Trajectory modulated prone breast irradiation: A LINAC-based technique combining intensity modulated delivery and motion of the couch
Trajectory modulated prone breast irradiation: A LINAC-based technique combining intensity modulated delivery and motion of the couch
复制标题
DOI：
10.1016/j.radonc.2013.10.031
复制
发表时间：
2013-12-01
影响因子：
5.7
通讯作者：
Hristov, Dimitre
中科院分区：
文献类型：
--
作者：
Fahimian, Benjamin;Yu, Victoria;Hristov, Dimitre
目的：外射束放射治疗（EBRT）为加速部分乳腺照射（APBI）提供了一种非侵入性治疗替代方案，然而，目前EBRT技术可实现的剂量符合性的局限性与报告的毒性相关。为了增强EBRT APBI的一致性，开发了一种用于常规LINAC的技术，该技术通过床的组合运动、强度调制递送和俯卧乳房设置，使得能够对同侧乳房进行广角冠状弧照射，而不通过胸部和对侧乳房进行照射。方法和材料：海螺轨迹优化技术的发展，以确定的轨迹，同时避免碰撞的直线加速器，并保持在MLC孔径内的目标。沿推导出的轨迹沿着执行逆向治疗计划。通过在开发者模式下对Varian TrueBeam（TM）STx进行编程来实验性地实现该技术。通过离子室和电影测量phantom.Results的剂量准确性的交付进行了评价：所得到的优化轨迹被证明是必要的非等中心，并包含平移和旋转的沙发。胶片测量结果显示，测量的二维剂量图中93%的点通过了3%/3 mm伽马标准。初步治疗计划比较5场三维适形，调强放射治疗，和VMAT表现出一致性增强，并减少正常组织V-50%和V-100%的参数，已与EBRT toxicity.Conclusions相关：广角强度调制部分乳腺照射使用运动的沙发上的可行性已被证明实验上的标准LINAC的第一次。对于适合俯卧位的患者，该技术可以改善剂量一致性和与毒性相关的相关剂量体积参数。(C)2013爱思唯尔爱尔兰有限公司版权所有。
Purpose: External beam radiation therapy (EBRT) provides a non-invasive treatment alternative for accelerated partial breast irradiation (APBI), however, limitations in achievable dose conformity of current EBRT techniques have been correlated to reported toxicity. To enhance the conformity of EBRT APBI, a technique for conventional LINACs is developed, which through combined motion of the couch, intensity modulated delivery, and a prone breast setup, enables wide-angular coronal arc irradiation of the ipsilateral breast without irradiating through the thorax and contralateral breast.Methods and materials: A conch trajectory optimization technique was developed to determine the trajectories that concurrently avoid collision with the LINAC and maintain the target within the MLC apertures. Inverse treatment planning was performed along the derived trajectory. The technique was experimentally implemented by programming the Varian TrueBeam (TM) STx in Developer Mode. The dosimetric accuracy of the delivery was evaluated by ion chamber and film measurements in phantom.Results: The resulting optimized trajectory was shown to be necessarily non-isocentric, and contain both translation and rotations of the couch. Film measurements resulted in 93% of the points in the measured two-dimensional dose maps passing the 3%/3 mm Gamma criterion. Preliminary treatment plan comparison to 5-field 3D-conformal, IMRT, and VMAT demonstrated enhancement in conformity, and reduction of the normal tissue V-50% and V-100% parameters that have been correlated with EBRT toxicity.Conclusions: The feasibility of wide-angular intensity modulated partial breast irradiation using motion of the couch has been demonstrated experimentally on a standard LINAC for the first time. For patients eligible for a prone setup, the technique may enable improvement of dose conformity and associated dose-volume parameters correlated with toxicity. (C) 2013 Elsevier Ireland Ltd. All rights reserved.