两种不同体位固定装置在肿瘤患者放疗中的应用研究

A Study on the Application of Two Different Position Fixation Devices in Radiotherapy of Tumor Patients

目的比较热塑个体化体垫联合体模、体架固定技术与体模联合体架固定技术对肿瘤放疗摆位误差的影响。方法采用热塑个体化体垫联合体模、体架固定技术与体模联合体架固定的患者(A组)52例,体模联合体架固定的患者(B组)58例,在放射治疗前、治疗2周、治疗4周各进行一次模拟定位机复位、采集图像(治疗次数少的腹盆肿瘤治疗前、治疗2周各复位一次,采集图像),对其X轴、Y轴和Z轴方向的摆位误差进行比较分析。结果总体而言,A组在放疗前、治疗第2周Y轴及Z轴方向摆位误差比B组更小(P<0.05),余无统计学差异。对不同部位的肿瘤分层分析,头颈部肿瘤:A组在放疗前X轴、Y轴,放疗2周Y轴、X轴,放疗4周Y轴的摆位误差小于B组(P<0.05),余差异无统计学意义(P>0.05);胸部肿瘤:A组与B组相比,除放疗前X轴、放疗2周X轴方向无统计学差异,其余A组摆位误差均小于B组(P<0.05);腹盆腔肿瘤:A组放疗前Y轴、放疗2周X、Y、Z轴各方向摆位误差小于B组(P<0.05),余无统计学差异。对头颈部肿瘤不同放疗时间点摆位误差比较分析,X轴放疗4周的摆位误差明显大于放疗前(P<0.05);Y轴放疗前与放疗4周,放疗2周与放疗4周比较有统计学差异(P<0.05),放疗摆位误差随时间延长而增大。结论针对不同部位的恶性肿瘤,热塑个体化体垫联合体模、体架固定技术摆位误差更小,具有更好的治疗精准性。对于头颈部恶性肿瘤,放疗4周摆位误差明显大于放疗前,若条件允许建议重新定位、制定放疗计划。

Objective To compare the effects of thermoplastic individual body pad combined with phantom,body frame fixation technology and phantom combined with body frame fixation technology on tumor radiotherapy setup error.Methods 52 patients were treated with thermoplastic individual body pad combined with phantom,body frame fixation technique(group A),and 58 patients were treated with phantom combined with body frame fixation(group B).Before radiotherapy,2 weeks and 4 weeks of treatment,simulated locator reduction was performed and images were collected(abdominal and pelvic tumors with less times of treatment were repositioned once before treatment and 2 weeks after treatment).The setup errors of X axis,Y axis and Z axis were compared and analyzed.Results The setup errors of Y axis and Z axis in group A were smaller than that in group B before radiotherapy and the second week of treatment(P<0.05).The others were no significant differences(P>0.05).The stratification of tumors in different parts were analyzed.In head and neck tumors,the setup errors of X axis,Y axis before radiotherapy,Y axis 2 weeks after radiotherapy and Y axis 4 weeks after radiotherapy in group A were less than those in group B(P<0.05).The others were no significant differences(P>0.05).In chest tumors,except X axis before radiotherapy and X axis direction 2 weeks after radiotherapy,the setup errors in group A were less than those in group B(P<0.05).In abdominal and pelvic tumors,the setup errors of Y axis and X,Y and Z axis 2 weeks before radiotherapy in group A were less than those in group B(P<0.05).The others were no significant differences.According to the comparative analysis of the setup errors of head and neck tumors at different time points of radiotherapy,the setup errors of X-axis radiotherapy at 4 weeks were significantly higher than that before radiotherapy(P<0.05).There were significant differences in Y-axis between before radiotherapy and 4 weeks of radiotherapy,2 weeks and 4 weeks of radiotherapy(P<0.05),and the setup errors of radiotherapy increased with time.Conclusion For different malignant tumors,the setup errors of thermoplastic individual body pad combined with phantom and frame fixation are smaller and has better therapeutic accuracy.For head and neck malignant tumors,the setup error of 4 weeks of radiotherapy is si-[LM]gnificantly larger than that before radiotherapy.If conditions permit,it is recommended to relocate and make radiotherapy plans.