宫颈癌放疗腰围变化与两种体位的相关性研究

Study on the correlation between the changes of waistline and two kinds of immobilization methods in cervical cancer radiotherapy

目的探究宫颈癌放疗中腰围变化与两种体位固定方式摆位误差的相关性。方法回顾性选取2019年6~12月在中山大学附属第一医院接受放疗的60例宫颈癌患者的临床资料,按照仰卧或俯卧治疗体位分为A、B两组,每组各30例。每周行一次锥形束CT(CBCT),离线回顾平移、旋转摆位误差,并计算定位、治疗腰围变化,分析两者相关性。结果A组X、Y、Z方向平移误差分别为(-0.5±2.7)、(-0.1±3.2)、(0.4±2.5)mm,B组为(-0.2±3.0)、(0.2±4.0)、(2.0±4.1)mm;A组Rx、Ry、Rz方向旋转误差分别为(-0.6±2.2)、(-0.2±0.8)、(0.1±0.8)°,B组为(0.5±2.3)、(-0.2±1.3)、(0.5±0.9)°,在Z、Rx与Rz方向,两组比较,差异有统计学意义(P<0.05)。A、B组腰围差△C分别为(-2.3±2.7)、(-1.4±2.0)cm,两组比较,差异有统计学意义(P<0.05)。B组在Z方向与腰围差△C呈负相关(r=-0.618,P<0.05)。结论宫颈癌放疗仰卧位摆位重复性较佳,但腰围变化会导致严重不良反应;俯卧位对小肠保护较佳,但腰围变化对Z方向精确度影响较大。临床上需重视腰围变化,必要时采取膀胱充盈与体重干预。

Objective To explore the correlation between the changes of waistline and set-up errors of two kinds of immobilization methods in cervical cancer radiotherapy.Methods A total of 60 patients with cervical cancer who received radiotherapy in the First Affiliated Hospital,Sun Yat-sen University from June to December 2019 were retrospectively selected and divided into group A and group B according to the supine or prone position,with 30 cases in each group.Cone beam CT(CBCT)was performed once a week.The set-up errors of translation,rotation and waistline were recorded offline,and the correlation between the changes of waistline and set-up errors were calculated.Results The translation errors of X,Y and Z directions in group A were(-0.5±2.7),(-0.1±3.2),(-0.4±2.5)mm,and(-0.2±3.0),(-0.2±4.0),(2.0±4.1)mm in group B;the rotation errors of Rx,Ry and Rz in group A were(-0.6±2.2),(-0.2±0.8),(0.1±0.8)°,and(0.5±2.3),(-0.2±1.3),(0.5±0.9)°in group B.In Z,Rx and Rz directions,the difference between two groups was statistically significant(P<0.05).The change of waistline△C in group A and B was(-2.3±2.7)and(-1.4±2.0)cm respectively,the difference between two groups was statistically significant(P<0.05).There was a negative correlation between error of Z direction in group B and change of waistline△C(r=-0.618,P<0.05).Conclusion In the supine position of cervical cancer radiotherapy,the repeatability is better,but the change of waistline will lead to serious adverse reactions.In the prone position,the protection of small bowel is better,but the change of waistline has a greater impact on the accuracy of Z direction.In clinic,the change of waistline should be paid attention and intervention of bladder filling and weight should be taken if necessary.