Kilovoltage Rotational External Beam Radiotherapy on a Breast Computed Tomography Platform: A Feasibility Study
Kilovoltage Rotational External Beam Radiotherapy on a Breast Computed Tomography Platform: A Feasibility Study
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DOI：
10.1016/j.ijrobp.2011.12.042
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发表时间：
2012-10-01
影响因子：
7
通讯作者：
Boone, John M.
中科院分区：
文献类型：
--
作者：
Prionas, Nicolas D.;McKenney, Sarah E.;Boone, John M.
目的：为了证明一个专用的乳腺计算机断层扫描（bCT）平台的可行性，提供旋转千伏（kV）外部束放射治疗（RT）的部分乳房照射，全乳房照射，和dose painting.Methods和Materials：旋转千伏外部束RT使用的原型bCT平台的几何形状进行了评估，使用Monte Carlo模拟器。发射178 keV光子的点源（近似于4 mm铜过滤的320 kVp光谱）围绕14 cm体素化聚乙烯盘（0.1 cm高）或圆柱体（9 cm高）旋转，以分别模拟初级和初级加散射光子相互作用。还使用体素化bCT患者图像进行模拟。射束准直在x-y平面（1-14 cm）和z方向（0.1-10 cm）上变化。使用具有不同射束准直的多次旋转证明了多焦点、线和环分布的剂量绘制。模拟使用扫描仪的本地硬件（120 kVp过滤0.2毫米铜）进行了实验validation.Results：作为xey准直器缩小，二维剂量分布从杯形轮廓与高边缘剂量转移到一个越来越多的峰值中心剂量分布与急剧剂量下降。使用1 cm射束，圆柱体边缘剂量为
Purpose: To demonstrate the feasibility of a dedicated breast computed tomography (bCT) platform to deliver rotational kilovoltage (kV) external beam radiotherapy (RT) for partial breast irradiation, whole breast irradiation, and dose painting.Methods and Materials: Rotational kV-external beam RT using the geometry of a prototype bCT platform was evaluated using a Monte Carlo simulator. A point source emitting 178 keV photons (approximating a 320-kVp spectrum with 4-mm copper filtration) was rotated around a 14-cm voxelized polyethylene disk (0.1 cm tall) or cylinder (9 cm tall) to simulate primary and primary plus scattered photon interactions, respectively. Simulations were also performed using voxelized bCT patient images. Beam collimation was varied in the x-y plane (1-14 cm) and in the z-direction (0.1-10 cm). Dose painting for multiple foci, line, and ring distributions was demonstrated using multiple rotations with varying beam collimation. Simulations using the scanner's native hardware (120 kVp filtered by 0.2-mm copper) were validated experimentally.Results: As the xey collimator was narrowed, the two-dimensional dose profiles shifted from a cupped profile with a high edge dose to an increasingly peaked central dose distribution with a sharp dose falloff. Using a 1-cm beam, the cylinder edge dose was