DEFORMATION OF PROSTATE AND SEMINAL VESICLES RELATIVE TO INTRAPROSTATIC FIDUCIAL MARKERS
DEFORMATION OF PROSTATE AND SEMINAL VESICLES RELATIVE TO INTRAPROSTATIC FIDUCIAL MARKERS
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DOI：
10.1016/j.ijrobp.2008.07.023
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发表时间：
2008-12-01
影响因子：
7
通讯作者：
de Boer, Hans C. J.
中科院分区：
文献类型：
--
作者：
van der Wielen, Gerard J.;Mutanga, Theodore F.;de Boer, Hans C. J.
目的：为了量化残余的几何不确定性后，在线校正intraprostate基准标记，本研究分析了前列腺的变形，特别是，相对于这样的markers.Patients和方法：计划计算机断层扫描（CT）扫描和三个重复CT扫描获得21例前列腺癌患者谁有三到四个圆柱形的黄金标记放置。前列腺和整个精囊（临床靶体积[CTV]）在每次扫描中以1.5 mm的切片厚度进行描绘。获得将标记映射到计划扫描位置的刚体变换（平移和旋转）。仅平移（仅L）或平移和旋转均应用于描绘的CTV。接下来，使用描绘的轮廓的非刚性配准来确定残余CTV表面位移。对于CTV的平移和旋转，残基代表变形;对于仅L-，残基源于变形和旋转。L-仅代表大多数当前应用的在线方案的残基。计算CTV表面位移的患者和人群统计数据。观察者内轮廓的变化同样量化使用重复描绘所有患者和校正。结果：最大的CTV变形观察到的前方和后方的精囊（群体平均标准差
Purpose: To quantify the residual geometric uncertainties after on-line corrections with intraprostatic fiducial markers, this study analyzed the deformation of the prostate and, in particular, the seminal vesicles relative to such markers.Patients and Methods: A planning computed tomography (CT) scan and three repeat CT scans were obtained for 21 prostate cancer patients who had had three to four cylindrical gold markers placed. The prostate and whole seminal vesicles (clinical target volume [CTV]) were delineated on each scan at a slice thickness of 1.5 mm. Rigid body transformations (translation and rotation) mapping the markers onto the planning scan positions were obtained. The translation only (L-only) or both translation and rotation were applied to the delineated CTVs. Next, the residue CTV surface displacements were determined using nonrigid registration of the delineated contours. For translation and rotation of the CTV, the residues represented deformation; for L-only, the residues stemmed from deformation and rotation. L-only represented the residues for most currently applied on-line protocols. The patient and population statistics of the CTV surface displacements were calculated. The intraobserver delineation variation was similarly quantified using repeat delineations for all patients and corrected for.Results: The largest CTV deformations were observed at the anterior and posterior side of the seminal vesicles (population average standard deviation