Seed-based transrectal ultrasound-fluoroscopy registration method for intraoperative dosimetry analysis of prostate brachytherapy.
Seed-based transrectal ultrasound-fluoroscopy registration method for intraoperative dosimetry analysis of prostate brachytherapy.
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基于种子的经直肠超声透视配准方法用于前列腺近距离放射治疗术中剂量分析。
DOI：
10.1118/1.2836422
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发表时间：
2008
期刊：
影响因子：
3.8
通讯作者：
Kim,Yongmin
中科院分区：
文献类型：
--
作者：
Tutar,IsmailB;Gong,Lixin;Narayanan,Sreeram;Pathak,SayanD;Cho,PaulS;Wallner,Kent;Kim,Yongmin
前列腺近距离放射治疗是早期前列腺癌的有效治疗选择。在前列腺近距离放射治疗过程中，经直肠超声（TRUS）和荧光透视成像模式通过分别提供软组织和植入粒子的良好可视化而相互补充。因此，这两种成像模式的配准（在手术室中很容易获得）可以促进术中剂量测定，从而使医生能够在患者仍在手术台上时将额外的种子植入前列腺的剂量不足部分。期望通过使用种子作为基准标记来配准TRUS和荧光透视图像。虽然所有植入粒子的位置都可以从三个荧光透视图像中重建，但只有一小部分粒子可以在TRUS图像中定位。通过使用识别的种子配准TRUS和荧光透视图像具有挑战性，因为它们之间的对应关系是未知的。此外，将非种子结构误检测为种子可能导致在数据集中包含伪点。我们开发了一种称为迭代最优分配（IOA）的新方法，以克服TRUS透视配准中的这些挑战。通过在优化框架中使用匈牙利方法，IOA计算一组转换参数，这些参数以最小成本产生一一对应。我们已经评估了我们的注册方法在不同的噪声水平，种子检测率，并使用从25名患者收集的数据的伪点的数量。我们已经发现，IOA可以执行注册的平均均方根误差约甚至当种子检测率仅为10%。我们相信IOA可以为基于种子的TRUS透视配准提供一个强大的解决方案，从而使术中剂量测定成为可能。
Prostate brachytherapy is an effective treatment option for early‐stage prostate cancer. During a prostate brachytherapy procedure, transrectal ultrasound (TRUS) and fluoroscopy imaging modalities complement each other by providing good visualization of soft tissue and implanted seeds, respectively. Therefore, the registration of these two imaging modalities, which are readily available in the operating room, could facilitate intraoperative dosimetry, thus enabling physicians to implant additional seeds into the underdosed portions of the prostate while the patient is still on the operating table. It is desirable to register TRUS and fluoroscopy images by using the seeds as fiducial markers. Although the locations of all the implanted seeds can be reconstructed from three fluoroscopy images, only a fraction of these seeds can be located in TRUS images. It is challenging to register the TRUS and fluoroscopy images by using the identified seeds, since the correspondence between them is unknown. Furthermore, misdetection of nonseed structures as seeds can lead to the inclusion of spurious points in the data set. We developed a new method called iterative optimal assignment (IOA) to overcome these challenges in TRUS‐fluoroscopy registration. By using the Hungarian method in an optimization framework, IOA computes a set of transformation parameters that yield the one‐to‐one correspondence with minimum cost. We have evaluated our registration method at varying noise levels, seed detection rates, and number of spurious points using data collected from 25 patients. We have found that IOA can perform registration with an average root mean square error of about even when the seed detection rate is only 10%. We believe that IOA can offer a robust solution to seed‐based TRUS‐fluoroscopy registration, thus making intraoperative dosimetry possible.