影像引导技术辅以6自由度治疗床调整对宫颈癌患者摆位误差及靶区偏移的影响

目的:探讨在治疗过程中患者产生的平移误差及旋转误差对靶区位置的影响，6自由度治疗床在治疗过程中的作用及靶区外放边界的变化。方法:顺序入组10例宫颈癌术后患者，所有患者常规摆位后行在线锥形束CT(CBCT)得出摆位误差后，联合6自由度治疗床进行调整，而后立即行第二次CBCT，治疗后行第三次CBCT，将所有摆位误差结果记录，用于分析摆位误差对靶区位置的影响及靶区外放边界的研究。结果:CBCT联合6自由度治疗床在线校正后的误差无论是系统误差还是随机误差均减小，而治疗后误差相较于校正后的误差在四个方向上有所增大（X、Z、RX、RY）；通过6自由度治疗床联合CBCT在线纠正可以发现CTV外放至PTV的边界在X方向上可以减少0.64 cm，在Y方向上可以减少0.96 cm，在Z方向上可以减少1.04 cm；在纠正摆位误差后靶区的偏移在X、Y、Z方向明显减小；在RX、RY、RZ方向上的靶区偏移在纠正摆位误差后也明显减小。结论:无论是平移误差还是旋转误差对靶区位置均有较大影响，6自由度治疗床联合在线CBCT完全可以减小摆位误差，并且可以为靶区外放边界提供可靠数据，缩小靶区外放边界。

The effect of image-guided technique supplemented with 6-DOF treatment bed adjustment on the positioning error and target deviation of cervical cancer

Objective:To explore the influence of translation errors and rotation errors on the target area and the surrounding normal organs in the treatment process,the role of HexaPODevo RT in the treatment process and the changes of the target area.Methods:10 patients with cervical cancer after surgery were collected.After all patients underwent routine setup and CBCT online,combining with the HexaPODevo RT was used,then the second CBCT was immediately underwent.The third CBCT after treatment was underwent.All the setup error results were recorded,to study the influence of setup error on the location and border of target area.Results:After CBCT combined with HexaPODevo RT adjusted,either system errors or random errors were reduced,and the error after treatment compared to the error after correction in four directions increased(X,Z,RX,RY).Through the HexaPODevo RT combined with CBCT online correct,the boundary of CTV to PTV can be reduced 0.64 cm in the X direction,reduced the 0.96 cm in the Y direction,reduced 1.04 cm in the Z direction.Setup errors in the target area were significantly reduced in X,Y,Z direction,RX,RY and RZ,too.Conclusion:Both the translation errors and the rotation errors on target position has great influence.HexaPODevo RT combined with online CBCT can reduce the setup errors,and can provide reliable data for the target area boundary,reduce the boundary of target.