Concurrent kilovoltage CBCT imaging and megavoltage beam delivery: suppression of cross-scatter with 2D antiscatter grids and grid-based scatter sampling.
Concurrent kilovoltage CBCT imaging and megavoltage beam delivery: suppression of cross-scatter with 2D antiscatter grids and grid-based scatter sampling.
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DOI：
10.1088/1361-6560/ac8268
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发表时间：
2022-08-09
影响因子：
3.5
通讯作者：
中科院分区：
文献类型：
--
作者：
同时使用千伏（kV）和兆伏（MV）射束的概念在锥形束计算机断层扫描（CBCT）引导的放射治疗中具有潜在的应用，例如单次屏气扫描、金属伪影减少和MV治疗递送期间的同时成像。然而，MV射束输送期间产生的MV交叉散射降低了CBCT图像质量。为了解决这一问题，在高剂量MV治疗输送的背景下研究了2D防散射网格和交叉散射校正方法。在kV CBCT扫描中使用了3D打印的钨2D防散射栅格原型，以减少并发MV射束输送期间的MV交叉散射注量。通过使用2D网格本身作为交叉散射强度采样装置（称为基于网格的散射采样）来校正投影中的剩余交叉散射。为了测试这种方法，在输送6和10 MV射束的同时进行kV CBCT采集，模拟高剂量率治疗输送场景。kV和MV射束输送不同步，以消除MV射束输送中断。在体模的投影和CBCT图像中评估了所提出的方法的MV交叉散射抑制性能。与传统防散射滤线栅相比，2D滤线栅将kV投影中MV交叉散射的强度平均降低了3倍。通过基于网格的散射采样方法测量的剩余交叉散射在测量的参考强度值的7%内，并且随后被校正。CBCT图像质量在同步kV-MV射束输送过程中得到显著改善。在没有我们的方法的情况下，Hounsfield单位（HU）不准确度的中位数高达182 HU，并且使用我们的2D网格和散射校正方法将其降低到中位数6.5HU。我们的方法提供了2-6倍的对比度噪声比的改善。本研究证明了二维抗散射网格和基于网格的散射采样在抑制MV交叉散射中的实用性。我们的方法成功地最大限度地减少了MV交叉散射的影响，同时kV CBCT成像和高剂量MV治疗输送的情况。因此，在没有MV射束输送中断或损害kV图像采集速率的情况下，稳健的MV交叉散射抑制是潜在可行的。
The concept of using kilovoltage (kV) and megavoltage (MV) beams concurrently has potential applications in cone beam computed tomography (CBCT) guided radiation therapy, such as single breath hold scans, metal artifact reduction, and simultaneous imaging during MV treatment delivery. However, MV cross-scatter generated during MV beam delivery degrades CBCT image quality. To address this, a 2D antiscatter grid and a cross-scatter correction method were investigated in the context of high dose MV treatment delivery. A 3D printed, tungsten 2D antiscatter grid prototype was utilized in kV CBCT scans to reduce MV cross-scatter fluence during concurrent MV beam delivery. Remaining cross-scatter in projections was corrected by using the 2D grid itself as a cross-scatter intensity sampling device, referred to as Grid-based Scatter Sampling. To test this approach, kV CBCT acquisitions were performed while delivering 6 and 10 MV beams, mimicking high dose rate treatment delivery scenarios. kV and MV beam deliveries were not synchronized to eliminate MV beam delivery interruption. MV cross-scatter suppression performance of the proposed approach was evaluated in projections and CBCT images of phantoms. 2D grid reduced the intensity of MV cross-scatter in kV projections by a factor of 3 on the average, when compared to conventional antiscatter grid. Remaining cross scatter as measured by the Grid-based Scatter Sampling method was within 7% of measured reference intensity values, and subsequently corrected. CBCT image quality was improved substantially during concurrent kV-MV beam delivery. Median Hounsfield Unit (HU) inaccuracy was up to 182 HU without our methods, and it was reduced to a median 6.5HU with our 2D grid and scatter correction approach. Our methods provided a factor of 2–6 improvement in contrast-to-noise ratio. This investigation demonstrates the utility of 2D antiscatter grids and grid-based scatter sampling in suppressing MV cross-scatter. Our approach successfully minimized the effects of MV cross-scatter in concurrent kV CBCT imaging and high dose MV treatment delivery scenarios. Hence, robust MV cross-scatter suppression is potentially feasible without MV beam delivery interruption or compromising kV image acquisition rate.
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影响因子：
3.8
作者：
Taylor, PL;Rodgers, JE;Shobe, J
通讯作者：
Shobe, J
影响因子：
2.1
作者：
Iramina H;Kitamura A;Nakamura M;Mizowaki T
通讯作者：
Mizowaki T
DOI：
10.1259/bjro.20190048
发表时间：
2020
期刊：
BJR open
影响因子：
--
作者：
Iramina H;Nakamura M;Miyabe Y;Mukumoto N;Ono T;Hirashima H;Mizowaki T
通讯作者：
Mizowaki T
影响因子：
5.7
作者：
van Herk, Marcel;Ploeger, Lennert;Sonke, Jan-Jakob
通讯作者：
Sonke, Jan-Jakob
DOI：
10.1016/j.ijrobp.2010.01.030
发表时间：
2010-11-15
影响因子：
7
作者：
Blessing, Manuel;Stsepankou, Dzmitry;Wenz, Frederik
通讯作者：
Wenz, Frederik