Abstract：
:A fully automatic radiophotoluminescent glass rod dosimeter (GRD) system has recently become commercially available. This article discusses the dosimetric properties of the GRD including uniformity and reproducibility of signal, dose linearity, and energy and directional dependence in high-energy photon beams. In addition, energy response is measured in electron beams. The uniformity and reproducibility of the signal from 50 GRDs using a 60Co beam are both +/- 1.1% (one standard deviation). Good dose linearity of the GRD is maintained for doses ranging from 0.5 to 30 Gy, the lower and upper limits of this study, respectively. The GRD response is found to show little energy dependence in photon energies of a 60Co beam, 4 MV (TPR20(10)=0.617) and 10 MV (TPR(20)10=0.744) x-ray beams. However, the GRD responses for 9 MeV (mean energy, Ez = 3.6 MeV) and 16 MeV (Ez = 10.4 MeV) electron beams are 4%-5% lower than that for a 60Co beam in the beam quality dependence. The measured angular dependence of GRD, ranging from 0 degrees (along the long axis of GRD) to 120 degrees is within 1.5% for a 4 MV x-ray beam. As applications, a linear accelerator-based radiosurgery system and Cyber-Knife output factors are measured by a GRD and compared with those from various detectors including a p-type silicon diode detector, a diamond detector, and an ion chamber. It is found that the GRD is a very useful detector for small field dosimetry, in particular, below 10 mm circular fields.
journal_name
Med Physjournal_title
Medical physicsauthors
Arakia F,Moribe N,Shimonobou T,Yamashita Ydoi
10.1118/1.1758351subject
Has Abstractpub_date
2004-07-01 00:00:00pages
1980-6issue
7eissn
0094-2405issn
2473-4209journal_volume
31pub_type
杂志文章相关文献
MEDICAL PHYSICS文献大全abstract：:Recent work has shown that there is significant uncertainty in measuring build-up doses in mega-voltage photon beams especially at high energies. In this present investigation we used a phantom-embedded extrapolation chamber (PEEC) made of Solid Water to validate Monte Carlo (MC)-calculated doses in the dose build-up ...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.1829401
更新日期：2005-01-01 00:00:00
abstract：:One of the key components in modern LINAC room shielding design is the amount of 90 degrees head leakage radiation levels. With the general clinical acceptance of intensity-modulated radiation therapy (IMRT) technique, accurate knowledge of this quantity has become even more important. Measurement of 90 degrees head l...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.2335489
更新日期：2006-09-01 00:00:00
abstract：PURPOSE:Radioembolization with yttrium-90 microspheres may be optimized with patient-specific pretherapy treatment planning. Dose verification and validation of treatment planning methods require quantitative imaging of the post-therapy distribution of yttrium-90 (Y-90). Methods for quantitative imaging of Y-90 using b...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4962472
更新日期：2016-10-01 00:00:00
abstract：PURPOSE:The accuracy of a six degree of freedom (6DoF) couch was evaluated using a novel method. METHODS:Cone beam CT (CBCT) images of a 3D phantom (IsoCal) were acquired with different, known combinations of couch pitch and roll angles. Pitch and roll angles between the maximum allowable values of 357 and 3 degrees w...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1002/mp.12342
更新日期：2017-08-01 00:00:00
abstract：:We investigated protection strategies of organs at risk (OARs) in intensity modulated radiation therapy (IMRT). These strategies apply to delivery of IMRT to moving body anatomies that show relative displacement of OAR in close proximity to a tumor target. We formulated an efficient genetic algorithm which makes it po...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.3132305
更新日期：2009-07-01 00:00:00
abstract：PURPOSE:Imaging the knee under realistic load-bearing conditions can be carried out in a horizontal plane using a C-arm CT scanner. Human subjects can be scanned in a standing position and acquired data successfully reconstructed. However, reconstructing this data is a challenge due to significant artifacts that are in...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4736213
更新日期：2012-06-01 00:00:00
abstract：:A number of relocatable head fixation systems have become commercially available or developed in-house to perform fractionated stereotactic radiotherapy (SRT) treatment. The uncertainty usually quoted for the target repositioning in SRT is over 2 mm, more than twice that of stereotactic radiosurgery (SRS) systems. Thi...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.598930
更新日期：2000-04-01 00:00:00
abstract：:Interchange or transfer of radiographic techniques through measurement of penetration quality is discussed. The usefulness of this achievement is verified using an aluminum step wedge. Also, the procedure described provides a method for performance evaluation of kVp compensation on diagnostic x-ray installations. ...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.594156
更新日期：1975-01-01 00:00:00
abstract：PURPOSE:A new technique called "curvilinear approach" for prostate seed implantation has been proposed. The purpose of this study is to evaluate the dosimetric benefit of curvilinear distribution of seeds for low-dose-rate (LDR) prostate brachytherapy. METHODS:Twenty LDR prostate brachytherapy cases planned intraopera...
