PurposeThe POP-ART RT study aims to determine what extent and how intrafractional real-time respiratory motion management (RRMM), plan adaptation for interfractional anatomical changes (ART) are used in clinical practice understand barriers implementation. Here we report on part II: ART using more than one per target treatment course.Materials methodsA questionnaire the current of ART, wishes expansion or implementation, implementation was distributed worldwide. Four types were...

Currently, most clinical range-modulated proton beams are assumed to have a fixed overall relative biological effectiveness (RBE) of 1.1. However, it is well known that the RBE increases with depth in spread-out Bragg peak (SOBP) and becomes about 10% higher than mid-SOBP at 2 mm from distal edge (Paganetti 2003 Technol. Cancer Res. Treat. 413-26) can reach values 1.3-1.4 vitro (Robertson et al 1975 35 1664-77, Courdi 1994 Br. J. Radiol. 67 800-4). We present fast method for applying...

Purpose: To outline the limitations of PENELOPE (acronym PENetration and Energy LOss Positrons Electrons) as a track-structure code, to comment on modifications that enable its fruitful use in certain microdosimetry nanodosimetry applications.Methods: Attention is paid way which inelastic collisions electrons are modelled ensuing implications for analysis.Results: Inelastic mean free paths collision stopping powers calculated with two well-known optical-data models compared. An ad hoc...

The POP-ART RT study aims to determine what extent and how intra-fractional real-time respiratory motion management (RRMM) plan adaptation for inter-fractional anatomical changes (ART), are used in clinical practice understand barriers implementation. Here we report on part I: RRMM.

Purpose: The LIonTrack (Light Ion Track) Monte Carlo (MC) code for the simulation of H + , He 2+ and other light ions in liquid water is presented together with results a novel investigation energy‐deposition site properties from single ion tracks. Methods: continuum distorted‐wave formalism eikonal initial state approximation (CDW‐EIS) employed to generate energy angle electrons emitted ionizing collisions 2 O molecules. model Dingfelder et al. [“Electron inelastic‐scattering cross sections...

Purpose: Biophysical models for predicting survival mixed LET radiations have been investigated by comparisons with experimental results from heavy ion irradiations. The aim was to choose a model further theoretical studies on the effects of variable RBE protons. Methods and materials: Predicted curves Katz track-structure model, linear quadratic LQ Kellerer Rossi lesion additivity Lam were compared V79 cells that irradiated mixture nitrogen ions an either 78 or 165keV/ mu m 60Co gamma-rays....

Abstract Monomeric chlorophyll a (Chl ) was obtained from the isolated core antenna complex CP47 of photo‐system II after incubation with detergent triton X‐100 and studied by low‐temperature polarized light spectroscopy aim to obtain model spectra for Chi in intact photosynthetic complexes. Evidence is presented circular dichroism anisotropy measurements that monomeric. The absorption bandwidths are relatively large compared those found complexes due inhomogeneous broadening introduced...

A beam source model, i.e. a model for the initial phase space of beam, scanned proton beams has been developed. The is based on parameterized particle sources with characteristics found by fitting towards measured data per individual line. specific aim this to make it applicable majority various systems currently available or under development, overall purpose drive dose calculations in treatment planning. characterized an energy spectrum, radial and angular distributions deflections...

Calculation of accumulated dose in fractionated radiotherapy based on spatial mapping the points generally requires deformable image registration (DIR). The accuracy thus depends heavily DIR quality. This motivates investigations how uncertainty influences planning objectives and treatment outcome predictions. A framework was developed where can be associated with a variable known to simulate uncertainties clinical workflow. enabled us study dependence metrics, predicted outcome,...

Purpose: To explore the use of frequency energy deposition (ED) clusters different sizes (cluster order, CO) as a surrogate (instead of, e.g., LET) classification physical characteristics ionizing radiation at nanometer scale, to construct framework for calculation relative biological effectiveness (RBE) with cell survival endpoint. Methods: The cluster order f CO is calculated by sorting ED sites generated Monte Carlo track structure code LIonTrack into based on single parameter called...

In order to give the correct dose a patient, monitor chamber for proton scanning system has be calibrated. As recombination of ion pairs occurs in chamber, relation between number particles traversing it per time unit and ionization signal is not linear. A method developed scanned pulsed beam taking nonlinear into account described. vital part reference dosimetry procedure determine absorbed under conditions, which recommended done with an chamber. For beam, negligible from corrected. this...

