Daily check instrument for photon and electron beam quality assurance of medical linacs.

Abstract:

:An instrument for daily beam checks of medical accelerators is described. Using three silicon diodes, the instrument provides information about calibration, beam symmetry, flatness, and energy variation for both photon and electron beams. Operating characteristics of the instrument and the electronic circuit design permit simple and reliable measurements.

journal_name

Med Phys

journal_title

Medical physics

authors

Lutz WR,Maddox BJ,Kase KR

doi

10.1118/1.595756

subject

Has Abstract

pub_date

1985-07-01 00:00:00

pages

462-5

issue

4

eissn

0094-2405

issn

2473-4209

journal_volume

12

pub_type

杂志文章
  • Examination of a deformable motion model for respiratory movements and 4D dose calculations using different driving surrogates.

    abstract:PURPOSE:The aim of this study was to evaluate a surrogate-driven motion model based on four-dimensional computed tomography that is able to predict CT volumes corresponding to arbitrary respiratory phases. Furthermore, the comparison of three different driving surrogates is examined and the feasibility of using the mod...

    journal_title:Medical physics

    pub_type: 杂志文章

    doi:10.1002/mp.12243

    authors: Wölfelschneider J,Seregni M,Fassi A,Ziegler M,Baroni G,Fietkau R,Riboldi M,Bert C

    更新日期:2017-06-01 00:00:00

  • Performance characteristics of transmission imaging using a uniform sheet source with parallel-hole collimation.

    abstract::Transmission imaging is receiving increasing attention in SPECT due to the need to compensate for nonuniform attenuation in cardiac-chest SPECT. The quality of a transmission image has an important effect on the measured attenuation distribution. To improve image quality, knowledge of the performance characteristics o...

    journal_title:Medical physics

    pub_type: 杂志文章

    doi:10.1118/1.596752

    authors: Cao Z,Tsui BM

    更新日期:1992-09-01 00:00:00

  • Errors in cerebral blood flow determinations by xenon-enhanced computed tomography due to estimation of arterial xenon concentrations.

    abstract::Errors in the determination of xenon concentrations in arterial blood during inhalation of xenon-oxygen mixtures are used to assess errors in the derivation of regional cerebral blood flow by the xenon-enhanced computed tomography (CT) method. The results of this study indicate that approximating the arterial buildup ...

    journal_title:Medical physics

    pub_type: 杂志文章

    doi:10.1118/1.596051

    authors: Good WF,Gur D,Yonas H,Herron JM

    更新日期:1987-05-01 00:00:00

  • Noise, resolution, and sensitivity considerations in the design of a single-slice emission-transmission computed tomographic system.

    abstract::A prototype Emission-Transmission Computed Tomography (ETCT) system is being developed that will acquire single-slice x-ray transmission CT images simultaneously with single photon emission computed tomography (SPECT) images. This system will permit the correlation of anatomical information from x-ray CT with function...

    journal_title:Medical physics

    pub_type: 杂志文章

    doi:10.1118/1.596643

    authors: Liew SC,Hasegawa BH

    更新日期:1991-09-01 00:00:00

  • Characterization of difference of Gaussian filters in the detection of mammographic regions.

    abstract::In this article, we present a characterization of the effect of difference of Gaussians (DoG) filters in the detection of mammographic regions. DoG filters have been used previously in mammographic mass computer-aided detection (CAD) systems. As DoG filters are constructed from the subtraction of two bivariate Gaussia...

    journal_title:Medical physics

    pub_type: 杂志文章

    doi:10.1118/1.2358326

    authors: Catarious DM Jr,Baydush AH,Floyd CE Jr

    更新日期:2006-11-01 00:00:00

  • Detector dose response in megavoltage small photon beams. II. Pencil beam perturbation effects.

    abstract:PURPOSE:To quantify detector perturbation effects in megavoltage small photon fields and support the theoretical explanation on the nature of quality correction factors in these conditions. METHODS:In this second paper, a modern approach to radiation dosimetry is defined for any detector and applied to small photon fi...

    journal_title:Medical physics

    pub_type: 杂志文章

    doi:10.1118/1.4930798

    authors: Bouchard H,Kamio Y,Palmans H,Seuntjens J,Duane S

    更新日期:2015-10-01 00:00:00

  • The Jacobian as a measure of planar dose congruence.

    abstract::We propose a new starting point for comparing planar dose distributions using a Jacobian-based measure. The measure is normalization independent, i.e., is sensitive to dose patterns while not being biased by global dose scaling. The measure is free of tunable parameters and is bounded between zero and one. We also pro...

