论文部分内容阅读
目的探讨头颈部肿瘤图像引导放射治疗(IGRT)不同图像配准方法对摆位误差的影响。方法利用Elekta Synergy直线加速器放射治疗49例头颈部肿瘤患者,利用机载锥形束CT(CBCT)XVI系统对患者进行治疗前摆位扫描、在线调整后扫描和治疗结束后扫描。对重建获得的CBCT图像与治疗计划系统CT图像进行骨性和灰度两种模式匹配,分析X、Y、Z轴水平方向的误差及GX、GY、GZ的旋转方向误差,比较两种匹配模式之间的差异。结果 49例患者分别进行109次CBCT扫描,其中骨性配准和灰度配准在X轴水平方向的误差分别为(0.127±0.143)、(0.002±0.147)cm;在Y轴水平方向的误差为(-0.086±0.169)、(0.084±0.183)cm;在Z轴水平方向的误差为(-0.057±0.175)、(-0.060±0.158)cm。骨性配准和灰度配准在X轴旋转方向的误差分别为(0.751±1.390)°、(0.534±1.374)°;在Y轴旋转方向的误差为(0.033±1.870)°、(0.064±1.870)°;在Z轴旋转方向的误差为(-0.079±1.486)°、(0.028±1.147)°。两种配准方式除了在X轴旋转方向有统计学差异(P<0.05)外,其他5个方向的误差数据均无统计学差异(均P>0.05)。结论头颈部肿瘤进行IGRT时,两种配准方式均可选择,建议首先使用骨性配准,必要时灰度配准辅之。
Objective To investigate the effect of different image registration methods of head and neck tumor image guided radiotherapy (IGRT) on setting error. Methods Ninety-nine patients with head and neck cancer were treated with Elekta Synergy linear accelerator. The patient was pre-treated with on-board cone beam CT (CBCT) XVI system and scanned online and scanned after treatment. The reconstructed images of CBCT and CT images of treatment planning system were matched by two patterns of bone and grayscale. The errors in the horizontal direction of X, Y and Z axes and the rotation direction errors of GX, GY and GZ were analyzed. Two matching modes difference between. Results Ninety-nine patients underwent CBCT scan 109 times. The errors of the horizontal and vertical registration were 0.127 ± 0.143 and 0.002 ± 0.147 cm, respectively. The errors in the horizontal direction of the Y-axis (-0.086 ± 0.169) and (0.084 ± 0.183) cm respectively. The errors in the horizontal direction of Z axis were (-0.057 ± 0.175) and (-0.060 ± 0.158) cm, respectively. The errors in the direction of X-axis rotation were (0.751 ± 1.390) ° and (0.534 ± 1.374 °), respectively. The errors in the direction of Y-axis rotation were (0.033 ± 1.870) ° and (0.064 ± 1.870) °. The errors in the Z axis rotation direction are (-0.079 ± 1.486) ° and (0.028 ± 1.147) °. There was no significant difference between the two registration methods except for the direction of X-axis rotation (P <0.05) (P> 0.05). Conclusion When IGRT is performed in head and neck cancer, both of the two registration methods can be selected. It is recommended to use the first bone registration and, if necessary, the grayscale registration.