keyword
MENU ▼
Read by QxMD icon Read
search

Sabr

keyword
https://www.readbyqxmd.com/read/28073251/interfaces-select-specific-stereochemical-conformations-the-isomerization-of-glyoxal-at-the-liquid-water-interface
#1
Chongqin Zhu, Sabre Kais, Xiao Cheng Zeng, Joseph S Francisco, Ivan Gladich
Interfacial chemistry involving glyoxal at aerosol surfaces is postulated to catalyze aerosol growth. This chemistry remains speculative due to a lack of detailed information concerning the physicochemical behavior of glyoxal at the interface of atmospheric aerosols. Here, we report results from high-level electronic structure calculations as well as both classical and Born-Oppenheimer ab initio molecular dynamics simulations of glyoxal solvation at the air/liquid water interface. When compared to the gas phase, the trans to cis isomerization of glyoxal at the liquid water interface is found to be catalyzed; additionally, the trans conformation is selectively solvated within the bulk to a greater degree than is the cis conformation...
January 11, 2017: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/28058710/stereotactic-ablative-radiotherapy-for-patients-with-unresectable-or-medically-inoperable-cholangiocarcinoma
#2
Ming-Yueh Liu, Cheng-Hsiang Lo, Chun-Shu Lin, Hsing-Lung Chao, Jen-Fu Yang, Kuen-Tze Lin, Chao-Yueh Fan, Yu-Fu Su, Wen-Yen Huang
PURPOSE: The role of stereotactic ablative radiotherapy (SABR) in patients with unresectable or medically inoperable cholangiocarcinoma remains unclear. We examined the efficacy and safety of SABR in this group of patients. METHODS: From January 2008 to December 2014, 15 patients with 17 lesions were included in this study. The lesions included 14 intrahepatic, 1 hilar, and 2 distal bile duct tumors. Three patients were classified as medically inoperable because of old age or multiple comorbidities...
January 5, 2017: Tumori
https://www.readbyqxmd.com/read/28055252/the-role-of-technology-in-clinical-trials-using-stereotactic-body-radiotherapy
#3
Marianne Camille Aznar, Alejandra Méndez Romero, Ben Jm Heijmen
Stereotactic body radiotherapy is a highly technology-driven treatment modality. The wider availability of in-room imaging and advanced radiotherapy delivery techniques has led to more and more institutions offering SABR. While some technological challenges remain, the crucial point for the next generation of SABR clinical trials is that today's technology is used correctly and close to its optimal potential for accuracy. The credentialing procedure of SABR needs to be extensive, but this investment will benefit the trial itself, the patients, and the professionals involved...
January 5, 2017: British Journal of Radiology
https://www.readbyqxmd.com/read/28048892/su-f-j-116-clinical-experience-based-verification-and-improvement-of-a-4dct-program
#4
P Fogg, M West, T Aland
PURPOSE: To demonstrate the role of continuous improvement fulfilled by the Medical Physicist in clinical 4DCT and CBCT scanning. METHODS: Lung (SABR and Standard) patients' 4D respiratory motion and image data were reviewed over a 3, 6 and 12 month period following commissioning testing. By identifying trends of clinically relevant parameters and respiratory motions, variables were tested with a programmable motion phantom and assessed. Patient traces were imported to a motion phantom and 4DCT and CBCT imaging were performed...
June 2016: Medical Physics
https://www.readbyqxmd.com/read/28048861/su-g-jep1-09-evaluation-of-transperineal-ultrasound-imaging-as-a-potential-solution-for-target-tracking-during-ablative-body-radiotherapy-for-prostate-cancer
#5
M Najafi, B Han, D Cooper, S Hancock, D Hristov
PURPOSE: Prostate SABR is emerging as a clinically viable, potentially cost effective alternative to prostate IMRT but its adoption is contingent on providing solutions for accurate tracking during beam delivery. Our goal is to evaluate the performance of the Clarity Autoscan ultrasound monitoring system for inter-fractional prostate motion tracking in both phantoms and in-vivo. METHODS: In-vivo evaluation was performed under IRB protocol to allow data collection in prostate patients treated with VMAT whereby prostate was imaged through the acoustic window of the perineum...
