OPS和CBCT在颈胸膜固定方式下食管中下段癌放疗中的临床应用比较

Comparison of OPS and CBCT for clinical application in radiotherapy of middle and lower esophageal cancer with cervical pleural fixation

目的:通过比较联合应用红外定位系统(optical positioning system,OPS)、锥形束计算机断层扫描(cone beam computed tomography,CBCT)和单纯应用CBCT在颈胸膜固定方式下在食管中下段癌放射治疗中的摆位误差,探讨OPS的临床应用价值。方法:选择病理及影像学明确诊断食管中下段癌患者20例,分为单纯CBCT验证(对照组)及联合OPS、CBCT验证(观察组)。对每例患者在首次放射治疗时通过加速器上的激光灯进行摆位,先行千伏级CBCT扫描,后在同一体位下,通过调整患者体位使红外激光十字线与体表标记线对齐且使机房内OPS实时监控数据均在3 mm以内再行CBCT扫描,从而采集和比较每例患者在OPS和CBCT不同引导技术下摆位误差数据,采用SPSS 26.0软件进行统计处理。结果:对照组和观察组患者在X、Y、Z轴方向上的摆位线性误差分别为(0.21±0.03)、(0.39±0.05)、(0.18±0.04)cm和(0.09±0.91)、(0.17±0.03)、(0.15±0.02)cm。两种验证方式在Z(腹背方向)方向摆位误差差异无统计学意义(P>0.05),在X(左右方向)及Y(头脚方向)方向摆位误差差异有统计学意义(P<0.05)。结论:食管中下段癌患者使用颈胸热塑膜配合OPS技术可有效提高患者放疗中左右方向及头脚方向的摆位精确性,对于提高食管中下段癌颈胸膜摆位的精度及放射治疗工作效率具有较高的临床应用价值。

Objective:By comparing optical positioning system(OPS)and cone beam computed tomography(CBCT)and the positioning error of cervical pleura in radiotherapy,to explore the application value of OPS in the accurate radiotherapy of middle and lower esophageal cancer.Methods:20 patients with middle and lower esophageal carcinoma diagnosed by pathology and imaging were divided into two groups:the simple CBCT group(control group)and the combined OPS+CBCT group(observation group).Each patient was placed with the laser light on the accelerator during the first radiotherapy.First,scan with kilovolt conical beam CT(CBCT).Then,in the same body position,adjust the patient′s body position to align the infrared laser cross line with the body surface marking line,and make the OPS real-time monitoring data in the machine room within 3 mm before CBCT scanning.The positioning error data of each patient under different guidance techniques of OPS and CBCT were collected and compared.The data were analyzed by SPSS 26.0 software.Results:The linear errors of the control group and the observation group were(0.21±0.03),(0.39±0.05),(0.18±0.04)cm and(0.09±0.91),(0.17±0.03),(0.15±0.02)cm respectively.There were no significant difference between the two verification methods in Z(ventral back direction)(P>0.05).There were significant difference in positioning error in X(left-right direction)and Y(head foot direction)(P<0.05).Conclusion:The use of cervical pleural thermoplastic film combined with OPS technology in patients with middle and lower esophageal cancer can effectively improve the positioning accuracy of left and right direction and head foot direction in radiotherapy.It has high clinical application value for improving the positioning accuracy of cervical pleural and the efficiency of radiotherapy.