四维CT（Four-Dimensional Computed Tomography，4D-CT）技术将时间与空间因素相结合，能够显示患者体内肿瘤 靶区的运动范围，在放疗工作中的应用日益广泛。然而，由于4D-CT的相关设备和技术较复杂，在放疗模拟定位的具体应 用中存在诸多问题，阻碍了该技术的进一步推广应用。对于使用西门子CT模拟机联合瓦里安实时位置管理系统进行4D-CT 扫描，本文首先介绍了应用上述设备对放疗患者进行4D-CT模拟定位过程中存在的诸多问题丨然后针对上述问题，参照本 部门的经验，介绍了相应的具体解决方案，包括对热塑膜做方形开口、制作泡沫楔形块、调节红外摄像头、去除金属饰 品、评估患者呼吸曲线、制作放疗4D-CT扫描协议模板等丨最后介绍了上述解决方案的具体应用效果，为工作人员更好地 应用4D-CT对患者进行放疗模拟定位，提供了有益的参考。

Four-dimensional computed tomography (4D-CT), which combines temporal and spatial information, can display the range of motion of patients’ tumor target. It is increasingly used in radiotherapy. However, due to the complexity of 4D-CT related equipment and technique, there are many problems in the specific application of radiotherapy simulation, which hinder the further promotion and application of this technique. In terms of 4D-CT scanning using the Siemens CT simulator combined with the Varian real-time position management system, this paper first introduced problems that exist in the process of using the above-mentioned equipment to perform 4D-CT simulation for radiotherapy patients. Then in view of the above problems, referring to the experience of our department, the corresponding specific solutions were introduced, including making square openings in thermoplastic mask, making foam wedge blocks, adjusting infrared cameras, removing metal jewelry, evaluating patient breathing curves, making the radiotherapy 4D-CT scan protocol, etc. In the last section, the paper explained the application effect of the above solutions. The solutions introduced in this paper provide useful reference and guidance for the staff to perform radiotherapy simulation for patients using 4D-CT.