June 2016: Medical Physics
https://www.readbyqxmd.com/read/28048770/su-g-jep1-05-clinical-impact-of-mlc-tracking-for-lung-sabr
#6
V Caillet, E Colvill, K Szymura, M Stevens, J Booth, P Keall
PURPOSE: The objective of this study was to investigate the dosimetric benefits of multi-leaf collimator (MLC) tracking for lung SABR treatments in end-to-end clinically realistic planning and delivery scenarios. METHODS: The clinical benefits of MLC tracking were assessed using previously delivered treatment plans and physical experiments. The 10 most recent single lesion lung SABR patients were re-planned following a 4D-GTV-based real-time adaptive protocol (PTV defined as the end-of-exhalation GTV plus 5...
June 2016: Medical Physics
https://www.readbyqxmd.com/read/28048479/we-ab-207b-01-dose-tolerance-for-sbrt-sabr
#7
J Grimm
PURPOSE: Stereotactic body radiation therapy (SBRT) / stereotactic ablative body radiotherapy (SABR) is gaining popularity, but quantitative dose tolerance has still been lacking. To improve this, the April 2016 issue of Seminars in Radiation Oncology will have normal tissue complication probability (NTCP) models for 10 critical structures: optic pathway, cochlea, oral mucosa, esophagus, chestwall, aorta, bronchi, duodenum, small bowel, and spinal cord. METHODS: The project included more than 1500 treatments in 1-5 fractions using CyberKnife, Gamma Knife, or LINAC, with 60 authors from 15 institutions...
June 2016: Medical Physics
https://www.readbyqxmd.com/read/28048369/su-f-t-558-arccheck-for-patient-specific-qa-in-stereotactic-ablativeradiotherapy
#8
P Ramachandran, A Tajaldeen, D Taylor, D Wanigaratne, K Roozen, N Esen, M Geso, T Kron
PURPOSE: Stereotactic Ablative Radiotherapy (SABR) is one of the most preferred treatment techniques for early stage lung cancer. This technique has been extended to other treatment sites like Spine, Liver, Scapula, Sternum etc., This has resulted in increased physics QA time on machine. In this study, we've tested the feasibility of using ArcCheck as an alternative method to replace film dosimetry. METHODS: Twelve patients with varied diagnosis of Lung, Liver, scapula, sternum and Spine undergoing SABR were selected for this study...
June 2016: Medical Physics
https://www.readbyqxmd.com/read/28048277/mo-fg-bra-06-electromagnetic-beacon-insertion-in-lung-cancer-patients-and-resultant-surrogacy-errors-for-dynamic-mlc-tumour-tracking
#9
N Hardcastle, J Booth, V Caillet, R O'Brien, C Haddad, C Crasta, K Szymura, P Keall
PURPOSE: To assess endo-bronchial electromagnetic beacon insertion and to quantify the geometric accuracy of using beacons as a surrogate for tumour motion in real-time multileaf collimator (MLC) tracking of lung tumours. METHODS: The LIGHT SABR trial is a world-first clinical trial in which the MLC leaves move with lung tumours in real time on a standard linear accelerator. Tracking is performed based on implanted electromagnetic beacons (CalypsoTM, Varian Medical Systems, USA) as a surrogate for tumour motion...
June 2016: Medical Physics
https://www.readbyqxmd.com/read/28048221/su-f-t-617-remotely-pre-planned-stereotactic-ablative-radiation-therapy-validation-of-treatment-plan-quality
#10
T Juang, K Bush, B Loo, M Gensheimer
PURPOSE: We propose a workflow to improve access to stereotactic ablative radiation therapy (SABR) for rural patients. When implemented, a separate trip to the central facility for simulation can be eliminated. Two elements are required: (1) Fabrication of custom immobilization devices to match positioning on prior diagnostic CT (dxCT). (2) Remote radiation pre-planning on dxCT, with transfer of contours/plan to simulation CT (simCT) and initiation of treatment same-day or next day. In this retrospective study, we validated part 2 of the workflow using patients already treated with SABR for upper lobe lung tumors...
