摘要目的 比较采用千伏级XGS-10与OBI系统在头颈部肿瘤IMRT中的摆位误差和图像采集、配准所需时间差异.方法 30例头颈部患者IMRT前分别采用OBI系统获取CBCT图像及XGS-10系统获取X线图像,将2套图像与计划图像及其靶中心匹配,分别得出靶中心左右、上下、前后方向摆位误差数据.采用Pearson法相关分析2套系统分别在3个方向上的相关性及一致性的可信区间.结果 左右、上下、前后方向摆位误差XGS-10系统的分别为(-1.03 ±2.15)、(0.86±2.59)、(0.42±1.66) mm,OBI系统的分别为(0.00±1.68)、(1.53±2.12)、(0.10±1.54) mm,二者差值分别为(-1.03±1.24)、(-0.68±1.78)、(0.32±1.61) mm.二者在左右、上下、前后方向的相关系数分别为0.817、0.731、0.495,95％CI值分别为(-1.47～-0.59)、(-1.32～0.04)、(-0.26 ～0.90)mm.XGS-10获取图像、配准平均时间分别为10s和＜15s,OBI的需3 min和8 min.结论 XGS-10系统与OBI系统均可提高摆位精度,但XGS-10系统可缩短摆位及摆位误差纠正时间.

abstractsObjective To analyze the discrepancies between position adjustments obtained with the stereoscopic 2DKV XGS-10 system and the Varian OBI system for head-and-neck region IMRT treatments,and to compare for image acquisition and registration time.Methods CBCT images were obtained with OBI system and 2DKV images were acquired by XGS-10 system for 30 head-and-neck patients prior to Varian21EX IMRT treatment.The images were registered with planning image for localization,and position adjustments were given in LR,SI and AP directions,then the discrepancies between them were analyzed.On the comparison of the two different systems,the Pearson coefficient was used to analyzed the correlation and 95％ CI analysis to discern the consistence.Results Analysis of images acquired for the 30 patients yielded the following results:position adjustments with XGS-10 system were (-1.03 ± 2.15) mm,(0.86 ± 2.59) mm,(0.42 ± 1.66) mm in LR,SI and AP directions,whereas (0.00 ± 1.68) mm,(1.53 ± 2.12) mm,(0.10 ± 1.54) mm with CBCT in LR,SI and AP directions.The discrepancies were (-1.03 ± 1.24) mm,(-0.68 ± 1.78) mm and (0.32±1.61) mm in LR,SI and AP directions.The correlation coefficients between them were 0.817,0.731 and 0.495 in LR,SI and AP directions.95％ CI were (-1.47--0.59),(-1.32-0.04),(-0.26-0.90) mm.The average image acquisition and registration time were 10 s and ＜ 15 s in XGS-10 system,with 3 min and 8 min in OBI system.Conclusions Both of XGS-10 system and OBI system could be used to improve patient position accuracy,but XGS-10 system could cut down the total time.