Guo Yanluan, Li Jianbin, Zhang Peng, Shao Qian, Xu Min, Li Yankang
Department of Radiation Oncology, Shandong Cancer Hospital and Institute, Jinan, Shandong, China.
Medicine (Baltimore). 2017 Jan;96(1):e5528. doi: 10.1097/MD.0000000000005528.
To evaluate the geometrical differences of target volumes propagated by deformable image registration (DIR) and rigid image registration (RIR) to assist target volume delineation between diagnostic Positron emission tomography/computed tomography (PET/CT) and planning CT for primary esophageal cancer (EC).
Twenty-five patients with EC sequentially underwent a diagnostic F-fluorodeoxyglucose (F-FDG) PET/CT scan and planning CT simulation. Only 19 patients with maximum standardized uptake value (SUVmax) ≥ 2.0 of the primary volume were available. Gross tumor volumes (GTVs) were delineated using CT and PET display settings. The PET/CT images were then registered with planning CT using MIM software. Subsequently, the PET and CT contours were propagated by RIR and DIR to planning CT. The properties of these volumes were compared.
When GTVCT delineated on CT of PET/CT after both RIR and DIR was compared with GTV contoured on planning CT, significant improvements using DIR were observed in the volume, displacements of the center of mass (COM) in the 3-dimensional (3D) direction, and Dice similarity coefficient (DSC) (P = 0.003; 0.006; 0.014). Although similar improvements were not observed for the same comparison using DIR for propagated PET contours from diagnostic PET/CT to planning CT (P > 0.05), for DSC and displacements of COM in the 3D direction of PET contours, the DIR resulted in the improved volume of a large percentage of patients (73.7%; 68.45%; 63.2%) compared with RIR. For diagnostic CT-based contours or PET contours at SUV2.5 propagated by DIR with planning CT, the DSC and displacements of COM in 3D directions in the distal segment were significantly improved compared to the upper and middle segments (P > 0.05).
We observed a trend that deformable registration might improve the overlap for gross target volumes from diagnostic PET/CT to planning CT. The distal EC might benefit more from DIR.
评估通过可变形图像配准（DIR）和刚性图像配准（RIR）传播的靶区体积的几何差异，以辅助原发性食管癌（EC）诊断性正电子发射断层扫描/计算机断层扫描（PET/CT）与计划CT之间的靶区体积勾画。
25例EC患者依次接受诊断性F-氟脱氧葡萄糖（F-FDG）PET/CT扫描和计划CT模拟。仅19例原发灶最大标准化摄取值（SUVmax）≥2.0的患者可用。使用CT和PET显示设置勾画大体肿瘤体积（GTV）。然后使用MIM软件将PET/CT图像与计划CT配准。随后，通过RIR和DIR将PET和CT轮廓传播到计划CT。比较这些体积的属性。
当将RIR和DIR后PET/CT的CT上勾画的GTVCT与计划CT上勾画的GTV进行比较时，在体积、三维（3D）方向上质心（COM）的位移和骰子相似系数（DSC）方面，使用DIR观察到显著改善（P = 0.００３；0.００６；0.０１４）。虽然从诊断性PET/CT到计划CT传播的PET轮廓使用DIR进行相同比较时未观察到类似改善（P＞0.０５），但对于PET轮廓的DSC和3D方向上COM的位移，与RIR相比，DIR使很大比例的患者体积得到改善（73.7%；68.45%；63.2%）。对于基于诊断CT的轮廓或通过DIR与计划CT传播的SUV2.5处的PET轮廓，与上段和中段相比，远端节段的DSC和3D方向上COM的位移显著改善（P＞0.０５）。
我们观察到一种趋势，即可变形配准可能会改善从诊断性PET/CT到计划CT的大体靶区体积的重叠。远端EC可能从DIR中获益更多。
