Abstract：
PURPOSE:The purpose of this technical note is to introduce variance component analysis to the estimation of systematic and random components in setup error of radiotherapy. METHODS:Balanced data according to the one-factor random effect model were assumed. RESULTS:Analysis-of-variance (anova)-based computation was applied to estimate the values and their confidence intervals (CIs) for systematic and random errors and the population mean of setup errors. The conventional method overestimates systematic error, especially in hypofractionated settings. The CI for systematic error becomes much wider than that for random error. The anova-based estimation can be extended to a multifactor model considering multiple causes of setup errors (e.g., interpatient, interfraction, and intrafraction). CONCLUSIONS:Variance component analysis may lead to novel applications to setup error analysis in radiotherapy.
journal_name
Med Physjournal_title
Medical physicsauthors
Matsuo Y,Nakamura M,Mizowaki T,Hiraoka Mdoi
10.1118/1.4961397subject
Has Abstractpub_date
2016-09-01 00:00:00pages
5195issue
9eissn
0094-2405issn
2473-4209journal_volume
43pub_type
杂志文章相关文献
MEDICAL PHYSICS文献大全abstract：PURPOSE:Radiosurgery uses small fields and high-radiation doses to treat intra- and extracranial lesions in a single session. The lack of a lateral electronic equilibrium and the presence of high-dose gradients in these fields are challenges for adequate measurements. The availability of radiation detectors with the hi...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4752211
更新日期：2012-10-01 00:00:00
abstract：:In previous work it has been shown that a standard backpropagation neural network can be trained to reconstruct sections of single photon emission computed tomography (SPECT) images based on the planar image projections as inputs. In this study, it is demonstrated that an artificial neural network (ANN) trained on a s...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.597586
更新日期：1995-05-01 00:00:00
abstract：PURPOSE:The performance of a newly developed, high resolution, microangiographic fluoroscope (MAF) (35 μm pixel pitch and 300 μm thick CsI phosphor) was evaluated using a generalized linear system analysis and compared with that of a standard amorphous Si thin film transistor flat panel detector (FPD) (194 μm pixel pit...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4792460
更新日期：2013-03-01 00:00:00
abstract：PURPOSE:Though failure mode and effects analysis (FMEA) is becoming more widely adopted for risk assessment in radiation therapy, to our knowledge, its output has never been validated against data on errors that actually occur. The objective of this study was to perform FMEA of a stereotactic body radiation therapy (SB...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4919440
更新日期：2015-06-01 00:00:00
abstract：:A slat collimator in single photon emission computed tomography consists of a set of parallel slats. As the collimator spins, the detector measures a one-dimensional projection data set. A complete data set can be obtained by rotating the detector/collimator assembly around the object (patient) while the collimator sp...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.1485057
更新日期：2002-07-01 00:00:00
abstract：PURPOSE:To investigate using 3D γ analysis for IMRT and VMAT QA. METHODS:We explored and studied 3D γ-analysis by comparing TPS computed and EPID back-projection reconstructed doses in patient's CT images. Two 3D γ quantities, γ(PTV) and γ(10), were proposed and studied for evaluating the QA results, and compared to 2...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4711755
更新日期：2012-06-01 00:00:00
abstract：:This paper examines the distributions of the SAR (specific absorption rate) ratio and temperature elevation when an ultrasound beam propagates through the interface of muscle and bone. This interface is regarded as a flat boundary to partition the energy of the ultrasound beam, and the analytical solution of temperatu...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.598979
更新日期：2000-05-01 00:00:00
abstract：:Double checking of the monitor units (MU) is an important step in the quality assurance (QA) process in radiosurgery. In this paper we propose the use of an independent algorithm constructed using the ellipsoid which best fits the measurements taken with the bubble head frame. The monitor units calculated by this inde...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.2815361
更新日期：2008-01-01 00:00:00
abstract：:Deformable registration is needed for a variety of tasks in establishing the voxel correspondence between respiratory phases. Most registration algorithms assume or imply that the deformation field is smooth and continuous everywhere. However, the lungs are contained within closed invaginated sacs called pleurae and a...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.2828378
更新日期：2008-02-01 00:00:00
abstract：:We applied Monte Carlo methods for the simulation of x-ray scattering in water phantoms. The phantom thickness was varied from 5 to 20 cm, and the monoenergetic incident x rays were varied from 15 to 100 keV. Eight screen pairs and a total absorption system were used as x-ray receptors. We determined the angular, spec...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.595771
更新日期：1985-03-01 00:00:00
abstract：PURPOSE:To construct a Monte Carlo (MC)-based simulation model for analyzing the dependence of tumor oxygen distribution on different variables related to tumor vasculature [blood velocity, vessel-to-vessel proximity (vessel proximity), and inflowing oxygen partial pressure (pO2)]. METHODS:A voxel-based tissue model c...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4892386
更新日期：2014-09-01 00:00:00
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
更新日期：2006-09-01 00:00:00
abstract：:To improve beam penetration into a head allowing the treatment of deeper seated tumors, two neutron collimators were built sequentially and tested for use in the clinical boron neutron capture therapy (BNCT) program at the epithermal neutron irradiation facility of the Brookhaven Medical Research Reactor. The collimat...