    journal_title:Medical physics

    pub_type: 杂志文章

    doi:10.1118/1.2982136

    authors: Paniak LD,Charland PM

    更新日期:2008-11-01 00:00:00

  • SU-E-T-567: Improve Dose Conformity with IMRT Using Shorter Source to Tumor Distance.

    abstract:PURPOSE:To reduce the potential of late toxicity (tissue necrosis and cognitive function loss) from brain radiotherapy, we studied a novel planning technique for MLC-equipped linear accelerators (LINACS) that reduces the high doses delivered outside the PTV, enhancing radiation dose conformity. METHODS:The feasibility...

    journal_title:Medical physics

    pub_type: 杂志文章

    doi:10.1118/1.4735656

    authors: Yang W,Sandler H,Fraass B

    更新日期:2012-06-01 00:00:00

  • A segmented 32P source Monte Carlo model to derive AAPM TG-60 dosimetric parameters used for intravascular brachytherapy.

    abstract::A new high dose rate 20 mm 32P intravascular brachytherapy (IVB) beta source used with automated stepping has recently been introduced. The AAPM Task Group 60 recommends that beta IVB sources should have well characterized dosimetric parameters in water. In this study, Monte Carlo simulations (MCNPX v 2.4) were used t...

    journal_title:Medical physics

    pub_type: 杂志文章

    doi:10.1118/1.1646651

    authors: Mourtada F,Soares CG,Horton JL

    更新日期:2004-03-01 00:00:00

  • Vision 20/20: Molecular-guided surgical oncology based upon tumor metabolism or immunologic phenotype: Technological pathways for point of care imaging and intervention.

    abstract::Surgical guidance with fluorescence has been demonstrated in individual clinical trials for decades, but the scientific and commercial conditions exist today for a dramatic increase in clinical value. In the past decade, increased use of indocyanine green based visualization of vascular flow, biliary function, and tis...

    journal_title:Medical physics

    pub_type: 杂志文章

    doi:10.1118/1.4951732

    authors: Pogue BW,Paulsen KD,Samkoe KS,Elliott JT,Hasan T,Strong TV,Draney DR,Feldwisch J

    更新日期:2016-06-01 00:00:00

  • Noise texture and signal detectability in propagation-based x-ray phase-contrast tomography.

    abstract:PURPOSE:X-ray phase-contrast tomography (PCT) is a rapidly emerging imaging modality for reconstructing estimates of an object's three-dimensional x-ray refractive index distribution. Unlike conventional x-ray computed tomography methods, the statistical properties of the reconstructed images in PCT remain unexplored. ...

    journal_title:Medical physics

    pub_type: 杂志文章

    doi:10.1118/1.3267548

    authors: Chou CY,Anastasio MA

    更新日期:2010-01-01 00:00:00

  • The influence of bowtie filtration on cone-beam CT image quality.

    abstract::The large variation of x-ray fluence at the detector in cone-beam CT (CBCT) poses a significant challenge to detectors' limited dynamic range, resulting in the loss of skinline as well as reduction of CT number accuracy, contrast-to-noise ratio, and image uniformity. The authors investigate the performance of a bowtie...

    journal_title:Medical physics

    pub_type: 杂志文章

    doi:10.1118/1.3017470

    authors: Mail N,Moseley DJ,Siewerdsen JH,Jaffray DA

    更新日期:2009-01-01 00:00:00

  • Comparison of Gafchromic EBT2 and EBT3 films for clinical photon and proton beams.

    abstract:PURPOSE:Dose verification in highly conformal radiation therapy such as IMRT or proton therapy can benefit from the high spatial resolution offered by radio-chromic films such as Gafchromic EBT or EBT2. Recently, a new generation of these films, EBT3, has become available. The composition and thickness of the sensitive...

    journal_title:Medical physics

    pub_type: 杂志文章

    doi:10.1118/1.4737890

    authors: Reinhardt S,Hillbrand M,Wilkens JJ,Assmann W

    更新日期:2012-08-01 00:00:00

  • Radiation dose to the lungs from ventilation studies with 133Xe.

    abstract::The radiation dose to the lungs from 133Xe in lung air is directly proportional to the time integral of 133Xe concentration; i.e., the cumulated concentration in the lungs. Using kinetic models developed to fit clinical observations, we have studied the effect of retention on cumulated concentration in lung air. The m...

    journal_title:Medical physics

    pub_type: 杂志文章

    doi:10.1118/1.594341

    authors: Watson EE,Cloutier RJ

    更新日期:1977-11-01 00:00:00

  • Performance of a 41 x 41 cm2 amorphous silicon flat panel x-ray detector designed for angiographic and R&F imaging applications.