June 2016: Medical Physics
https://www.readbyqxmd.com/read/28047754/su-f-t-644-reproducibility-of-target-position-using-moderate-voluntary-breath-hold-during-liver-stereotactic-ablative-radiotherapy
#11
G Cui, N Trakul, E Chang, A Shiu
PURPOSE: To evaluate the reproducibility of target position using moderate voluntary breath-hold during liver stereotactic ablative radiotherapy (SABR). METHODS: Two patients who underwent liver SABR on a Varian TrueBeam STx linac were used for this study. Fiducial markers were placed in and around the target in the liver as surrogates for the target position and motion. GTVs were contoured by assessing tumor extent on contrast enhanced CT. The PTV was created from the GTV by adding 2 mm margins to account for the residual motion during breath-holds...
June 2016: Medical Physics
https://www.readbyqxmd.com/read/28047581/su-g-jep2-01-a-new-approach-for-mr-only-treatment-planning-tissue-segmentation-based-pseudo-ct-generation-using-t1-weighted-mri
#12
H Yu, Y Lee, B Chugh, C Tseng, M Campbell, K Leszczynski, A Sahgal
PURPOSE: To evaluate MR-only treatment planning for brain Stereotactic Ablative Radiotherapy (SABR) based on pseudo-CT (pCT) generation using one set of T1-weighted MRI. METHODS: T1-weighted MR and CT images from 12 patients who were eligible for brain SABR were retrospectively acquired for this study. MR-based pCT was generated by using a newly in-house developed algorithm based on MR tissue segmentation and voxel-based electron density (ED) assignment (pCTv). pCTs using bulk density assignment (pCTb where bone and soft tissue were assigned 800HU and 0HU,respectively), and water density assignment (pCTw where all tissues were assigned 0HU) were generated for comparison of ED assignment techniques...
June 2016: Medical Physics
https://www.readbyqxmd.com/read/28047237/tu-h-campus-tep1-01-variable-beam-fractionation-for-sabr
#13
A Modiri, A Sawant
PURPOSE: In current conventionally-fractionated as well as hypofractionated 3D conformal radiotherapy (CRT), the same beam arrangement is employed from fraction to fraction. We challenge this notion and postulate that by varying the beam arrangement between fractions we can achieve greater sparing of organs at risk (OARs) while maintaining PTV coverage. We use an inverse planning strategy using a swarm intelligence-based global optimization algorithm to exploit the additional degree of freedom represented by inter-fractional variation in beam angles...
June 2016: Medical Physics
https://www.readbyqxmd.com/read/28047101/we-ab-207b-10-on-spinal-nerve-toxicity-from-single-session-sabr-in-pigs-and-the-translation-of-small-animal-ntcp-models
#14
B Hrycushko, P Medin
PURPOSE: The incidence of peripheral neuropathy has risen with increased utilization of SAbR. There is no consensus regarding the dose-tolerance of the peripheral nervous system. In 2015, we commenced an investigation to test the hypotheses that single-session irradiation to the pig spinal nerves exhibit a similar dose-tolerance as that of the spinal cord and that a dose-length effect exists. This work evaluates the direct application of small animal NTCP models to both large animal spinal cord and preliminary peripheral nerve data...
June 2016: Medical Physics
https://www.readbyqxmd.com/read/28046985/su-f-t-567-sensitivity-and-reproducibility-of-the-portal-imaging-panel-for-routine-fff-qc-and-patient-plan-dose-measurements
#15
A Willett, M Gilmore, C Rowbottom
PURPOSE: The purpose of this work was to see if the EPID is a viable alternative to other QA devices for routine FFF QA and plan dose measurements. METHODS: Sensitivity measurements were made to assess response to small changes in field size and beam steering. QA plans were created where field size was varied from baseline values (5-5.5cm, 20-20.5cm). Beam steering was adjusted by altering values in service mode (Symmetry 0-3%). Plans were measured using the Varian portal imager (aS1200 DMI panel), QA3 (Sun Nuclear), and Starcheck Maxi (PTW)...
