نتایج جستجو برای: low density polymer gel dosimetry

تعداد نتایج: 1684054  

Journal: :Medical physics 2001
M Oldham J H Siewerdsen A Shetty D A Jaffray

The increased intricacy of Intensity-Modulated-Radiation-Therapy (IMRT) delivery has created the need for a high-resolution 3D-dosimetry (three-dimensional) system capable of measuring and verifying the complex delivery. Present clinical methods are inadequate being restricted to single points (e.g., ion-chambers) or to 2D planes (e.g., film), and are labor intensive. In this paper we show that...

Journal: :journal of biomedical physics and engineering 0
m. dehghan master student of physics, department of physics, yazd university, yazd, iran h. mokhtari assistant professor of physics, department of physics, yazd university, yazd, iran f. bouzarjomehri associate professor of medical physics, shahid sadoughi university of medical sciences, yazd, iran

background: over recent decades, modern protocols of external beam radio¬therapy and radiation techniques such as intensity-modulated radiotherapy (imrt) have been developed. these methods are extremely sensitive to errors in treatment delivery, so that it is essential to apply a high resolution 3d dosimetry system that has high sensitivity and is capable of measuring and verifying the complex ...

Journal: :iranian journal of radiation research 0
s.m. abtahi university of shahid beheshti, radiation medicine department, p. o. box 19839- 63113, tehran, iran s.m.r. aghamiri university of shahid beheshti, radiation medicine department, p. o. box 19839- 63113, tehran, iran h khalafi nuclear science and technology research institute (nstri), tehran, iran f. rahmani university of shahid beheshti, radiation medicine department, p. o. box 19839- 63113, tehran, iran

background: the aim of this work was to establish how well gel dosimeters performed, as substitutes for brain tissue compared with standard phantom materials such as water, polymethyl-methacrylate (or pmma), a150 plastic and te- liquid phantom material for dosimetry of neutron beams in boron neutron capture therapy. materials and methods: thermal neutron fluence, photon dose and epithermal neut...

2017
Yongpeng Sun Yanchao Fang Ang Chen Qing You Caili Dai Rui Cheng Yifei Liu

Mature oilfields usually encounter the problem of high watercut. It is practical to use chemical methods for water-shutoff in production wells, however conventional water-shutoff agents have problems of long gelation time, low gel strength, and poor stability under low temperature and high salinity conditions. In this work a novel polymer gel for low temperature and high salinity reservoirs was...

2011
Timothy Olding Oliver Holmes Paul DeJean Kim B. McAuley Ken Nkongchu Giles Santyr L. John Schreiner

This paper explores the combination of cone beam optical computed tomography with an N-isopropylacrylamide (NIPAM)-based polymer gel dosimeter for three-dimensional dose imaging of small field deliveries. Initial investigations indicate that cone beam optical imaging of polymer gels is complicated by scattered stray light perturbation. This can lead to significant dosimetry failures in comparis...

Ahmad Mostaar, Mohammad Houshyari Zeinab Sattari

Introduction: Polymer gel dosimeters contain chemical materials sensitive to the radiation which are polymerized by the radiation as a function of absorbed dose. So information of spatial dose distribution can be extracted by imaging from irradiated gel. Among imaging techniques, computed tomography (CT) poses as an attractive method because of practical advantages such as acce...

2006

ID: 5462 Title: Advances in Co-60 based Tomotherapy Including Megavoltage CT Purpose: To evaluate the potential for Co-60 based tomotherapy including dose delivery and mega-voltage CT (MVCT). Tomotherapy is a rotational implementation of IMRT that provides highly conformal doses and patient setup verification using MVCT. Current tomotherapy is limited to linear accelerators. This poster present...

Journal: :Journal of Physics: Conference Series 2015

2012
N. Gopishankar S. Vivekanandhan S.S. Kale G.K. Rath S. Senthilkumaran S. Thulkar V. Subramani M.A. Laviraj R.K. Bisht A.K. Mahapatra

This work illustrates a procedure to assess the overall accuracy associated with Gamma Knife treatment planning using plugging. The main role of source plugging or blocking is to create dose falloff in the junction between a target and a critical structure. We report the use of MAGAT gel dosimeter for verification of an experimental treatment plan based on plugging. The polymer gel contained in...

Journal: :Journal of Physics: Conference Series 2009

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