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Experimental measurements and Monte Carlo modelling of the XSTRAHL 150 superficial X-ray therapy unit

Published online by Cambridge University Press:  21 November 2014

Fayez H. H. Al-Ghorabie*
Affiliation:
Department of Physics, Faculty of Science, Umm Al-Qura University, Makkah, Saudi Arabia
*
Correspondence to: Fayez H. H. Al-Ghorabie, Department of Physics, Faculty of Science, Umm Al-Qura University, Makkah 21955, Saudi Arabia. Tel: +96 612 527 0000. Fax: +96 612 556 4560. E-mail: [email protected]

Abstract

Background

Superficial X-ray therapy units are used for the treatment of certain types of skin cancer and some severe dermatological conditions. The performance assessment and beam characteristics of the superficial unit are very important to ensure accurate dose delivery during patient treatment. Both experimental measurements and Monte Carlo calculations can be used for this purpose.

Purpose

This study aims to investigate whether it is possible to reproduce experimentally measured data for the XSTRAHL 150 superficial X-ray unit with simulations using the BEAMnrc Monte Carlo code.

Materials and Methods

The experimental procedure applied in this study included the following: experimental measurements of different X-ray spectra, half-value layers, percentage depth dose and beam profiles. Monte Carlo modelling of the XSTRAHL 150 unit was performed with the BEAMnrc code. The validity of the model was checked by comparing the theoretical calculations with experimental measurements.

Results

There was good agreement (∼1%) between experimentally measured and simulated X-ray spectra. Results of half-value layers obtained from simulated and measured spectra showed that there was a maximum of 3·6% difference between BEAMnrc and measurements and a minimum of 2·3%. In addition, simulated percentage depth dose and profile curves have been compared against experimental measurements and show good agreement (within 2% for the depth dose curves and 3–5% for beam profile curves, depending on the applicator size).

Conclusion

The results of this study provide information about particles’ interaction in different kilovoltage and filter combinations. This information is useful for X-ray tube design and development of new target/filter combinations to improve beam quality in superficial X-ray radiotherapy. The data presented here may provide a base for comparison and a reference for other or potential new users of the XSTRAHL 150 X-ray unit.

Type
Original Articles
Copyright
© Cambridge University Press 2014 

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