Physical Properties of Ethyl Methacrylate as a Bolus in Radiotherapy

Document Type : Original Paper

Authors

1 Radiotherapy Department of Pars Hospital, Tehran, Iran.

2 Medical Physics Department, Faculty of Medicine, Tehran University of Medical Sciences, Tehran, Iran.

Abstract

Introduction
Bolus is a soft and resilient material which is used for increasing skin dose or to even out the irregular patient contour. The main property of various materials used presently as bolus is the water-equivalent electron density. Ethyl methacrylate is used as a soft-liner in dentistry and its physical and chemical properties are proved to be nontoxic for human body. The goal of this study was to assess the feasibility of using this material as bolus in radiotherapy and also evaluating some parameters such as mass, electron densities, and transmission factors.
Materials and Methods
Computed tomography data from the sample material were acquired to assess mass and electron densities with various techniques (mA and kVp). Circular ROIs were delineated on CT DICOM images and densities were calculated using CT numbers. Transmission factors were calculated for 6 and 18 MV.
Results
Evaluation of our results are evident that showed that mass and electron densities of ethyl methacrylate are similar to those of water and soft tissue. Furthermore, transmission factors are close to those of water.
Conclusion
According to the results of this study and other properties such as flexibility and harmlessness, it seems that ethyl methacrylate is a suitable material to be used as bolus in radiotherapy.

Keywords

Main Subjects

References

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Iranian Journal of Medical Physics
Volume 9, Issue 2 - Serial Number 2
May and June 2012
Pages 127-134

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History

  • Receive Date: 12 January 2012
  • Revise Date: 03 March 2013
  • Accept Date: 09 July 2012

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