keyword
MENU ▼
Read by QxMD icon Read
search

Dose Error Reduction System

keyword
https://www.readbyqxmd.com/read/28048403/th-ab-201-12-using-machine-log-files-for-treatment-planning-and-delivery-qa
#1
C Stanhope, J Liang, D Drake, D Yan
PURPOSE: To determine the segment reduction and dose resolution necessary for machine log-files to effectively replace current phantom-based patient-specific quality assurance, while minimizing computational cost. METHODS: Elekta's Log File Convertor R3.2 records linac delivery parameters (dose rate, gantry angle, leaf position) every 40ms. Five VMAT plans [4 H&N, 1 Pulsed Brain] comprised of 2 arcs each were delivered on the ArcCHECK phantom. Log-files were reconstructed in Pinnacle on the phantom geometry using 1/2/3/4° control point spacing and 2/3/4mm dose grid resolution...
June 2016: Medical Physics
https://www.readbyqxmd.com/read/28047871/su-f-t-471-simulated-external-beam-delivery-errors-detection-with-a-large-area-ion-chamber-transmission-detector
#2
D Hoffman, B Dyer, C Kumaran Nair, R Stern, S Benedict, U C Davis
PURPOSE: The Integral Quality Monitor (IQM), developed by iRT Systems GmbH (Koblenz, Germany) is a large-area, linac-mounted ion chamber used to monitor photon fluence during patient treatment. Our previous work evaluated the change of the ion chamber's response to deviations from static 1×1 cm2 and 10×10 cm2 photon beams and other characteristics integral to use in external beam detection. The aim of this work is to simulate two external beam radiation delivery errors, quantify the detection of simulated errors and evaluate the reduction in patient harm resulting from detection...
June 2016: Medical Physics
https://www.readbyqxmd.com/read/28047845/we-ab-207a-01-best-in-physics-imaging-high-resolution-cone-beam-ct-of-the-extremities-and-cancellous-bone-architecture-with-a-cmos-detector
#3
Q Cao, M Brehler, A Sisniega, E Marinetto, A Zyazin, I Peters, J Stayman, J Yorkston, J Siewerdsen, W Zbijewski
PURPOSE: Extremity cone-beam CT (CBCT) with an amorphous silicon (aSi) flat-panel detector (FPD) provides low-dose volumetric imaging with high spatial resolution. We investigate the performance of the newer complementary metal-oxide semiconductor (CMOS) detectors to enhance resolution of extremities CBCT to ∼0.1 mm, enabling morphological analysis of trabecular bone. Quantitative in-vivo imaging of bone microarchitecture could present an important advance for osteoporosis and osteoarthritis diagnosis and therapy assessment...
June 2016: Medical Physics
https://www.readbyqxmd.com/read/28047286/su-f-t-241-reduction-in-planning-errors-via-a-process-control-developed-using-the-eclipse-scripting-api
#4
D Barbee, A McCarthy, P Galavis, A Xu
PURPOSE: Errors found during initial physics plan checks frequently require replanning and reprinting, resulting decreased departmental efficiency. Additionally, errors may be missed during physics checks, resulting in potential treatment errors or interruption. This work presents a process control created using the Eclipse Scripting API (ESAPI) enabling dosimetrists and physicists to detect potential errors in the Eclipse treatment planning system prior to performing any plan approvals or printing...
June 2016: Medical Physics
https://www.readbyqxmd.com/read/28047113/su-g-tep2-13-patient-specific-reduction-of-range-uncertainties-in-proton-therapy-by-proton-radiography-with-a-multi-layer-ionization-chamber
#5
S Deffet, P Farace, R Righetto, B Macq, F Vander Stappen
PURPOSE: The conversion from Hounsfield units (HU) to stopping powers is a major source of range uncertainty in proton therapy (PT). Our contribution shows how proton radiographs (PR) acquired with a multi-layer ionization chamber in a PT center can be used for accurate patient positioning and subsequently for patient-specific optimization of the conversion from HU to stopping powers. METHODS: A multi-layer ionization chamber was used to measure the integral depth-dose (IDD) of 220 MeV pencil beam spots passing through several anthropomorphic phantoms...
