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 treatment plans based on patient physical dimensions to eliminate plan optimization time. A planning study cohort of 47 TBI patients previously treated with optimized VMAT ARC 6 MV beams was retrospectively examined. These patients were sorted into six categories depending on height and anteroposterior (AP) width at the umbilicus. Using Varian Eclipse, clinical 40 cm × 10 cm open field arcs were substituted with 6 MV FFF. Mid-plane lateral dose profiles in conjunction with relative arc output factors (RAOF) yielded how far a given multileaf collimator (MLC) leaf must move in order to achieve a mid-plane 100% isodose for a specific control point. Linear interpolation gave the dynamic MLC aperture for the entire arc for each patient AP width category, which was subsequently applied through Python scripting. All FFF VMAT TBI plans were then evaluated by two radiation oncologists and deemed clinically acceptable. The FFF and clinical VMAT TBI plans had similar Body-5 mm D98% distributions, but overall the FFF plans had statistically significantly increased or broader Body-5 mm D2% and mean lung dose distributions. These differences are not considered clinically significant. Median beam-on times for the FFF and clinical VMAT TBI plans were 11.07 and 18.06 min, respectively, and planning time for the FFF VMAT TBI plans was reduced by 34.1 min. In conclusion, use of FFF beams in VMAT TBI treatment planning resulted in dose homogeneity similar to our current VMAT TBI technique. Clinical dosimetric criteria were achieved for a majority of patients while planning and calculated beam-on times were reduced, offering the possibility of improved patient experience.
journal_name
J Appl Clin Med Physjournal_title
Journal of applied clinical medical physicsauthors
Frederick R,Hudson A,Balogh A,Cao JQ,Pierce Gdoi
10.1002/acm2.12827subject
Has Abstractpub_date
2020-03-01 00:00:00pages
75-86issue
3issn
1526-9914journal_volume
21pub_type
杂志文章abstract::In this work, leakage radiation from EA200 series electron applicators on Siemens Primus accelerators is quantified, and its penetration ability in water and/or the shielding material Xenolite-NL established. Initially, measurement of leakage from 10 x 10 - 25 x 25 cm2 applicators was performed as a function of height...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v11i3.3105
更新日期:2010-06-15 00:00:00
abstract:PURPOSE:We introduce a technique that employs a 2D detector in transmission mode (TM) to verify dose maps at a depth of dmax in Solid Water. TM measurements, when taken at a different surface-to-detector distance (SDD), allow for the area at dmax (in which the dose map is calculated) to be adjusted. METHODS:We conside...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1002/acm2.12744
更新日期:2019-11-01 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
abstract::Remote afterloading devices used for high-dose-rate (HDR) brachytherapy may be supplied with different sources, and these sources typically have differing initial source strengths. In addition, the proposed frequency for source changes may also vary, depending upon the source type. Dosimetric parameters unique to each...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v14i6.4239
更新日期:2013-11-04 00:00:00
abstract::A quality assurance (QA) procedure was developed to evaluate the congruence between the cone-beam computed tomography (CBCT) image center and the radiation isocenter on a Varian Trilogy linac. In contrast to the published QA procedures, this method did not require a ball bearing (BB) phantom to be placed exactly at th...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v11i4.3297
更新日期:2010-07-02 00:00:00
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 ...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v10i3.2844
更新日期:2009-06-17 00:00:00
abstract::The assessment of the coincidence of imaging and radiation isocenters is an important task of regular quality assurance of medical linear accelerators (linacs) as recommended in national and international quality assurance guidelines. A previously reported investigation of the accuracy of the Elekta XVI software to lo...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1002/acm2.12861
更新日期:2020-05-01 00:00:00
abstract::Significant controversy surrounds the 2012 / 2014 decision announced by the Trustees of the American Board of Radiology (ABR) in October of 2007. According to the ABR, only medical physicists who are graduates of a Commission on Accreditation of Medical Physics Education Programs, Inc. (CAMPEP) accredited academic or ...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v11i2.3005
更新日期:2010-04-12 00:00:00
abstract:PURPOSE:To evaluate the quality of patient-specific complicated treatment plans, including commercialized treatment planning systems (TPS) and commissioned beam data, we developed a process of quality assurance (QA) using a Monte Carlo (MC) platform. Specifically, we constructed an interface system that automatically c...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1002/acm2.12718
更新日期:2019-10-01 00:00:00
abstract::Locally advanced non-small-cell lung cancer (NSCLC) is a common disease with a low overall survival even with aggressive treatments. Standard imaging (CT and PET/CT) provide no information about normal lung function. We therefore, sought to pilot HeMRI in patients with non-small-cell lung cancer before and after defin...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v12i2.3357
更新日期:2011-01-31 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::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::The purpose of this study was to assess treatment margins in free-breathing irradiation of pancreatic cancer after bone alignment, and evaluate their impact on conformal radiotherapy. Fifteen patients with adenocarcinoma of the head of the pancreas underwent implantation of single fiducial marker. Intrafraction uncert...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v14i4.4152
更新日期:2013-07-08 00:00:00
