keyword
MENU ▼
Read by QxMD icon Read
search

Varian

keyword
https://www.readbyqxmd.com/read/29691387/fetal-demise-and-failed-antibody-therapy-during-zika-virus-infection-of-pregnant-macaques
#1
Diogo M Magnani, Thomas F Rogers, Nicholas J Maness, Nathan D Grubaugh, Nathan Beutler, Varian K Bailey, Lucas Gonzalez-Nieto, Martin J Gutman, Núria Pedreño-Lopez, Jaclyn M Kwal, Michael J Ricciardi, Tereance A Myers, Justin G Julander, Rudolf P Bohm, Margaret H Gilbert, Faith Schiro, Pyone P Aye, Robert V Blair, Mauricio A Martins, Kathrine P Falkenstein, Amitinder Kaur, Christine L Curry, Esper G Kallas, Ronald C Desrosiers, Pascal J Goldschmidt-Clermont, Stephen S Whitehead, Kristian G Andersen, Myrna C Bonaldo, Andrew A Lackner, Antonito T Panganiban, Dennis R Burton, David I Watkins
Zika virus (ZIKV) infection of pregnant women is associated with pathologic complications of fetal development. Here, we infect pregnant rhesus macaques (Macaca mulatta) with a minimally passaged ZIKV isolate from Rio de Janeiro, where a high rate of fetal development complications was observed. The infection of pregnant macaques with this virus results in maternal viremia, virus crossing into the amniotic fluid (AF), and in utero fetal deaths. We also treated three additional ZIKV-infected pregnant macaques with a cocktail of ZIKV-neutralizing human monoclonal antibodies (nmAbs) at peak viremia...
April 24, 2018: Nature Communications
https://www.readbyqxmd.com/read/29667933/a-cbct-study-of-the-gravity-induced-movement-in-rotating-rabbits
#2
Jeffrey Barber, Chun-Chien Shieh, William Counter, Jonathan R Sykes, Peter Bennett, Verity Ahern, Stéphanie Corde, Soo-Min Heng, Paul White, Michael Jackson, Paul Liu, Paul J Keall, Ilana Feain
Fixed-beam radiotherapy systems with subjects rotating about a longitudinal (horizontal) axis are subject to gravity-induced motion. Limited reports on the degree of this motion, and any deformation, has been reported previously. The purpose of this study is to quantify the degree of anatomical motion caused by rotating a subject around a longitudinal axis, using cone-beam CT (CBCT). 
 
 In the current study, a purpose-made longitudinal rotating was aligned to a Varian TrueBeam kV imaging system...
April 18, 2018: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/29619962/a-prospective-4%C3%AF-radiation-therapy-clinical-study-in-recurrent-high-grade-glioma-patients
#3
Victoria Y Yu, Angelia Landers, Kaley Woods, Dan Nguyen, Minsong Cao, Dongsu Du, Robert K Chin, Ke Sheng, Tania B Kaprealian
PURPOSE: To evaluate the feasibility, safety, dosimetric benefits, delivery efficiency, and patient comfort in the clinical implementation of 4π radiation therapy. METHODS AND MATERIALS: Eleven patients with recurrent high-grade glioma were recruited for the trial. 4π plans integrating beam orientation and fluence-map optimization were created using an in-house column-generation algorithm. The collision-free beam solution space throughout the 4π steradian was determined using a computer-aided-design model of the Varian TrueBeam system and a human subject...
May 1, 2018: International Journal of Radiation Oncology, Biology, Physics
https://www.readbyqxmd.com/read/29618564/postnatal-zika-virus-infection-is-associated-with-persistent-abnormalities-in-brain-structure-function-and-behavior-in-infant-macaques
#4
Maud Mavigner, Jessica Raper, Zsofia Kovacs-Balint, Sanjeev Gumber, Justin T O'Neal, Siddhartha K Bhaumik, Xiaodong Zhang, Jakob Habib, Cameron Mattingly, Circe E McDonald, Victoria Avanzato, Mark W Burke, Diogo M Magnani, Varian K Bailey, David I Watkins, Thomas H Vanderford, Damien Fair, Eric Earl, Eric Feczko, Martin Styner, Sherrie M Jean, Joyce K Cohen, Guido Silvestri, R Paul Johnson, David H O'Connor, Jens Wrammert, Mehul S Suthar, Mar M Sanchez, Maria C Alvarado, Ann Chahroudi
The Zika virus (ZIKV) epidemic is associated with fetal brain lesions and other serious birth defects classified as congenital ZIKV syndrome. Postnatal ZIKV infection in infants and children has been reported; however, data on brain anatomy, function, and behavioral outcomes following infection are absent. We show that postnatal ZIKV infection of infant rhesus macaques (RMs) results in persistent structural and functional alterations of the central nervous system compared to age-matched controls. We demonstrate ZIKV lymphoid tropism and neurotropism in infant RMs and histopathologic abnormalities in the peripheral and central nervous systems including inflammatory infiltrates, astrogliosis, and Wallerian degeneration...
