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Percentage depth dose fragmentation for investigating and assessing the photon beam dosimetry quality

Published online by Cambridge University Press:  04 December 2018

Mohamed Bencheikh Open the ORCID record for Mohamed Bencheikh [Opens in a new window] ,
Abdelmajid Maghnouj  and
Jaouad Tajmouati
Mohamed Bencheikh*
Affiliation:
LISTA Laboratory, Physics Department, Faculty of Sciences Dhar El-Mahraz, University of Sidi Mohamed Ben Abdellah, Fez, Morocco
Abdelmajid Maghnouj
Affiliation:
LISTA Laboratory, Physics Department, Faculty of Sciences Dhar El-Mahraz, University of Sidi Mohamed Ben Abdellah, Fez, Morocco
Jaouad Tajmouati
Affiliation:
LISTA Laboratory, Physics Department, Faculty of Sciences Dhar El-Mahraz, University of Sidi Mohamed Ben Abdellah, Fez, Morocco
*
Author for correspondence: Mohamed Bencheikh, Physics Department, Faculty of Sciences Dhar El-Mahraz, University of Sidi Mohamed Ben Abdellah, Fez, 30000, Morocco. E-mail: bc.mohamed@gmail.com
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Abstract

Aim

The purpose of this study is to introduce a new approach to assess the dosimetry quality of photon beam with energy and irradiation field size. This approach is based on percentage depth dose (PDD) fragmentation for investigating the dosimetry quality.

Materials and methods

For the investigation of the dosimetry quality of 6 and 18 MV photon beams, we have proceeded to fragment the PDD at different field sizes. This approach checks the overall PDD and is not restricted to the exponential decay regions, as per the International Atomic Energy Agency Technical Reports Series No 398 and the American Association of Physicist in Medicine Task Group 51 recommendations.

Results and discussion

The 6 MV photon beam deposited more energy in the target volume than the 18 MV photon beam. The dose delivered by the 6 MV beam is greater by a factor of 1·5 than that delivered by the 18 MV beam in the build-up region and the dose delivered by the 6 MV beam is greater by a factor of 2·6 than that delivered by the 18 MV beam in the electronic equilibrium and the exponential decay regions.

Conclusion

The dose measured at different points of the beam is higher for 6 MV than for 18 MV photon beam. Therefore, the 6 MV beam is more dosimetrically efficient than the 18 MV beam. Using the proposed approach, we can assess the dosimetry quality by taking into account overall PDD not only in the exponential decay region but also in the field.

Keywords

dosimetry qualityfragmentationphoton beam energyquality indexradiotherapy efficiency
Type
Original Article
Information
Journal of Radiotherapy in Practice , Volume 18 , Issue 3 , September 2019 , pp. 280 - 284
Copyright
© Cambridge University Press 2018 

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Footnotes

Cite this article: Bencheikh M, Maghnouj A, Tajmouati J. (2019) Percentage depth dose fragmentation for investigating and assessing the photon beam dosimetry quality. Journal of Radiotherapy in Practice18: 280–284. doi: 10.1017/S1460396918000687

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