journal_title：Medical physics
pub_type： 杂志文章,随机对照试验
doi：10.1118/1.3694110
更新日期：2012-04-01 00:00:00
abstract：PURPOSE:To correlate the Cole relaxation frequencies obtained from measurements of the electrical properties of breast tissue to the presence or absence of cancer. METHODS:Four-lead impedance measurements were obtained on ex vivo specimens extracted during surgery from 187 volunteer patients. Data were acquired with a...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4725172
更新日期：2012-07-01 00:00:00
abstract：:The use of dedicated magnetic resonance simulation (MR-SIM) platforms in Radiation Oncology has expanded rapidly, introducing new equipment and functionality with the overall goal of improving the accuracy of radiation treatment planning. However, this emerging technology presents a new set of challenges that need to ...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1002/mp.14695
更新日期：2021-01-01 00:00:00
abstract：PURPOSE:A multi-institutional planning study was performed to evaluate the frequency that current guidelines established by Radiation Therapy Oncology Group (RTOG) protocols and other literature for lung stereotactic body radiotherapy (SBRT) treatments are followed. METHODS:A total of 300 patients receiving lung SBRT ...
journal_title：Medical physics
pub_type： 杂志文章,多中心研究
doi：10.1118/1.4926551
更新日期：2015-08-01 00:00:00
abstract：:Electron spectral reconstruction of medical accelerators from measured depth doses is a practical method for providing the input initial phase space distribution at the patient surface that is required by Monte Carlo treatment planning systems. The posed inverse problem of spectral reconstruction is ill conditioned an...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.2161404
更新日期：2006-02-01 00:00:00
abstract：PURPOSE:To introduce a novel laser-based optical-CT scanner for the readout of three-dimensional (3D) radiation dosimeters. METHODS:The scanner employs a diode laser, a cylindrical lens, a motorized linear rail, a rotation stage, and a charge-coupled device camera. The scanner operates in a translate-rotate fashion an...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.3538924
更新日期：2011-02-01 00:00:00
abstract：PURPOSE:A dosimetry evaluation model for treatment planning of esophageal radiation therapy is developed using a deep learning model. The model predicts dose volume histogram (DVH) from distance to target histogram (DTH) based on stacked de-noise auto-encoder (SDAE) and one-dimensional convolutional network (1D-CN). M...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1002/mp.14434
更新日期：2020-10-01 00:00:00
abstract：PURPOSE:The quality of tomographic images is directly affected by the system model being used in image reconstruction. An accurate system matrix is desirable for high-resolution image reconstruction, but it often leads to high computation cost. In this work the authors present a maximum a posteriori reconstruction algo...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.3284980
更新日期：2010-02-01 00:00:00
abstract：:The accurate calculation of the skeleton of an object is a problem not satisfactorily solved by existing approaches. Most algorithms require a significant amount of user interaction and use a voxel grid to compute discrete and often coarse approximations of this representation of the data. We present a novel, automati...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.2409238
更新日期：2007-02-01 00:00:00
abstract：:A cumulative dose histogram is the graph of an integral function integrated over a domain VCR3 and is dubbed the dose-volume histogram (DVH), the dose-surface histogram (DSH) or the dose-wall histogram (DWH), depending on the dimension and structure of the region V. This paper presents a comparative study of the three...
