锥形束CT引导下前列腺癌调强放疗图像配准的研究

Image alignment assessed with k V cone beam CT for image guided prostate radiotherapy

目的:通过千伏级锥形束CT(KV-CBCT)引导的前列腺癌调强放疗的数据,探讨前列腺癌图像配准的最佳模式。方法:入选16例接受根治性调强放疗的前列腺癌患者,共行KV-CBCT在线校正治疗体位214次。采用常规皮肤标记激光对位后采集图像,离线将所获得CBCT图像与计划CT图像进行自动配准、骨性配准、软组织配准及手动配准。比较四种配准方式之间的差异。结果:16例患者四种配准方式在X(左右)、Y(升降)、Z(头脚)三个方向的摆位误差分别为-0.060±0.28、-0.062±0.45、-0.065±0.38;-0.071±0.27、-0.098±0.45、-0.085±0.41;-0.077±0.26、-0.027±0.44、-0.111±0.40;-0.059±0.29、-0.075±0.51、-0.098±0.39。经分析四种配准方式之间没有统计学差异。结论:综合各种因素考虑,应用在线自动配准KV—CBCT引导放疗技术治疗前列腺癌患者更为合适。

Objective: To investigate the optimal alignment methods with kilovohage cone-beam CT ( KV-CBCT) for the treat-ment of prostate cancer.Metheds: 16 patients with prostate cancer undergoing IMRT were enrolled onto the study and 214 CBCT im-agings were obtained from this study.After initial set-up using the skin marks, a CBCT scan was acquired and registered with the planning CT.The difference in auto alignment, bone alignment, soft tissue alignment and manual alignment was compared.Results:There was no statistical difference between the four alignment methods.The comparisons of setup errors in the vertical direction、lateral direction and longitudinal direction were -0.060 ±0.28、 -0.062 ±0.45、 -0.065 ±0.38; -0.071 ±0.27、 -0.098 ±0.45、-0.085 ±0.41; -0.077 ±0.26、 -0.027 ±0.44、 -0.111 ±0.40; -0.059 ±0.29、 -0.075 ±0.51、 -0.098 ±0.39 re-spectively.Conclusions Due to the comprehensive factors, the auto alignment should be used in the treatment.