Dosimetric effects of a high-density spinal implant

7th International Conference on 3D Radiation Dosimetry

Kairn, T.^1,2 ; Crowe, S.B.^2 ; Kenny, J.^1,3 ; Mitchell, J.^1 ; Burke, M.^1 ; Schlect, D.^1 ; Trapp, J.V.^2

Premion, Wesley Medical Centre, 40 Chasely St, Auchenflower, QLD 4066, Australia^1

Science and Engineering Faculty, Queensland University of Technology, GPO Box 2434, Brisbane, QLD 4001, Australia^2

Australian Clinical Dosimetry Service, ARPANSA, Yallambie, VIC, Australia^3

关键词: Detailed modeling;    Dose distributions;    Monte Carlo calculation;    Monte Carlo codes;    Monte Carlo model;    Radiotherapy treatment;    Three-dimensional dose distribution;    Treatment planning systems;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/444/1/012108/pdf
DOI  :  10.1088/1742-6596/444/1/012108

来源: IOP

【 摘 要 】

In this study, a treatment plan for a spinal lesion, with all beams transmitted though a titanium vertebral reconstruction implant, was used to investigate the potential effect of a high-density implant on a three-dimensional dose distribution for a radiotherapy treatment. The BEAMnrc/DOSXYZnrc and MCDTK Monte Carlo codes were used to simulate the treatment using both a simplified, recltilinear model and a detailed model incorporating the full complexity of the patient anatomy and treatment plan. The resulting Monte Carlo dose distributions showed that the commercial treatment planning system failed to accurately predict both the depletion of dose downstream of the implant and the increase in scattered dose adjacent to the implant. Overall, the dosimetric effect of the implant was underestimated by the commercial treatment planning system and overestimated by the simplified Monte Carlo model. The value of performing detailed Monte Carlo calculations, using the full patient and treatment geometry, was demonstrated.