نتایج جستجو برای: dosimetric audit absolute photon dose linacs

تعداد نتایج: 491847  

Journal: :Medical physics 2005
S Vedam A Docef M Fix M Murphy P Keall

The synchronization of dynamic multileaf collimator (DMLC) response with respiratory motion is critical to ensure the accuracy of DMLC-based four dimensional (4D) radiation delivery. In practice, however, a finite time delay (response time) between the acquisition of tumor position and multileaf collimator response necessitates predictive models of respiratory tumor motion to synchronize radiat...

2015
Alessandro Clivio Eugenio Vanetti Steven Rose Giorgia Nicolini Maria F Belosi Luca Cozzi Christof Baltes Antonella Fogliata

BACKGROUND Machine Performance Check (MPC) is an application to verify geometry and beam performances of TrueBeam Linacs, through automated checks based on their kV-MV imaging systems. In this study, preliminary tests with MPC were analyzed using all photon beam energies of our TrueBeam, comparing whenever possible with external independent checks. METHODS Data acquisition comprises a series ...

2013
Mohamad Javad Tahmasebi Birgani Nahid Chegeni Shole Arvandi Sasan Razmjoo Ghalaee Mansoor Zabihzadeh Davood Khezerloo

Nowadays, in most radiotherapy departments, the commercial treatment planning systems (TPS) used to calculate dose distributions needs to be verified; therefore, quick, easy-to-use, and low-cost dose distribution algorithms are desirable to test and verify the performance of the TPS. In this paper, we put forth an analytical method to calculate the phantom scatter contribution and depth dose on...

2016
P. Fenoglietto M. Khodri D. Nguyen F. Josserand-Pietri N. Aillères

PURPOSE To verify the accuracy of volumetric arc therapy (VMAT) using the RapidArc™ device when switching patients from one single linear accelerator (linac) to a paired energy and mechanics "twin" linac without reoptimization of the original treatment plan. PATIENTS AND METHODS Four centers using 8 linacs were involved in this study. Seventy-four patients previously treated with the 6MV phot...

2010
Vladimir Feygelman Geoffrey Zhang Craig Stevens

We performed an initial dosimetric evaluation of SmartArc - a novel VMAT planning module for Philips Pinnacle treatment planning system. A test suite of structure sets and dose objectives provided by the AAPM for multi-institutional comparison of IMRT dosimetry was used. A total of fifty plans were successfully delivered. The effect of control point spacing on dosimetric accuracy was investigat...

2004
J. C. Sáez-Vergara R. Rodríguez Jiménez E. Correa Garcés

The calibration methods for in-situ gamma spectrometry systems used CIEMAT include semiempirical approaches using point sources, pure mathematical calibrations using the ISOCS software and a stripping method developed at CIEMAT. The two first procedures give information about the activity concentration in the soil, and the third method provides distributions of dosimetric quantities as a functi...

Journal: :iranian journal of radiation research 0
n. banaee department of engineering, science and research branch, islamic azad university, tehran, iran h.a. nedaie radiotherapy oncology department, cancer research centre, tehran university of medical sciences, tehran, iran e. esmati radiotherapy oncology department, cancer research centre, tehran university of medical sciences, tehran, iran h. nosrati shahid beheshti university of medical sciences, tehran, iran m. jamali radiotherapy oncology department, cancer research centre, tehran university of medical sciences, tehran, iran

background: in radiation therapy, peripheral dose or the dose outside the radiotherapy field, is important when anatomical structures with very low dose tolerances are involved. one of these critical organs in pelvic irradiation is testis. the amount of radiation delivered to the testes in radiotherapy must be kept as small as possible, consistent with the limit dose of this organ. the threshol...

Journal: :Medical physics 2014
Arthur J Olch Lee Gerig Heng Li Ivaylo Mihaylov Andrew Morgan

The dosimetric impact from devices external to the patient is a complex combination of increased skin dose, reduced tumor dose, and altered dose distribution. Although small monitor unit or dose corrections are routinely made for blocking trays, ion chamber correction factors, e.g., accounting for temperature and pressure, or tissue inhomogeneities, the dose perturbation of the treatment couch ...

2015
Jinhan Zhu Lixin Chen Along Chen Guangwen Luo Xiaowu Deng Xiaowei Liu

PURPOSE To use a graphic processing unit (GPU) calculation engine to implement a fast 3D pre-treatment dosimetric verification procedure based on an electronic portal imaging device (EPID). METHODS The GPU algorithm includes the deconvolution and convolution method for the fluence-map calculations, the collapsed-cone convolution/superposition (CCCS) algorithm for the 3D dose calculations and ...

2017
Jinyu Xue Jared D. Ohrt James Fan Peter Balter Joo Han Park Leonard Kim Steven M. Kirsner Geoffrey S. Ibbott

Recently published Medical Physics Practice Guideline 5.a. (MPPG 5.a.) by American Association of Physicists in Medicine (AAPM) sets the minimum requirements for treatment planning system (TPS) dose algorithm commissioning and quality assurance (QA). The guideline recommends some validation tests and tolerances based primarily on published AAPM task group reports and the criteria used by IROC H...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید