Abstract:
:We examined the dose distributions generated by Pinnacle3 (Philips Radiation Oncology Systems, Milpitas, CA) for intensity-modulated radiotherapy (IMRT) plans using a cubic-block-piled compensator as the intensity modulator for 4-MV and 10-MV photon beams. The Pinnacle treatment planning system (TPS) uses an algorithm in which only the physical density of the absorber is required for calculating the characteristics of the modulator. The intensity modulator consists of cubic blocks (attenuator) of a tungsten alloy, plus cubic blocks of polyethylene resin foam that fill the spaces between the attenuator blocks and polymethyl methacrylate (PMMA) boards that act as the platform for the modulator. By measuring the transmission for various thicknesses of attenuator and by deriving values for the total physical density of the modulator, we determined the optimal effective density by comparing the curves fitted for the actual transmission data with the transmission calculated by the TPS. Using these effective densities, we examined the accuracy of Pinnacle3 for dose profiles of specific geometric patterns. The levels of consistency between the measurements and the calculations were within a tolerance of 3% of the dose difference and had a 3-mm distance to agreement for the ladder-, stairstep-, and pyramid-shaped test patterns, except in the high dose gradient region. In this modulator assembly, leakage occurred from the slits between the cubic blocks. This leakage was about 1.6% at maximum, and its influence on dose distribution was not crucial. In the TPS, in which physical density was the only usercontrollable parameter, we used the effective density of the absorber deduced from the effective mass attenuation coefficient. We conclude that the intensity modulation compensator system, together with a piled cubic attenuator, is clinically applicable, with an acceptable tolerance level. For the intensity map of the IMRT plan, measurements in treatment fields met 3% and 3-mm criteria, excluding some regions of high gradient, which had a discrepancy of less than 5% and 4 mm.
journal_name
J Appl Clin Med Physjournal_title
Journal of applied clinical medical physicsauthors
Sasaki K,Obata Ydoi
10.1120/jacmp.v8i1.2323subject
Has Abstractpub_date
2006-06-16 00:00:00pages
85-100issue
1issn
1526-9914journal_volume
8pub_type
杂志文章abstract::Chest wall radiation therapy treatment delivery was monitored using a 5 mm thick radiochromic poly(vinyl alcohol) cryogel that also provided buildup material. The cryogels were used to detect positioning errors and measure the impact of shifts for a chest wall treatment that was delivered to a RANDO phantom. The phant...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v17i5.6148
更新日期:2016-09-08 00:00:00
abstract::The aim of this study was to report a single-institution experience and commissioning data for Elekta VersaHD linear accelerators (LINACs) for photon beams in the Eclipse treatment planning system (TPS). Two VersaHD LINACs equipped with 160-leaf collimators were commissioned. For each energy, the percent-depth-dose (P...
journal_title:Journal of applied clinical medical physics
pub_type: 临床试验,杂志文章
doi:10.1002/acm2.12709
更新日期:2019-10-01 00:00:00
abstract::Magnetic Resonance Imaging (MRI) is increasingly being used for improving tumor delineation and tumor tracking in the presence of respiratory motion. The purpose of this work is to design and build an MR compatible motion platform and to use it for evaluating the geometric accuracy of MR imaging techniques during resp...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1002/acm2.12274
更新日期:2018-03-01 00:00:00
abstract::Varian (Palo Alto, California, United States) recently released an online adaptation treatment platform, Ethos, which has introduced a new Dose Preview and Automated Plan Generation module despite sharing identical beam data with the existing Halcyon linac. The module incorporates a preconfigured beam model and the Ac...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1002/acm2.13056
更新日期:2020-12-01 00:00:00
abstract::The goal of this study was to investigate small field output factors (OFs) for flat-tening filter-free (FFF) beams on a dedicated stereotactic linear accelerator-based system. From this data, the collimator exchange effect was quantified, and detector-specific correction factors were generated. Output factors for 16 j...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v17i6.6433
更新日期:2016-11-08 00:00:00
abstract::This study utilizes process control techniques to identify action limits for TomoTherapy couch positioning quality assurance tests. A test was introduced to monitor accuracy of the applied couch offset detection in the TomoTherapy Hi-Art treatment system using the TQA "Step-Wedge Helical" module and MVCT detector. Ind...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1002/acm2.12136
更新日期:2017-09-01 00:00:00
