The evaluation of change in attenuation coefficient of cerrobend block used for radiation protection of healthy tissues in megavoltage photon radiation therapy after multiple melting

Tahmasebi Birgani, Mohamad Javad; Behrooz, Mohammad Ali; Maghsoodinia, Fatemeh; Farhadi Birgani, Fariba

doi:10.22038/ijmp.2018.13070

The evaluation of change in attenuation coefficient of cerrobend block used for radiation protection of healthy tissues in megavoltage photon radiation therapy after multiple melting

Document Type : Conference Proceedings

Authors

Mohamad Javad Tahmasebi Birgani ¹

Mohammad Ali Behrooz ²

Fatemeh Maghsoodinia ³

Fariba Farhadi Birgani ²

¹ Radiation Therapy and Medical Physics Department, Golestan Hospital, Jundishapur University of Medical Sciences, Ahvaz, Iran

² Department of Medical Physics, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran

³ Department of Medical Physics, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran

10.22038/ijmp.2018.13070

Abstract

Introduction:
Protecting the vital organs in radiation therapy is one of the most important issues. Cerrobend alloy, the most common material used as the shield, is melted several times and used for different patients. In this study changes in attenuation coefficient of cerrobend due to melting was investigated.

Materials and Methods:
In melting furnace, cerrobend was melted up to nine times and irradiated by Varian accelerator at radiotherapy department of Golestan hospital and the dose was measured by CC-13 ionization chamber with and without cerrobend blocks. The attenuation coefficients of cerrobend blocks were measured for irradiation fields of 6 × 6 cm2 and 10×10 cm2 at the photon energies of 6 mv and 18mv and analyzed by statistical methods.

Results:
Results of regression analysis with P<0.05, indicated that there was a significant relationship between the attenuation coefficient and frequencies of cerrobend melting: the attenuation coefficient increases with the increasing frequency of cerrobend melting.

Conclusion:
Continuous increasing in the frequency of cerrobend melting leads to increase in the attenuation coefficient of cerrobend block, thus cerrobend blocks can be used for patients, safely.

Keywords

Cerrobend block

Shielding

Beam

collimation

Compensator

Attenuation coefficient