Journal of Biomedical Physics and Engineering

An Analytical-empirical Calculation of Linear Attenuation Coefficient of Megavoltage Photon Beams

Document Type : Original Research

Authors

F Seif 1
M J Tahmasebi-Birgani 2
M R Bayatiani 1

1 Assistant professor, Department of Medical Physics and Radiotherapy, Arak University of Medical Sciences, Arak, Iran

2 Professor, Department of Medical Physics and Radiotherapy, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran

Abstract
Background: In this study, a method for linear attenuation coefficient calculation was introduced.Methods: Linear attenuation coefficient was calculated with a new method that base on the physics of interaction of photon with matter, mathematical calculation and x-ray spectrum consideration. The calculation was done for Cerrobend as a common radiotherapy modifier and Mercury.Results: The values of calculated linear attenuation coefficient with this new method are in acceptable range. Also, the linear attenuation coefficient decreases slightly as the thickness of attenuating filter (Cerrobend or mercury) increased, so the procedure of linear attenuation coefficient variation is in agreement with other documents. The results showed that the attenuation ability of mercury was about 1.44 times more than Cerrobend. Conclusion: The method that was introduced in this study for linear attenuation coefficient calculation is general enough to treat beam modifiers with any shape or material by using the same formalism; however, calculating was made only for mercury and Cerrobend attenuator. On the other hand, it seems that this method is suitable for high energy shields or protector designing.
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Journal of Biomedical Physics and Engineering
Volume 7, Issue 3 - Serial Number 3
25
September and October 2017
Pages 225-232

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