Abstract：
:For most computed tomography (CT) simulators, radiation therapists must remove the flat couch top to perform daily CT quality assurance (QA), and then use separate tools to perform localization-laser QA. This process wastes time and effort and creates the opportunity for accidents to occur. In this study, we tested a simple yet comprehensive daily QA program and phantom that we designed for CT simulators used in radiation oncology that would enable us to use only one tool to perform laser and imaging QA on a flat couch. To construct a modified QA phantom, we attached three adjustable legs and fastened two metric scales (one vertically and one horizontally) to a commercial CT QA phantom. The adjustable legs helped to position the phantom conveniently in the needed position. The two metric scales were used for localization-laser QA, while the phantom body was used for CT imaging QA. We used five different scanners with their designated couches from two manufacturers to evaluate this phantom. Since the couch was scanned with the phantom, we evaluated the couch's effect on image quality. We found that the presence of the couch top changed the uniformity of water's CT number but did not change the visual image resolution; it also produced different, yet reproducible, effects on image quality. The effects were greatest in the section of the phantom closest to the couch top. For a commercial carbon fiber couch top, the variation was within 3 Hounsfield Unit (HU). The effect was couch- and scanner-specific and could be incorporated into the QA acceptability criteria for each CT scanner. By using the proposed program and phantom, we have been able to implement a more thorough QA program while decreasing the amount of effort and time the simulation therapists spend performing laser and imaging QA.
journal_name
J Appl Clin Med Physjournal_title
Journal of applied clinical medical physicsauthors
Liu RR,Prado K,Gillin Mdoi
10.1120/jacmp.v10i3.2844subject
Has Abstractpub_date
2009-06-17 00:00:00pages
49-55issue
3issn
1526-9914journal_volume
10pub_type
杂志文章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
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更新日期：2020-07-01 00:00:00
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journal_title：Journal of applied clinical medical physics
pub_type： 杂志文章
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更新日期：2018-01-01 00:00:00
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更新日期：2014-09-08 00:00:00
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更新日期：2015-03-08 00:00:00
abstract：:High dose rate (HDR) brachytherapy often involves optimization routines to calculate the dwell times and positions of a radioactive source along specified applicator paths. These routines optimize the dwells in such a way as to deliver the prescribed dose at one or more points while satisfying various constraints. The...
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doi：10.1120/jacmp.v4i2.2530
更新日期：2003-04-01 00:00:00
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journal_title：Journal of applied clinical medical physics
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更新日期：2013-09-06 00:00:00
abstract：:The objectives of this project are to quantify the dose reduction effect provided by a lead shield for patients with cardiac implantable electronic devices (CIED) during a clinically realistic radiation treatment on phantom and to provide a simple model of dose estimation to predict dose received by CIED in a wide ran...
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更新日期：2015-11-08 00:00:00
abstract：:Dental amalgams are a common source of artifacts in head and neck (HN) images. Commercial artifact reduction techniques have been offered, but are substantially ineffectual at reducing artifacts from dental amalgams, can produce additional artifacts, provide inaccurate HU information, or require extensive computation ...
journal_title：Journal of applied clinical medical physics
pub_type： 杂志文章
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更新日期：2020-08-01 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
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更新日期：2017-11-01 00:00:00
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pub_type： 杂志文章,实务指引
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更新日期：2005-10-01 00:00:00
abstract：:Four-dimensional computerized tomography (4DCT) is required for stereotactic ablative body radiotherapy (SABR) of mobile targets to account for tumor motion during treatment planning and delivery. In this study, we report on the impact of an image review quality assurance process performed prior to treatment planning ...
journal_title：Journal of applied clinical medical physics
pub_type： 杂志文章
doi：10.1002/acm2.12825
更新日期：2020-03-01 00:00:00
abstract：:Doses in Leksell GammaPlan (Elekta, Stockholm, Sweden) are calculated for each shot by summing the contribution from the 201 radiation beams emitted by the Gamma Knife (Elekta), weighted for attenuation in the tissue traversed. The patient's head is modeled based on 24 skull measurements, from which the depth to the c...
journal_title：Journal of applied clinical medical physics
pub_type： 杂志文章
doi：10.1120/jacmp.v8i3.2377
更新日期：2007-07-17 00:00:00
abstract：PURPOSE:The aim of the current study was to evaluate the backscatter dose and energy spectrum from the Lipiodol with flattening filter (FF) and flattening filter-free (FFF) beams. Moreover, the backscatter range, that was defined as the backscatter distance (BD) are revealed. METHODS:6 MVX FF and FFF beams were delive...
