宫颈癌在图像引导调强放疗中摆位误差的分析  

Study in the setup errors with image guided radiation therapy for uterine cervix cancer

作　　者：王多明[1] 秦永辉[1] 古丽娜.库尔班 候友翔[1] 王若峥[1] 

机构地区：[1]新疆医科大学附属肿瘤医院放疗一科,乌鲁木齐830011

出　　处：《新疆医科大学学报》2012年第3期288-292,296,共6页Journal of Xinjiang Medical University

基　　金：国家自然科学基金资助项目(编号:30960432;81160327);新疆维吾尔自治区科技支疆项目(编号:200991137);新疆维吾尔自治区国际合作项目(编号:201141138);新疆维吾尔自治区自然基金资助项目(编号:2009211B09);乌鲁木齐市人才工程重点培养对象专项基金资助项目(编号:P112310001)

摘　　要：目的探讨宫颈癌在图像引导调强放射治疗中的摆位误差对靶区和危及器官剂量变化的影响。方法对22例宫颈癌患者分别在首次摆位后、摆位误差纠正后及治疗后验证采集3组锥形束CT图像,每周1次,获得首次摆位后、摆位误差纠正后及治疗后X(左右)、Y(腹背)、Z(头脚)方向偏移误差,计算出摆位误差值下靶区和危及器官剂量分布,对比分析摆位误差对靶区和危及器官剂量分布的影响。结果在X、Y、Z方向上首次摆位后系统误差±随机误差分别为(1.100±2.984)、(0.883±2.210)、(1.083±2.738)mm,纠正后X、Y、Z方向上的摆位误差分别为(0.200±0.708)、(0.061±0.624)、(0.066±0.606)mm与首次摆位误差比较差异均有统计学意义(P<0.05)。治疗后X、Y、Z方向轴上的摆位误差分别为(0.066±0.578)、(0.033±0.780)、(0.116±0.884)mm,与纠正后摆位误差比较差异均无统计学意义(P>0.05)。因摆位误差所致的宫颈癌原发肿瘤平均剂量变化为-2.58%～3.54%,股骨头平均剂量变化为-7.03%～8.45%,膀胱平均剂量变化为-12.28%～3.79%,小肠平均剂量变化为-3.06%～15.32%,直肠平均剂量变化范围为-10.53%～12.83%,脊髓平均剂量变化为-3.67%～18.14%。结论采用图像引导技术对宫颈癌的调强放疗进行误差纠正,可以缩小分次治疗间摆位误差,而宫颈癌分次治疗内摆位误差较小。宫颈癌的摆位误差可引起靶区和危及器官剂量明显变化,应用图像引导技术使靶区及周围正常组织器官剂量分布准确,提高放疗过程的精度,为临床放疗提供质量保证。Objective To study in the setup errors with image guided radiation therapy（IGRT） for uterine cervix cancer（UCC）,to evaluate the influence of the setup errors on the physics dose distribution of targets and peripheral organs at risk（OAR）.Methods Twenty two UCC patients were collected the images by cone beam computerized tomography（CBCT） after initial setup,after re-positioning and after radiation delivery,3 groups of CBCT scans were collected every week for one patient,and got the setup errors after initial setup,after re-positioning and after radiation delivery in X（left-right）,Y（ventral-dorsal） and Z（cranial-caudal） directions,calculated the influence of the setup errors on the physics dose distribution of targets and peripheral OAR.Results A total of 330 CBCT scans were obtained.The systematic±random errors in X,Y and Z directions were（1.100 0±2.984 1）,（0.883 3±2.210 1）,and（1.083 3±2.738 9） mm,respectively after initial setup,the setup errors in X,Y and Z directions were（0.200 0±0.708 3）,（0.061 7±0.624 1）,and（0.066 7±0.606 9） mm,respectively after re-positioning,and there was significant difference between the two.The setup errors in X,Y and Z directions were（0.066 7±0.578 3）,（0.033 3±0.780 4） and（0.116 7±0.884 7） mm,respectively after radiation delivery,but didn′t exist significant difference between after re-positioning and after radiation delivery.Because of setup errors,the mean dose variation of UCC gross tumor volume（GTV） was-2.58%~3.54%,the mean dose variation of femoral head was-7.03%~8.45%,the mean dose variation of bladder was-12.28%~3.79%,the mean dose variation of small intestine was-3.06%~15.32%,the mean dose variation of rectum was-10.53%~12.83%,the mean dose variation of spinal cord was-3.67%~18.14%.Conclusion Rectification UCC setup errors by IGRT could reduce inter fractionation setup errors,and intra fractionation setup errors couldn＇t influence radiation therapy.The setup errors may lead obviously targets and OA

关 键 词：宫颈癌 图像引导放射治疗 摆位误差 剂量分布 

分 类 号：R737.3[医药卫生—肿瘤] R730.5[医药卫生—临床医学]