Prostate brachytherapy seed reconstruction with Gaussian blurring and optimal coverage cost.
Prostate brachytherapy seed reconstruction with Gaussian blurring and optimal coverage cost.
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DOI：
10.1109/tmi.2009.2026412
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发表时间：
2009-12
影响因子：
10.6
通讯作者：
Fichtinger G
中科院分区：
文献类型：
--
作者：
Lee J;Liu X;Jain AK;Song DY;Burdette EC;Prince JL;Fichtinger G
前列腺近距离放射治疗的术中剂量测定需要对植入的放射性粒子进行定位。提出了一种基于断层合成的种子重建方法。从高斯模糊投影图像重建三维体积，并且从重建体积计算候选种子位置。一个假阳性种子去除过程，制定为一个最佳的覆盖问题，迭代地删除“鬼”的种子，创建断层合成重建。为了最小化在常规C形臂中常见的姿态误差，通过使用检测到的候选种子作为基准来迭代地校正初始姿态参数估计，这自动地“聚焦”所收集的图像并改进连续的重建体积。模拟结果表明，当C形臂被校准并且C形臂的姿态已知时，植入的种子位置可以分别从三幅和四幅图像中以≥ 97.9%和≥ 99.3%的检测率来估计。该算法还在体模数据集上进行了验证，成功定位了来自四个或五个图像的植入粒子。在1期临床试验中，我们能够从5张术中透视图像中定位植入的粒子，总体检出率为98.8%（STD=1.6）。
Intraoperative dosimetry in prostate brachytherapy requires localization of the implanted radioactive seeds. A tomosynthesis-based seed reconstruction method is proposed. A three-dimensional volume is reconstructed from Gaussian-blurred projection images and candidate seed locations are computed from the reconstructed volume. A false positive seed removal process, formulated as an optimal coverage problem, iteratively removes “ghost” seeds that are created by tomosynthesis reconstruction. In an effort to minimize pose errors that are common in conventional C-arms, initial pose parameter estimates are iteratively corrected by using the detected candidate seeds as fiducials, which automatically “focuses” the collected images and improves successive reconstructed volumes. Simulation results imply that the implanted seed locations can be estimated with a detection rate of ≥ 97.9% and ≥ 99.3% from three and four images, respectively, when the C-arm is calibrated and the pose of the C-arm is known. The algorithm was also validated on phantom data sets successfully localizing the implanted seeds from four or five images. In a Phase-1 clinical trial, we were able to localize the implanted seeds from five intraoperative fluoroscopy images with 98.8% (STD=1.6) overall detection rate.