Modelling of electron contamination in clinical photon beams for Monte Carlo dose calculation.


:The purpose of this work is to model electron contamination in clinical photon beams and to commission the source model using measured data for Monte Carlo treatment planning. In this work, a planar source is used to represent the contaminant electrons at a plane above the upper jaws. The source size depends on the dimensions of the field size at the isocentre. The energy spectra of the contaminant electrons are predetermined using Monte Carlo simulations for photon beams from different clinical accelerators. A 'random creep' method is employed to derive the weight of the electron contamination source by matching Monte Carlo calculated monoenergetic photon and electron percent depth-dose (PDD) curves with measured PDD curves. We have integrated this electron contamination source into a previously developed multiple source model and validated the model for photon beams from Siemens PRIMUS accelerators. The EGS4 based Monte Carlo user code BEAM and MCSIM were used for linac head sinulation and dose calculation. The Monte Carlo calculated dose distributions were compared with measured data. Our results showed good agreement (less than 2% or 2 mm) for 6, 10 and 18 MV photon beams.


Phys Med Biol


Yang J,Li JS,Qin L,Xiong W,Ma CM




Has Abstract


2004-06-21 00:00:00












  • Fricke dosimetry: the difference between G(Fe3+) for 60Co gamma-rays and high-energy x-rays.

    abstract::A calibration of the Fricke dosimeter is a measurement of epsilon G(Fe3+). Although G(Fe3+) is expected to be approximately energy independent for all low-LET radiation, existing data are not adequate to rule out the possibility of changes of a few per cent with beam quality. When a high-precision Fricke dosimeter, wh...

    journal_title:Physics in medicine and biology

    pub_type: 杂志文章


    authors: Klassen NV,Shortt KR,Seuntjens J,Ross CK

    更新日期:1999-07-01 00:00:00

  • Optimization of attenuation correction for positron emission tomography studies of thorax and pelvis using count-based transmission scans.

    abstract::The quality of thorax and pelvis transmission scans and therefore of attenuation correction in PET depends on patient thickness and transmission rod source strength. The purpose of the present study was to assess the feasibility of using count-based transmission scans, thereby guaranteeing more consistent image qualit...

    journal_title:Physics in medicine and biology

    pub_type: 杂志文章


    authors: Boellaard R,van Lingen A,van Balen SC,Lammertsma AA

    更新日期:2004-02-21 00:00:00

  • A new approach to account for the medium-dependent effect in model-based dose calculations for kilovoltage x-rays.

    abstract::This study presents a new approach to accurately account for the medium-dependent effect in model-based dose calculations for kilovoltage (kV) x-rays. This approach is based on the hypothesis that the correction factors needed to convert dose from model-based dose calculations to absorbed dose-to-medium depend on both...

    journal_title:Physics in medicine and biology

    pub_type: 杂志文章


    authors: Pawlowski JM,Ding GX

    更新日期:2011-07-07 00:00:00

  • The impact of calibration phantom errors on dual-energy digital mammography.

    abstract::Microcalcification is one of the earliest and main indicators of breast cancer. Because dual-energy digital mammography could suppress the contrast between the adipose and glandular tissues of the breast, it is considered a promising technique that will improve the detection of microcalcification. In dual-energy digit...

    journal_title:Physics in medicine and biology

    pub_type: 杂志文章


    authors: Mou X,Chen X,Sun L,Yu H,Ji Z,Zhang L

    更新日期:2008-11-21 00:00:00

  • Optical-thermal characterization of cutaneous transilluminators.

    abstract::In recent years, there has been an increase in the popularity of light-emitting diode (LED)-based, battery-powered transilluminators (BPTs) for facilitating transdermal vascular access in adults and neonates. BPTs are believed to have lower potential for inducing skin burns than prior devices based on high-power broad...

    journal_title:Physics in medicine and biology

    pub_type: 杂志文章


    authors: Pfefer TJ,Mehrabi A,James R,Landry R,Weininger S,Chang I,Kaufman D,Miller S

    更新日期:2009-11-21 00:00:00

  • Measurement of the dielectric properties of the epidermis and dermis at frequencies from 0.5 GHz to 110 GHz.

    abstract::Numerous studies have reported the measurements of the dielectric properties of the skin. Clarifying the manner in which the human body interacts with electromagnetic waves is essential for medical research and development, as well as for the safety assessment of electromagnetic wave exposure. The skin comprises sever...

    journal_title:Physics in medicine and biology

    pub_type: 杂志文章


    authors: Sasaki K,Wake K,Watanabe S

    更新日期:2014-08-21 00:00:00

  • Influence of sulphuric acid contaminants on Fricke dosimetry.

