Abstract：
:The purpose of this study was to develop and evaluate a noninvasive method to assess rotation time in modern commercial computed tomography (CT) systems. The rotation time was measured at a selected nominal rotation time (400 ms) utilizing two types of solid-state detectors: the RTI's CT Dose Profiler (CTDP) and Unfors' Xi (Xi) probes. Either CTDP or Xi was positioned on the inner cover of the gantry and a sheet of lead (1 mm thick) placed on top of the detector. Since a pair of two successive peaks is used to determine the gantry rotation time, by necessity the helical scan must be employed. Upon completion of the data acquisition, these peak times were determined with the dedicated software to obtain rotation time. The average rotation time obtained with CTDP and Xi operated under the dedicated software was found to be 400.6 and 400.5 ms, respectively. The detector for this measurement need not be specifically designed for CT dosimetry. The measurements of CT scanner rotation time can be accomplished with a radiation probe designed for the CT application or a conventional radiation probe designed for radiography and fluoroscopy applications. It is also noteworthy to point out that the measurement results are in good agreement between the two radiation detector systems. Finally, clinical medical physicists should be aware of the accuracy and precision of gantry rotation time, and take into consideration for QA where and when applicable.
journal_name
J Appl Clin Med Physjournal_title
Journal of applied clinical medical physicsauthors
Fukuda A,Lin PJ,Matsubara K,Miyati Tdoi
10.1120/jacmp.v15i1.4517subject
Has Abstractpub_date
2014-01-06 00:00:00pages
4517issue
1issn
1526-9914journal_volume
15pub_type
杂志文章abstract：:The aim of this work is to evaluate the performance of a commercial brachytherapy treatment planning system (TPS) with TG-43 Vendors Input Data (VID), analyze possible discrepancies with respect to a proper reference source and its implications for standard treatments, and judge the effectiveness of certain widespread...
journal_title：Journal of applied clinical medical physics
pub_type： 杂志文章
doi：10.1120/jacmp.v16i4.4730
更新日期：2015-07-08 00:00:00
abstract：OBJECTIVES:To evaluate the influence of MRI scanning parameters on texture analysis features. METHODS:Publicly available data from the Reference Image Database to Evaluate Therapy Response (RIDER) project sponsored by The Cancer Imaging Archive included MRIs on a phantom comprised of 18 25-mm doped, gel-filled tubes, ...
journal_title：Journal of applied clinical medical physics
pub_type： 杂志文章
doi：10.1002/acm2.12482
更新日期：2018-11-01 00:00:00
abstract：PURPOSE:Volumetric modulated arc therapy (VMAT) is gaining popularity for stereotactic treatment of lung lesions for medically inoperable patients. Due to multiple beamlets in delivery of highly modulated VMAT plans, there are dose delivery uncertainties associated with small-field dosimetry error and interplay effects...
journal_title：Journal of applied clinical medical physics
pub_type： 杂志文章
doi：10.1002/acm2.12878
更新日期：2020-07-01 00:00:00
abstract：:The analysis of dynamic multileaf collimator (MLC) positions for the delivered intensity-modulated radiotherapy (IMRT) plans is crucial in that it may capture dose delivery problems otherwise difficult to observe and quantify in the conventional dosimetric measurements with film or with an ionization chamber. In some ...
journal_title：Journal of applied clinical medical physics
pub_type： 杂志文章
doi：10.1120/jacmp.v6i2.2076
更新日期：2005-04-01 00:00:00
abstract：:The assessment of intracranial aneurysms is increasingly performed using three-dimensional cone-beam rotational angiography (3D CBRA). To reduce the dose to the patient during 3D CBRA procedures, filtered region-of-interest imaging (FROI) is presented in literature to be an effective technique as the dose in regions o...
journal_title：Journal of applied clinical medical physics
pub_type： 杂志文章
doi：10.1120/jacmp.v16i2.5306
更新日期：2015-03-08 00:00:00
abstract：:The use of a radioactive check device containing Strontium 90 was investigated to carry out the redundancy checks of Farmer-type ionization chambers. It was not possible to meet the recommended tolerance limits of the redundancy checks without taking into account the angular response of the ionization chambers. The io...
journal_title：Journal of applied clinical medical physics
pub_type： 杂志文章
doi：10.1120/jacmp.v1i4.2636
更新日期：2000-10-01 00:00:00
abstract：:To estimate the lung tumor position from multiple anatomical features on four-dimensional computed tomography (4D-CT) data sets using single regression analysis (SRA) and multiple regression analysis (MRA) approach and evaluate an impact of the approach on internal target volume (ITV) for stereotactic body radiotherap...
journal_title：Journal of applied clinical medical physics
pub_type： 杂志文章
doi：10.1002/acm2.12121
更新日期：2017-09-01 00:00:00
abstract：:The nonphysical wedge is a modality that uses computer-controlled jaw motion to generate wedge-shaped dose distributions. There are Varian enhanced dynamic wedges (EDWs) and Siemens virtual wedges (VWs). We recently commissioned dynamic wedges on both Varian and Siemens LINACs. The beam data, acquired with a Wellhofer...
