Abstract：
:Reported MOSFET measurements concern mostly external radiotherapy and in vivo dosimetry. In this paper, we apply the technique for absolute dosimetry in the context of HDR brachytherapy using an 192Ir source. Measured radial dose rate distributions in water for different planes perpendicular to the source axis are presented and special attention is paid to the calibration of the R and K type detectors, and to the determination of appropriate correction factors for the sensitivity variation with the increase of the threshold voltage and the energy dependence. The experimental results are compared with Monte Carlo simulated dose rate distributions. The experimental results show a good agreement with the Monte Carlo simulations: the discrepancy between experimental and Monte Carlo results being within 5% for 82% of the points and within 10% for 95% of the points. Moreover, all points except two are found to lie within the experimental uncertainties, confirming thereby the quality of the results obtained.
journal_name
Med Physjournal_title
Medical physicsauthors
Zilio VO,Joneja OP,Popowski Y,Rosenfeld A,Chawla Rdoi
10.1118/1.2198168subject
Has Abstractpub_date
2006-06-01 00:00:00pages
1532-9issue
6eissn
0094-2405issn
2473-4209journal_volume
33pub_type
杂志文章相关文献
MEDICAL PHYSICS文献大全abstract：PURPOSE:Deformable registration generally relies on the assumption that the sought spatial transformation is smooth. Yet, breathing motion involves sliding of the lung with respect to the chest wall, causing a discontinuity in the motion field, and the smoothness assumption can lead to poor matching accuracy. In respon...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.3679009
更新日期：2012-02-01 00:00:00
abstract：:In computer simulations of x-ray CT systems one can either use continuous geometrical descriptions for phantoms or a voxelized representation. The voxelized approach allows arbitrary phantoms to be defined without being confined to geometrical shapes. The disadvantage of the voxelized approach is that inherent errors ...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.1461841
更新日期：2002-04-01 00:00:00
abstract：PURPOSE:Within the European project ALLEGRO (grant agreement no. 231965), the out-of-field dose delivered to a patient when treated with different radiotherapy modalities was investigated. The study compared the dose distribution during photon and particle irradiations both in a water and an anthropomorphic phantom to ...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4735792
更新日期：2012-06-01 00:00:00
abstract：PURPOSE:To investigate tight-frame based iterative reconstruction (TFIR) technique for spectral breast computed tomography (CT) using fewer projections while achieving greater image quality. METHODS:The experimental data were acquired with a fan-beam breast CT system based on a cadmium zinc telluride photon-counting d...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4790468
更新日期：2013-03-01 00:00:00
abstract：:Breast density, the percentage of glandular breast tissue, has been identified as an important yet underutilized risk factor in the development of breast cancer. A quantitative method to measure breast density with dual energy imaging was investigated using a computer simulation model. Two configurations to measure br...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.3002308
更新日期：2008-12-01 00:00:00
abstract：PURPOSE:Onboard imaging-currently performed primarily by x-ray transmission modalities-is essential in modern radiation therapy. As radiation therapy moves toward personalized medicine, molecular imaging, which views individual gene expression, may also be important onboard. Nuclear medicine methods, such as single pho...
journal_title：Medical physics
pub_type： 信件
doi：10.1118/1.4845195
更新日期：2014-01-01 00:00:00
abstract：PURPOSE:This study (1) examines a variety of real-world cases where systematic errors were not detected by widely accepted methods for IMRT/VMAT dosimetric accuracy evaluation, and (2) drills-down to identify failure modes and their corresponding means for detection, diagnosis, and mitigation. The primary goal of detai...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4826166
更新日期：2013-11-01 00:00:00
abstract：PURPOSE:Very fast Monte Carlo (MC) simulations of proton transport have been implemented recently on graphics processing units (GPUs). However, these MCs usually use simplified models for nonelastic proton-nucleus interactions. Our primary goal is to build a GPU-based proton transport MC with detailed modeling of elast...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4921046
更新日期：2015-06-01 00:00:00
abstract：:Administration of x-ray contrast agents during heart catheterization examination increases the absorbed radiation dose in tissue. To estimate the dose absorbed by the blood of children undergoing diagnostic heart catheterization and angiocardiography, a number of measurements and calculations were conducted. First, en...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.594613
更新日期：1979-11-01 00:00:00
abstract：:Positron emission tomography (PET) is increasingly considered as an effective imaging method to support several stages of radiation therapy. The combined usage of functional and morphological imaging in state-of-the-art PET/CT scanners is rapidly emerging to support the treatment planning process in terms of improved ...