    abstract::The sulphuric acid used for the preparation of the Fricke dosimeter solution may contain trace impurities that can affect the yield of ferric ions. Two methods, pre-irradiation or oxidation with hydrogen peroxide, have been proposed to reduce the influence of these impurities. Fricke users sometimes omit this treatmen...

    journal_title:Physics in medicine and biology

    pub_type: 杂志文章


    authors: Palm A,Mattsson O

    更新日期:2000-09-01 00:00:00

  • Variation of the dielectric properties of tissues with age: the effect on the values of SAR in children when exposed to walkie-talkie devices.

    abstract::In vitro dielectric properties of ageing porcine tissues were measured in the frequency range of 50 MHz-20 GHz, and the total combined uncertainties of the measurements were assessed. The results show statistically significant reduction with age in both permittivity and conductivity of 10 out of 15 measured tissues. A...

    journal_title:Physics in medicine and biology

    pub_type: 杂志文章


    authors: Peyman A,Gabriel C,Grant EH,Vermeeren G,Martens L

    更新日期:2009-01-21 00:00:00

  • The production of positron emitters with millisecond half-life during helium beam radiotherapy.

    abstract::Therapy with helium ions is currently receiving significantly increasing interest because helium ions have a sharper penumbra than protons and undergo less fragmentation than carbon ions and thus require less complicated dose calculations. For any ion of interest in hadron therapy, the accuracy of dose delivery is lim...

    journal_title:Physics in medicine and biology

    pub_type: 杂志文章


    authors: Ozoemelam I,van der Graaf E,Brandenburg S,Dendooven P

    更新日期:2019-12-05 00:00:00

  • Quenching correction for volumetric scintillation dosimetry of proton beams.

    abstract::Volumetric scintillation dosimetry has the potential to provide fast, high-resolution, three-dimensional radiation dosimetry. However, scintillators exhibit a nonlinear response at the high linear energy transfer (LET) values characteristic of proton Bragg peaks. The purpose of this study was to develop a quenching co...

    journal_title:Physics in medicine and biology

    pub_type: 杂志文章


    authors: Robertson D,Mirkovic D,Sahoo N,Beddar S

    更新日期:2013-01-21 00:00:00

  • The ArcCHECK diode array for dosimetric verification of HybridArc.

    abstract::The aim of this work is to evaluate dosimetric accuracy of a new treatment modality, HybridArc, in iPlan RT Dose 4.5 (BrainLAB, Feldkirchen, Germany) using a four-dimensional diode array (ArcCHECK, Sun Nuclear Corporation, Melbourne, USA). HybridArc is able to enhance dynamic conformal arcs with inversely planned elem...

    journal_title:Physics in medicine and biology

    pub_type: 杂志文章


    authors: Petoukhova AL,van Egmond J,Eenink MG,Wiggenraad RG,van Santvoort JP

    更新日期:2011-08-21 00:00:00

  • The GSF family of voxel phantoms.

    abstract::Voxel phantoms are human models based on computed tomographic or magnetic resonance images obtained from high-resolution scans of a single individual. They consist of a huge number of volume elements (voxels) and are at the moment the most precise representation of the human anatomy. The purpose of this paper is to in...

    journal_title:Physics in medicine and biology

    pub_type: 杂志文章,评审


    authors: Petoussi-Henss N,Zanki M,Fill U,Regulla D

    更新日期:2002-01-07 00:00:00

  • Energy response of optically stimulated luminescent dosimeters for non-reference measurement locations in a 6 MV photon beam.

    abstract::Optically stimulated luminescent dosimeters (OSLDs) are becoming increasingly popular for measuring an absorbed dose in clinical radiotherapy. OSLDs have known energy dependence, and this is accounted for by either calibrating the OSLD with a specific nominal energy, or using a standard energy correction factor to acc...

    journal_title:Physics in medicine and biology

    pub_type: 杂志文章


    authors: Scarboro SB,Followill DS,Kerns JR,White RA,Kry SF

    更新日期:2012-05-07 00:00:00

  • The impact of morphology on light transport in cancellous bone.

    abstract::In recent years, optical techniques based on diffusion approximation have demonstrated their ability to gain rich spectral information about bone. However, these methods normally assume homogeneity, while cancellous bone and marrow form a highly heterogeneous two-phase medium. This paper studies the limitations of thi...