journal_title：Journal of applied clinical medical physics
pub_type： 杂志文章
doi：10.1120/jacmp.v5i4.1964
更新日期：2004-10-01 00:00:00
abstract：:IMRT QA requires, among other tests, a time-consuming process of measuring the absorbed dose, at least to a point, in a high-dose, low-dose-gradient region. Some clinics use a technique of measuring this dose with all beams delivered at a single gantry angle (collapsed delivery), as opposed to the beams delivered at t...
journal_title：Journal of applied clinical medical physics
pub_type： 杂志文章
doi：10.1120/jacmp.v15i3.4681
更新日期：2014-05-08 00:00:00
abstract：:It is important to improve the magnitude of dose variation that is caused by the interplay effect. The aim of this study was to investigate the impact of the number of breaths (NBs) to the dose variation for VMAT-SBRT to lung cancer. Data on respiratory motion and multileaf collimator (MLC) sequence were collected fro...
journal_title：Journal of applied clinical medical physics
pub_type： 杂志文章
doi：10.1002/acm2.12264
更新日期：2018-03-01 00:00:00
abstract：BACKGROUND:We analyzed the clinical and imaging characteristics of patients with breast ductal carcinoma in situ with microinvasion (DCISM) and breast ductal carcinoma in situ (DCIS). METHODS:We analyzed the records of 40 patients diagnosed with DCISM and 61 patients with DCIS who were hospitalized at Shengjing Hospit...
journal_title：Journal of applied clinical medical physics
pub_type： 杂志文章
doi：10.1002/acm2.13122
更新日期：2020-12-17 00:00:00
abstract：:To improve the penumbra of low-energy beams used in spot-scanning proton therapy, various collimation systems have been proposed and used in clinics. In this paper, focused on patient-specific brass collimators, the collimator-scattered protons' physical and biological effects were investigated. The Geant4 Monte Carlo...
journal_title：Journal of applied clinical medical physics
pub_type： 杂志文章
doi：10.1002/acm2.12653
更新日期：2019-07-01 00:00:00
abstract：:The aim of this study is to compare the dosimetric characteristics of robotic and conventional linac-based SBRT techniques for lung cancer, and to provide planning guidance for each modality. Eight patients who received linac-based SBRT were retrospectively included in this study. A dose of 60 Gy given in three fracti...
journal_title：Journal of applied clinical medical physics
pub_type： 杂志文章
doi：10.1120/jacmp.v11i3.3223
更新日期：2010-06-29 00:00:00
abstract：:The purpose was to study correlations amongst IMRT DVH evaluation points and how their relaxation impacts the overall plan. 100 head-and-neck cancer cases, using the Eclipse treatment planning system with the same protocol, are statisti-cally analyzed for PTV, brainstem, and spinal cord. To measure variations amongst ...
journal_title：Journal of applied clinical medical physics
pub_type： 杂志文章
doi：10.1120/jacmp.v17i6.6411
更新日期：2016-11-08 00:00:00
abstract：:A method to evaluate the electron beam energy constancy by employing the computed radiography (CR) system has been developed. In this method, a right triangular plastic wedge is used to produce a curve of the CR storage phosphor plate signal versus the wedge thickness. The curve, which resembles the percentage depth i...
journal_title：Journal of applied clinical medical physics
pub_type： 杂志文章
doi：10.1120/jacmp.v10i4.2911
更新日期：2009-10-15 00:00:00
abstract：:In Winston-Lutz (WL) tests, the isocenter of a linear accelerator (linac) is determined as the intersection of radiation central axes (CAX) from multiple gantry, collimator, and couch angles. It is well known that the CAX can wobble due to mechanical imperfections of the linac. Previous studies suggested that the wobb...
journal_title：Journal of applied clinical medical physics
pub_type： 杂志文章
doi：10.1120/jacmp.v17i1.5792
更新日期：2016-01-08 00:00:00
abstract：:A Histogram Analysis in Radiation Therapy (HART) program was primarily developed to increase the efficiency and accuracy of dose-volume histogram (DVH) analysis of large quantities of patient data in radiation therapy research. The program was written in MATLAB to analyze patient plans exported from the treatment plan...
journal_title：Journal of applied clinical medical physics
pub_type： 杂志文章
doi：
更新日期：2010-01-28 00:00:00
abstract：:This work introduces a new technology for electron intensity modulation, which uses small area island blocks within the collimating aperture and small area island apertures in the collimating insert. Due to multiple Coulomb scattering, electrons contribute dose under island blocks and lateral to island apertures. By s...
journal_title：Journal of applied clinical medical physics
pub_type： 杂志文章
doi：10.1002/acm2.12163
更新日期：2017-11-01 00:00:00
abstract：:Performing a procedure on the wrong patient or site is one of the greatest errors that can occur in medicine. The addition of automation has been shown to reduce errors in many processes. In this work we explore the use of an automated patient identification process using optical surface imaging for radiotherapy treat...
journal_title：Journal of applied clinical medical physics
pub_type： 杂志文章
doi：10.1120/jacmp.v17i2.6066
更新日期：2016-03-08 00:00:00
abstract：:Substantial disagreement exists over appropriate PET segmentation techniques for non-small cell lung cancer. Currently, no segmentation algorithm explicitly considers tumor motion in determining tumor borders. We developed an automatic PET segmentation model as a function of target volume, motion extent, and source-to...