The stochastic nature of ionizing radiation interactions causes a microdosimetric spread in energy depositions for cell or nucleus-sized volumes. magnitude the may be confounding factor dose response analysis. aim this work is to give values range doses imparted by 125I and 192Ir brachytherapy radionuclides, 60Co source. An upgraded version Monte Carlo code PENELOPE was used obtain frequency distributions specific each these qualities four different results demonstrate that increases when...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSite-Selection Spectroscopy of the Reaction Center Complex Photosystem II. 2. Identification Fluorescing Species at 4 KStefan L. S. Kwa, Nina T. Tilly, Camiel Eijckelhoff, Rienk van Grondelle, and Jan P. DekkerCite this: J. Phys. Chem. 1994, 98, 31, 7712–7716Publication Date (Print):August 1, 1994Publication History Published online1 May 2002Published inissue 1 August...

When analysing the factors affecting relative biological effectiveness (RBE) of different radiation qualities, it is essential to consider particularly low-energy slowing-down electrons (around 100 eV 1 keV) since they have potential inflicting severe damage DNA. We present a modified and extended version Monte Carlo code PENELOPE that enables scoring spectra, mean local energy imparted spectra average intra-track nearest-neighbour deposition distances secondary generated by such as...

The ability of the Monte Carlo (MC) particle transport codes GEANT4.8.1 and GEANT4.8.2, FLUKA2006 MCNPX2.4.0 to model proton at grazing incidence onto tungsten blocks has been tested compared experimental measurements. test geometry consisted a narrow beam two energies, 98 MeV 180 MeV, impinging on thick alloy block incidence. distribution forward out-scatter from was measured with fluorescent screen viewed CCD camera via mirror. In MC simulations, setup modelled dose deposited material...

In this paper we present the recent developments made for scanning system proton beams at TSL in Uppsala, showing that is now fully functional being able to produce conformal intensity modulated scan patterns with sufficient accuracy. A new control and supervising handling beam delivery including of synchrocyclotron developed described detail. complete dosimetry transmission ionization chambers a multi-wire chamber monitoring during has been constructed. The details dose monitors position...

The aim was to investigate and compare the influence of linear energy transfer (LET), dose time on induction apoptosis in a human melanoma cell line exposed accelerated light boron (10B) ions photons. Cells were vitro doses up 6 Gy (40, 80, 125 160 eV nm – 1) 12 photons (0.2 1). measured 9 days after irradiation using morphological characterization apoptotic cells bodies. In parallel, measurements cell-cycle distribution, monitored by DNA flow cytometry, survival based clonogenic assay,...

We present the nanoCluE model, which uses nano- and microdosimetric quantities to model RBE for protons carbon ions. Under hypothesis that correlates with generation of complex DNA double strand breakes, we wish investigate whether an improved accuracy in predicting LQ parameters may be achieved, compared some published models.The is based on experimental data generated a database track structure number proton ion kinetic energies Geant4-DNA Monte Carlo code. These were used obtain both...

A scanned proton beam yields dose distributions that in most cases are superior to passively scattered beams and other external radiation treatment modalities. The present paper gives a description of the scanning system has been developed at Svedberg Laboratory (TSL) Uppsala. technique technical design described. solution with small pole gap magnets moveable second magnet results very compact head, which can therefore be incorporated gantry relatively limited size. prototype was constructed...

Collimators are routinely used in proton radiotherapy to laterally confine the field and improve penumbra. Collimator scatter contributes up 15% of local dose is therefore important include treatment planning calculation. We present a method for reconstruction collimator phase space based on parametrization pre-calculated kernels. distributions, generated by Monte Carlo (MC) package GEANT4.8.2, were scored differential direction energy. The distributions then parametrized so as enable fast...

The linear-quadratic (LQ) parameterization of survival fraction [SF(D)] inherently assumes that all cells in a population receive the same dose (D), albeit distribution specific energy z over individual f(z,D) can be very wide. From these microdosimetric distributions, which are target size dependent, we estimate cellular sensitive volume by analyzing its influence on LQ cell survival. A Monte Carlo track structure code was used to simulate detailed tracks from 60Co source as well proton and...

Journal Article Microdosimetric spread for cell-sized targets exposed to 60Co, 192Ir and 125I sources Get access F. Villegas, Villegas * 1Department of Immunology, Genetics Pathology, Medical Radiation Physics, Uppsala University, Akademiska Sjukhuset, SE-75185, Sweden *Corresponding author: Fernanda.villegas-navarro@igp.uu.se Search other works by this author on: Oxford Academic PubMed Google Scholar N. Tilly, Tilly Sweden2Elekta Instrument AB, Box 1704, SE-75147, A. Ahnesjö Protection...