journal_title：Medical physics
pub_type： 临床试验,杂志文章
doi：10.1118/1.1852811
更新日期：2005-02-01 00:00:00
abstract：:An automated technique has been developed for the verification of treatment field size and shape in external beam radiation therapy. Portal images from film or digital on-line imaging system are analyzed, and basic parameters are derived to describe the field size and shape from the contour points on the field boundar...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.597017
更新日期：1993-05-01 00:00:00
abstract：:The purpose of this study was to investigate the effect of z overscanning on eye lens dose and effective dose received by pediatric patients undergoing head CT examinations. A pediatric patient study was carried out to obtain the exposure parameters and data regarding the eye lens position with respect to imaged volum...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.2207212
更新日期：2006-07-01 00:00:00
abstract：:The ability of Leksell GammaPlan to perform stereotactic space localizations with image sets where there is misalignment of the patient's head (stereotactic frame and fiducial apparatus) relative to the computed tomography (CT) scanner coordinate system was studied. Misalignment is sometimes necessary for patient comf...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.2179751
更新日期：2006-04-01 00:00:00
abstract：:The focal spot of a linear accelerator is often considered to have a fully stable position. In practice, however, the beam control loop of a linear accelerator needs to stabilize after the beam is turned on. As a result, some motion of the focal spot might occur during the start-up phase of irradiation. When acquiring...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.1576229
更新日期：2003-06-01 00:00:00
abstract：PURPOSE:The standardized uptake value (SUV) is a quantitative measure of FDG tumor uptake frequently used as a tool to monitor therapeutic response. This study aims to (i) assess the reproducibility and uncertainty of SUV max and SUV mean, due to purely statistical, i.e., nonbiological, effects and (ii) to establish th...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.3578604
更新日期：2011-05-01 00:00:00
abstract：PURPOSE:To develop a new design of an x-ray beam shaper for helical computed tomography (CT) that increases the dose utilization. METHODS:For typical reconstruction algorithms in helical CT, different data are utilized with different weights during back-projection. In particular, data of the outer detector rows, i.e.,...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.3577766
更新日期：2011-07-01 00:00:00
abstract：PURPOSE:We report on the development of the open-source cross-platform radiation treatment planning toolkit matRad and its comparison against validated treatment planning systems. The toolkit enables three-dimensional intensity-modulated radiation therapy treatment planning for photons, scanned protons and scanned carb...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1002/mp.12251
更新日期：2017-06-01 00:00:00
abstract：PURPOSE:The authors' objective was to compare internal dose estimates obtained using the Organ Level Dose Assessment with Exponential Modeling (OLINDA/EXM) software, the voxel S value technique, and Monte Carlo simulation. Monte Carlo dose estimates were used as the reference standard to assess the impact of patient-sp...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4892606
更新日期：2014-09-01 00:00:00
abstract：:To develop volumetric micro-CT fluoroscopy for small animal imaging, we have proposed a cone-beam system with multiple x-ray sources. In this paper, we extend Parker's single-source half-scan weighting scheme to the case of an odd number of x-ray sources that are equiangularly distributed, and apply it for half-scan F...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.1381549
更新日期：2001-07-01 00:00:00
abstract：PURPOSE:High-intensity focused ultrasound (HIFU) has been investigated for ablative therapy and drug enhancement for gene therapy and chemotherapy. The aim of this work is to explore the feasibility of pulsed focused ultrasound (pFUS) for cancer therapy using an in vivo animal model. METHODS:A clinical HIFU system (In...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4901352
更新日期：2014-12-01 00:00:00
abstract：:Deformable image registration is an important tool for image-guided radiotherapy. Physics-model-based deformable image registration using finite element analysis is one of the methods currently being investigated. The calculation accuracy of finite element analysis is dependent on given boundary conditions, which are ...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.1774131
更新日期：2004-09-01 00:00:00
abstract：PURPOSE:Mammography is known to be one of the most difficult radiographic exams to interpret. Mammography has important limitations, including the superposition of normal tissue that can obscure a mass, chance alignment of normal tissue to mimic a true lesion and the inability to derive volumetric information. It has b...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.3562901
更新日期：2011-04-01 00:00:00