journal_title：Journal of applied clinical medical physics
pub_type： 杂志文章
doi：10.1120/jacmp.v15i1.4600
更新日期：2014-01-06 00:00:00
abstract：:Studies have shown that source dwells within Varian's HDR CT/MR compatible ring applicators can deviate from intended positions by several millimeters. Quantifying this offset is an important part of commissioning. The aims of this study were to: 1) determine the reproducibility of the offset, 2) study the interobserv...
journal_title：Journal of applied clinical medical physics
pub_type： 杂志文章
doi：10.1120/jacmp.v12i4.3447
更新日期：2011-11-15 00:00:00
abstract：:Monte Carlo simulations are widely used for calculation of the dosimetric parameters of brachytherapy sources. MCNP4C2, MCNP5, MCNPX, EGS4, EGSnrc, PTRAN, and GEANT4 are among the most commonly used codes in this field. Each of these codes utilizes a cross-sectional library for the purpose of simulating different elem...
journal_title：Journal of applied clinical medical physics
pub_type： 杂志文章
doi：10.1120/jacmp.v17i2.5797
更新日期：2016-03-08 00:00:00
abstract：PURPOSE:To assess the setup errors in radiation therapy for thoracic tumors patients of different somatotypes, and to seek an individualized mathematical basis for defining the planning target volume (PTV). METHODS:Sixty patients with thoracic tumors were divided into four somatotypes according to their body mass inde...
journal_title：Journal of applied clinical medical physics
pub_type： 杂志文章
doi：10.1002/acm2.12270
更新日期：2018-05-01 00:00:00
abstract：:Physical and dosimetric characteristics of HDMLC were studied for SRS6, 6, and 10 MV X-rays from Novalis Tx. This in-built tertiary collimator consists of 60 pairs (32 × 0.25 cm; 26 × 0.5 cm and 2 × 0.7 cm) of leaves. Properties of HDMLC studied included alignment, readout and radiation field congruence, radiation pen...
journal_title：Journal of applied clinical medical physics
pub_type： 杂志文章
doi：10.1120/jacmp.v12i3.3475
更新日期：2011-04-14 00:00:00
abstract：:To monitor delivered dose and trigger plan adaptation when deviation becomes unacceptable, a clinical treatment dose (Tx-Dose) reconstruction system based on three-dimensional (3D)/four-dimensional (4D)-cone beam computed tomograpy (CBCT) images was developed and evaluated on various treatment sites, particularly for ...
journal_title：Journal of applied clinical medical physics
pub_type： 杂志文章
doi：10.1002/acm2.12474
更新日期：2018-11-01 00:00:00
abstract：:The purpose of this study is to describe the comprehensive commissioning process and initial clinical experience of the Mevion S250 proton therapy system, a gantry-mounted, single-room proton therapy platform clinically implemented in the S. Lee Kling Proton Therapy Center at Barnes-Jewish Hospital in St. Louis, MO, U...
journal_title：Journal of applied clinical medical physics
pub_type： 杂志文章
doi：10.1120/jacmp.v17i2.5868
更新日期：2016-03-08 00:00:00
abstract：:The use of solid carbon fiber table materials in radiotherapy has become more common with the implementation of image-guided radiotherapy (IGRT), since the solid materials give less imaging artifacts than the so-called tennis racket couchtops. The downside of the solid carbon fiber couch inserts is that they increase ...
journal_title：Journal of applied clinical medical physics
pub_type： 杂志文章
doi：10.1120/jacmp.v12i4.3554
更新日期：2011-11-15 00:00:00
abstract：PURPOSE:We conducted this dosimetric analysis to evaluate the feasibility of a multi-center stereotactic body radiation therapy (SBRT) trial for renal cell carcinoma (RCC) using different SBRT platforms. MATERIALS/METHODS:The computed tomography (CT) simulation images of 10 patients with unilateral RCC previously trea...
journal_title：Journal of applied clinical medical physics
pub_type： 杂志文章
doi：10.1002/acm2.12308
更新日期：2018-03-14 00:00:00
abstract：:The objective of this work is the investigation of intense pulsed light (IPL) photoepilation using Monte Carlo simulation to model the effect of the output dosimetry with millisecond exposure used by typical commercial IPL systems. The temporal pulse shape is an important parameter, which may affect the biological tis...
journal_title：Journal of applied clinical medical physics
pub_type： 杂志文章
doi：10.1120/jacmp.v13i5.3702
更新日期：2012-09-06 00:00:00
abstract：BACKGROUND AND PURPOSE:Along with the increasing demand for high-quality radiotherapy and the growing number of high-precision radiotherapy devices, precise radiotherapy workflow management and accurate time evaluation of the entire radiotherapy process are crucial to providing appropriate, timely treatment for cancer ...
journal_title：Journal of applied clinical medical physics
pub_type： 杂志文章
doi：10.1002/acm2.12959
更新日期：2020-09-01 00:00:00