journal_title：Journal of applied clinical medical physics
pub_type： 杂志文章
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更新日期：2019-06-01 00:00:00
abstract：PURPOSE:The weighted CT dose index (CTDIw ) has been extended for a nominal total collimation width (nT) greater than 40 mm and relies on measurements of CTDIfreeair. The purpose of this work was to compare three methods of measuring CTDIfreeair and subsequent calculations of CTDIw to investigate their clinical appropr...
journal_title：Journal of applied clinical medical physics
pub_type： 杂志文章
doi：10.1002/acm2.12363
更新日期：2018-07-01 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：:Special attention is required in planning and administering radiation therapy to patients with cardiac implantable electronic devices (CIEDs), such as pacemaker and defibrillator. The range of dose to CIEDs that can induce malfunction is large among CIEDs. Clinically significant defects have been reported at dose as l...
journal_title：Journal of applied clinical medical physics
pub_type： 杂志文章
doi：10.1002/acm2.12229
更新日期：2018-01-01 00:00:00
abstract：:We have investigated the combined effect of tissue heterogeneity and its variation associated with geometric error in stereotactic body radiotherapy (SBRT) for lung cancer. The treatment plans for eight lung cancer patients were calculated using effective path length (EPL) correction and Monte Carlo (MC) algorithms, w...
journal_title：Journal of applied clinical medical physics
pub_type： 杂志文章
doi：10.1120/jacmp.v16i5.5397
更新日期：2015-09-08 00:00:00
abstract：:The purpose of this study was to implement full/half bowtie filter models in a com-mercial treatment planning system (TPS) to calculate kilovoltage (kV) cone-beam CT (CBCT) doses of Varian On-Board Imager (OBI) kV X-ray imaging system. The full/half bowtie filter models were created as compensators in Pinnacle TPS usi...
journal_title：Journal of applied clinical medical physics
pub_type： 杂志文章
doi：10.1120/jacmp.v17i2.5988
更新日期：2016-03-08 00:00:00
abstract：:External beam radiation therapy (RT) is often offered to breast cancer patients after surgical mastectomy followed by breast reconstruction with silicone implants. In some cases, the RT is administered while the patient is still implanted with a temporary tissue expander including a high-density metallic port, which i...
journal_title：Journal of applied clinical medical physics
pub_type： 杂志文章
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更新日期：2011-01-19 00:00:00
abstract：:The image-guided radiotherapy technique (IGRT) makes use of imaging devices to verify the positions of the target volume and organs at risk during the treatment sessions. In this work we evaluate the image quality provided by an imaging system based on a kilovoltage cone-beam CT, and explore its ability to perform IGR...
journal_title：Journal of applied clinical medical physics
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更新日期：2013-01-07 00:00:00
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journal_title：Journal of applied clinical medical physics
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更新日期：2018-05-01 00:00:00
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journal_title：Journal of applied clinical medical physics
pub_type： 杂志文章
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更新日期：2020-12-01 00:00:00
abstract：:Detection and accurate quantification of treatment delivery errors is important in radiation therapy. This study aims to evaluate the accuracy of DVH based QA in quantifying delivery errors. Eighteen previously treated VMAT plans (prostate, H&N, and brain) were randomly chosen for this study. Conventional IMRT deliver...
journal_title：Journal of applied clinical medical physics
pub_type： 杂志文章
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更新日期：2016-09-08 00:00:00
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journal_title：Journal of applied clinical medical physics
pub_type： 杂志文章
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更新日期：2017-01-01 00:00:00
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journal_title：Journal of applied clinical medical physics
pub_type： 杂志文章
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更新日期：2017-11-01 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
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更新日期：2010-06-29 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
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更新日期：2014-01-06 00:00:00
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journal_title：Journal of applied clinical medical physics
pub_type： 杂志文章
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更新日期：2021-01-10 00:00:00
abstract：:In this work, the feasibility of using flattening filter free (FFF) beams in volumetric modulated arc therapy (VMAT) total body irradiation (TBI) treatment planning to decrease protracted beam-on times for these treatments was investigated. In addition, a methodology was developed to generate standardized VMAT TBI tre...
journal_title：Journal of applied clinical medical physics
pub_type： 杂志文章
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更新日期：2020-03-01 00:00:00
abstract：:This work compares two accelerated partial breast irradiation modalities, MammoSite brachytherapy and three dimensional conformal radiotherapy (3D-CRT), to a new method, SAVI brachytherapy, following NSABP B-39 guidelines. A total of 21 patients treated at UC San Diego with the SAVI device were evaluated in this compa...
journal_title：Journal of applied clinical medical physics
pub_type： 杂志文章
doi：10.1120/jacmp.v11i1.3021
更新日期：2009-12-03 00:00:00
