نتایج جستجو برای: dose calculation inhomogeneity phantom tigrt

تعداد نتایج: 427787  

Journal: :Medical physics 2009
Mark J Rivard Christopher S Melhus David E Wazer Raymond J Bricault

PURPOSE The AccuBoost brachytherapy system applies HDR 192Ir beams peripherally to the breast using collimating applicators. The purpose of this study was to benchmark Monte Carlo simulations of the HDR 192Ir source, to dosimetrically characterize the round applicators using established Monte Carlo simulation and radiation measurement techniques and to gather data for clinical use. METHODS Do...

Journal: :Medical physics 2012
Nicholas Hardcastle Adam Bayliss Jeannie Hsiu Ding Wong Anatoly B Rosenfeld Wolfgang A Tomé

PURPOSE A recent field safety notice from TomoTherapy detailed the underdosing of small, off-axis targets when receiving high doses per fraction. This is due to angular undersampling in the dose calculation gantry angles. This study evaluates a correction method to reduce the underdosing, to be implemented in the current version (v4.1) of the TomoTherapy treatment planning software. METHODS T...

Journal: :iranian journal of radiation research 0
m.n. anjum mcgill university health centre l5-112, 1650-cedar avenue, montreal general hospital, canada h3g 1a4 w. parker mcgill university health centre l5-112, 1650-cedar avenue, montreal general hospital, canada h3g 1a4 i. aldahlawi mcgill university health centre l5-112, 1650-cedar avenue, montreal general hospital, canada h3g 1a4 r. ruo mcgill university health centre l5-112, 1650-cedar avenue, montreal general hospital, canada h3g 1a4 m. afzal department of physics, the islamia university of bahawalpur, pakistan

background: we have validated the monitor unit calculations from a commercially available treatment planning system (tps) for three intensity modulated radiotherapy (imrt) planning techniques for tangential breast irradiation by using ionization chamber measurements. materials and methods: treatment plans were generated for forty-two breast patients by a forward planned field in field technique...

2015
Heming Zhen Brian Hrycushko Huichen Lee Robert Timmerman Arnold Pompoš Strahinja Stojadinovic Ryan Foster Steve B. Jiang Timothy Solberg Xuejun Gu

The aim of this study is to compare the recent Eclipse Acuros XB (AXB) dose calculation engine with the Pinnacle collapsed cone convolution/superposition (CCC) dose calculation algorithm and the Eclipse anisotropic analytic algorithm (AAA) for stereotactic ablative radiotherapy (SAbR) treatment planning of thoracic spinal (T-spine) metastases using IMRT and VMAT delivery techniques. The three c...

Journal: :Physica medica : PM : an international journal devoted to the applications of physics to medicine and biology : official journal of the Italian Association of Biomedical Physics 2008
Martin J Butson Tsang Cheung Peter K N Yu Sian Price Michael Bailey

Accurate measurement and knowledge of dose delivered under eye shield during superficial X-ray radiotherapy is required for patient peripheral dose assessment. Critical structures can include the cornea, lens and retina. Measurement of dose under eye shields has been historically performed with Thermoluminescent Dosimeters (TLD's) due to their small size and design. Restrictions include the ene...

Journal: :Medical physics 2006
Ann Van Esch Laura Tillikainen Jukka Pyykkonen Mikko Tenhunen Hannu Helminen Sami Siljamäki Jyrki Alakuijala Marta Paiusco Mauro Iori Dominique P Huyskens

The analytical anisotropic algorithm (AAA) was implemented in the Eclipse (Varian Medical Systems) treatment planning system to replace the single pencil beam (SPB) algorithm for the calculation of dose distributions for photon beams. AAA was developed to improve the dose calculation accuracy, especially in heterogeneous media. The total dose deposition is calculated as the superposition of the...

Ahmad Mostaar, Ghazaleh Sadrieh Khajoo Mahdi Salehi Barough Mohammad Ali Ostadrahimi

Introduction: In the last few decades, a lot of monte carlo codes have been introduced for medical applications. this is important because through simulation, we are fully independent of the spectral scattering factor that we are not able measure in real terms. The effect of the radiation energy, the dimension of the radiation field, the sensitive volume of the ion chamber on t...

2016
A R Barbeiro A Ureba J A Baeza R Linares M Perucha E Jiménez-Ortega S Velázquez J C Mateos A Leal

A model based on a specific phantom, called QuAArC, has been designed for the evaluation of planning and verification systems of complex radiotherapy treatments, such as volumetric modulated arc therapy (VMAT). This model uses the high accuracy provided by the Monte Carlo (MC) simulation of log files and allows the experimental feedback from the high spatial resolution of films hosted in QuAArC...

D Shahbazi-Gahrouei P Shokrani S Nikzad Sh Monadi Z Shahi

  Introduction: In patients with thyroid carcinoma, radiation absorbed doses of the thyroid and surrounding tissues is important to weigh risk and benefit considerations. In nuclear medicine, the accuracy of absorbed dose of internally distributed radionuclides is estimated by different methods such as MIRD and direct method using TLD. The aim of this study is using T...

2010
T. Allahverdi Pourfallah M. Allahverdi N. Riyahi Alam M. R. Ay M. H. Zahmatkesh

*Corresponding author: Dr. Tayyeb Allahverdi Pourfallah, Department of Medical Physics and Biomedical Engineering, Tehran University of Medical Sciences, Tehran, Iran. Fax: +98 21 88973653 E-mail: [email protected] Background: Polymer gel dosimetry is still the only dosimetry method for direct measuring of threedimensional dose distributions. MRI Polymer gel dosimeters are tissue equi...

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