SU-E-T-264: New Concrete Designed and Evaluation for Megavoltage X Radiotherapy Facilities (CONTEK-RFH2).

Abstract:

PURPOSE:The most common material for shielding is concrete, which can be made using various materials of different densities as aggregates. New techniques in radiotherapy, as IMRT and VMAT, require more monitor units and it is important to develop specifically designed shielding materials. METHODS:Arraela S.L. has developed new concrete (CONTEK®-RFH2), which is made from an arid with a high percentage in iron (> 60%), and using the suitable sieve size, enables optimum compaction of the material and a high mass density, about 4.1-4.2 g/cm3 . Moreover, aluminate cement, used as base, gives high resistance to high temperatures what makes this product be structurally resistant to temperatures up to 1200 ° C. The measurements were made in a LINAC Elekta SL18 to energies 6MV and 15 MV with a field size of 10×10 cm2 for concrete samples in the form of tile 25cm×25cm with variable thickness. RESULTS:The linear attenuation coefficient, μm, was determined for each energy by fitting the data to Eq. 1, where Xxm is the exposure in air behind a thickness xm of the material, and X0 is the exposure in the absence of shielding. These results are compared with the ordinary concrete (2.35 g cm-3) for 6MV and 15MV energies (Ref. NCRP Report No.151). Results are tabulated in Table1. Results of attenuation are compared with ordinary concrete in Fig. 1. CONCLUSIONS:The new concrete CONTEK®-RFH2 increases photon attenuation and reduces the size of a shielded wall. A very high percentage in iron and a suitablesieve size approximately double the density of ordinary concrete. High mass attenuation coefficient makes this concrete an extremely desirable material for use in radiation facilities as shielding material for photon beam, and for upgrading facilities designed for less energy or less workload.

journal_name

Med Phys

journal_title

Medical physics

authors

Mera M,Pereira L,Mera M,Pereira L,Meilán E,Moral FD,Teijeiro A,Salgado M,Andrade B,Gomez F,Fuentes-Vázquez V,Caruncho J,Medina A

doi

10.1118/1.4735331

subject

Has Abstract

pub_date

2012-06-01 00:00:00

pages

3764

issue

6Part14

eissn

0094-2405

issn

2473-4209

journal_volume

39

pub_type

杂志文章
  • Evaluating the impact of extended field-of-view CT reconstructions on CT values and dosimetric accuracy for radiation therapy.

    abstract:PURPOSE:Wide bore CT scanners use extended field-of-view (eFOV) reconstruction algorithms to attempt to recreate tissue truncated due to large patient habitus. Radiation therapy planning systems rely on accurate CT numbers in order to correctly plan and calculate radiation dose. This study looks at the impact of eFOV r...

    journal_title:Medical physics

    pub_type: 杂志文章

    doi:10.1002/mp.13299

    authors: Cheung JP,Shugard E,Mistry N,Pouliot J,Chen J

    更新日期:2019-02-01 00:00:00

  • Automatic needle segmentation in three-dimensional ultrasound images using two orthogonal two-dimensional image projections.

    abstract::In this paper, we describe an algorithm to segment a needle from a three-dimensional (3D) ultrasound image by using two orthogonal two-dimensional (2D) image projections. Not only is the needle more conspicuous in a projected (volume-rendered) image, but its direction in 3D lies in the plane defined by the projection ...

    journal_title:Medical physics

    pub_type: 杂志文章

    doi:10.1118/1.1538231

    authors: Ding M,Cardinal HN,Fenster A

    更新日期:2003-02-01 00:00:00

  • Sinusoidal modulation analysis for optical system MTF measurements.

    abstract::The modulation transfer function (MTF) is a commonly used metric for defining the spatial resolution characteristics of imaging systems. While the MTF is defined in terms of how an imaging system demodulates the amplitude of a sinusoidal input, this approach has not been in general use to measure MTFs in the medical i...

    journal_title:Medical physics

    pub_type: 杂志文章

    doi:10.1118/1.597840

    authors: Boone JM,Yu T,Seibert JA

    更新日期:1996-12-01 00:00:00

  • A generic TG-186 shielded applicator for commissioning model-based dose calculation algorithms for high-dose-rate 192 Ir brachytherapy.

