基于锥形束CT图像引导的食管癌摆位精度相关因素分析

Analysis of factors related to esophageal cancer set-up accuracy based on CBCT image guidance

目的 探讨基于锥形束CT(CBCT)图像引导下食管癌患者的性别、体位固定方法、年龄和身体质量指数(BMI)对摆位精准度的影响,为临床决策提供参考。方法 回顾性分析2021-08-12-2022-07-19在中山大学肿瘤防治中心放疗的353例食管癌患者临床资料,纳入患者共进行CBCT扫描3 855次。根据患者首次治疗前的身高、体质量、年龄、性别和固定方式,以及每次CBCT扫描后的摆位误差数据,应用单因素分析探讨患者在左右(LR)、进出(SI)和升降(AP)方向上的摆位误差分别与BMI值和固定方式的关系。Pearson相关性分析探讨患者在LR、SI和AP方向上的摆位误差与年龄和性别的关系。对于女性患者,根据是否有男性治疗师参与,分为无女性治疗师参与组(408次)和女性治疗师参与组(340次),采用单因素分析的方法分析2组与摆位误差的关系。结果 在LR、SI和AP方向上,男性患者三维摆位误差分别为(3.32±1.80)、(2.03±1.13)和(2.20±1.18) mm,女性患者三维摆位误差分别为(3.84±1.91)、(2.01±0.88)和(2.93±1.70) mm,F值分别为4.213、0.014和16.254,P值为0.041、0.904和<0.001。无女性治疗师参与组在LR、SI和AP方向的摆位误差分别为(4.43±3.24)、(2.00±1.64)和(3.33±2.91) mm;女性治疗师参与组分别为(4.15±3.42)、(2.00±1.44)和(2.74±2.30) mm,F值分别为1.353、0.001和9.030,P值分别为0.245、0.979和<0.001。真空袋[(3.81±1.96)和(2.59±1.41) mm]、发泡胶[(3.09±1.58)和(2.12±1.18) mm]以及发泡胶联合热塑面罩[(2.49±1.80)和(1.64±1.00) mm]3种体位固定装置的摆位误差在LR和AP方向差异有统计学意义,F值分别为8.841和7.775,均P<0.001;SI方向[(2.02±1.10)、(2.03±1.11)和(1.94±0.79) mm]则差异无统计学意义,F=0.047,P=0.954。Pearson相关性分析结果显示,BMI与摆位误差在LR方向呈轻度正相关,r=0.134;P=0.012;年龄与摆位误差无相关性。结论 女性患者较男性患者的摆位误差大,女性治疗师参与摆位时能减少女性患者的摆位误差;使用发泡胶以及发泡胶联合热塑面罩的体位装置效果优于真空袋;患者BMI和年龄对体位固定精度无影响。

Objective To investigate the effect of gender,position fixation method,age,and body mass index(BMI)on the precision of positioning in patients with esophageal cancer based on CBCT image guidance and to provide a reference for clinical decision-making.Methods The clinical data of 353patients with esophageal cancer undergoing radiotherapy from 2021-08-12to 2022-07-19were retrospectively analyzed and 3855CBCT scans were performed in 353patients.According to the height,weight,age,sex and fixation mode before the first treatment and the position error data after each CBCT scan,the univariate analysis method was used to analyze the relationship between the position error and BMI value in the left right(LR),superior inferior(SI)and anterior posterior(AP)direction.The Pearson correlation analysis was applied to analyze the relationship between patient positioning error in LR,SI and AP directions with age and sex.For female patients,according to whether there were male therapists involved,they were divided into no female therapist involved or a female therapist involved,and the relationship with positioning error in the two groups was analyzed by univariate analysis.Results A total of 3855CBCT scans were performed in 353patients and in the LR,SI and AP directions.The three-dimensional placement errors were(3.32±1.80),(2.03±1.13)and(2.20±1.18)mm for male patients and(3.84±1.91),(2.01±0.88)and(2.93±1.70)mm for female patients with Fvalues of 4.213,0.014and 16.254and Pvalues of 0.41,0.904and<0.001.Positioning errors in the LR,SI and AP directions in the group without the participation of female therapists were(4.43±3.24),(2.00±1.64)and(3.33±2.91)mm and those in the group with the participation of female therapists were(4.15±3.42),(2.00±1.44)and(2.74±2.30)mm with Fvalues of 1.353,0.001and 9.030and Pvalues of 0.245,0.979and<0.001.The differences in the positioning errors of the three positional immobilization devices of vacuum bags[(3.81±1.96)and(2.59±1.41)mm],styrofoam[(3.09±1.58)and(2.12±1.18)mm]and styrofoam combined with thermoplastic masks[(2.49±1.80)and(1.64±1.00)mm]were statistically significant in the LR and AP directions,with F-values of 8.841and 7.775,all P<0.001.In the SI direction[(2.02±1.10),(2.03±1.11)and(1.94±0.79)mm]the difference was not statistically significant,F=0.047,P=0.954.The results showed that BMI was mildly positively correlated with positioning error in the LR direction(r=0.134,P=0.012),and there was no correlation between age and positioning error in any of them.Conclusions Positioning errors are greater in female patients than in male patients and can be reduced when a female therapist is involved in positioning.The use of styrofoam and styrofoam combined with a thermoplastic mask is better than vacuum bags for positional devices and the patient's BMI and age have no effect on the precision of positional fixation.