目的 应用锥形束CT比较改良颈肩体热塑膜和传统颈肩体热塑膜体位固定装置在颈胸段食管癌患者放射治疗中的摆位差异,分析两种固定方式对锁骨上下区摆位误差的影响。方法 分析2021年6月—2022年10月在南京医科大学第一附属医院行放射治疗的29例食管癌患者的临床资料。将患者分为改良颈肩体热塑膜组（改良组）和光板颈肩体热塑膜组（对照组）,对比分析2组病例不同配准区域的摆位误差。结果 改良组在X（左右）方向的平移误差及Rz（冠状面）方向的旋转误差小于对照组,差异有统计学意义（P<0.05）。改良组锁骨上下区在X（左右）方向的平移误差以及Rx（矢状面）方向的旋转误差小于对照组,差异有统计学意义（P<0.05）。改良组的整体靶区外放范围在X、Y方向上均小于颈肩体组,改良组在锁骨上下区的X方向靶区外放范围也更小。结论 对于颈胸段食管癌需行锁骨上下区放疗的患者,应用改良颈肩体热塑膜可减少平移误差,控制旋转角度,减少靶区外放范围。

Objective To compare the set-up errors between the modified neck-shoulder body thermoplastic film and the traditional neck-shoulder body thermoplastic film fixation device in the radiotherapy of patients with cervical and thoracic esophageal cancer by cone beam CT,and to analyze the influence of the two fixation methods on the positioning error of the upper and lower clavicular region．Methods The clinical data of 29 patients with esophageal cancer who underwent radiotherapy in the First Affiliated Hospital of Nanjing Medical University from June 2021 to October 2022 were analyzed．The patients were divided into two groups：the modified neck-shoulder body thermoplastic film group（the modified group）and the smooth neck-shoulder body thermoplastic film group（the control group）,the positioning errors in different regions of the two groups were compared and analyzed．Results The translation error in the X（left and right）direction and the rotation error in the Rz（coronal plane）direction of the modified group were smaller than those of the control group,and the differences were statistically significant（P<0.05）．The translation error in the X（left and right）direction and the rotation error in the Rx（sagittal plane）direction of the superior and inferior clavicular region in the modified group were smaller than those in the control group,and the differencs were statistically significant（P<0.05）．The overall target area of the modified group was smaller in X and Y directions than that of the neck-shoulder body group,and the target area of the improved group in X direction was also smaller in the upper and lower clavicle area．Conclusions For patients with cervical and thoracic esophageal cancer who need radiotherapy in the upper and lower clavicular region,the application of modified neck shoulder body thermoplastic film can reduce the translation error,control the rotation angle and reduce the external radiation range of the target region．

目的 利用高精确的外照射治疗技术,即图像引导放射治疗/容积旋转调强放疗(IGRT/VMAT) 时,使用千伏锥形束CT (kV-CBCT)定位来获得最佳的宫颈癌治疗获益。方法 205例接受IGRT/VMAT治疗的宫颈癌患者纳入实验组。每周做一次kV-CBCT定位后,将这些图像与计划CT扫描图像匹配后记录摆位误差。总共研究了1 025个kV-CBCT图像。采取同时期常规X片定位的90例宫颈癌患者作为对照组。根据定位中的摆位误差计算计划靶区(PTV)的边界。结果 实验组前后、上下和左右方向的摆位误差分别为(1.8±1.1)mm、(2.8±2.2)mm和(1.7±1.4)mm,对照组分别为(2.8±2.1)mm、(3.9±2.2)mm和(2.7±2.4)mm,两组差异具有统计学意义(P<0.05)。实验组前后、上下和左右方向的CTV-PTV边界分别为5.27 mm、8.54 mm和5.23 mm,对照组分别为8.47 mm、11.29 mm和8.43 mm。结论 在采用高精度技术治疗宫颈癌时,每周kV-CBCT是一种令人满意的精确定位方法,有助于减少CTV-PTV边界。

Objective To obtain the best cervical cancer treatment benefit through kilovoltage cone-beam CT (kV-CBCT) positioning, by using high-precision external beam therapy technology, that is, image-guided radiation therapy/volumetric modulated arc therapy (IGRT/VMAT). Methods Two hundred and five patients with cervical cancer treated with IGRT/VMAT were included in the experimental group. After kV-CBCT positioning once a week, these images were matched with the planned CT scan images and the setup errors were recorded. A total of 1 025 kV-CBCT images were studied. Ninety patients with cervical cancer positioned by conventional X-ray during the same period were selected as the control group. The boundary of the planned target volume (PTV) was calculated based on the setup errors. Results In the experimental group, the setup errors in the anteroposterior, superoinferior and mediolateral direction were (1.8±1.1) mm, (2.8±2.2) mm, and (1.7±1.4) mm, respectively. And in the control group, the setup errors were (2.8±2.1) mm, (3.9±2.2) mm, and (2.7±2.4) mm, respectively. The differences between the two groups were statistically significant (P<0.05). In the experimental group, the CTV-PTV boundaries in the anteroposterior, superoinferior and mediolateral direction were 5.27 mm, 8.54 mm, and 5.23 mm, respectively. And in the control group, the CTV-PTV boundaries were 8.47 mm, 11.29 mm, and 8.43 mm, respectively. Conclusion When using high-precision technology to treat cervical cancer, weekly kV-CBCT is a satisfactory and accurate positioning method, which helps to reduce the CTV-PTV boundary.