    abstract:PURPOSE:A joint working group was created by the American Association of Physicists in Medicine (AAPM), the European Society for Radiotherapy and Oncology (ESTRO), and the Australasian Brachytherapy Group (ABG) with the charge, among others, to develop a set of well-defined test case plans and perform calculations and ...

    journal_title:Medical physics

    pub_type: 杂志文章

    doi:10.1002/mp.12459

    authors: Ma Y,Vijande J,Ballester F,Tedgren ÅC,Granero D,Haworth A,Mourtada F,Fonseca GP,Zourari K,Papagiannis P,Rivard MJ,Siebert FA,Sloboda RS,Smith R,Chamberland MJP,Thomson RM,Verhaegen F,Beaulieu L

    更新日期:2017-11-01 00:00:00

  • Re-examining TG-142 recommendations in light of modern techniques for linear accelerator based radiosurgery.

    abstract:PURPOSE:The recent development of multifocal stereotactic radiosurgery (SRS) using a single isocenter volumetric modulated arc theory (VMAT) technique warrants a re-examination of the quality assurance (QA) tolerances for routine mechanical QA recommended by the American Association of Physicists in Medicine Task Group...

    journal_title:Medical physics

    pub_type: 杂志文章

    doi:10.1118/1.4962471

    authors: Faught AM,Trager M,Yin FF,Kirkpatrick J,Adamson J

    更新日期:2016-10-01 00:00:00

  • Soft-tissue detectability in cone-beam CT: evaluation by 2AFC tests in relation to physical performance metrics.

    abstract::Soft-tissue detectability in cone-beam computed tomography (CBCT) was evaluated via two-alternative forced-choice (2AFC) tests. Investigations included the dependence of detectability on radiation dose, the influence of the asymmetric three-dimensional (3D) noise-power spectrum (NPS) in axial and sagittal or coronal p...

    journal_title:Medical physics

    pub_type: 杂志文章

    doi:10.1118/1.2790586

    authors: Tward DJ,Siewerdsen JH,Daly MJ,Richard S,Moseley DJ,Jaffray DA,Paul NS

    更新日期:2007-11-01 00:00:00

  • Reconstruction of diagnostic x-ray spectra by numerical analysis of transmission data.

    abstract::Numerical reconstruction of x-ray spectra from narrow-beam transmission data was tested with published spectra in the range from 45 to 100 kVp. Transmission curves were calculated from the spectra to simulate measured data. Spectra were reconstructed from these transmission curves with use of an iterative numerical an...

    journal_title:Medical physics

    pub_type: 杂志文章

    doi:10.1118/1.595834

    authors: Huang PH,Chen TS,Kase KR

    更新日期:1986-09-01 00:00:00

  • Indirect flat-panel detector with avalanche gain: fundamental feasibility investigation for SHARP-AMFPI (scintillator HARP active matrix flat panel imager).

    abstract::An indirect flat-panel imager (FPI) with avalanche gain is being investigated for low-dose x-ray imaging. It is made by optically coupling a structured x-ray scintillator CsI(Tl) to an amorphous selenium (a-Se) avalanche photoconductor called HARP (high-gain avalanche rushing photoconductor). The final electronic imag...

    journal_title:Medical physics

    pub_type: 杂志文章

    doi:10.1118/1.2008428

    authors: Zhao W,Li D,Reznik A,Lui BJ,Hunt DC,Rowlands JA,Ohkawa Y,Tanioka K

    更新日期:2005-09-01 00:00:00

  • On the accuracy of techniques for obtaining the calibration coefficient N(K) of 192Ir HDR brachytherapy sources.

    abstract::The accuracy of interpolation or averaging procedures for obtaining the calibration coefficient N(K) for 192Ir high-dose-rate brachytherapy sources has been investigated using the EGSnrc Monte Carlo simulation system. It is shown that the widely used two-point averaging procedure of Goetsch et al. [Med. Phys. 18, 462 ...

    journal_title:Medical physics

    pub_type: 杂志文章

    doi:10.1118/1.2239198

    authors: Mainegra-Hing E,Rogers DW

    更新日期:2006-09-01 00:00:00

  • SU-E-J-81: Beveled Needle Tip Detection Error in Ultrasound-Guided Prostate Brachytherapy.

