نتایج جستجو برای: electron dosimetry

تعداد نتایج: 315962  

Journal: :iranian journal of medical physics 0
hadis ansari mehr1 department of medical radiation engineering, science and research branch, islamic azad university, tehran, iran

introduction the use of cut-outs in electron applicators make changes on output, isodose, and percentage depth dose (pdd) curves. these changes and electron beam dose distribution in the form of three-dimensional (3d) can be measured by gel dosimeters. materials and methods dosimetry was performed with and without a square shield (6×6 cm2 field). the energies were 4, 9, and 16 mev and phantom w...

Journal: :Medical physics 2001
D W Jokisch P W Patton D A Rajon B A Inglis W E Bolch

Radiation dose estimates to the trabecular region of the skeleton are of primary importance due to recent advancements in nuclear medicine. Establishing methods for accurately calculating dose in these regions is difficult due to the complex microstructure of this anatomic site and the typical ranges of beta-particles in both bone and marrow tissues. At the present time, models of skeletal dosi...

Journal: :iranian journal of medical physics 0
mohammad taghi bahreyni toossi professor, medical physics research center, bu-ali research institute, mashhad university of medical sciences, mashhad, iran mehdi momen nezhad ph.d., linear accelerator dept., imam reza hospital, mashhad university of medical sciences, mashhad, iran seyed mohammad hashemi m.sc., medical physics research center, mashhad university of medical sciences, mashhad, iran

introduction: in recent decades, several monte carlo codes have been introduced for research and medical applications. these methods provide both accurate and detailed calculation of particle transport from linear accelerators. the main drawback of monte carlo techniques is the extremely long computing time that is required in order to obtain a dose distribution with good statistical accuracy. ...

Journal: :Radiation research 2005
D J Lynch W E Wilson M T Batdorf M B Sowa Resat G A Kimmel J H Miller

Dosimetry calculations characterizing the spatial variation of the energy deposited by the slowing and stopping of energetic electrons are reported and compared with experimental measurements from an electron microbeam facility. The computations involve event-by-event, detailed-histories Monte Carlo simulations of low-energy electrons interacting in water vapor. Simulations of electron tracks w...

A.H. Barati, H.A. Nedaie, M. Afkhami, M. Yarahmadi, M.H. Zahmatkesh, W. Parwaie,

Background: Accurate small radiation field dosimetry is essential in modern radiotherapy techniques such as stereotactic radiosurgery (SRS) and intensity modulated radiotherapy (IMRT). Precise measurement of dosimetric parameters such as beam profile, percentage depth doses and output factor of these beams are complicated due to the electron disequilibrium and the steep dose gradients. In the p...

Journal: :Medical physics 2000
D A Rajon D W Jokisch P W Patton A P Shah W E Bolch

An important problem in internal dosimetry is the assessment of energy deposition by beta particles within trabecular regions of the skeleton. Recent dosimetry methods for trabecular bone are based on Monte Carlo particle transport simulations within three-dimensional (3D) images of real human bone samples. Nuclear magnetic resonance (NMR) microscopy is a 3D imaging technique of choice due to t...

2012
Qinan Bao Brian A Hrycushko Joseph P Dugas Frederick H Hager Timothy D Solberg

BACKGROUND Total skin electron irradiation (TSEI) is a special radiotherapy technique which has generally been used for treating adult patients with mycosis fungoides. Recently, two infants presented with leukemia cutis isolated to the skin requiring TSEI. This work discusses the commissioning and quality assurance (QA) methods for implementing a modified Stanford technique using a rotating har...

2017
Mihaela Ghita Stephen J McMahon Hannah F Thompson Conor K McGarry Raymond King Sarah O S Osman Jonathan L Kane Amanda Tulk Giuseppe Schettino Karl T Butterworth Alan R Hounsell Kevin M Prise

BACKGROUND Preclinical radiation biology has become increasingly sophisticated due to the implementation of advanced small animal image guided radiation platforms into laboratory investigation. These small animal radiotherapy devices enable state-of-the-art image guided therapy (IGRT) research to be performed by combining high-resolution cone beam computed tomography (CBCT) imaging with an isoc...

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