June 2016: Medical Physics
https://www.readbyqxmd.com/read/28046812/su-g-brb-07-developing-a-qa-procedure-for-gated-vmat-sabr-treatments-using-10-mv-beam-in-flattening-filter-free-mode
#16
S Chitsazzadeh, D Wells, A Mestrovic
PURPOSE: To develop a QA procedure for gated VMAT stereotactic ablative radiotherapy (SABR) treatments. METHODS: An interface was constructed to attach the translational stage of a Quasar respiratory motion phantom to a pinpoint ion chamber insert and move the ion chamber inside an ArcCheck diode array. The Quasar phantom controller used a patient specific breathing pattern to translate the ion chamber in a superior-inferior direction inside the ArcCheck. An amplitude-based RPM tracking system was specified to turn the beam on during the exhale phase of the breathing pattern...
June 2016: Medical Physics
https://www.readbyqxmd.com/read/28046651/mo-fg-bra-08-swarm-intelligence-based-personalized-respiratory-gating-in-lung-sabr
#17
A Modiri, P Sabouri, X Gu, R Timmerman, A Sawant
PURPOSE: Respiratory gating is widely deployed as a clinical motion-management strategy in lung radiotherapy. In conventional gating, the beam is turned on during a pre-determined phase window; typically, around end-exhalation. In this work, we challenge the notion that end-exhalation is always the optimal gating phase. Specifically, we use a swarm-intelligence-based, inverse planning approach to determine the optimal respiratory phase and MU for each beam with respect to (i) the state of the anatomy at each phase and (ii) the time spent in that state, estimated from long-term monitoring of the patient's breathing motion...
June 2016: Medical Physics
https://www.readbyqxmd.com/read/28046542/th-ab-bra-08-simulated-tumor-tracking-in-an-mri-linac-for-lung-tumor-lesions-using-the-monaco-treatment-planning-system
#18
S Al-Ward, A Kim, C McCann, M Ruschin, P Cheung, A Sahgal, B Keller
PURPOSE: To simulate tumor tracking in an Elekta MRI-linac (MRL) and to compare this tracking method with our current ITV approach in terms of OAR sparing for lung cancer patients. METHODS: Five SABR-NSCLC patients with central lung tumors were selected for reasons of potential enhancement of tumor-tissue delineation using MRI. The Monaco TPS was used to compare the current clinical ITV approach to a simulated, novel tracking method which used a 7MV MRL beam in the presence of an orthogonal 1...
June 2016: Medical Physics
https://www.readbyqxmd.com/read/28046501/su-f-t-451-doses-to-organs-at-risk-in-the-presence-and-absence-of-a-1-5-t-magnetic-field-for-nsclc-patients-undergoing-sabr
#19
S Al-Ward, A Kim, C McCann, M Ruschin, P Cheung, A Sahgal, B Keller
PURPOSE: To determine whether the electron return effect (ERE) has deleterious effects on lung SABR plans optimized in the presence of an orthogonal 1.5 T magnetic field. METHODS: Data from five NSCLC-SABR patients were used. The Dose was modeled with a 2.5 mm dose grid in the presence and absence of a magnetic field using the Monaco (Elekta) TPS with the Monte Carlo GPUMCD (v5.1) algorithm. For each patient, two plans were generated, one using our conventional Elekta Agility linac beam model and another using the Elekta MRI Linac (MRL) model...
June 2016: Medical Physics
https://www.readbyqxmd.com/read/28032895/analysis-of-components-of-variance-determining-probability-of-setup-errors-in-cbct-guided-stereotactic-radiotherapy-of-lung-tumors
#20
Johan P Cuijpers, Max Dahele, Marianne Jonker, Bianca Kraan, Suresh Senan, Ben Slotman, Wilko Far Verbakel
PURPOSE: On-line tumor matching for SABR lung setup requires margins for inaccuracies due to intra-fraction variability of breathing-averaged tumor position (BATP), and CBCT image guidance. We studied intra-fraction variability during SABR delivery using VMAT, corrected these for measurement inaccuracies and quantified the CBCT image-guidance uncertainties. MATERIALS AND METHODS: For 193 fractions in 38 patients positioned without immobilization devices, CBCT scans were acquired before and after 2 arcs of a RapidArc treatment...
December 29, 2016: Medical Physics
keyword
keyword
11415
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"