    journal_title:Physics in medicine and biology

    pub_type: 杂志文章


    authors: Margallo-Balbás E,Taroni P,Pifferi A,Koolstra JH,v Ruijven LJ,French PJ

    更新日期:2010-09-07 00:00:00

  • The energy response of a T.P.A. Mk-II ionization chamber using GEANT4 Monte Carlo simulation.

    abstract::The low energy model of the GEANT4 Monte Carlo toolkit was used to simulate the energy response of a T.P.A. Mk-II ionization chamber under a variety of different conditions. The sample position resulting in the maximum response along the axial direction of the chamber was obtained. The parameters of the simulation wer...

    journal_title:Physics in medicine and biology

    pub_type: 杂志文章


    authors: Seneviratne MD,Reinhard MI,Baldock C

    更新日期:2007-07-07 00:00:00

  • Quantitative analysis of bony birth canal for periacetabular osteotomy patient by template fitting.

    abstract::Periacetabular osteotomy (PAO) is a joint preservation procedure for developmental dysplasia of the hip. Such a procedure requires osteotomy of the medial wall of the acetabulum, which may cause the narrow of the bony birth canal and increase the risk of complications during the childbirth process in the future. Using...

    journal_title:Physics in medicine and biology

    pub_type: 杂志文章


    authors: Shao L,Li H,Liu X,Wang Y,Shi L,Ai D,Fan J,Song H,Zhang H,Yang J

    更新日期:2021-01-22 00:00:00

  • An analytical reconstruction model of the spread-out Bragg peak using laser-accelerated proton beams.

    abstract::With the development of laser technology, laser-driven proton acceleration provides a new method for proton tumor therapy. However, it has not been applied in practice because of the wide and decreasing energy spectrum of laser-accelerated proton beams. In this paper, we propose an analytical model to reconstruct the ...

    journal_title:Physics in medicine and biology

    pub_type: 杂志文章


    authors: Tao L,Zhu K,Zhu J,Xu X,Lin C,Ma W,Lu H,Zhao Y,Lu Y,Chen JE,Yan X

    更新日期:2017-07-07 00:00:00

  • Gating characteristics of an Elekta radiotherapy treatment unit measured with three types of detector.

    abstract::The characteristics of an Elekta Precise treatment machine with a gating interface were investigated. Three detectors were used: a Farmer ionization chamber, a MatriXX ionization chamber array and an in-house, single pulse-measurement ionization chamber (IVC). Measurements were made of dosimetric accuracy, flatness an...

    journal_title:Physics in medicine and biology

    pub_type: 杂志文章


    authors: Evans PM,Symonds-Tayler JR,Colgan R,Hugo GD,Letts N,Sandin C

    更新日期:2010-04-21 00:00:00

  • A double-tuned (1)H/(23)Na dual resonator system for tissue sodium concentration measurements in the rat brain via Na-MRI.

    abstract::A method for quantifying the tissue sodium concentration (TSC) in the rat brain from ²³Na-MR images was developed. TSC is known to change in a variety of common human diseases and holds considerable potential to contribute to their study; however, its accurate measurement in small laboratory animals has been hindered ...

    journal_title:Physics in medicine and biology

    pub_type: 杂志文章


    authors: Wetterling F,Tabbert M,Junge S,Gallagher L,Macrae IM,Fagan AJ

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  • Influence of the physical state and straggling on the computation of the radiation dose due to radon daughters deposited in the lung.

    abstract::The effect of the physical state (phase) of the absorbing medium and the energy straggling of the alpha particles on the calculation of the radiation dose due to the daughter products of radon deposited in the lung have been studied in detail. The stopping power data for alpha particles in water and water vapour have ...

    journal_title:Physics in medicine and biology

    pub_type: 杂志文章


    authors: Haque AK,Al-affan IA

    更新日期:1987-08-01 00:00:00

  • Normalized glandular dose (DgN) coefficients from experimental mammographic x-ray spectra.

    abstract::Mean glandular dose is the quantity used for dosimetry in mammography and depends on breast-related characteristics, such as thickness and density, and on the x-ray spectrum used for breast imaging. This work aims to present an experimentally-based method to derive polyenergetic normalized glandular dose coefficients ...

    journal_title:Physics in medicine and biology

    pub_type: 杂志文章


    authors: Santos JC,Tomal A,de Barros N,Costa PR

    更新日期:2019-05-10 00:00:00

  • A rapid, accurate image simulation strategy for mega-voltage cone-beam computed tomography.

    abstract::Intensive computation time is required to simulate images of electronic portal imaging device (EPID) using Monte Carlo (MC) technique, limiting the development of applications associated with EPID, such as mega-voltage cone-beam computed tomography (MV-CBCT). In this study, a fast, accurate simulation strategy for MV-...

