摘要
目的探讨宫颈癌患者不同体位固定技术、脐平面体积变化(ΔV)、体重变化率(ΔW%)与放疗摆位误差的关系,并对计划靶区外扩边界(MPTV)提供建议。方法回顾性分析2022年6月至2023年5月于该院行宫颈癌放疗的57例患者临床资料,根据体位固定方式的不同分为观察组(采用体膜联合热塑型垫固定,n=24)和对照组(采用体膜固定,n=33),再按中位BMI分为BMI≥23.82 kg/m^(2)和BMI<23.82 kg/m^(2)患者。记录左右方向(X方向)、头脚方向(Y方向)、腹背方向(Z方向)摆位误差数据,同时记录首次CT定位图像的脐平面体积和定位前的患者体重,以及每周放疗过程中CBCT验证图像的脐平面体积和扫描前的患者体重,计算ΔV和ΔW%。比较两组摆位误差,分析总体患者、两组及不同BMI患者ΔV、ΔW%与摆位误差的相关性,计算X、Y、Z方向MPTV,采用受试者工作特征(ROC)曲线分析摆位误差达该院放疗科MPTV时ΔV、ΔW%截断值。结果与对照组比较,观察组X、Y、Z方向摆位误差更小,差异有统计学意义(P<0.05)。总体患者、对照组及BMI≥23.82 kg/m^(2)患者ΔV、ΔW%与X、Y方向摆位误差均呈正相关(P<0.05),观察组BMI<23.82 kg/m^(2)患者ΔW%与Z方向摆位误差呈正相关(P<0.05),对照组BMI≥23.82 kg/m^(2)患者ΔV、ΔW%与X、Y方向摆位误差呈正相关(P<0.05)。ROC曲线显示,Y方向摆位误差达本院放疗科MPTV时(8.41 mm),ΔV、ΔW%截断值分别为8.045 cm 3、4.12%。结论体膜联合热塑型垫固定技术可降低摆位误差及ΔV、ΔW%对X、Y方向摆位误差的影响,当该院患者ΔV、ΔW%超过截断值时应增加CBCT次数,必要时重新制作体膜。
Objective To investigate the relationship between different body position fixation techniques,umbilical plane volume change(ΔV),body weight change rate(ΔW%),and radiotherapy setup errors in cervical cancer patients,and to provide recommendations for determining the margin of planning target volume(MPTV).Methods A retrospective analysis was performed on the clinical data of 57 cervical cancer patients who underwent radiotherapy at this hospital from June 2022 to May 2023.Patients were divided into the observation group(fixed with body membrane+thermoplastic pad,n=24)and the control group(fixed with body membrane alone,n=33)based on different positioning fixation methods.They were also further stratified by median BMI into BMI≥23.82 kg/m^(2)and BMI<23.82 kg/m^(2)patients.Setup errors in the left-right(X),cranio-caudal(Y),and anterior-posterior(Z)directions were recorded.Meanwhile,the umbilical plane volume on the first CT positioning image and the patient’s body weight before positioning were recorded,as well as umbilical plane volume of cone-beam CT(CBCT)verification images during weekly radiotherapy and body weight before scan,theΔV andΔW%were calculated.Setup errors were compared between two groups,and correlations betweenΔV,ΔW%and setup errors were analyzed in all patients,in two groups(the observation group and the control group)and in two BMI subgroups.MPTV values in X,Y,and Z directions were calculated,and receiver operating characteristic(ROC)curve determined the cut off values ofΔV andΔW%when setup errors met the department’s MPTV criteria.Results Compared with the control group,the observation group showed significantly smaller setup errors in X,Y,and Z directions(P<0.05).BothΔV andΔW%were positively correlated with setup errors in X and Y direction in all patients,patients in the control group,and patients with BMI≥23.82 kg/m^(2)(P<0.05).In the observation group,ΔW%was positively correlated with setup errors in Z direction in patients with BMI<23.82 kg/m^(2)(P<0.05);In the control group,ΔV andΔW%were positively correlated with setup errors in X and Y direction in patients with BMI≥23.82 kg/m^(2).ROC curve analysis showed that when setup errors in Y direction reached the department’s MPTV criteria(8.41 mm),the cutoff valuesΔV andΔW%were 8.045 cm^(2)and 4.12%,respectively.Conclusion The body membrane+thermoplastic pad fixation technique reduces setup errors and mitigates the impact ofΔV andΔW%on setup errors in X and Y directions.WhenΔV orΔW%exceeds the cutoff values,increasing CBCT verification frequency and re-fabricating the body membrane are recommended.
作者
吴珊瑜
黄勇志
蔡栋荣
傅秋萍
陈耀桐
王燕红
WU Shanyu;HUANG Yongzhi;CAI Dongrong;FU Qiuping;CHEN Yaotong;WANG Yanhong(Department of Radiotherapy,the Second Affiliated Hospital of Fujian Medical University,Quanzhou,Fujian 362300,China)
出处
《重庆医学》
2025年第6期1334-1338,共5页
Chongqing Medical Journal
基金
福建省自然科学基金面上项目(2020J01210)
关键词
宫颈癌
热塑型垫
脐平面体积
体重变化
摆位误差
cervical cancer
thermoplastic pad
umbilical plane volume
body weight change
setup error
作者简介
通信作者:王燕红,E-mail:992415639@qq.com。
