For tumor therapy with light ions and for experimental aspects in particle radiobiology the relative biological effectiveness (RBE) is an important quantity to describe increased of radiation.By establishing analysing a database ion photon cell survival data, some remarkable properties RBE-related quantities were observed.The consists 855 vitro experiments after irradiation.The comprise curves obtained different labs, using species, irradiation modalities, whole range accessible energies...

To present details of the recent version 'Local Effect Model' (LEM), that has been developed and implemented in treatment planning for ion beam therapy pilot project performed at GSI Helmholtzzentrum für Schwerionenforschung Darmstadt, Germany.The new model is based on a detailed consideration spatial distribution initial damages, i.e., double-strand breaks (DSB). This DSB obtained from radial dose profile track using Monte Carlo methods. These distributions are then analyzed with regard to...

Abstract Solid tumours often present regions with severe oxygen deprivation (hypoxia), which are resistant to both chemotherapy and radiotherapy. Increased radiosensitivity as a function of the concentration is well described for X-rays. It has also been demonstrated that radioresistance in anoxia reduced using high-LET radiation rather than conventional However, dependence enhancement ratio (OER) on quality intermediate concentrations, those normally found tumours, had never measured...

Biological optimization for treatment planning in carbon ion therapy is currently based on the first version of local effect model (LEM I). Further developments implemented latest IV) allowed to predict more accurately Relative Effectiveness (RBE) in-vitro. The main goal this study compare LEM IV against I under treatment-like conditions idealized target geometries. Therefore, physical dose distributions resulting from biological with were used recalculate RBE-weighted distribution IV. Input...

A new, simple mechanistic dose-response model for cell survival after photon irradiation is presented. Its ingredients are motivated by the concept of giant loops, which constitute a level chromatin organization on megabase pair length scale. Double-strand breaks (DSBs) that induced within different loop domains DNA assumed to be processed independently cell's repair mechanism. The distinguishes between two classes damage, characterized either single DSB or multiple DSBs loop. Different...

Different ion types offer different physical and biological advantages for therapeutic applications. The purpose of this work is to assess the most commonly used ions in particle therapy, i.e., carbon ((12)C), helium ((4)He), protons ((1)H) treatment scenarios.A planning analysis based on idealized target geometries was performed using software TRiP98. For prediction relative effectiveness (RBE) that required optimization local effect model (LEM IV) used. To compare three types,...

Nowadays there is a rising interest towards exploiting new therapeutical beams beyond carbon ions and protons. In particular, [Formula: see text]O are being widely discussed due to their increased LET distribution. this contribution, we report on the first experimental verification of biologically optimized treatment plans, accounting for different biological effects, generated with TRiP98 planning system beams, performed at HIT GSI. This implies measurements 3D profiles absorbed dose as...

Abstract Multipotential stem cells of a murine teratocarcinoma are resistant to typical infection with either polyoma virus (PV) or Simian 40 (SV ). Differentiated progeny the susceptible in manner identical other mouse somatic cells, i.e., they permissive for PV and nonpermissive SV . The early interactions between (embryonal carcinoma EC cells) were studied. Virions adsorbed penetrated into cytoplasm nucleus but did not induce expression T antigen nuclei. Purified DNA was capable inducing...

In a frequency range where microwave resonator simulates chaotic quantum billiard, we have measured moduli and phases of reflection transmission amplitudes in the regimes both isolated weakly overlapping resonances for resonators with without time-reversal invariance. Statistical measures $S$-matrix fluctuations were determined from data compared extant and/or newly derived theoretical results obtained random-matrix approach to scattering. The latter contained small number fit parameters....

The dose-averaged linear energy transfer (LETD ) is frequently used as representative quantity for the biological effectiveness of a radiation field. Moreover, relative (RBE) values measured or calculated in mixed fields are typically plotted vs LETD . In this study, we will investigate whether an appropriate to describe RBE any field protons and heavier ions discuss potential limitations.To study reliability , model predictions monoenergetic beams under track segment conditions pristine...

Proton radiotherapy is rapidly becoming a standard treatment option for cancer. However, even though experimental data show an increase of the relative biological effectiveness (RBE) with depth, particularly at distal end field, generic RBE 1.1 currently used in proton radiotherapy. This discrepancy might affect effective penetration depth beam and thus dose to surrounding tissue organs risk. The purpose this study was analyze impact dependent protons on range comparison based 1.1.Factors...

The purpose of this study is to compare the predictions local effect model (LEM) in an extensive analysis proton relative biological effectiveness (RBE) experiments found literature, and demonstrate capabilities as well discuss potential limitations.

The particle irradiation data ensemble (PIDE) is the largest database of cell survival measured after exposure to ion beams and photon reference radiation. We report here on updated version PIDE demonstrate how investigate generic properties radiation dose response using these sets raw data. now contains information over 1100 pairs curves. It provides originally published in addition given linear quadratic (LQ) model parameters. If available, were used derive LQ parameters same way for all...

We experimentally investigated the decay behavior with time $t$ of resonances near and at exceptional points, where two complex eigenvalues also associated eigenfunctions coalesce. The measurements were performed a dissipative microwave billiard, whose shape depends on parameters. ${t}^{2}$ dependence predicted point basis two-state matrix model could be verified. Outside Rabi oscillations, called quantum echoes in this context, detected.

Background. The aim of the present study was to compare biological effectiveness carbon ions relative x-rays between tumor control, acute skin reaction and late RIF CDF1 mice.

We report here on a DNA double-strand break (DSB) kinetic rejoining model applicable to wide range of radiation qualities based the damage pattern predicted by local effect (LEM). In LEM this is derived from SSB and DSB yields after photon irradiation in combination with an amorphous track structure approach. Together assumption giant-loop organization describe higher order chromatin allows definition two different classes DSB. These are defined level clustering micrometer scale, i.e.,...

DNA double strand breaks (DSB) play a pivotal role for cellular damage, which is hazard encountered in toxicology and radiation protection, but also exploited e.g. eradicating tumors therapy. It still debated whether how far clustering of such lesions leads to an enhanced severity induced damage. Here we investigate - using focused spots ionizing as damaging agent the spatial extension lesion patterns causing cell inactivation. We find that damage on both nm µm scale inactivation compared...

We measure the complex scattering amplitudes of a flat microwave cavity (a "chaotic billiard"). Time-reversal (T) invariance is partially broken by magnetized ferrite placed within cavity. extend random-matrix approach to T violation in scattering, determine parameters from some properties amplitudes, and successfully predict others. Our work constitutes most precise test theoretical so far available.

With a perturbation body technique intensity distributions of the electric field strength in flat microwave billiard with barrier inside up to mode numbers as large about 700 were measured. A method for reconstruction amplitudes and phases from those has been developed. Recently predicted superscars have identified experimentally and--using well-known analogy between quantum mechanical wave function two-dimensional billiard--their properties determined.

The relative biological effectiveness (RBE) is a central quantity in particle radiobiology and depends on many physical factors. local effect model (LEM) allows one to predict the RBE for radiobiologic experiments therapy. In this work sensitivity of its determining factors elucidated based monitoring dependence input parameters LEM. relevance meaning all are discussed within formalism While most fixed by experimental constraints, parameter, threshold dose Dt, may remain free then regarded...