Asian Pacific Journal of Cancer Prevention

Asian Pacific Journal of Cancer Prevention (아시아태평양암예방학회)
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Dosimetric Characteristics of 6 MV Modified Beams by Physical Wedges of a Siemens Linear Accelerator

  • Zabihzadeh, Mansour (Department of Medical Physics, Faculty of Medicine, Ahvaz Jundishapur University of Medical Sciences) ;
  • Birgani, Mohammad Javad Tahmasebi (Department of Medical Physics, Faculty of Medicine, Ahvaz Jundishapur University of Medical Sciences) ;
  • Hoseini-Ghahfarokhi, Mojtaba (Department of Medical Physics, Faculty of Medicine, Ahvaz Jundishapur University of Medical Sciences) ;
  • Arvandi, Sholeh (Departments of Clinical Oncology, Golestan Hospital) ;
  • Hoseini, Seyed Mohammad (Departments of Clinical Oncology, Golestan Hospital) ;
  • Fadaei, Mahbube (Department of Medical Physics, Faculty of Medicine, Ahvaz Jundishapur University of Medical Sciences)
  • Published : 2016.06.01
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Abstract

Physical wedges still can be used as missing tissue compensators or filters to alter the shape of isodose curves in a target volume to reach an optimal radiotherapy plan without creating a hotspot. The aim of this study was to investigate the dosimetric properties of physical wedges filters such as off-axis photon fluence, photon spectrum, output factor and half value layer. The photon beam quality of a 6 MV Primus Siemens modified by 150 and 450 physical wedges was studied with BEAMnrc Monte Carlo (MC) code. The calculated present depth dose and dose profile curves for open and wedged photon beam were in good agreement with the measurements. Increase of wedge angle increased the beam hardening and this effect was more pronounced at the heal region. Using such an accurate MC model to determine of wedge factors and implementation of it as a calculation algorithm in the future treatment planning systems is recommended.

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References

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