结合CBCT观察食管癌肿瘤放疗后的靶区移位

Observation of Target Displacement of Esophageal Cancer after Radiotherapy Combined with CBCT

摘要: 目的：探讨食管癌患者通过CBCT观察靶区在放疗过程中的移位规律，并找出较合适的CBCT频次。方法：取2017年11月至20年12月在烟台毓璜顶医院接受单纯放疗或放化疗患者85例，分别于放疗首次及之后每5次行CBCT扫描，在Aria系统中与原始定位图像以椎体为参照配准后，观察整个纵隔的位置变化，推断出靶区位置的相对变化。结果：共64例患者完成了CBCT扫描，其中，2例患者因为靶区位置变化较大进行了二次定位。CBCT显示放疗在第16次时出现整个疗程最大移位。结论：通过结合CBCT能反映出食管癌放疗患者放疗过程中的靶区位置变化并及时做出调整。放疗在第16次时，较易出现较大移位，需要多加注意。CBCT频次为每5次进行扫描，可以较早发现患者靶区位置变化并减少患者不必要的射线伤害。

Abstract: Objective: To investigate the displacement of target area in patients with esophageal cancer during radiotherapy by CBCT, and to find out a more appropriate frequency to carry out CBCT during a complete course of radiotherapy. Methods: Eight-five patients who received simple radiotherapy or chemo-radiotherapy in Yantai Yuhuangding Hospital from November 2017 to December 2020 were enrolled. CBCT scans were performed for the first time and every 5 times for the following treatment. The original positioning image was compared with the positioning image in the Aria system for reference, and the relative changes in the position of the entire mediastinum can be calculated according to the position of the target area. Results: A total of 64 patients completed all CBCT scannings, of which 2 patients underwent secondary localization due to tremendous change of the target location. CBCT showed that the maximum displacement of the whole course of radiotherapy occurred at the 16th time. Conclusion: CBCT reflects the changes of target position in patients with esophageal cancer during radiotherapy, and make adjustments in time. The combination of CBCT can reflect the changes in the target area during radiotherapy in patients with esophageal cancer and make timely adjustments. It was found that at the 16th time of radiotherapy, it is more likely to have a large shift, which means the preventive CBCT scan should be ordered for target displacement precaution.