journal_title：Medical physics
pub_type： 杂志文章,评审
doi：10.1118/1.4935869
更新日期：2015-12-01 00:00:00
abstract：:A Monte Carlo study of dosimetry for eye plaque brachytherapy is performed. BrachyDose, an EGSnrc user code which makes use of Yegin's multi-geometry package, is used to fully model I125 (model 6711) and Pd103 (model 200) brachytherapy seeds and the standardized plaques of the Collaborative Ocular Melanoma Study (COMS...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.3002412
更新日期：2008-12-01 00:00:00
abstract：:Several investigators have approximated the scatter component of digital radiographic images by applying a constant weighting factor to a convolved version of the detected image. The scatter approximation is then subtracted from the detected image. When a constant weighting factor is used, the scatter in areas of low ...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.596088
更新日期：1987-05-01 00:00:00
abstract：:Angioplasty balloons inflated with a solution of the beta-emitter Re-188 have been used for intravascular brachytherapy to prevent restenosis. Coronary stents are in extensive clinical use for the treatment of de novo atherosclerotic stenoses. In this study, the effect of an interposed stent on the dose distribution h...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.1533749
更新日期：2003-02-01 00:00:00
abstract：PURPOSE:To investigate how the setting of optimization parameters, fractional dose and tuning structure in tomotherapy treatment planning affects plan dosimetric quality and treatment efficiency. METHODS:A digital phantom to simulate head and neck radiotherapy was constructed for this study. Tumor was 10cm long C-shap...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4735724
更新日期：2012-06-01 00:00:00
abstract：PURPOSE:Automated 3D breast ultrasound (ABUS) has gained interest in breast imaging. Especially for screening women with dense breasts, ABUS appears to be beneficial. However, since the amount of data generated is large, the risk of oversight errors is substantial. Computer aided detection (CADe) may be used as a secon...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4914162
更新日期：2015-04-01 00:00:00
abstract：PURPOSE:The purpose of this study is to quantify the change in monthly VMAT quality assurance (QA) and determine the tests to maintain consistent delivery with a baseline. METHODS:VMAT monthly QA has been performed for over 14 months on two Elekta Synergy LINACs. A baseline was established at acceptance and the monthl...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4735470
更新日期：2012-06-01 00:00:00
abstract：:In this paper we examine the few-view reconstruction problem as it applies to imaging vascular trees. A fully automated reconstruction algorithm is described that circumvents the traditional "correspondence problem," using only notions of consistency and connectivity. It is assumed that the vascular tree is a connecte...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.597704
更新日期：1996-02-01 00:00:00
abstract：:A computer program was implemented to predict mammography x-ray beam parameters in the range 20-40 kV for Mo/Mo, Mo/Rh, Rh/Rh, and W/Al target/filter combinations. The computation method used to simulate mammography x-ray spectra is based on the Boone et al. model. The beam quality parameters such as the half-value la...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.1608498
更新日期：2003-10-01 00:00:00
abstract：PURPOSE:The response of human cells to applied electrical signals depends on the cellular health status, because it is influenced by the composition and structure of the main cellular components. Therefore, electrical impedance-based techniques can be considered as sensitive tools to investigate healthy or disease stat...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1002/mp.14425
更新日期：2020-10-01 00:00:00
abstract：:Accurate targeting is important in intensity-modulated radiation therapy (IMRT). The positional uncertainties of structures with respect to the external beams arise in part from random organ motion and patient setup errors. While it is important to improve immobilization and reduce the influence of organ motion, the r...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.599023
更新日期：2000-07-01 00:00:00
abstract：:The aim of the present study is to examine the validity of using silicon semiconductor detectors in degraded electron beams with a broad energy spectrum and a wide angular distribution. A comparison is made with diamond detector measurements, which is the dosimeter considered to give the best results provided that dos...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.1315317
更新日期：2000-11-01 00:00:00
abstract：:Treatment planning for brachytherapy requires the acquisition of geometrical information of the implant applicator and the patient anatomy. This is typically done using a simulator or a computed tomography scanner. In this study, we present a different method by which orthogonal images from a C-arm fluoroscopic machin...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.1598851
更新日期：2003-09-01 00:00:00
abstract：:We are evaluating the usefulness of stereomammography in improving breast cancer diagnosis. One area that we are investigating is whether the improved depth perception associated with stereomammography might be significantly enhanced with the use of a virtual 3D cursor. A study was performed to evaluate the accuracy o...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.599008
更新日期：2000-06-01 00:00:00
abstract：:Because of complex dose distributions and dose gradients that are created in three-dimensional conformal radiotherapy (3D-CRT) and intensity-modulated radiation therapy (IMRT), photon- and electron-energy spectra might change significantly with spatial locations and doses. This study examined variations in photon- and...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.2710550
更新日期：2007-04-01 00:00:00
abstract：:The effectiveness of film-screen mammography is limited by tradeoffs between latitude and contrast, film granularity, and the need to increase dose when antiscatter methods are used. We are currently developing a scanned-projection digital mammography (SPDM) system to overcome these limitations. The system consists of...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.596147
更新日期：1987-09-01 00:00:00
abstract：:The verification of dose distributions with high dose gradients as appearing in brachytherapy or stereotactic radiotherapy for example, calls for dosimetric methods with sufficiently high spatial resolution. Polymer gels in combination with a MR or optical scanner as a readout device have the potential of performing t...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.2898173
更新日期：2008-05-01 00:00:00
abstract：:Two experimental methods are described for obtaining average energies of neutron spectra produced by an electron accelerator in a medical treatment room. In the first method, the dose equivalent is measured by means of indium activation foils in an Andersson-Braun moderator. Fluences are determined by the usual activa...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.595662
更新日期：1985-11-01 00:00:00
abstract：:The relatively precise placement of brachytherapy sources afforded by stereotactic frames for brain implants is not generally achievable for other sites, which lack the fixed geometry of the cranium and its contents. An exception is a source-containing rigid mold that delivers brachytherapy when inserted securely in a...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.597454
更新日期：1995-03-01 00:00:00
abstract：PURPOSE:Radiotherapy, especially with charged particles, is sensitive to executional and preparational uncertainties that propagate to uncertainty in dose and plan quality indicators, for example, dose-volume histograms (DVHs). Current approaches to quantify and mitigate such uncertainties rely on explicitly computed e...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1002/mp.14414
更新日期：2020-10-01 00:00:00
abstract：PURPOSE:Tumor motion during radiotherapy can cause a reduction in target dose coverage and an increase in healthy tissue exposure. Tumor motion is not strictly translational and often exhibits complex six degree-of-freedom (6DoF) translational and rotational motion. Although the dosimetric impact of prostate tumor tran...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1002/mp.14502
更新日期：2020-12-01 00:00:00
