نتایج جستجو برای: 3D film dosimetry DVH

تعداد نتایج: 284641  

Ahad Zainali, Leila Mahani

Introduction: Inclusion of inhomogeneities such as air-filled cavities in the head and neck treatment fields may result in potential dosimetric disagreement which was caused by electronic disequilibrium. Most of treatments planning systems (TPS) are not able to predict dose distribution of inhomogeneous regions accurately. EBT2 films are used frequently in radiotherapy quality ass...

2010
M. Lawrence T. Cullip L. Potter S. Wang Z. Xu K. Burkhardt S. Chang

Intensity-modulated radiation therapy (IMRT) quality assurance (QA) is often performed using a 2D device and compares measured and computed fluence maps to determine if a field passes or fails certain dose and position criteria. The effects of a measured deviation to the 3D patient spatial dosimetry and dose volume histogram (DVH) are largely unknown because they cannot be analyzed using commer...

2014
Mohammad Bakhtiari Ashkan Parniani Fritz Lerma Shannon Reynolds James Jordan Alireza Sedaghat Mehrdad Sarfaraz James Rodgers

BACKGROUND Intensity modulated radiation therapy (IMRT) dosimetry verification is routinely conducted via integrated or individual field dosimetry using film or a matrix of detectors. Techniques and software systems are commercially available which use individual field dosimetry measurements as input into algorithms that estimate 3D patient dose distributions on CT scan derived target volumes a...

Journal: :Medical physics 2013
M Carroll G Ibbott M Gillin J Adamovics

PURPOSE This investigation studies the feasibility of PRESAGE, a 3D polyurethane dosimeter, for relative dosimetry measurements of clinically relevant proton treatments using an anthropomorphic head phantom developed by the Radiological Physics Center (RPC). Performance of a low-LET dependent PRESAGE was evaluated by comparison to the traditionally used radiochromic film, EBT2, and thermolumine...

2017
M. Keshtkar A. Takavar M. H. Zahmatkesh H. A. Nedaie A. Vaezzadeh M. Naderi

Background: Some ssues in human body are radiobiologically different from water and these inhomogeneity must be considered in dose calcula on in order to achieve an accurate dose delivery. Dose verifica on in complex radia on therapy techniques, such as intensity‐modulated radia on therapy (IMRT) calls for volumetric, ssue equivalent and energy independent dosimeter. The purpose of this study i...

Ahad Zeinali Kamal Mostafanezhad Leila Mahani Milad Zeinali Kermani

Introduction: The presence of heterogeneities such as air-filled cavities in the head and neck treatment fields region, may result in potential dosimetric disagreement because the losses of charged particle equilibrium. Most of treatments planning systems are not able to predict dose distribution of inhomogeneities region accurately. Therefore, dose calculation algorithms need to...

A. Takavar, A. Vaezzadeh, H.A. Nedaie, M. Keshtkar, M. Naderi, M.H. Zahmatkesh,

Background: Some tissues in human body are radiobiologically different from water and these inhomogeneity must be considered in dose calculation in order to achieve an accurate dose delivery. Dose verification in complex radiation therapy techniques, such as intensity‐modulated radiation therapy (IMRT) calls for volumetric, tissue equivalent and energy independent dosimeter. The purpose of this...

2016
Ryan G Lafratta

Gamma index pass rates were evaluated for an anthropomorphic phantom using both 2D and 3D calculations. The phantom was irradiated with the traditional dosimetry insert loaded with radiochromic film and TLD, and then with a 3D dosimetry insert. A comparison with the calculated dose distribution showed that both the PRESAGE® dosimeter and the film and TLD system agreed with the plan to within 5%...

2010
Tzung-Chi Huang Ji-An Liang Thomas Dilling Tung-Hsin Wu Geoffrey Zhang

Thoracic cancer treatment presents dosimetric difficulties due to respiratory motion and lung inhomogeneity. Monte Carlo and deformable image registration techniques have been proposed to be used in four-dimensional (4D) dose calculations to overcome the difficulties. This study validates the 4D Monte Carlo dosimetry with measurement, compares 4D dosimetry of different tumor sizes and tumor mot...

Journal: :iranian journal of medical physics 0
somayeh nourollahi m.sc.in medical physics, faculty of medicine, tehran university of medical sciences, tehran, iran mahmoud allahverdi associate professor, medical physics dept., faculty of medicine, tehran university of medical sciences, tehran, iran mahbod esfahani m.sc.in medical physics, radiotherapy dept., cancer institute, tehran university of medical sciences, tehran, iran mehdi aghili assistant professor, radiotherapy dept., cancer institute, tehran university of medical sciences, tehran, iran vahid changizi assistant professor, radiology technology dept., faculty of allied medical sciences, tehran university of medical sciences, tehran, iran

introduction: the complex geometry of breast and also lung and heart inhomogeneities near the planning target volume (ptv) result in perturbations in dose distribution. this problem can result in overdosage or underdosage in the match region of the three treatment fields. the purpose of this study is to create a homogeneous dose distribution in the match region between the supraclavicular and t...

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