June 2016: Medical Physics
https://www.readbyqxmd.com/read/28047030/su-g-iep3-05-effects-of-image-receptor-technology-and-dose-reduction-software-on-radiation-dose-estimates-for-fluoroscopically-guided-interventional-fgi-procedures
#6
Z Merritt, J Dave, D Eschelman, C Gonsalves
PURPOSE: To investigate the effects of image receptor technology and dose reduction software on radiation dose estimates for most frequently performed fluoroscopically-guided interventional (FGI) procedures at a tertiary health care center. METHODS: IRB approval was obtained for retrospective analysis of FGI procedures performed in the interventional radiology suites between January-2011 and December-2015. This included procedures performed using image-intensifier (II) based systems which were subsequently replaced, flat-panel-detector (FPD) based systems which were later upgraded with ClarityIQ dose reduction software (Philips Healthcare) and relatively new FPD system already equipped with ClarityIQ...
June 2016: Medical Physics
https://www.readbyqxmd.com/read/28046935/su-d-206-07-cbct-scatter-correction-based-on-rotating-collimator
#7
G Yu, Y Yin, L Qiang, B Li, Z Feng, P Huang, D Li
PURPOSE: Scatter correction in cone-beam computed tomography (CBCT) has obvious effect on the removal of image noise, the cup artifact and the increase of image contrast. Several methods using a beam blocker for the estimation and subtraction of scatter have been proposed. However, the inconvenience of mechanics and propensity to residual artifacts limited the further evolution of basic and clinical research. Here, we propose a rotating collimator-based approach, in conjunction with reconstruction based on a discrete Radon transform and Tchebichef moments algorithm, to correct scatter-induced artifacts...
June 2016: Medical Physics
https://www.readbyqxmd.com/read/28046922/we-fg-207b-08-dual-energy-ct-iodine-accuracy-across-vendors-and-platforms
#8
M Jacobsen, C Wood, D Cody
PURPOSE: Although a major benefit of dual-energy CT is its quantitative capabilities, it is critical to understand how results vary by scanner manufacturer and/or model before making clinical patient management decisions. Each manufacturer utilizes a specific dual-energy CT approach; cross-calibration may be required for facilities with more than one dual-energy CT scanner type. METHODS: A solid dual-energy quality control phantom (Gammex, Inc.; Appleton, WI) representing a large body cross-section containing three Iodine inserts (2mg/ml, 5mg/ml, 15 mg/ml) was scanned on these CT systems: GE HD-750 (80/140kVp), prototype GE Revolution CT with GSI (80/140kVp), Siemens Flash (80/140kVp and 100/140kVp), and Philips IQon (120kVp and 140kVp)...
June 2016: Medical Physics
https://www.readbyqxmd.com/read/28046892/su-g-brc-17-using-generalized-mean-for-equivalent-square-estimation
#9
S Zhou, Q Wu, Q Fan, Y Lei, S Li, X Li, R Ma, S Wang, X Wang, D Zheng, X Zhu, C Enke
PURPOSE: Equivalent Square (ES) is a widely used concept in radiotherapy. It enables us to determine many important quantities for a rectangular treatment field, without measurement, based on the corresponding values from its ES field. In this study, we propose a Generalized Mean (GM) type ES formula and compare it with other established formulae using benchmark datasets. METHODS: Our GM approach is expressed as ES=(w•fx^α+(1-w)•fy^α)^(1/α), where fx, fy, α, and w represent field sizes, power index, and a weighting factor, respectively...
June 2016: Medical Physics
https://www.readbyqxmd.com/read/28046678/su-f-t-147-an-alternative-parameterization-of-scatter-behavior-allows-significant-reduction-of-beam-characterization-for-pencil-beam-proton-therapy
#10
F Van den Heuvel, F Fiorini, B George
PURPOSE: 1) To describe the characteristics of pencil beam proton dose deposition kernels in a homogenous medium using a novel parameterization. 2) To propose a method utilizing this novel parametrization to reduce the measurements and pre-computation required in commissioning a pencil beam proton therapy system. METHODS: Using beam data from a clinical, pencil beam proton therapy center, Monte Carlo simulations were performed to characterize the dose depositions at a range of energies from 100...
June 2016: Medical Physics
https://www.readbyqxmd.com/read/28046549/tu-fg-brb-10-a-new-approach-to-proton-radiography-using-the-beamline-x-ray-flat-panel
#11
R Zhang, K Jee, G Sharp, J Flanz, H Lu
PURPOSE: Proton radiography, which images the patients with the same type of particles that they are to be treated with, is a promising approach for image guidance and range uncertainties reduction. This study aimed to realize quality proton radiography by measuring dose rate functions (DRF) in time domain using a single flat panel and retrieve water equivalent path length (WEPL) from them. METHODS: An amorphous silicon flat panel (PaxScan™ 4030CB, Varian Medical Systems, Inc...
