Instituto de Física, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brasil.
PLoS One. 2010 May 3;5(5):e10466. doi: 10.1371/journal.pone.0010466.
In the radiotherapy treatment planning of a lesion located in the head region with small field radiation beams, the heterogeneity corrections play an important role. In this work, we investigated the influence of a bony heterogeneity on dose profile inside a soft tissue phantom containing a bony material. PDD curves were obtained by simulation using the Monte Carlo code EGSnrc and employing Eclipse(R) treatment planning system algorithms (Batho, Modified Batho, Equivalent TAR and Anisotropic Analytic Algorithm) for a 15 MV photon beam and field sizes of 2x2 and 10x10 cm(2). The Equivalent TAR method exhibited better agreement with Monte Carlo simulations for the 2x2 cm(2) field size. The magnitude of the effect on PDD due to the bony heterogeneity for 1x1, 2x2 and 10x10 cm(2) field sizes increases to 10, 5 and 3%, respectively.
在头部病变的小射野放射治疗计划中，不均匀性校正起着重要作用。在这项工作中，我们研究了含有骨材料的软组织体模中骨不均匀性对剂量分布的影响。通过使用蒙特卡罗代码 EGSnrc 进行模拟，并采用 Eclipse（R）治疗计划系统算法（Batho、Modified Batho、等效 TAR 和各向异性解析算法），获得了 15MV 光子束和 2x2cm(2)和 10x10cm(2)射野大小的 PDD 曲线。等效 TAR 方法对于 2x2cm(2)射野大小与蒙特卡罗模拟的吻合度更好。由于骨不均匀性对 1x1、2x2 和 10x10cm(2)射野大小的 PDD 的影响分别增加到 10%、5%和 3%。
