目的 分析上颌前部埋伏牙诊断中锥形束CT（CBCT）的应用价值,以期提升疾病诊出率和定位准确率,继而提高治疗有效性。方法 分析2021年1月—2022年7月间于我院口腔门诊进行检查的150例阻生齿患者基本资料,对患者实施口腔锥形束CT检查,进行定位分型。结果 150例患者中阻生牙率100%,其中存在埋伏牙20例,占比13.33%。所有埋伏牙均经CBCT 扫描准确确定了牙体大小、埋伏牙形态、埋伏深度、萌出方向、与相邻齿的位置关系等,为临床医师提供了准确图像参考;共有上颌前部埋伏牙21颗,包括左上颌埋伏牙9颗、右上颌埋伏牙12颗。结论 CBCT检测能够极大提升埋伏牙检测定位的准确性,为医师提供准确影像学参考,以此制定针对性手术方案,在保证治疗效果的同时提升手术安全性,避免一系列并发症的发生,可在埋伏牙阻生齿诊断及治疗中进行推广使用。

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.