Journal of Cancer Research and Therapeutics

ORIGINAL ARTICLE
Year
: 2019  |  Volume : 15  |  Issue : 1  |  Page : 237--244

Tissue composition effect on dose distribution in radiotherapy with a 6 MV photon beam of a medical linac


Mahdi Ghorbani1, Atefeh Vejdani Noghreiyan2, Zahra Sadat Tabatabaei2, Delaram Pakravan3, David Davenport4 
1 Department of Biomedical Engineering and Medical Physics, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
2 Physics Research Center, Mashhad University of Medical Sciences, Mashhad, Iran
3 Department of Physics, Faculty of Basic Sciences, Islamic Azad University, Ahvaz, Iran
4 Comprehensive Cancer Centers of Nevada, Las Vegas, Nevada, USA

Correspondence Address:
Dr. Atefeh Vejdani Noghreiyan
Student Research Committee, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad
Iran

Aim: The aim of this study is to evaluate soft-tissue composition effect on dose distribution for various soft tissues in radiotherapy with a 6 MV photon beam of a medical linac. Background: The compositions of various soft tissues are different which could affect dose calculations. Materials and Methods: A phantom and Siemens Primus linear accelerator were simulated using MCNPX Monte Carlo code. In a homogeneous cubic phantom, six types of soft tissue and three types of tissue-equivalent materials were defined separately. The soft tissues were muscle (skeletal), adipose tissue, blood (whole), breast tissue, soft tissue (9-component), and soft tissue (4-component). The tissue-equivalent materials included water, A-150 tissue equivalent plastic and perspex. Photon dose relative to dose in 9-component soft tissue at various depths on the beam's central axis was determined for the 6 MV photon beam. The relative dose was also calculated and compared for various MCNPX tallies including *F8, F6, and *F4. Results: The results of the relative photon dose in various materials relative to dose in 9-component soft tissue using different tallies are reported in the form of tabulated data. Minor differences between dose distributions in various soft tissues and tissue-equivalent materials were observed. The results from F6 and F4 were practically the same but differ with the *F8 tally. Conclusions: Based on the calculations performed, the differences in dose distributions in various soft tissues and tissue-equivalent materials are minor but they could be corrected in radiotherapy calculations to upgrade the accuracy of the dosimetric calculations.


How to cite this article:
Ghorbani M, Noghreiyan AV, Tabatabaei ZS, Pakravan D, Davenport D. Tissue composition effect on dose distribution in radiotherapy with a 6 MV photon beam of a medical linac.J Can Res Ther 2019;15:237-244


How to cite this URL:
Ghorbani M, Noghreiyan AV, Tabatabaei ZS, Pakravan D, Davenport D. Tissue composition effect on dose distribution in radiotherapy with a 6 MV photon beam of a medical linac. J Can Res Ther [serial online] 2019 [cited 2019 Nov 20 ];15:237-244
Available from: http://www.cancerjournal.net/article.asp?issn=0973-1482;year=2019;volume=15;issue=1;spage=237;epage=244;aulast=Ghorbani;type=0