journal_title：Medical physics
pub_type： 临床试验,杂志文章
doi：10.1118/1.597772
更新日期：1996-12-01 00:00:00
abstract：:Transthoracic electrical impedance Z consists of a constant baseline component Z0 and the time variable component delta Z such that Z = Z0 + delta Z. The first time derivative of Z has a negative peak, the magnitude of which is (dZ/dt)min. Measurements of 170 volunteers show that (dZ/dt)min is a function of the consta...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.594910
更新日期：1981-01-01 00:00:00
abstract：:A double-mirror multilayer monochromator was developed for the purpose of irradiating live cell cultures at the Synchrotron Radiation Center, University of Wisconsin-Madison. The monochromator is designed for the soft x-ray region with photon energies between 270 and 2400 eV. Multilayer mirrors with 55 bilayers of W/C...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.598259
更新日期：1998-05-01 00:00:00
abstract：PURPOSE:CT reconstruction algorithms implemented on the GPU are highly sensitive to their implementation details and the hardware they run on. Fine-tuning an implementation for optimal performance can be a time consuming task and require many updates when the hardware changes. There are some techniques that do automati...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4773045
更新日期：2013-03-01 00:00:00
abstract：:An applicator system for intraoperative radiation therapy has been fabricated which does not require physical docking with the accelerator. A dosimetric study has been completed which documents the properties of this system for a variety of electron beam energies, applicator sizes, collimator settings, both primary an...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.596338
更新日期：1989-09-01 00:00:00
abstract：:Intensity modulated radiation therapy (IMRT) is used to deliver highly conformal radiation doses to tumors while sparing nearby sensitive tissues. Discrepancies between calculated and measured dose distributions have been reported for regions of high dose gradients corresponding to complex radiation fluence patterns. ...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.1812851
更新日期：2004-12-01 00:00:00
abstract：PURPOSE:To investigate dosimetry for ocular brachytherapy for a range of eye plaque models containing(103)Pd, (125)I, or (131)Cs seeds with model-based dose calculations. METHODS:Five representative plaque models are developed based on a literature review and are compared to the standardized COMS plaque, including pla...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4864474
更新日期：2014-03-01 00:00:00
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
更新日期：2006-08-01 00:00:00
abstract：PURPOSE:To investigate the inconsistency of recent literature on the effect of magnetic field on the response of radiochromic films, we studied the influence of 0.35 T magnetic field on dosimetric response of EBT3 and EBT-XD GafchromicTM films. METHODS:Two different models of radiochromic films, EBT3 and EBT-XD, were ...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1002/mp.14313
更新日期：2020-09-01 00:00:00
abstract：:One limitation to the widespread implementation of Monte Carlo (MC) patient dose-calculation algorithms for radiotherapy is the lack of a general and accurate source model of the accelerator radiation source. Our aim in this work is to investigate the sensitivity of the photon-beam subsource distributions in a MC sour...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.1884385
更新日期：2005-04-01 00:00:00
abstract：:Accelerator-based neutron source have been considered to be practical for boron neutron capture therapy (BNCT). Based on experience with a parameters of the Brookhaven National Laboratory BMRR reactor neutron source, which has been used in treatment experiments, the future accelerator-based neutron source for BNCT sho...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.598299
更新日期：1998-07-01 00:00:00
abstract：PURPOSE:Pulse pileup occurring at high x-ray fluxes can severely degrade the energy resolution provided by a photon counting detector, which can represent a problem in spectroscopic CT when performing quantitative material discrimination tasks. As the effects of pileup can be most easily seen as a degradation of a dete...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4820535
更新日期：2013-10-01 00:00:00
abstract：:The output factor for a therapy photon beam is defined as the dose per monitor unit relative to the dose per monitor unit in a reference field. Convolution models for photon dose calculations yield the dose in units normalized to the incident energy fluence with phantom scatter intrinsically modeled. Output factors ca...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.596859
更新日期：1992-03-01 00:00:00
abstract：PURPOSE:Breast density is a significant breast cancer risk factor. Although various methods are used to estimate breast density, there is no standard measurement for this important factor. The authors are developing a breast density standardization method for use in full field digital mammography (FFDM). The approach c...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.3250842
更新日期：2009-12-01 00:00:00
abstract：PURPOSE:Anomalous pixels may be defined as those pixels whose exposure response relationship is deviant from the typical, expected or calibrated response. A group of anomalous pixels may Result in visible correlated artifacts. Here we demonstrate an approach to identify anomalous pixels and correlated artifacts using f...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4734820
更新日期：2012-06-01 00:00:00
abstract：PURPOSE:Credentialing can have an impact on whether or not a clinical trial produces useful quality data that is comparable between various institutions and scanners. With the recent increase of dynamic contrast enhanced-computed tomography (DCE-CT) usage as a companion biomarker in clinical trials, effective quality a...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4812429
更新日期：2013-08-01 00:00:00
abstract：:The half-life of two I-125 encapsulated clinical seeds was measured with a Si(Li) semiconductor detector. Two measurements of each seed yielded an average half-life of 59.56 +/- 0.17 days. The results are discussed in terms of the influence of possible I-126 contamination and leakage of I-125 activity through encapsul...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.595423
更新日期：1983-11-01 00:00:00
abstract：PURPOSE:On-board MRI can provide superb soft tissue contrast for improving liver SBRT localization. However, the availability of on-board MRI in clinics is extremely limited. On the contrary, on-board kV imaging systems are widely available on radiotherapy machines, but its capability to localize tumors in soft tissue ...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1002/mp.12998
更新日期：2018-07-01 00:00:00
