应用锥形束计算机断层扫描和机载影像系统分析鼻咽癌调强放疗的摆位误差比较  

Comparison of setup errors in intensity-modulated radiotherapy for nasopharyngeal carcinoma using cone-beam computed tomography and on board image systems

作　　者：张璋[1] 罗剑锋[1] 刘美莲[1] 王文华[2] ZHANG Zhang;LUO Jianfeng;LIU Meilian;WANG Wenhua(Department of Radiotherapy,Affiliated Hospital of Guilin Medical College,Guilin,Guangxi,541001,China;Department of Otolaryngology Head and Neck Surgery,Affiliated Hospital of Guilin Medical College,Guilin,Guangxi,541001,China)

机构地区：[1]桂林医学院附属医院放疗科,广西桂林541001 [2]桂林医学院附属医院耳鼻咽喉头颈外科,广西桂林541001

出　　处：《中国耳鼻咽喉头颈外科》2023年第1期5-9,共5页Chinese Archives of Otolaryngology-Head and Neck Surgery

基　　金：桂林市科技局立项自筹课题项目(2019414)。

摘　　要：目的探究鼻咽癌患者调强放射治疗(IMRT)中应用锥形束计算机断层扫描(CBCT)和机载影像系统(on Board Image,OBI)分析对摆位误差的影响。方法筛选2018年7月~2021年7月桂林医学院附属医院接诊的140例鼻咽癌患者进行分组对照研究,所有患者均依据数字表法随机分为CBCT组和OBI组,每组各70例患者。比较两组的摆位误差及放射剂量差异,分析CBCT、OBI系统在降低鼻咽癌患者IMRT的摆位误差中的价值。结果(1)相比于校正前,校正后两组的摆位误差均明显降低,并且相比于OBI组,校正后CBCT组的摆位误差明显更低(P均<0.05);(2)在降低鼻咽癌患者IMRT的摆位误差中,CBCT的ROC曲线下面积(area under curve,AUC)、特异度、敏感度与OBI对比均明显升高(Z=2.241,P<0.000);(3)相比于校正前,校正后两组的计划靶区边界(margins of planning target volume,MPTV)值均明显降低,并且相比于OBI组,校正后CBCT组的MPTV值明显更低(P均<0.05);(4)两组脑干、脊髓、晶状体和视交叉的实际剂量高于计划剂量,且CBCT组低于OBI组,差异有统计学意义(P<0.05)。结论鼻咽癌患者应用CBCT、OBI系统分析均可校正摆位误差,提高患者的摆位与调强放疗精确度。CBCT、OBI系统可以通过减少摆位误差,有可能进一步缩小计划靶区范围,从而减少靶区临近危机器官的照射剂量的临床目的。CBCT的作用更明显,是值得临床推广应用的方案。OBJECTIVE To investigate the effect of cone-beam computed tomography(CBCT)and on board image(OBI)system on positioning error in intensity modulated radiotherapy(IMRT)for patients with nasopharyngeal carcinoma.METHODS A total of 140 nasopharyngeal carcinoma patients were selected in this study in our hospital from July 2018 to July 2021.All patients were randomly divided into CBCT group and OBI group according to number table method,with 70 patients in each group.The positioning errors and radiation dose differences between the two groups were compared,and the value of CBCT and OBI system in reducing IMRT positioning errors in nasopharyngeal carcinoma patients was compared.RESULTS 1.The positioning errors of the two groups after correction significantly decreased than those before correction,and the positioning errors of the CBCT group after correction significantly decreased than those of the OBI group(P<0.05);2.In the reduction of IMRT positioning error in nasopharyngeal carcinoma patients,the AUC,specificity and sensitivity of CBCT significantly increased than those of OBI system(Z=2.241,P<0.000);3.The MPTV values of the two groups after correction were significantly lower than those before correction,and the MPTV values of the CBCT group after correction were significantly lower than those of the OBI group(P<0.05);4.Compared with the planned dose,the actual dose of brainstem,spinal cord,lens and optic chiasma in both groups significantly increased,and the CBCT group was lower than the OBI group,and the difference was statistically significant(P<0.05).CONCLUSION Using CBCT and OBI system,NPC patients can correct the positioning error and improve the accuracy of positioning of the intensity modulation radiotherapy.CBCT,OBI system can further reduce the planned target area,thus reducing the irradiation dose adjacent to the target area.The effect of CBCT is more obvious,which is worthy of clinical promotion and application.

关 键 词：鼻咽癌 锥形束计算机断层扫描 OBI系统 调强放疗 摆位误差 放射剂量 

分 类 号：R739.63[医药卫生—肿瘤] R730.55[医药卫生—临床医学]