    abstract:PURPOSE:To quantify the needle tip detection errors in ultrasound images due to bevel-tip orientation in relation to the location on template grid. METHODS:Transrectal ultrasound (TRUS) system (BK Medical) with physical template grid and 18-gauge bevel-tip (20-deg beveled angle) brachytherapy needle (Bard Medical, Cov...

    journal_title:Medical physics

    pub_type: 杂志文章

    doi:10.1118/1.4734916

    authors: Leu S,Ruiz B,Podder T

    更新日期:2012-06-01 00:00:00

  • Feasibility of estimating regional mechanical properties of cerebral aneurysms in vivo.

    abstract:PURPOSE:In this article, the authors studied the feasibility of estimating regional mechanical properties in cerebral aneurysms, integrating information extracted from imaging and physiological data with generic computational models of the arterial wall behavior. METHODS:A data assimilation framework was developed to ...

    journal_title:Medical physics

    pub_type: 杂志文章

    doi:10.1118/1.3355933

    authors: Balocco S,Camara O,Vivas E,Sola T,Guimaraens L,Gratama van Andel HA,Majoie CB,Pozo JM,Bijnens BH,Frangi AF

    更新日期:2010-04-01 00:00:00

  • TU-E-217BCD-10: Dose Reduction in Digital Breast Tomosynthesis with the Dose Reduction Prior Image Constrained Compressed Sensing (DR-PICCS) Algorithm.

    abstract:PURPOSE:To reduce image noise and radiation dose in Digital Breast Tomosynthesis (DBT) reconstructions. METHODS:A retrospective study was performed on clinical data sets acquired at a normal dose with Hologic Selenia Dimensions DBT systems. The Prior Image Constrained Compressed Sensing (PICCS) algorithm was used to r...

    journal_title:Medical physics

    pub_type: 杂志文章

    doi:10.1118/1.4735982

    authors: Garrett J,Tang J,Zhang Y,Ruth C,Jing Z,Chen GH

    更新日期:2012-06-01 00:00:00

  • Depth dose characteristics of 24-MV x-ray beams at extended SSD.

    abstract::Depth dose characteristics of 24-MV beams from a medical linear accelerator at various SSDs have been measured. The dose buildup, percent depth dose (PDD), and output were measured using ionization chambers and a diode detector under full scatter. Surface dose ranged from 8% to 51% depending upon the collimator settin...

    journal_title:Medical physics

    pub_type: 杂志文章

    doi:10.1118/1.596673

    authors: Jani SK,Pennington EC

    更新日期:1991-03-01 00:00:00

  • Sheet beam x-ray fluorescence computed tomography (XFCT) imaging of gold nanoparticles.

    abstract:PURPOSE:X-ray fluorescence computed tomography (XFCT) experiments have typically used pencil beams for data acquisition, which yielded good quality images of gold nanoparticles (AuNP) but prolonged the imaging time. Here we propose three novel collimator geometries for use with faster sheet beam XFCT data acquisition. ...

    journal_title:Medical physics

    pub_type: 杂志文章

    doi:10.1002/mp.12893

    authors: Dunning CAS,Bazalova-Carter M

    更新日期:2018-06-01 00:00:00

  • Spectra and air-kerma strength for encapsulated 192Ir sources.

    abstract::The photon spectra in vacuum around four types of 192Ir HDR brachytherapy sources are calculated using the Monte Carlo code EGS4 and the most recent spectral information on 192Ir decay. The air-kerma strengths per unit activity are calculated based on the photon fluence around a bare 192Ir source and around each of fo...

    journal_title:Medical physics

    pub_type: 杂志文章

    doi:10.1118/1.598763

    authors: Borg J,Rogers DW

    更新日期:1999-11-01 00:00:00

  • Technical Note: Influence of Compton currents on profile measurements in small-volume ion chambers.

    abstract:PURPOSE:This work is to evaluate the effects of Compton current generation in three small-volume ionization chambers on measured beam characteristics for electron fields. METHODS:Beam scans were performed using Exradin A16, A26, and PTW 31014 microchambers. Scans with varying chamber components shielded were performed...

    journal_title:Medical physics

    pub_type: 杂志文章

    doi:10.1118/1.4929555

    authors: Tanny S,Holmes S,Sperling N,Parsai EI

    更新日期:2015-10-01 00:00:00

  • Quantitative simultaneous 99mTc/123I cardiac SPECT using MC-JOSEM.

