster size probability distributions could be obtained by a small and compact nanodosimeter detector. This signifies the achievement of a critical step toward the wide application of nanodosimetric characterization of radiation types including in clinical environments.

show abstract

Section: Introductionmentioning

confidence: 99%

First measurements of ionization cluster‐size distributions with a compact nanodosimeter

Vasi

Schneider

2021

Medical Physics

View full text Add to dashboard Cite

show abstract

“…For details the reader is referred to reference [18].In a subsequent work by Conte et al, these finding were exploited even further to establish a link between measured nanodosimetric parameters of ion track structure and the coefficients of the linear-quadratic model for cell survival [19]. This progress has stimulated investigations into the potential use of nanodosimetric parameters in treatment planning, as these offer the advantage of measurable quantities linked to the biological outcome of the irradiation [20], [21], [22].Despite the undeniable and impressive evidence found by Conte et al [18], [19], a major concern that is often raised is the implication that radiation interaction with a single nanometric target should decide the fate of the irradiated cell. It is still an open issue to resolve how these finding can be reconciled with the overwhelming evidence of the importance of indirect radiation effects (i.e.…”

mentioning

confidence: 99%

“…In a subsequent work by Conte et al, these finding were exploited even further to establish a link between measured nanodosimetric parameters of ion track structure and the coefficients of the linear-quadratic model for cell survival [19]. This progress has stimulated investigations into the potential use of nanodosimetric parameters in treatment planning, as these offer the advantage of measurable quantities linked to the biological outcome of the irradiation [20], [21], [22].…”

mentioning

confidence: 99%

Nanodosimetry – on the ''tracks'' of biological radiation effectiveness

Rabus¹

2020

Zeitschrift für Medizinische Physik

Self Cite

View full text Add to dashboard Cite

It is well known that the biological effectiveness of a certain absorbed dose of ionizing radiation depends on the radiation quality, i. e. the spectrum of ionizing particles and their energy distribution [1], [2], [3]. As has been shown in several studies, the biological effectiveness is related to the pattern of energy deposits on the microscopic scale, the socalled track structure [4]. Clusters of lesions in the DNA molecule within site sizes of few nanometers play a particular role in this context [4], [5], [6]. A first approach to measure track structure of ionizing radiation with nanometric resolution was proposed already in 1975 [7]. However, the extension of microdosimetric measurements to site sizes of few nanometer dimension was facing the fundamental problem that in such small sites the number of interactions is too low, such that the assumption fails that the imparted energy is the number of ionizations multiplied by a simple conversion factor [8]. Therefore, the development of methods for measuring track structure details with nanometric resolution required a change of paradigm, namely restricting the characterization of track structure to its ionization component [9], [10].In should be noted in this context that the term nanodosimetry is used in the literature in different meanings. These include ongoing endeavors to extend microdosimetry into the nanometer range to below 100 nm site sizes [11], [12] as well as simulation studies of various kinds that are not focused on quantities that are directly measurable. In this paper we use the term nanodosimetry for studies of charged particle track structure, considering the stochastics of ionizations in nanometric targets.The quantity of interest is the relative frequency distribution of the so-called ionization cluster size, i.e. the number of ionizations inside a considered target (often called the 'site'). As is illustrated in Figure 1, the ionization cluster size distribution (ICSD) varies with the geometrical position of the target with respect to the particle track. Furthermore, it also depends on the size and composition of the target and, most importantly, on the radiation quality. The ICSD can also be characterized by its statistical moments or the complementary cumulative frequencies of ionization clusters exceeding a certain minimum size [13].Around the turn of the century, three different types of nanodosimeters have been developed to measure the frequency distribution of ionization cluster size [14]. All devices are gas counters that simulate nanometric sensitive volumes based on a density scaling principle [15]. They Figure 1. Schematic illustration of nanodosimetric ionization cluster size (ICS) distributions in a spread-out Bragg peak (SOBP) of protons in water. The orange spheres indicate the loci of ionizing interactions of the proton or of the emitted secondary electrons. The blue and red cylinders represent nanometric targets located in the core and in the penumbra region of the track, respectively. The histograms with the blue and red...

show abstract

“…This is an area where there is much uncertainty on particle transport and cross-sections for interactions, because initial high-energy particles result in many lower-energy electrons and photons that are responsible for the ionisations that cause DNA damage. Working Group 6 is investigating these aspects of dose deposition via collaborative research (Alexander et al, 2015;Bueno et al, 2015;Dressel et al, 2017;Villagrasa et al, 2017;Dressel et al, 2018). For high energies, there are similar problems for MC methods as cross-section data are largely missing, and nuclear models are applied to simulate scattering and secondary particle generation.…”

Section: Computational Dosimetrymentioning

confidence: 99%

The work programme of EURADOS on internal and external dosimetry

et al. 2018

View full text Add to dashboard Cite

Since the early 1980s, the European Radiation Dosimetry Group (EURADOS) has been maintaining a network of institutions interested in the dosimetry of ionising radiation. As of 2017, this network includes more than 70 institutions (research centres, dosimetry services, university institutes, etc.), and the EURADOS database lists more than 500 scientists who contribute to the EURADOS mission, which is to promote research and technical development in dosimetry and its implementation into practice, and to contribute to harmonisation of dosimetry in Europe and its conformance with international practices. The EURADOS working programme is organised into eight working groups dealing with environmental, computational, internal, and retrospective dosimetry; dosimetry in medical imaging; dosimetry in radiotherapy; dosimetry in high-energy radiation fields; and harmonisation of individual monitoring. Results are published as freely available EURADOS reports and in the peer-reviewed scientific literature. Moreover, EURADOS organises winter schools and training courses on various aspects relevant for radiation dosimetry, and formulates the strategic research needs in dosimetry important for Europe. This paper gives an overview on the most important EURADOS activities. More details can be found at www.eurados.org .

show abstract

Energy dependent track structure parametrisations for protons and carbon ions based on nanometric simulations

Cited by 13 publications

References 30 publications

First measurements of ionization cluster‐size distributions with a compact nanodosimeter

First measurements of ionization cluster‐size distributions with a compact nanodosimeter

Nanodosimetry – on the ''tracks'' of biological radiation effectiveness

The work programme of EURADOS on internal and external dosimetry

Contact Info

Product

Resources

About