Photon beam dose distributions for patients with implanted temporary tissue expanders

8th International Conference on 3D Radiation Dosimetry

Asena, A.^1 ; Kairn, T.^1,2 ; Crowe, S.B.^1 ; Trapp, J.V.^1

School of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology, Brisbane, Australia^1

Genesis CancerCare Queensland, Brisbane, Australia^2

关键词: Breast Cancer;    Dose distributions;    Dose reduction;    Inhomogeneities;    Radiochromic film;    Silicone elastomer shells;    Target volumes;    Treatment planning systems;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/573/1/012062/pdf
DOI  :  10.1088/1742-6596/573/1/012062

来源: IOP

【 摘 要 】

This study examines the effects of temporary tissue expanders (TTEs) on the dose distributions of photon beams in breast cancer radiotherapy treatments. EBT2 radiochromic film and ion chamber measurements were taken to quantify the attenuation and backscatter effects of the inhomogeneity. Results illustrate that the internal magnetic port present in a tissue expander causes a dose reduction of approximately 25% in photon tangent fields immediately downstream of the implant. It was also shown that the silicone elastomer shell of the tissue expander reduced the dose to the target volume by as much as 8%. This work demonstrates the importance for an accurately modelled high-density implant in the treatment planning system for post-mastectomy breast cancer patients.