    abstract::Simultaneous rest 99mTc-Sestamibi/ 123I-BMIPP cardiac SPECT imaging has the potential to replace current clinical 99mTc-Sestamibi rest/stress imaging and therefore has great potential in the case of patients with chest pain presenting to the emergency department. Separation of images of these two radionuclides is diff...

    journal_title:Medical physics

    pub_type: 杂志文章

    doi:10.1118/1.3063544

    authors: Ouyang J,Zhu X,Trott CM,El Fakhri G

    更新日期:2009-02-01 00:00:00

  • False-positive reduction in CAD mass detection using a competitive classification strategy.

    abstract::High false-positive (FP) rate remains to be one of the major problems to be solved in CAD study because too many false-positively cued signals will potentially degrade the performance of detecting true-positive regions and increase the call-back rate in CAD environment. In this paper, we proposed a novel classificatio...

    journal_title:Medical physics

    pub_type: 杂志文章

    doi:10.1118/1.1344203

    authors: Li L,Zheng Y,Zhang L,Clark RA

    更新日期:2001-02-01 00:00:00

  • Combined mixed approach algorithm for in-line phase-contrast x-ray imaging.

    abstract:PURPOSE:In the past decade, phase-contrast imaging (PCI) has been applied to study different kinds of tissues and human body parts, with an increased improvement of the image quality with respect to simple absorption radiography. A technique closely related to PCI is phase-retrieval imaging (PRI). Indeed, PCI is an ima...

    journal_title:Medical physics

    pub_type: 杂志文章

    doi:10.1118/1.3447727

    authors: De Caro L,Scattarella F,Giannini C,Tangaro S,Rigon L,Longo R,Bellotti R

    更新日期:2010-07-01 00:00:00

  • Automated lung segmentation of diseased and artifact-corrupted magnetic resonance sections.

    abstract::Segmentation of the lungs within magnetic resonance (MR) scans is a necessary step in the computer-based analysis of thoracic MR images. This process is often confounded by image acquisition artifacts and disease-induced morphological deformation. We have developed an automated method for lung segmentation that is ins...

    journal_title:Medical physics

    pub_type: 杂志文章

    doi:10.1118/1.2214165

    authors: Sensakovic WF,Armato SG 3rd,Starkey A,Caligiuri P

    更新日期:2006-09-01 00:00:00

  • Automated polyp segmentation for colonoscopy images: A method based on convolutional neural networks and ensemble learning.

    abstract:PURPOSE:To automatically and efficiently segment the lesion area of the colonoscopy polyp image, a polyp segmentation method has been presented. METHODS:An ensemble model of pretrained convolutional neural networks was proposed, using Unet-VGG, SegNet-VGG, and PSPNet. Firstly, the Unet-VGG is obtained by the first 10 ...

    journal_title:Medical physics

    pub_type: 杂志文章

    doi:10.1002/mp.13865

    authors: Guo X,Zhang N,Guo J,Zhang H,Hao Y,Hang J

    更新日期:2019-12-01 00:00:00

  • Development and validation of a measurement-based source model for kilovoltage cone-beam CT Monte Carlo dosimetry simulations.

    abstract:PURPOSE:The purpose of this study is to adapt an equivalent source model originally developed for conventional CT Monte Carlo dose quantification to the radiation oncology context and validate its application for evaluating concomitant dose incurred by a kilovoltage (kV) cone-beam CT (CBCT) system integrated into a lin...

    journal_title:Medical physics

    pub_type: 杂志文章

    doi:10.1118/1.4823795

    authors: McMillan K,McNitt-Gray M,Ruan D

    更新日期:2013-11-01 00:00:00

  • Selective enhancement filters for nodules, vessels, and airway walls in two- and three-dimensional CT scans.

    abstract::Computer-aided diagnostic (CAD) schemes have been developed to assist radiologists in the early detection of lung cancer in radiographs and computed tomography (CT) images. In order to improve sensitivity for nodule detection, many researchers have employed a filter as a preprocessing step for enhancement of nodules. ...