abstract::A wide variety of existing combinations of target and filter materials (target/filter combinations) are used in mammography equipment. The patient dose depends on the X-ray quality that is derived from the target/filter combination, and a calibration of the dosimeter that is used in the measurement that corresponds to...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v16i6.5604
更新日期:2015-11-08 00:00:00
abstract::Documentation is a required component of a residency program, but can be difficult to collect and disseminate, resulting in minimal utilization by residents and faculty. The purpose of this work is to adapt a commercially-available Web-based medical residency management system to improve the learning experience by eff...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v15i6.4866
更新日期:2014-11-08 00:00:00
abstract:PURPOSE:To establish a streamlined end-to-end test of a 6 degrees-of-freedom (6DoF) robotic table using a 3D printed phantom for periodic quality assurance. METHODS:A 3D printed phantom was fabricated with translational and rotational offsets and an imbedded central ball-bearing (BB). The phantom underwent each step o...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1002/acm2.12227
更新日期:2018-01-01 00:00:00
abstract::Traditional quality assurance checks of a patient's radiation therapy plan involve printing out treatment parameters from the treatment planning system and the "record and verify" (R&V) system and visually checking the information for one-to-one correspondence. In a paperless environment, one can automate this process...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v10i1.2905
更新日期:2009-01-27 00:00:00
abstract::This work illustrates a procedure to assess the overall accuracy associated with Gamma Knife treatment planning using plugging. The main role of source plugging or blocking is to create dose falloff in the junction between a target and a critical structure. We report the use of MAGAT gel dosimeter for verification of ...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v13i6.3877
更新日期:2012-11-08 00:00:00
abstract::Precise radiation therapy (RT) for abdominal lesions is complicated by respiratory motion and suboptimal soft tissue contrast in 4D CT. 4D MRI offers improved con-trast although long scan times and irregular breathing patterns can be limiting. To address this, visual biofeedback (VBF) was introduced into 4D MRI. Ten v...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v17i3.6017
更新日期:2016-05-08 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::Atlas-based autosegmentation is an established tool for segmenting structures for CT-planned head and neck radiotherapy. MRI is being increasingly integrated into the planning process. The aim of this study is to assess the feasibility of MRI-based, atlas-based autosegmentation for organs at risk (OAR) and lymph node ...
journal_title:Journal of applied clinical medical physics
pub_type: 临床试验,杂志文章
doi:10.1120/jacmp.v17i4.6051
更新日期:2016-07-08 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::Small field dosimetry is a challenging task. The difficulties of small field measurements, particularly stereotactic field size measurements, are highlighted by the large interinstitution variability that can be observed for circular cone collimator commissioning measurements. We believe the best way to improve the co...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v14i6.4493
更新日期:2013-11-04 00:00:00
abstract::We clarified the relationship between the display size of MRI images and observer performance using a digital contrast-detail (d-CD) phantom. The d-CD phantom was developed using Microsoft Visual Basic 2010 Express. It had a 512 × 512 matrix in size and a total of 100 holes, whose diameter increased stepwise from 4 to...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v17i1.5876
更新日期:2016-01-08 00:00:00
abstract:PURPOSE:To provide insight into the types of questions asked to medical physicists by patients during one-on-one physicist-patient consults at one institution. MATERIALS AND METHODS:Medical physicists trained in patient communication techniques met with patients to provide an overview of the treatment planning and del...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1002/acm2.12942
更新日期:2020-08-01 00:00:00
abstract::The longitudinal coverage of a LINAC-mounted CBCT scan is limited to the corresponding dimensional limits of its flat panel detector, which is often shorter than the length of the treatment field. These limits become apparent when fields are designed to encompass wide regions, as when providing nodal coverage. Therefo...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v13i4.3796
更新日期:2012-07-05 00:00:00
abstract::Part II of this review article presents four case studies for which peak skin doses are calculated following the methods outlined in Part I of this review. The data available in the cases ranges from proprietary dose reports to fluoroscopy time and number of digital acquisition frames only. Flowcharts are provided for...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v13i1.3693
更新日期:2012-01-05 00:00:00
abstract::A custom-made computer program, SWIMRT, to construct "multileaf collimator (MLC) machine" file for intensity-modulated radiotherapy (IMRT) fluence maps was developed using MATLAB and the sliding window algorithm. The user can either import a fluence map with a graphical file format created by an external treatment-pla...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v7i2.2231
更新日期:2006-05-25 00:00:00
abstract::The authors compared the relative dosimetric merits of Gamma Knife (GK) and CyberKnife (CK) in 15 patients with 26 brain metastases. All patients were initially treated with the Leksell GK 4C. The same patients were used to generate comparative CK treatment plans. The tissue volume receiving more than 12 Gy (V12), the...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v15i1.4095
更新日期:2014-01-06 00:00:00
abstract:PURPOSE:Previous studies suggest that within radiation oncology, medical physicists (MP) experience high workloads. Little is known about how MPs use social support (SS) in times of stress. METHODS:In collaboration with the Workgroup on Prevention of Medical Error, the American Association of Physicists in Medicine ad...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1002/acm2.12675
更新日期:2019-09-01 00:00:00