نتایج جستجو برای: gafchromic ebt2

تعداد نتایج: 444  

2016
Toshizo Katsuda Rumi Gotanda Tatsuhiro Gotanda Takuya Akagawa Nobuyoshi Tanki Tadao Kuwano Kouichi Yabunaka

This study investigates an X-ray dose measurement method for computed tomography using Gafchromic films. Nonuniformity of the active layer is a major problem in Gafchromic films. In radiotherapy, nonuniformity error is reduced by applying the double-exposure technique, but this is impractical in diagnostic radiology because of the heel effect. Therefore, we propose replacing the X-rays in the d...

Journal: :iranian journal of radiation research 0
m. yarahmadi kurdistan university of medical sciences, sanandaj, iran h.a. nedaie department of medical physics , faculty of medicine, tehran university of medical sciences, tehran, iran m. allahverdi department of medical physics , faculty of medicine, tehran university of medical sciences, tehran, iran kh. asnaashari department of radiotherapy , cancer institute, tehran university of medical sciences, tehran, iran o.a. sauer klinik und poliklinik für strahlentherapie, university of würzburg, josef-schneider-strasse 11, 97080 würzburg, germany

background: small photon fields are increasingly used in modern radiotherapy especially in intensity modulated radiation therapy (imrt) and stereotactic radiosurgery (srs) treatments. accurate beam profile and central axis depth doses measurements of such beams are complicated due to the electron disequilibrium. hence the ebt2 (external beam therapy) gafchromic film was used for dosimetry of sm...

2015
Toshizo Katsuda Rumi Gotanda Tatsuhiro Gotanda Takuya Akagawa Nobuyoshi Tanki Tadao Kuwano Kouichi Yabunaka

Gafchromic films are used for X-ray dose measurements during diagnostic examinations and have begun to be used for three-dimensional X-ray dose measurements using the high-resolution characteristics of Gafchromic films for computed tomography. However, the problem of unevenness in Gafchromic film active layers needs to be resolved. Double exposures using X-rays are performed during therapeutic ...

H.A. Nedaie, Kh. Asnaashari, M. Allahverdi, M. Yarahmadi, O.A. Sauer,

Background: Small photon fields are increasingly used in modern radiotherapy especially in intensity modulated radiation therapy (IMRT) and stereotactic radiosurgery (SRS) treatments. Accurate beam profile and central axis depth doses measurements of such beams are complicated due to the electron disequilibrium. Hence the EBT2 (external beam therapy) Gafchromic film was used for dosimetry of sm...

2012
Chris J. Mart Howard R. Elson Michael A. S. Lamba

Some of the lowest voltages used in radiotherapy are termed Grenz and superficial X-rays of ~ 20 and ~ 100 kVp, respectively. Dosimetrically, the surface doses from these beams are calculated with the use of a free in-air air kerma measurement combined with a backscatter factor and the appropriate ratio of mass energy absorption coefficients from the measurement material to water. Alternative t...

Journal: :Physics in medicine and biology 2014
A Subiel V Moskvin G H Welsh S Cipiccia D Reboredo P Evans M Partridge C DesRosiers M P Anania A Cianchi A Mostacci E Chiadroni D Di Giovenale F Villa R Pompili M Ferrario M Belleveglia G Di Pirro G Gatti C Vaccarezza B Seitz R C Isaac E Brunetti S M Wiggins B Ersfeld M R Islam M S Mendonca A Sorensen M Boyd D A Jaroszynski

Very high energy electrons (VHEE) in the range from 100-250 MeV have the potential of becoming an alternative modality in radiotherapy because of their improved dosimetry properties compared with MV photons from contemporary medical linear accelerators. Due to the need for accurate dosimetry of small field size VHEE beams we have performed dose measurements using EBT2 Gafchromic® film. Calibrat...

Journal: :basic and clinical cancer research 0
narges jooladi tehran university of medical sciences, tehran, iran seyed rabee mahdavi iran university of medical sciences, tehran, iran hasanali nedaei shahid beheshti university of medical sciences, tehran, iran hasan nosrati shahid beheshti university of medical sciences, tehran, iran mansour naderi tehran university of medical sciences, tehran, iran mahbod esfehani tehran university of medical sciences, tehran, iran

background : this study was set to determine the optimal technique of breast cancer with supraclavicular fossa irradiation. methods : three techniques was compared in this study. techniques were two point symmetric (2p-sym), two point asymmetric (2p-asym) and single point (sp). in 2p-sym all of beams were symmetric, in 2p-asym tangential beams were symmetric and supra was asymmetric, in sp all ...

Journal: :Journal of Applied Clinical Medical Physics 2012

2012
Masahiro Nakano Robin F. Hill May Whitaker Jung‐Ha Kim Zdenka Kuncic

The present study quantified surface doses on several rectangular phantom setups and on curved surface phantoms for a 6 MV photon field using the Attix parallel-plate chamber and Gafchromic EBT2 film. For the rectangular phantom setups, the surface doses on a homogenous water equivalent phantom and a water equivalent phantom with 60 mm thick lung equivalent material were measured. The measureme...

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