Image quality evaluation of intra-irradiation cone-beam computed tomography acquired during one- and two-arc prostate volumetric-modulated arc therapy delivery: A phantom study.
Image quality evaluation of intra-irradiation cone-beam computed tomography acquired during one- and two-arc prostate volumetric-modulated arc therapy delivery: A phantom study.
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DOI：
10.1002/acm2.13095
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发表时间：
2020-12
影响因子：
2.1
通讯作者：
Mizowaki T
中科院分区：
文献类型：
--
作者：
Iramina H;Kitamura A;Nakamura M;Mizowaki T
旨在评价（a）兆伏（MV）散射对旋转输送期间采集的并发千伏（kV）投影（P MVkV）的影响，以及（B）前列腺调容弧治疗（VMAT）输送期间采集的照射内锥形束计算机断层扫描（ii‐CBCT）图像的图像质量。实验（1）：使用圆柱体模，使用各种MV射束参数采集P MVkVs：射野大小（FS）、MV能量（6或15 MV）、剂量率（DR）和机架速度。在每个P MVkV上的一个区域中计算平均像素值，该区域是在八个等距机架角度处提取的。实验（2）：沿着使用了11个单弧和7个双弧15 MV前列腺VMAT计划以及骨盆体模。从每个弧形计划中选择一个计划，并将其MV能量更改为6 MV。采集P MVkVs后，使用闭合kV叶片采集仅由MV散射组成的投影（P MVS），并从P MVkV（P MVScorr）中减去。仅获得kV射束的投影（P kV）。重建相应的CBCT图像（CBCTMVkV、CBCTMVScorr和CBCTkV）。计算前列腺区域的均方根误差（RMSE），并进行3D伽马分析，其中使用CBCT编号代替ii-CBCT图像和CBCTkV（30 HU/1 mm）之间的剂量。实验（1）：MV散射取决于FS、MV能量和DR。实验（2）：与CBCTMVkV相比，CBCTMVScorr的中位RMSE分别降低了107.5 HU（1弧）和42.9 HU（2弧）。CBCTMVScorr的中位GPR分别为94.7%（1弧）和93.4%（2弧），而CBCTMVkV的中位GPR分别为61.1%和79.9%。6个MV计划的GPR小于15个MV计划的GPR。MV散射的数量随着FS和DR的增大以及MV能量的减小而增加。在CBCTMVScorr上校正MV散射，无论弧数如何。
To evaluate (a) the effects of megavoltage (MV)‐scatter on concurrent kilovoltage (kV) projections (P MVkV) acquired during rotational delivery, and (b) the image quality of intra‐irradiation cone‐beam computed tomography (ii‐CBCT) images acquired during prostate volumetric‐modulated arc therapy (VMAT) delivery. Experiment (1): P MVkVs were acquired with various MV beam parameters using a cylindrical phantom: field size (FS), MV energy (6 or 15 MV), dose rate (DR), and gantry speed. The average pixel values were calculated in a region on each P MVkV which were extracted at eight equally spaced gantry angles. Experiment (2): 11 one‐arc and seven two‐arc 15 MV prostate VMAT plans were used along with a pelvis phantom. One plan was selected from each of arc plans and its MV energy was changed to 6 MV. After P MVkVs were acquired, projections consisting of MV‐scatter only (P MVS) were acquired with closing kV blades and subtracted from P MVkV (P MVScorr). Projections by kV beams only were acquired (P kV). The corresponding CBCT images were reconstructed (CBCTMVkV, CBCTMVScorr, and CBCTkV). The root‐mean‐square errors (RMSEs) were calculated in prostate region and 3D gamma analysis was conducted, in which the CBCT‐number was used instead of doses between ii‐CBCT images and CBCTkV (30 HU/1 mm). Experiment (1): The MV‐scatters were dependent on the FSs, MV energies, and DRs. Experiment (2): The median RMSEs for CBCTMVScorr were decreased by 107.5 HU (1‐arc) and 42.9 HU (2‐arc) compared to those for CBCTMVkV. The median GPRs for CBCTMVScorr were 94.7% (1‐arc) and 93.4% (2‐arc), while those for CBCTMVkV were 61.1% and 79.9%, respectively. GPRs for 6 MV plans were smaller than those for 15 MV plans. The number of MV‐scatters increased with larger FSs and DRs, and smaller MV energy. The MV‐scatters were corrected on the CBCTMVScorr regardless of the number of arcs.
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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：
3.8
作者：
Low, DA;Dempsey, JF
通讯作者：
Dempsey, JF
DOI：
10.1016/s0360-3016(02)02884-5
发表时间：
2002-08-01
影响因子：
7
作者：
Jaffray, DA;Siewerdsen, JH;Martinez, AA
通讯作者：
Martinez, AA
影响因子：
3.3
作者：
Aizawa, Rihito;Takayama, Kenji;Mizowaki, Takashi
通讯作者：
Mizowaki, Takashi
DOI：
10.1016/j.ijrobp.2015.10.009
发表时间：
2016-04-01
影响因子：
7
作者：
Keall, Paul J.;Ng, Jin Aun;Booth, Jeremy T.
通讯作者：
Booth, Jeremy T.