abstract::A thermobrachytherapy surface applicator (TBSA) was developed for simultaneous heat and brachytherapy treatment of chest wall (CW) recurrence of breast cancer. The ability to comfortably secure the applicator over the upper torso relative to the CW target throughout treatment is assessed on volunteers. Male and postma...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v13i5.3845
更新日期:2012-09-06 00:00:00
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journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1002/acm2.12854
更新日期:2020-05-01 00:00:00
abstract::Hepatic encephalopathy (HE) is normally diagnosed by neuropsychological (NP) tests, which are not very specific and do not reveal the underlying pathology. Magnetic resonance imaging (MRI) and spectroscopy (MRS) of the brain offer alternative and possibly more specific markers for HE. These methods were applied in con...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v7i1.2151
更新日期:2006-01-01 00:00:00
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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
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journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1002/acm2.13163
更新日期:2021-01-10 00:00:00
abstract:PURPOSE:To investigate the effect of the marker placement on the correlation relationship between the motions of external markers and the internal target under different breathing patterns for several lung cancer patients. METHOD AND MATERIAL:To monitor and record simultaneous motions of internal target and associated...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v9i2.2758
更新日期:2008-04-16 00:00:00
abstract::Quality control (QC) of CT scanners is important to evaluate image quality and radiation dose. Different QC phantoms for testing image quality parameters on CT are commercially available, and Catphan phantoms are widely used for this purpose. More data from measured image quality parameters on CT are necessary to asse...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1002/acm2.12186
更新日期:2017-11-01 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:BACKGROUND:We study the changes in organs-at-risk (OARs) morphology as contoured on serial MRIs during chemoradiation therapy (CRT) of glioblastoma (GBM). The dosimetric implication of assuming non-deformable OAR changes and the accuracy and feasibility of semi-automatic OAR contour propagation are investigated. METHO...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1002/acm2.12758
更新日期:2019-12-01 00:00:00
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journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1002/acm2.12462
更新日期:2018-11-01 00:00:00
abstract:PURPOSE:Two different respiratory monitoring systems (Varian's Real-Time Position Management (RPM) System and Siemens' ANZAI belt Respiratory Gating System) are compared in the context of respiratory signals and 4D CT images that are accordingly reconstructed. This study aims to evaluate the feasibility of combined use...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1002/acm2.12434
更新日期:2018-09-01 00:00:00
abstract::We have developed a treatment planning protocol for intensity-modulated radiation therapy of the prostate using commercially available inverse planning software. Treatment plans were developed for ten patients using the Corvus version 3.8 planning system, testing various prescription options, including tissue types, d...
journal_title:Journal of applied clinical medical physics
pub_type: 临床试验,杂志文章
doi:10.1120/jacmp.v2i2.2614
更新日期:2001-04-01 00:00:00
abstract:OBJECT:The purpose of this study was to compare two methods of stereotactic localization in Gamma Knife treatment planning: cone beam computed tomography (CBCT) or fiducial. While the fiducial method is the traditional method of localization, CBCT is now available for use with the Gamma Knife Icon. This study seeks to ...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1002/acm2.12745
更新日期:2019-11-01 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:2014-01-06 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
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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:2002-04-01 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:2001-10-01 00:00:00
abstract::We conducted a metrological evaluation of the dosimetric impact due to the polysulfone cap used with the Fletcher-Williamson (FW) colpostat for 192Ir high-dose rate and pulsed-dose rate intracavitary brachytherapy using Monte Carlo simulations. Polysulfone caps with diameter of 30 mm, 25 mm, 20 mm, and 16 mm (mini-ovo...
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更新日期:2010-01-28 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:2009-04-22 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:2016-05-08 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:2011-01-31 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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journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
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更新日期:2009-09-03 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:2010-04-12 00:00:00