June 2016: Medical Physics
https://www.readbyqxmd.com/read/27925849/development-and-prospective-federal-state-wide-evaluation-of-a-device-for-height-based-dose-recommendations-in-prehospital-pediatric-emergencies-a-simple-tool-to-prevent-most-severe-drug-errors
#12
Jost Kaufmann, Bernhard Roth, Thomas Engelhardt, Alex Lechleuthner, Michael Laschat, Christoph Hadamitzky, Frank Wappler, Martin Hellmich
OBJECTIVE: Drug dosing errors pose a particular threat to children in prehospital emergency care. With the Pediatric emergency ruler (PaedER), we developed a simple height-based dose recommendation system and evaluated its effectiveness in a pre-post interventional trial as the Ethics Committee disapproved randomization due to the expected positive effect of the PaedER on outcome. METHODS: Pre-interventional data were retrospectively retrieved from the electronic records and medical protocols of the Cologne Emergency Medical Service over a two-year period prior to the introduction of the PaedER...
December 7, 2016: Prehospital Emergency Care
https://www.readbyqxmd.com/read/27908164/comparison-of-low-contrast-detectability-between-two-ct-reconstruction-algorithms-using-voxel-based-3d-printed-textured-phantoms
#13
Justin Solomon, Alexandre Ba, François Bochud, Ehsan Samei
PURPOSE: To use novel voxel-based 3D printed textured phantoms in order to compare low-contrast detectability between two reconstruction algorithms, FBP (filtered-backprojection) and SAFIRE (sinogram affirmed iterative reconstruction) and determine what impact background texture (i.e., anatomical noise) has on estimating the dose reduction potential of SAFIRE. METHODS: Liver volumes were segmented from 23 abdominal CT cases. The volumes were characterized in terms of texture features from gray-level co-occurrence and run-length matrices...
December 2016: Medical Physics
https://www.readbyqxmd.com/read/27888168/estimating-the-duration-of-public-concern-after-the-fukushima-dai-ichi-nuclear-power-station-accident-from-the-occurrence-of-radiation-exposure-related-terms-on-twitter-a-retrospective-data-analysis
#14
Naoki Nishimoto, Mizuki Ota, Ayako Yagahara, Katsuhiko Ogasawara
BACKGROUND: After the Fukushima Dai-ichi Nuclear Power Station accident in Japan on March 11, 2011, a large number of comments, both positive and negative, were posted on social media. OBJECTIVE: The objective of this study was to clarify the characteristics of the trend in the number of tweets posted on Twitter, and to estimate how long public concern regarding the accident continued. We surveyed the attenuation period of the first term occurrence related to radiation exposure as a surrogate endpoint for the duration of concern...
November 25, 2016: JMIR Public Health and Surveillance
https://www.readbyqxmd.com/read/27867176/impact-of-pelvic-rotational-setup-error-on-lymph-nodal-dose-in-whole-pelvic-imrt-using-fiducial-markers
#15
Hiroki Katayama, Masaomi Ookubo, Masato Tsuzuki, Yasuhiro Sasakawa, Shigeo Takahashi, Toru Shibata
PURPOSE: The aim of this study was to investigate the impact of pelvic rotational setup error on lymph nodal dose in the whole pelvic intensity-modulated radiation therapy using the fiducial marker. METHODS: The dose differences of clinical target volume for pelvic lymph node (CTVLN) due to isocenter (IC) shift and pelvic rotation were evaluated using the radiation treatment planning system. The rotated computed tomography (CT) images were created for the simulation of the pelvic rotation...
2016: Nihon Hoshasen Gijutsu Gakkai Zasshi
https://www.readbyqxmd.com/read/27819251/reconstruction-of-high-resolution-mlc-leaf-positions-using-a-low-resolution-detector-for-accurate-3d-dose-reconstruction-in-imrt
#16
R Visser, J Godart, D J L Wauben, J A Langendijk, A A Van't Veld, E W Korevaar
In pre-treatment dose verification, low resolution detector systems are unable to identify shifts of individual leafs of high resolution multi leaf collimator (MLC) systems from detected changes in the dose deposition. The goal of this study was to introduce an alternative approach (the shutter technique) combined with a previous described iterative reconstruction method to accurately reconstruct high resolution MLC leaf positions based on low resolution measurements. For the shutter technique, two additional radiotherapy treatment plans (RT-plans) were generated in addition to the original RT-plan; one with even MLC leafs closed for reconstructing uneven leaf positions and one with uneven MLC leafs closed for reconstructing even leaf positions...
