Comparison of selected dose calculation algorithms in radiotherapy treatment planning for tissues with inhomogeneities

13th South-East Asian Congress of Medical Physics 2015

物理学;医药卫生

Woon, Y.L.^1,2 ; Heng, S.P.^3 ; Wong, J.H.D.^1,4 ; Ung, N.M.^5

Department of Biomedical Imaging, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia^1

Department of Radiotherapy and Oncology, Sarawak General Hospital, Malaysia^2

Radiotherapy Unit, Pantai Hospital Kuala Lumpur, Kuala Lumpur, Malaysia^3

University of Malaya Research Imaging Centre, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia^4

Clinical Oncology Unit, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia^5

关键词: Anisotropic analytical algorithms;    Dosimetric impact;    Inhomogeneity correction;    Inhomogeneous phantom;    Inhomogeneous structure;    Intensity-modulated radiotherapy;    Radiotherapy treatment planning;    Treatment planning;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/694/1/012024/pdf
DOI  :  10.1088/1742-6596/694/1/012024

学科分类：卫生学

来源: IOP

【 摘 要 】

Inhomogeneity correction is recommended for accurate dose calculation in radiotherapy treatment planning since human body are highly inhomogeneous with the presence of bones and air cavities. However, each dose calculation algorithm has its own limitations. This study is to assess the accuracy of five algorithms that are currently implemented for treatment planning, including pencil beam convolution (PBC), superposition (SP), anisotropic analytical algorithm (AAA), Monte Carlo (MC) and Acuros XB (AXB). The calculated dose was compared with the measured dose using radiochromic film (Gafchromic EBT2) in inhomogeneous phantoms. In addition, the dosimetric impact of different algorithms on intensity modulated radiotherapy (IMRT) was studied for head and neck region. MC had the best agreement with the measured percentage depth dose (PDD) within the inhomogeneous region. This was followed by AXB, AAA, SP and PBC. For IMRT planning, MC algorithm is recommended for treatment planning in preference to PBC and SP. The MC and AXB algorithms were found to have better accuracy in terms of inhomogeneity correction and should be used for tumour volume within the proximity of inhomogeneous structures.