April 4, 2018: Science Translational Medicine
https://www.readbyqxmd.com/read/29609845/evolution-of-brachytherapy-treatment-planning-to-deterministic-radiation-transport-for-calculation-of-cardiac-dose
#5
REVIEW
Peter A Sandwall, Yuntao Feng, Michael Platt, Michael Lamba, Sudha Mahalingam
Brachytherapy was among the first methods of radiotherapy and has steadily continued to evolve. Here we present a brief review of the progression of dose calculation methods in brachytherapy to the current state-of-the art computerized methods for heterogeneity correction. We further review the origin and development of the BrachyVision (Varian Medical Systems, Inc., Palo Alto, CA) treatment planning system and evaluate dosimetric results from 12 patients implanted with the strut-assisted volumetric implant (SAVI) applicator (Cianna Medical, Aliso Viejo, CA) for accelerated partial breast irradiation (APBI)...
March 30, 2018: Medical Dosimetry: Official Journal of the American Association of Medical Dosimetrists
https://www.readbyqxmd.com/read/29609815/monte-carlo-uncertainty-analysis-of-dose-estimates-in-radiochromic-film-dosimetry-with-single-channel-and-multichannel-algorithms
#6
Juan Antonio Vera-Sánchez, Carmen Ruiz-Morales, Antonio González-López
PURPOSE: To provide a multi-stage model to calculate uncertainty in radiochromic film dosimetry with Monte-Carlo techniques. This new approach is applied to single-channel and multichannel algorithms. MATERIAL AND METHODS: Two lots of Gafchromic EBT3 are exposed in two different Varian linacs. They are read with an EPSON V800 flatbed scanner. The Monte-Carlo techniques in uncertainty analysis provide a numerical representation of the probability density functions of the output magnitudes...
March 2018: Physica Medica: PM
https://www.readbyqxmd.com/read/29609812/correlation-between-gamma-passing-rate-and-complexity-of-imrt-plan-due-to-mlc-position-errors
#7
Yewei Wang, Xueying Pang, Lina Feng, Helong Wang, Yanling Bai
PURPOSE: This study evaluates the correlation between the susceptibility of the γ passing rate of IMRT plans to the multi-leaf collimator (MLC) position errors and a quantitative plan complexity metric. METHODS: Twenty patients were selected for this study. For each patient, two IMRT plans were generated using sliding window and step-&-shoot techniques, respectively. Modulation complexity score (MCS) was calculated for all IMRT plans, and symmetric MLC leaf bank errors, ranging from 0...
March 2018: Physica Medica: PM
https://www.readbyqxmd.com/read/29607624/burden-and-consequences-of-retained-cardiovascular-implantable-electronic-device-lead-fragments-after-heart-transplantation
#8
Paulino A Alvarez, Brett W Sperry, Antonio L Perez, Kenneth Varian, Timothy Raymond, Michael Tong, Ayman A Hussein, David O Taylor
We performed a retrospective review of 402 consecutive patients who underwent heart transplantation at our institution between January 2009 and March 2017. A retained cardiovascular implantable electronic device (CIED) fragment was identified after transplantation in 49 of the 301 patients (16.2%) with CIED at baseline. Patients with retained fragments had leads with longer dwell times (median 2596 [1982, 3389] vs 1384 [610, 2202] days, p<0.001), higher prevalence of previously abandoned leads (14.3% vs 2...
April 1, 2018: American Journal of Transplantation
https://www.readbyqxmd.com/read/29603100/relationship-of-dietary-and-serum-zinc-with-depression-score-in-iranian-adolescent-girls
#9
Kayhan Gonoodi, Alireza Moslem, Mahsa Ahmadnezhad, Susan Darroudi, Zahra Mazloum, Maryam Tayefi, Seyed Amir Tabatabaeizadeh, Saeid Eslami, Mojtaba Shafiee, Zahra Khashayarmanesh, Hamideh Moalemzadeh Haghighi, Gordon A Ferns, Majid Ghayour-Mobarhan
Zinc deficiency, which is common among Iranian populations, is believed to play a crucial role in the onset and progression of mood disorders such as depression in different stages of life. We have therefore investigated the relationship between serum/dietary zinc status and depression scores among adolescent girls living in northeastern Iran. Serum zinc was measured by flame atomic absorption (Varian AA240FS) and the mean zinc intake was assessed using 3-day food record. A validated Persian version of the Beck Depression Inventory (BDI) was used to determine the severity of depressive symptoms for all subjects...
