THE EXPERIMENTAL ASSESSMENT OF BUILD UP FACTOR AND ATTENUATION COEFFICIENT OF BRASS COMPENSATOR APPLIED IN INTENSITY-MODULATED RADIATION THERAPY (IMRT) FOR 6MV PHOTON BEAM

Authors

  • Elnaz B Department of Medical Physics, Semnan University of Medical Sciences, Semnan, Iran
  • Peyman H Department of Medical Physics, Semnan University of Medical Sciences, Semnan, Iran
  • Abbas H Department of Medical Physics, Kermanshah University of Medical Sciences, Kermanshah, Iran
  • Raheb G Department of Epidemiology, Semnan University of Medical Sciences, Semnan, Iran
  • Zaker S Department of Radiation Sciences, Lorestan University of Medical Sciences, Lorestan, Khorramabad, Iran

DOI:

https://doi.org/10.22452/jummec.vol20no2.4

Keywords:

Intensity Modulated Radiation Therapy, Compensators, Brass, Effective Attenuation Coefficient, Build up Factor

Abstract

Introduction: Recent compensators are commonly applied in IMRT. The precise properties of applied compensators such as thickness, attenuation coefficient and build up factor are intensively important for IMRT calculations. Method: The brass compensator used for 6 MV photon beam was studied to estimate the relative effect of thickness and field size on IMRT calculations. Various field size together with several compensator thicknesses were examined. Result: The average reduction of effective attenuation coefficient (EAC), for the fields of 10×10 cm2 to 20×20 cm2, was 9.94%. By increasing the field size, EAC was decreased. The major reduction of EAC due to increasing field size was found to be 9.62%. The build up factor was increased by 2% to 21.8% respect to field size and compensator thickness. Also, the build up factor was increased by adding up the thickness. The rate of changes ranged from 24% to 48 %. Conclusion: The compensator thickness and field size are significantly important to calculate the effective attenuation coefficient and build up factor.

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Published

2017-12-15

Issue

Section

Research article