نتایج جستجو برای: heterogeneous phantom

تعداد نتایج: 142666  

Journal: :Medical physics 2013
Monica W K Kan Lucullus H T Leung Ronald W K So Peter K N Yu

PURPOSE To compare the doses calculated by the Acuros XB (AXB) algorithm and analytical anisotropic algorithm (AAA) with experimentally measured data adjacent to and within heterogeneous medium using intensity modulated radiation therapy (IMRT) and RapidArc(®) (RA) volumetric arc therapy plans for nasopharygeal carcinoma (NPC). METHODS Two-dimensional dose distribution immediately adjacent to...

Background: Prediction of the absorbed dose in irradiated volume plays an important role in the outcome of radiotherapy. Application of small fields for radiotherapy of thorax makes the dose calculation process inaccurate due to the existence of electronic disequilibrium and intrinsic deficiencies in dose calculation algorithms. To study the lung absorbed dose in radiotherapy with smal...

ژورنال: سنجش و ایمنی پرتو 2020

Nowadays, in order to improve the accuracy of treatment in radiation therapy, there are many attempts to use magnetic resonance imaging (MRI) due to the advantages of excellent soft tissue contrast and ultra-fast pulse sequences. On the other hand, carbon-ion radiation therapy is developing rapidly due to the benefits of greater relative biological effectiveness (RBE) and the application in the...

Journal: :iranian journal of medical physics 0
zahra anjomani m.sc. in medical physics, nuclear engineering dept., shahid beheshti university, tehran, iran hasan nedaie assistant professor, radiotherapy physics dept., tehran university of medical science, tehran, iran majid shariari associate professor, nuclear engineering dept, shahid beheshti university, tehran, iran

introduction: nowadays new radiochromic films have an essential role in radiotherapy dosimetry. properties such as high sensitivity, good reproducibility, high spatial resolution, easy readout and portability have made them attractive for dosimetry, especially in high-dose-gradient regions. material and methods: in this study, electron-beam dose distributions in homogenous and heterogeneous pha...

Journal: :Physics in medicine and biology 2015
M Moreau I Buvat L Ammour N Chouin F Kraeber-Bodéré M Chérel T Carlier

Iodine-124 is a radionuclide well suited to the labeling of intact monoclonal antibodies. Yet, accurate quantification in preclinical imaging with I-124 is challenging due to the large positron range and a complex decay scheme including high-energy gammas. The aim of this work was to assess the quantitative performance of a fully 3D Monte Carlo (MC) reconstruction for preclinical I-124 PET. The...

Journal: :journal of biomedical physics and engineering 0
k hadad shiraz university m zohrevand shiraz university r faghihi shiraz university a sedighi pashaki mahdieh m.r.i center, hamedan

background: hdr brachytherapy is one of the commonest methods of nasopharyngeal cancer treatment. in this method, depending on how advanced one tumor is, 2 to 6 gy dose as intracavitary brachytherapy is prescribed. due to high dose rate and tumor location, accuracy evaluation of treatment planning system (tps) is particularly important. common methods used in tps dosimetry are based on computat...

Journal: :Physics in medicine and biology 2007
Brian Kanagaki Paul W Read Janelle A Molloy James M Larner Ke Sheng

Helical tomotherapy (HT) can potentially be used for lung cancer treatment including stereotactic radiosurgery because of its advanced image guidance and its ability to deliver highly conformal dose distributions. However, previous theoretical and simulation studies reported that the effect of respiratory motion on statically planned tomotherapy treatments may cause substantial differences betw...

2016
Moti R. Paudel Anthony Kim Arman Sarfehnia Sayed B. Ahmad David J. Beachey Arjun Sahgal Brian M. Keller

A new GPU-based Monte Carlo dose calculation algorithm (GPUMCD), devel-oped by the vendor Elekta for the Monaco treatment planning system (TPS), is capable of modeling dose for both a standard linear accelerator and an Elekta MRI linear accelerator. We have experimentally evaluated this algorithm for a standard Elekta Agility linear accelerator. A beam model was developed in the Monaco TPS (res...

2011
Veronica Ardu Sara Broggi Giovanni Mauro Cattaneo Paola Mangili Riccardo Calandrino

BACKGROUND To analyse limits and capabilities in dose calculation of collapsed-cone-convolution (CCC) algorithm implemented in helical tomotherapy (HT) treatment planning system for thorax lesions. METHODS The agreement between measured and calculated dose was verified both in homogeneous (Cheese Phantom) and in a custom-made inhomogeneous phantom. The inhomogeneous phantom was employed to mi...

Journal: :Physics in medicine and biology 2002
Indrin J Chetty Jean M Moran Teamor S Nurushev Daniel L McShan Benedick A Fraass Scott J Wilderman Alex F Bielajew

A comprehensive set of measurements and calculations has been conducted to investigate the accuracy of the Dose Planning Method (DPM) Monte Carlo code for electron beam dose calculations in heterogeneous media. Measurements were made using 10 MeV and 50 MeV minimally scattered, uncollimated electron beams from a racetrack microtron. Source distributions for the Monte Carlo calculations were rec...

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