目的 分析安氏Ⅲ类错牙合正畸治疗牙合患者中切牙牙根及牙槽骨形态变化的影响。方法 分析2020年1月—2021年12月于我院口腔科进行正畸治疗的23例安氏Ⅲ类错牙合患者基本资料,对患者予以治疗前后的对锥形束CT测量,记录并对比相关数据,分析正畸治疗对于患者中切牙牙根及牙槽骨的影响。结果 （1）治疗后牙体及牙根长度较治疗前明显减小;（2）患者在治疗后唇、舌侧牙槽骨宽度呈下降趋势,与其他位点相比,上下颌舌侧中牙槽骨更易出现牙根吸收;下颌唇侧中牙槽骨宽度增加明显;（3）治疗后唇、舌侧牙槽骨缺损高度上有所增加,骨开窗、骨开裂位点增多。结论 安氏Ⅲ类错牙合有一定概率会出现牙根吸收等损伤,定期对患者实施锥形束CT检查能够为医生提供清晰准确图像资料支持,帮助医生更好判断患者状况并及时调整和优化治疗方法,以此进一步改善患者预后。

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.