    abstract::We measured the physical imaging performance of a 41 x 41 cm2 amorphous silicon flat panel detector designed for angiographic and R&F imaging applications using methods from the emerging IEC standard for the measurement of detective quantum efficiency (DQE) in digital radiographic detectors. Measurements on 12 product...

    journal_title:Medical physics

    pub_type: 杂志文章

    doi:10.1118/1.1609151

    authors: Granfors PR,Aufrichtig R,Possin GE,Giambattista BW,Huang ZS,Liu J,Ma B

    更新日期:2003-10-01 00:00:00

  • The determination of electron density by the dual-energy Compton scatter method.

    abstract::The intensity of Compton scattered photons is directly proportional to the electron density of a substance; therefore it is possible to detect changes in electron density by this noninvasive method. The source-detector geometry has been varied to study the effects of geometry on the calculated electron density values,...

    journal_title:Medical physics

    pub_type: 杂志文章

    doi:10.1118/1.595730

    authors: Huddleston AL,Sackler JP

    更新日期:1985-01-01 00:00:00

  • Resampling: an optimization method for inverse planning in robotic radiosurgery.

    abstract::By design, the range of beam directions in conventional radiosurgery are constrained to an isocentric array. However, the recent introduction of robotic radiosurgery dramatically increases the flexibility of targeting, and as a consequence, beams need be neither coplanar nor isocentric. Such a nonisocentric design per...

    journal_title:Medical physics

    pub_type: 杂志文章

    doi:10.1118/1.2357020

    authors: Schweikard A,Schlaefer A,Adler JR Jr

    更新日期:2006-11-01 00:00:00

  • Smoothing intensity-modulated treatment delivery under hardware constraints.

    abstract::A method is developed to smooth intensity-modulated beam delivery while considering hardware constraints. The method uses matrix algebra to model MLC leaf motion and hardware constraints such as interleaf digitization, synchronization requirements, and intersegment field abutment to deliver intensity modulated beam se...

    journal_title:Medical physics

    pub_type: 杂志文章

    doi:10.1118/1.1521121

    authors: Ma L

    更新日期:2002-12-01 00:00:00

  • Superiorization: an optimization heuristic for medical physics.

    abstract:PURPOSE:To describe and mathematically validate the superiorization methodology, which is a recently developed heuristic approach to optimization, and to discuss its applicability to medical physics problem formulations that specify the desired solution (of physically given or otherwise obtained constraints) by an opti...

    journal_title:Medical physics

    pub_type: 杂志文章

    doi:10.1118/1.4745566

    authors: Herman GT,Garduno E,Davidi R,Censor Y

    更新日期:2012-09-01 00:00:00

  • A time-domain wavelet-based approach for fluorescence diffuse optical tomography.

    abstract:PURPOSE:In the context of fluorescence diffuse optical tomography, determining the optimal way to exploit the time-resolved information has been receiving much attention and different features of the time-resolved signals have been introduced. In this article, the authors revisit and generalize the notion of feature, c...

    journal_title:Medical physics

    pub_type: 杂志文章

    doi:10.1118/1.3431571

    authors: Ducros N,Da Silva A,Dinten JM,Seelamantula CS,Unser M,Peyrin F

    更新日期:2010-06-01 00:00:00

  • A nonvoxel-based dose convolution/superposition algorithm optimized for scalable GPU architectures.

    abstract:PURPOSE:Real-time adaptive planning and treatment has been infeasible due in part to its high computational complexity. There have been many recent efforts to utilize graphics processing units (GPUs) to accelerate the computational performance and dose accuracy in radiation therapy. Data structure and memory access pat...

    journal_title:Medical physics

    pub_type: 杂志文章

    doi:10.1118/1.4895822

    authors: Neylon J,Sheng K,Yu V,Chen Q,Low DA,Kupelian P,Santhanam A

    更新日期:2014-10-01 00:00:00

  • Use of local noise power spectrum and wavelet analysis in quantitative image quality assurance for EPIDs.

    abstract:PURPOSE:To investigate the use of local noise power spectrum (NPS) to characterize image noise and wavelet analysis to isolate defective pixels and inter-subpanel flat-fielding artifacts for quantitative quality assurance (QA) of electronic portal imaging devices (EPIDs). METHODS:A total of 93 image sets including cus...

    journal_title:Medical physics

    pub_type: 杂志文章

    doi:10.1118/1.4959541

    authors: Lee S,Yan G,Bassett P,Gopal A,Samant S

    更新日期:2016-09-01 00:00:00

  • Measurement of energy dependence for XRCT radiochromic film.