    journal_title:Medical physics

    pub_type: 杂志文章

    doi:10.1118/1.1581411

    authors: Li Q,Sone S,Doi K

    更新日期:2003-08-01 00:00:00

  • Optimization of the dose delivery in a few field techniques using radiobiological objective functions.

    abstract::A method for finding optimal primary fluence profiles for multiple field external beam radiation therapy techniques has been developed using a radiobiologically based objective function that quantifies the probability of achieving complication-free tumor control, P+. The objective function P+ has the valuable property...

    journal_title:Medical physics

    pub_type: 杂志文章

    doi:10.1118/1.596971

    authors: Södertröm S,Brahme A

    更新日期:1993-07-01 00:00:00

  • Development of an automated region of interest selection method for 3D surface monitoring of head motion.

    abstract:PURPOSE:To simplify the often complex and user-dependent manual region of interest (ROI) selection process for head motion monitoring, an automatic ROI selection method was developed. METHODS:The automatic ROI selection algorithm calculated the displacements and velocities of 3D surface points between a temporally cor...

    journal_title:Medical physics

    pub_type: 杂志文章

    doi:10.1118/1.4711805

    authors: Kang HJ,Grelewicz Z,Wiersma RD

    更新日期:2012-06-01 00:00:00

  • A piecewise-focused high DQE detector for MV imaging.

    abstract:PURPOSE:Electronic portal imagers (EPIDs) with high detective quantum efficiencies (DQEs) are sought to facilitate the use of the megavoltage (MV) radiotherapy treatment beam for image guidance. Potential advantages include high quality (treatment) beam's eye view imaging, and improved cone-beam computed tomography (CB...

    journal_title:Medical physics

    pub_type: 杂志文章

    doi:10.1118/1.4927786

    authors: Star-Lack J,Shedlock D,Swahn D,Humber D,Wang A,Hirsh H,Zentai G,Sawkey D,Kruger I,Sun M,Abel E,Virshup G,Shin M,Fahrig R

    更新日期:2015-09-01 00:00:00

  • Feldkamp-based cone-beam reconstruction for gantry-tilted helical multislice CT.

    abstract::Depending on the clinical application, it is frequently necessary to tilt the gantry of an x-ray CT system with respect to the patient and couch. For single-slice fan-beam systems, tilting the gantry introduces no errors or artifacts. Most current systems, however, are helical multislice systems with up to 16 slices. ...

    journal_title:Medical physics

    pub_type: 杂志文章

    doi:10.1118/1.1625443

    authors: Hein I,Taguchi K,Silver MD,Kazama M,Mori I

    更新日期:2003-12-01 00:00:00

  • Uncertainties in IMRT dosimetry.

    abstract:PURPOSE:The purpose of this study is to investigate some characteristics of the beam delivery system and their effects on the dose distribution of intensity-modulated radiation therapy (IMRT) and the results of patient-specific IMRT quality assurance (QA). These characteristics include the accelerator source distributi...

    journal_title:Medical physics

    pub_type: 杂志文章

    doi:10.1118/1.3413997

    authors: Li JS,Lin T,Chen L,Price RA Jr,Ma CM

    更新日期:2010-06-01 00:00:00

  • Technical Note: Impact of the geometry dependence of the ion chamber detector response function on a convolution-based method to address the volume averaging effect.

    abstract:PURPOSE:To investigate the geometry dependence of the detector response function (DRF) of three commonly used scanning ionization chambers and its impact on a convolution-based method to address the volume averaging effect (VAE). METHODS:A convolution-based approach has been proposed recently to address the ionization...

    journal_title:Medical physics

    pub_type: 杂志文章

    doi:10.1118/1.4944783

    authors: Barraclough B,Li JG,Lebron S,Fan Q,Liu C,Yan G

    更新日期:2016-05-01 00:00:00

  • A method to estimate transmission profiles of bow-tie filters using rotating tube measurements.

    abstract:PURPOSE:The purpose of this paper was to present a method of determining the dose profile of the beam bow-tie filter (BTF) without the need for fixing the x ray tube in a position or using special instruments or dosimeters other than the ordinary types of ion chambers used for CT dosimetry (e.g., Farmer chamber). METH...

    journal_title:Medical physics

    pub_type: 杂志文章

    doi:10.1002/mp.13203

    authors: Al-Senan R

    更新日期:2018-11-01 00:00:00