Improved targeting accuracy of lung tumor biopsies with scanning-beam digital x-ray tomosynthesis image guidance.
Improved targeting accuracy of lung tumor biopsies with scanning-beam digital x-ray tomosynthesis image guidance.
复制标题
利用扫描束数字 X 射线断层合成图像引导提高肺肿瘤活检的靶向准确性。
DOI：
10.1118/1.4966025
复制
发表时间：
2016
期刊：
影响因子：
3.8
通讯作者：
Fahrig,Rebecca
中科院分区：
文献类型：
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作者：
Nelson,Geoff;Wu,Meng;Hinkel,Cameron;Krishna,Ganesh;Funk,Tobias;Rosenberg,Jarrett;Fahrig,Rebecca
目的电磁导航支气管镜检查（ENB）可提高可疑结节经支气管活检的靶向准确性。基于ENB的指导的最大弱点是，在干预前几天或几周获得的计划CT与干预当天手术台上的患者之间存在注册差异。在干预期间用实时断层合成成像增强ENB引导可以减轻分化，并进一步提高ENB引导下的经支气管活检的产量。实时断层合成原型，即扫描束数字x射线（SBDX）系统，目前还不能显示为这种肺部成像应用而开发的迭代算法重建的图像。因此，实施了一项使用基准标记物的协议，以评估SBDX系统在临床环境中可能提供的改进。方法在保存的4只猪肺周围各注射5个7 mm的病灶。然后将肺部放置在真空室中，以模拟真实的运动和呼吸引起的变形。获得猪肺影的标准临床CT扫描图，各向同性分辨率为0.625 mm。标准的ENB引导活检程序包括目标识别、路径规划、CT -肺定位和病变导航，并在需要活检的位置放置基准标记。在基准放置之前，ENB系统提供的通道到目标的距离被记录下来。然后使用SBDX系统和高分辨率锥束CT对肺影进行成像。在SBDX图像和金标准锥束CT图像中测量基准标记点尖端与病变之间的距离。将ENB系统预测的通道-目标偏差和SBDX图像测量的通道-目标偏差与金标准进行比较，以确定使用SBDX图像制导是否可以实现更高的瞄准精度。结果正如预期的那样，ENB系统对周围小结节的靶向准确性较差。仅使用ENB引导，40个注射结节中只有20个可以充分到达。SBDX系统能够可视化这些小病变，并且在SBDX上测量的基准到目标距离与金标准锥束CT图像的测量结果非常吻合（p= 0.0001）。金标准锥束CT距离与ENB系统提供的预测基准到目标距离之间的相关性很差（p= 0.72），主要是由于ENB CT到身体的登记和呼吸引起的运动不准确。结论SBDX系统可以显示小肺结节，并精确测量通道到目标的距离。联合使用ENB和SBDX实时图像引导可以提高活检的准确性和产量，特别是那些位于肺周围的病变。
PurposeElectromagnetic navigation bronchoscopy (ENB) provides improved targeting accuracy during transbronchial biopsies of suspicious nodules. The greatest weakness of ENB‐based guidance is the registration divergence that exists between the planning CT, acquired days or weeks before the intervention, and the patient on the table on the day of the intervention. Augmenting ENB guidance with real‐time tomosynthesis imaging during the intervention could mitigate the divergence and further improve the yield of ENB‐guided transbronchial biopsies. The real‐time tomosynthesis prototype, the scanning‐beam digital x‐ray (SBDX) system, does not currently display images reconstructed by the iterative algorithm that was developed for this lung imaging application. A protocol using fiducial markers was therefore implemented to permit evaluation of potential improvements that would be provided by the SBDX system in a clinical setting.MethodsTen 7 mm lesions (5 per side) were injected into the periphery of each of four preserved pig lungs. The lungs were then placed in a vacuum chamber that permitted simulation of realistic motion and deformation due to breathing. Standard clinical CT scans of the pig lung phantoms were acquired and reconstructed with isotropic resolution of 0.625 mm. Standard ENB‐guided biopsy procedures including target identification, path planning, CT‐to‐lung registration and navigation to the lesion were carried out, and a fiducial marker was placed at the location at which a biopsy would have been acquired. The channel‐to‐target distance provided by the ENB system prior to fiducial placement was noted. The lung phantoms were then imaged using the SBDX system, and using high‐resolution conebeam CT. The distance between the fiducial marker tip and the lesion was measured in SBDX images and in the gold‐standard conebeam‐CT images. The channel‐to‐target divergence predicted by the ENB system and measured in the SBDX images was compared to the gold standard to determine if improved targeting accuracy could be achieved using SBDX image guidance.ResultsAs expected, the ENB system showed poorer targeting accuracy for small peripheral nodules. Only 20 nodules of the 40 injected could be adequately reached using ENB guidance alone. The SBDX system was capable of visualizing these small lesions, and measured fiducial‐to‐target distances on SBDX agreed well with measurements in gold‐standard conebeam‐CT images (p= 0.0001). The correlation between gold‐standard conebeam‐CT distances and predicted fiducial‐to‐target distances provided by the ENB system was poor (p= 0.72), primarily due to inaccurate ENB CT‐to‐body registration and movement due to breathing.ConclusionsThe SBDX system permits visualization of small lung nodules, as well as accurate measurement of channel‐to‐target distances. Combined use of ENB with SBDX real‐time image guidance could improve accuracy and yield of biopsies, particularly of those lesions located in the periphery of the lung.