Feasibility of MRI-based reference images for image-guided radiotherapy of the pelvis with either cone-beam computed tomography or planar localization images
Feasibility of MRI-based reference images for image-guided radiotherapy of the pelvis with either cone-beam computed tomography or planar localization images
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DOI：
10.3109/0284186x.2014.958197
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发表时间：
2015-06-01
期刊：
影响因子：
3.1
通讯作者：
Tenhunen, Mikko
中科院分区：
文献类型：
--
作者：
Korhonen, Juha;Kapanen, Mika;Tenhunen, Mikko
目的。本研究介绍了仅依靠基于磁共振成像 (MRI) 的参考图像，通过锥形束计算机断层扫描 (CBCT) 或平面定位图像对骨盆进行图像引导放射治疗 (IGRT) 的方法。材料和方法。通过将实现的患者位置校正与基于标准 CT 的参考图像获得的位置校正进行比较，针对 kV CBCT（50 次扫描，5 名前列腺癌患者）和 kV & MV 平面（5 和 5 个图像对和患者）定位图像评估基于 MRI 的 IGRT 参考图像的可行性。应用T1/T2*加权同相MRI、基于Hounsfield单位转换的异质伪CT和体块伪CT图像作为定位CBCT的参考，并通过自动图像配准获得患者位置校正。具有平面定位图像的 IGRT 由 10 名观察者使用从伪 CT 和标准 CT 重建的参考数字重建射线照片 (DRR) 手动执行。使用图像相似性指标评估伪 DRR 与 CT-DRR 的质量。结果。 CBCT-to-MRI 和 CBCT-to-CT 自动灰度值配准之间差异的 SD 为
Purpose. This study introduces methods to conduct image-guided radiotherapy (IGRT) of the pelvis with either cone-beam computed tomography (CBCT) or planar localization images by relying solely on magnetic resonance imaging (MRI)-based reference images.Material and methods. Feasibility of MRI-based reference images for IGRT was evaluated against kV CBCT (50 scans, 5 prostate cancer patients) and kV & MV planar (5 & 5 image pairs and patients) localization images by comparing the achieved patient position corrections to those obtained by standard CT-based reference images. T1/T2*-weighted in-phase MRI, Hounsfield unit conversion-based heterogeneous pseudo-CT, and bulk pseudo-CT images were applied for reference against localization CBCTs, and patient position corrections were obtained by automatic image registration. IGRT with planar localization images was performed manually by 10 observers using reference digitally reconstructed radiographs (DRRs) reconstructed from the pseudo-CTs and standard CTs. Quality of pseudo-DRRs against CT-DRRs was evaluated with image similarity metrics.Results. The SDs of differences between CBCT-to-MRI and CBCT-to-CT automatic gray-value registrations were