    abstract::Gafchromic XRCT, radiochromic film is assessed over a broad energy range, from kilovoltage to megavoltage x rays for variations in reflected optical density to dose response. A large energy dependence was found with reflected optical density output for the same delivered dose varying from 7.8 +/- 0.35 at 25.5 keV (50 ...

    journal_title:Medical physics

    pub_type: 杂志文章

    doi:10.1118/1.2219330

    authors: Butson MJ,Cheung T,Yu PK

    更新日期:2006-08-01 00:00:00

  • Principles in positioning cross-projecting lasers.

    abstract::With the increased sophistication of lasers used for patient positioning in radiotherapy comes increased possibilities for mistakes in installing the lasers, which can result in serious patient positioning errors. Two principles must be followed when mounting cross-projecting lasers: (1) the horizontal line must be on...

    journal_title:Medical physics

    pub_type: 杂志文章

    doi:10.1118/1.594960

    authors: Thomadsen BR

    更新日期:1981-05-01 00:00:00

  • A computer simulation of wavelet noise reduction in computed tomography.

    abstract::We describe the use of a graphical mathematical spreadsheet programming environment which can be used to simulate the acquisition and reconstruction processes of an x-ray computed tomography (CT) machine. The simulation is used to study the effect of photon counting statistics on the noise in the reconstructed image. ...

    journal_title:Medical physics

    pub_type: 杂志文章

    doi:10.1118/1.598654

    authors: Harpen MD

    更新日期:1999-08-01 00:00:00

  • Average glandular dose coefficients for pendant-geometry breast CT using realistic breast phantoms.

    abstract:PURPOSE:To design volume-specific breast phantoms from breast CT (bCT) data sets and estimate the associated normalized mean glandular dose coefficients for breast CT using Monte Carlo methods. METHODS:A large cohort of bCT data sets (N = 215) was used to evaluate breast volume into quintiles (plus the top 5%). The av...

    journal_title:Medical physics

    pub_type: 杂志文章

    doi:10.1002/mp.12477

    authors: Hernandez AM,Boone JM

    更新日期:2017-10-01 00:00:00

  • Dual-storage phosphor proton therapy dosimetry: simultaneous quantification of dose and linear energy transfer.

    abstract:PURPOSE:To investigate the feasibility of using the high Zeff storage phosphor material BaFBrI:Eu2+ in conjunction with the low Zeff storage phosphor material KCl:Eu2+ for simultaneous proton dose and linear energy transfer (LET) measurements by 1) measuring the fundamental optical and dosimetric properties of BaFBrI:E...

    journal_title:Medical physics

    pub_type: 杂志文章

    doi:10.1002/mp.14748

    authors: Setianegara J,Mazur TR,Yang D,Li HH

    更新日期:2021-02-01 00:00:00

  • On the new metrics for IMRT QA verification.

    abstract:PURPOSE:The aim of this work is to search for new metrics that could give more reliable acceptance/rejection criteria on the IMRT verification process and to offer solutions to the discrepancies found among different conventional metrics. Therefore, besides conventional metrics, new ones are proposed and evaluated with...

    journal_title:Medical physics

    pub_type: 杂志文章

    doi:10.1118/1.4964796

    authors: Garcia-Romero A,Hernandez-Vitoria A,Millan-Cebrian E,Alba-Escorihuela V,Serrano-Zabaleta S,Ortega-Pardina P

    更新日期:2016-11-01 00:00:00

  • Calculation of x-ray spectra emerging from an x-ray tube. Part II. X-ray production and filtration in x-ray targets.

    abstract::A new approach to the calculation of the x-ray spectrum emerging from an x-ray tube is proposed. Theoretical results for the bremsstrahlung cross section appearing in the literature are summarized. Four different treatments of electron penetration, based on the work presented in Part I, are then used to generate brems...

    journal_title:Medical physics

    pub_type: 杂志文章

    doi:10.1118/1.2734726

    authors: Poludniowski GG

    更新日期:2007-06-01 00:00:00

  • Dosimetric impact of motion in free-breathing and gated lung radiotherapy: a 4D Monte Carlo study of intrafraction and interfraction effects.

    abstract::The purpose of this study was to investigate if interfraction and intrafraction motion in free-breathing and gated lung IMRT can lead to systematic dose differences between 3DCT and 4DCT. Dosimetric effects were studied considering the breathing pattern of three patients monitored during the course of their treatment ...

    journal_title:Medical physics

    pub_type: 杂志文章

    doi:10.1118/1.2821704

    authors: Seco J,Sharp GC,Wu Z,Gierga D,Buettner F,Paganetti H

    更新日期:2008-01-01 00:00:00