March 30, 2018: Biological Trace Element Research
https://www.readbyqxmd.com/read/29594230/local-control-and-overall-survival-after-frameless-radiosurgery-a-single-center-experience
#10
Angelika Bilger, Florian Frenzel, Oliver Oehlke, Rolf Wiehle, Dusan Milanovic, Vesna Prokic, Carsten Nieder, Anca-Ligia Grosu
Introduction: Stereotactic radiosurgery (SRS) has been increasingly advocated for 1-3 small brain metastases. The goal of this study was to evaluate the clinical results in patients with brain metastases treated with LINAC-based SRS using a thermoplastic mask (non-invasive fixation system) and Image-Guided Radiotherapy (IGRT). Material and Methods: In this single-institution study 48 patients with 77 brain metastases were treated between February 2012 and January 2014...
December 2017: Clinical and Translational Radiation Oncology
https://www.readbyqxmd.com/read/29577603/comparative-analysis-of-respiratory-motion-tracking-using-microsoft-kinect-v2-sensor
#11
Evan Silverstein, Michael Snyder
PURPOSE: To present and evaluate a straightforward implementation of a marker-less, respiratory motion-tracking process utilizing Kinect v2 camera as a gating tool during 4DCT or during radiotherapy treatments. METHODS: Utilizing the depth sensor on the Kinect as well as author written C# code, respiratory motion of a subject was tracked by recording depth values obtained at user selected points on the subject, with each point representing one pixel on the depth image...
March 25, 2018: Journal of Applied Clinical Medical Physics
https://www.readbyqxmd.com/read/29577578/quantification-of-beam-steering-with-an-ionization-chamber-array
#12
Song Gao, Peter A Balter, Benjamin Tran, Mark Rose, William E Simon
Routine quality assurance for linear accelerators (linacs) usually involves verification of beam steering with a water scanning system. We established a beam steering procedure that uses a 2D ionization chamber array (ICA) and verified the equivalence of beam symmetry between the ICA and a water scanning system. The ICA calibration accuracy, reproducibility and stability were evaluated and the uncertainty in the measurement of beam symmetry due to the array calibration was examined. Forty-five photon beams and 80 electron beams across 7 Varian C-series and 4 TrueBeam linacs were steered in the radial and transverse directions using an ICA...
March 25, 2018: Journal of Applied Clinical Medical Physics
https://www.readbyqxmd.com/read/29556140/assessment-of-the-monitor-unit-objective-tool-for-vmat-in-the-eclipse-treatment-planning-system
#13
Sara Jiménez-Puertas, David Sánchez-Artuñedo, Marcelino Hermida-López
Aim: This work aims to achieve the highest possible monitor units (MU) reduction using the MU Objective tool included in the Eclipse treatment planning system, while preserving the plan quality. Background: The treatment planning system Eclipse (Varian Medical Systems, Palo Alto, CA) includes a control mechanism for the number of monitor units of volumetric modulated arc therapy (VMAT) plans, named the MU Objective tool. Material and methods: Forty prostate plans, 20 gynecological plans and 20 head and neck plans designed with VMAT were retrospectively studied...
March 2018: Reports of Practical Oncology and Radiotherapy
https://www.readbyqxmd.com/read/29553478/validation-of-a-virtual-source-model-of-medical-linac-for-monte-carlo-dose-calculation-using-multi-threaded-geant4
#14
Zakaria Aboulbanine, Naïma El Khayati
The use of phase space in medical linear accelerator Monte Carlo (MC) simulations significantly improves the execution time and leads to results comparable to those obtained from full calculations. The classical representation of phase space stores directly the information of millions of particles, producing bulky files. This paper presents a virtual source model (VSM) based on a reconstruction algorithm, taking as input a compressed file of roughly 800 kb derived from phase space data freely available in the International Atomic Energy Agency (IAEA) database...
March 19, 2018: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/29542016/effect-of-region-extraction-and-assigned-mass-density-values-on-the-accuracy-of-dose-calculation-with-magnetic-resonance-based-volumetric-arc-therapy-planning
#15
Keisuke Usui, Keisuke Sasai, Koichi Ogawa
This study aimed to verify the validity of generating treatment plans for volumetric arc therapy (VMAT) for prostate cancer using magnetic resonance (MR) imaging with a dose calculation algorithm in Acuros XB (Eclipse version 13.6; Varian Medical Systems, Palo Alto, CA, USA) based on deterministically solving the linear Boltzmann transport equations. Four different classes were applied to prostate MR images: MRW (all water equivalent); MRW+B (water and bone); MRS+B (soft tissue and bone); and MRS+B+G (soft tissue, bone, and rectal gas)...