December 7, 2016: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/27810995/a-mobile-computerized-decision-support-system-to-prevent-hypoglycemia-in-hospitalized-patients-with-type-2-diabetes-mellitus-lessons-learned-from-a-clinical-feasibility-study
#17
Stephan Spat, Klaus Donsa, Peter Beck, Bernhard Höll, Julia K Mader, Lukas Schaupp, Thomas Augustin, Franco Chiarugi, Katharina M Lichtenegger, Johannes Plank, Thomas R Pieber
BACKGROUND: Diabetes management requires complex and interdisciplinary cooperation of health care professionals (HCPs). To support this complex process, IT-support is recommended by clinical guidelines. The aim of this article is to report on results from a clinical feasibility study testing the prototype of a mobile, tablet-based client-server system for computerized decision and workflow support (GlucoTab®) and to discuss its impact on hypoglycemia prevention. METHODS: The system was tested in a monocentric, open, noncontrolled intervention study in 30 patients with type 2 diabetes mellitus (T2DM)...
November 2, 2016: Journal of Diabetes Science and Technology
https://www.readbyqxmd.com/read/27806581/analytically-based-photon-scatter-modeling-for-a-multipinhole-cardiac-spect-camera
#18
Amir Pourmoghaddas, R Glenn Wells
PURPOSE: Dedicated cardiac SPECT scanners have improved performance over standard gamma cameras allowing reductions in acquisition times and/or injected activity. One approach to improving performance has been to use pinhole collimators, but this can cause position-dependent variations in attenuation, sensitivity, and spatial resolution. CT attenuation correction (AC) and an accurate system model can compensate for many of these effects; however, scatter correction (SC) remains an outstanding issue...
November 2016: Medical Physics
https://www.readbyqxmd.com/read/27782689/online-4d-ultrasound-guidance-for-real-time-motion-compensation-by-mlc-tracking
#19
Svenja Ipsen, Ralf Bruder, Rick O'Brien, Paul J Keall, Achim Schweikard, Per R Poulsen
PURPOSE: With the trend in radiotherapy moving toward dose escalation and hypofractionation, the need for highly accurate targeting increases. While MLC tracking is already being successfully used for motion compensation of moving targets in the prostate, current real-time target localization methods rely on repeated x-ray imaging and implanted fiducial markers or electromagnetic transponders rather than direct target visualization. In contrast, ultrasound imaging can yield volumetric data in real-time (3D + time = 4D) without ionizing radiation...
October 2016: Medical Physics
https://www.readbyqxmd.com/read/27727279/regulatory-t-cell-responses-in-participants-with-type-1-diabetes-after-a-single-dose-of-interleukin-2-a-non-randomised-open-label-adaptive-dose-finding-trial
#20
John A Todd, Marina Evangelou, Antony J Cutler, Marcin L Pekalski, Neil M Walker, Helen E Stevens, Linsey Porter, Deborah J Smyth, Daniel B Rainbow, Ricardo C Ferreira, Laura Esposito, Kara M D Hunter, Kevin Loudon, Kathryn Irons, Jennie H Yang, Charles J M Bell, Helen Schuilenburg, James Heywood, Ben Challis, Sankalpa Neupane, Pamela Clarke, Gillian Coleman, Sarah Dawson, Donna Goymer, Katerina Anselmiova, Jane Kennet, Judy Brown, Sarah L Caddy, Jia Lu, Jane Greatorex, Ian Goodfellow, Chris Wallace, Tim I Tree, Mark Evans, Adrian P Mander, Simon Bond, Linda S Wicker, Frank Waldron-Lynch
BACKGROUND: Interleukin-2 (IL-2) has an essential role in the expansion and function of CD4+ regulatory T cells (Tregs). Tregs reduce tissue damage by limiting the immune response following infection and regulate autoreactive CD4+ effector T cells (Teffs) to prevent autoimmune diseases, such as type 1 diabetes (T1D). Genetic susceptibility to T1D causes alterations in the IL-2 pathway, a finding that supports Tregs as a cellular therapeutic target. Aldesleukin (Proleukin; recombinant human IL-2), which is administered at high doses to activate the immune system in cancer immunotherapy, is now being repositioned to treat inflammatory and autoimmune disorders at lower doses by targeting Tregs...
October 2016: PLoS Medicine
keyword
keyword
11538
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"