    journal_title:Physics in medicine and biology

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    authors: Shi M,Myronakis M,Jacobson M,Lehmann M,Ferguson D,Baturin P,Huber P,Fueglistaller R,Harris T,Lozano IV,Williams C,Morf D,Berbeco RI

    更新日期:2020-07-06 00:00:00

  • Comparison between TG-51 and TRS-398: electron contamination effect on photon beam-quality specification.

    abstract::Two dosimetry protocols based on absorbed dose to water have recently been implemented: TG-51 and TRS-398. These protocols use different beam-quality indices: %dd(10)x and TPR20,10. The effect of electron contamination in measurements of %dd(10)x has been proposed as a disadvantage of the TG-51. For actual measurement...

    journal_title:Physics in medicine and biology

    pub_type: 杂志文章


    authors: Lopez Medina A,Teijeiro A,Salvador F,Medal D,Vazquez J,Salgado M,Carrion MC

    更新日期:2004-01-07 00:00:00

  • A proposal concerning the absorbed dose conversion factor.

    abstract::New definitions of the absorbed dose conversion factors Clambda and CE are proposed. The absorbed dose in water is given by the product of absorbed dose conversion factor, exposure calibration factor, ionisation chamber reading, cap displacement correction factor and perturbation correction factor. At exposure calibra...

    journal_title:Physics in medicine and biology

    pub_type: 杂志文章


    authors: Shiragai A

    更新日期:1978-03-01 00:00:00

  • A new method to reconstruct intra-fractional prostate motion in volumetric modulated arc therapy.

    abstract::Intra-fractional motion is a concern during prostate radiation therapy, as it may cause deviations between planned and delivered radiation doses. Because accurate motion information during treatment delivery is critical to address dose deviation, we developed the projection marker matching method (PM3), a novel method...

    journal_title:Physics in medicine and biology

    pub_type: 杂志文章


    authors: Chi Y,Rezaeian NH,Shen C,Zhou Y,Lu W,Yang M,Hannan R,Jia X

    更新日期:2017-07-07 00:00:00

  • Introducing the Jacobian-volume-histogram of deforming organs: application to parotid shrinkage evaluation.

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    journal_title:Physics in medicine and biology

    pub_type: 杂志文章


    authors: Fiorino C,Maggiulli E,Broggi S,Liberini S,Cattaneo GM,Dell'oca I,Faggiano E,Di Muzio N,Calandrino R,Rizzo G

    更新日期:2011-06-07 00:00:00

  • Dynamic manipulation of the subharmonic scattering of phospholipid-coated microbubbles.

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    journal_title:Physics in medicine and biology

    pub_type: 杂志文章


    authors: Faez T,Renaud G,Defontaine M,Calle S,de Jong N

    更新日期:2011-10-07 00:00:00

  • Image reconstruction and scan configurations enabled by optimization-based algorithms in multispectral CT.

    abstract::Optimization-based algorithms for image reconstruction in multispectral (or photon-counting) computed tomography (MCT) remains a topic of active research. The challenge of optimization-based image reconstruction in MCT stems from the inherently non-linear data model that can lead to a non-convex optimization program f...

    journal_title:Physics in medicine and biology

    pub_type: 杂志文章


    authors: Chen B,Zhang Z,Sidky EY,Xia D,Pan X

    更新日期:2017-11-02 00:00:00

  • A novel description of FDG excretion in the renal system: application to metformin-treated models.

    abstract::This paper introduces a novel compartmental model describing the excretion of 18F-fluoro-deoxyglucose (FDG) in the renal system and a numerical method based on the maximum likelihood for its reduction. This approach accounts for variations in FDG concentration due to water re-absorption in renal tubules and the increa...

    journal_title:Physics in medicine and biology

    pub_type: 杂志文章


    authors: Garbarino S,Caviglia G,Sambuceti G,Benvenuto F,Piana M

    更新日期:2014-05-21 00:00:00

  • Scatter compensation methods in 3D iterative SPECT reconstruction: a simulation study.

    abstract::Effects of different scatter compensation methods incorporated in fully 3D iterative reconstruction are investigated. The methods are: (i) the inclusion of an 'ideal scatter estimate' (ISE); (ii) like (i) but with a noiseless scatter estimate (ISE-NF); (iii) incorporation of scatter in the point spread function during...

    journal_title:Physics in medicine and biology

    pub_type: 杂志文章


    authors: Beekman FJ,Kamphuis C,Frey EC

    更新日期:1997-08-01 00:00:00