March 14, 2018: Radiological Physics and Technology
https://www.readbyqxmd.com/read/29520733/dosimetric-analysis-of-unflattened-fffb-and-flattened-fb-photon-beam-energy-for-gastric-cancers-using-imrt-and-vmat-a-comparative-study
#16
Manindra Bhushan, Girigesh Yadav, Deepak Tripathi, Lalit Kumar, Vimal Kishore, Abhinav Dewan, Gourav Kumar, Inderjit Kaur Wahi, Munish Gairola
PURPOSE: To evaluate the feasibility of flattening filter free beam (FFFB) for the treatment of gastric tumors and to review their benefits over 6MV flatten beam (6MV_FFB). METHODS: Fifteen patients with histologically proven gastric carcinoma were selected. CT scans with slice thickness of 0.3 cm were acquired and planning target volume (PTV) and organ at risk (OAR) were delineated. Plans were made retrospectively for each patient for the prescription dose of 45 Gy/25 fractions to the PTV...
March 8, 2018: Journal of Gastrointestinal Cancer
https://www.readbyqxmd.com/read/29519413/a-collapsed-cone-based-transit-epid-dosimetry-method
#17
Jaime Martínez Ortega, María Pinto Monedero, Nuria Gómez González, Naresh B Tolani, Pablo Castro Tejero, Miguel Castanedo Álvarez, Luis Núñez Martín, R Sánchez Montero
PURPOSE: To develop a transit-dose portal dosimetry method based on a commercial collapsed-cone algorithm. METHODS: A Varian Clinac21EX (Varian Medical Systems, USA), equipped with an amorphous-silicon EPID aS1000, was used. Dose calculations were performed with the collapsed-cone algorithm of Pinnacle3 v8.0 m (Philips Medical Systems, USA). A model for the energy of 6 MV was made in Pinnacle3 and afterwards validated for clinical use. A virtual phantom with different densities was contoured and superimposed on the patient images, simulating the presence of the EPID during the treatment...
February 2018: Physica Medica: PM
https://www.readbyqxmd.com/read/29519412/a-constrained-linear-regression-optimization-algorithm-for-diaphragm-motion-tracking-with-cone-beam-ct-projections
#18
Jie Wei, Ming Chao
PURPOSE: We presented a feasibility study to extract the diaphragm motion from the inferior contrast cone beam computed tomography (CBCT) projection images using a constrained linear regression optimization algorithm. METHODS: The shape of the diaphragm was fitted by a parabolic function which was initialized by five manually placed points on the diaphragm contour of a pre-selected projection. A constrained linear regression model by exploiting the spatial, algebraic, and temporal constraints of the diaphragm, approximated by a parabola, was employed to estimate the parameters...
February 2018: Physica Medica: PM
https://www.readbyqxmd.com/read/29509970/acuros-cts-a-fast-linear-boltzmann-transport-equation-solver-for-computed-tomography-scatter-part-i-core-algorithms-and-validation
#19
Alexander Maslowski, Adam Wang, Mingshan Sun, Todd Wareing, Ian Davis, Josh Star-Lack
PURPOSE: To describe Acuros® CTS, a new software tool for rapidly and accurately estimating scatter in x-ray projection images by deterministically solving the linear Boltzmann transport equation (LBTE). METHODS: The LBTE describes the behavior of particles as they interact with an object across spatial, energy, and directional (propagation) domains. Acuros CTS deterministically solves the LBTE by modeling photon transport associated with an x-ray projection in three main steps: 1) Ray tracing photons from the x-ray source into the object where they experience their first scattering event and form scattering sources...
March 6, 2018: Medical Physics
https://www.readbyqxmd.com/read/29507849/exceptional-eight-year-response-to-stereotactic-radiosurgery-monotherapy-for-multiple-brain-metastases
#20
Ronny Kalash, Phillip M Pifer, Sushil Beriwal, Scott M Glaser, John A Vargo, Dwight E Heron
Breast cancer represents the second leading cause of brain metastases in women. Once diagnosed, brain metastases have been associated with a rapidly progressive and universally poor prognosis. Breast cancer patients, particularly those with advantageous disease characteristics, may achieve extended survival. This extended life expectancy highlights the importance of effective intracranial treatments that minimize treatment-related late toxicity. Whole brain radiation therapy (WBRT) remains a standard of care palliative option; however, concerns remain regarding the late neurocognitive effects...
December 29, 2017: Curēus
keyword
keyword
47924
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"