Department of Radiation Oncology, Brigham and Women's Hospital & Dana Faber Cancer Institute, Harvard Medical School, Boston, MA 02115, USA.
Phys Med. 2013 Jan;29(1):75-82. doi: 10.1016/j.ejmp.2011.12.001. Epub 2011 Dec 28.
The objective of this study is to develop an automatic clip localization procedure for breast cancer patient setup based on Digital Tomosynthesis (DTS) and to characterize its performance with respect to the overall registration accuracy and robustness. The study was performed under an IRB-approved protocol for 12 breast cancer patients with surgical clips implanted around the tumor cavity. The registration of DTS images to planning CTs was performed using an automatic algorithm developed to overcome specific challenges of localization and registration of clips in the breast setup images. The automatic method consisted of auto-segmentation (intensity-based thresholding with a priori knowledge about clip size and location to distinguish clips from bony features) and auto-registration of the segmented clip clusters. To determine the inherent accuracy and robustness of the registration algorithm, additional simulated DTS data was analyzed. The developed algorithm is efficient in removing false positives and negatives and provides an accuracy of better than 2.3mm for 60° and 3.3mm for 40° DTS. When incorporated in clinical software, this algorithm helps to facilitate fast and accurate setup evaluation with minimal dose delivered to patients.
本研究旨在开发一种基于数字断层合成术（DTS）的乳腺癌患者摆位自动夹定位程序，并针对整体注册准确性和鲁棒性对其性能进行特征描述。该研究是在经过 IRB 批准的协议下，对 12 名在肿瘤腔内周围植入手术夹的乳腺癌患者进行的。使用一种自动算法将 DTS 图像与计划 CT 进行配准，该算法是为了克服在乳房设置图像中夹的定位和配准的特定挑战而开发的。自动方法包括自动分割（基于强度的阈值处理，具有关于夹大小和位置的先验知识，以将夹与骨特征区分开来）和分割夹簇的自动配准。为了确定注册算法的固有准确性和鲁棒性，还分析了额外的模拟 DTS 数据。所开发的算法能够有效地去除假阳性和假阴性，对于 60°的 DTS，其精度优于 2.3mm，对于 40°的 DTS，其精度优于 3.3mm。当将该算法纳入临床软件中时，它有助于实现快速准确的摆位评估，同时将对患者的辐射剂量降至最低。
