摘要
背景与目的:准确的靶区位置是肺部肿瘤立体定向放疗的重要影响因素。该研究旨在分析在肺部肿瘤患者立体定向放疗中基于锥形束CT(cone-beam CT,CBCT)影像的摆位误差及其影响因素。方法:29例单发肺部恶性肿瘤行立体定向放疗的患者,每次放疗前行CBCT扫描,将得到的CBCT图像与定位CT图像匹配,获得前后、头脚和左右方向的摆位误差值,并计算临床靶区(clinical target volume,CTV)外扩至计划靶区(planning target volume,PTV)的边界。同时,还分析对可能影响摆位误差的临床参数等进行分层比较。结果:29例患者共获得155幅CBCT图像。考虑误差方向时前后、头脚和左右方向摆位误差分别为(-1.68±3.62)、(-1.34±3.90)和(0.36±2.15)mm,只考虑误差数值大小时分别为(3.16±2.42)、(3.29±2.48)和(1.74±1.30)mm。根据摆位误差得到CTV外扩至PTV的边界在前后、头脚和左右方向分别为9.6、10.0和5.3 mm。病灶位于周围的肺部肿瘤患者前后方向摆位误差更大(P=0.007),下肺病灶、右肺病灶、肺转移灶在头脚方向摆位误差更大(P=0.008、0.000和0.000)。结论:肺部肿瘤患者放疗中的头脚和前后方向摆位误差较大,立体定向放疗需采用锥形束CT扫描、呼吸控制等技术以减少摆位误差。
Background and purpose:Correct target positioning is an important factor affecting the precision of stereotactic body radiotherapy(SBRT)in patients with lung tumors.This study investigated the setup errors in patients with malignant lung tumors receiving SBRT with cone-beam CT(CBCT)and analyzed the factors influencing setup errors.Methods:Twenty-nine patients with solitary malignant lung tumors were enrolled in the study.Each patient underwent SBRT with CBCT before each treatment.Setup errors in CBCT were obtained according to the matched and planned CT images in anterior-posterior(AP),superior-inferior(SI)and left-right(LR)directions.The expanding margins of clinical target volume(CTV)to planning target volume(PTV)according to the analyzed setup errors were then calculated.And the influencing factors of setup errors were analyzed.Results:A total of155CBCT images from29patients were obtained during the treatment.The setup errors were(-1.68±3.62),(-1.34±3.90)and(0.36±2.15)mm in the AP,SI and LR directions,respectively.The absolute setup errors were(3.16±2.42),(3.29±2.48)and(1.74±1.30)mm in the AP,SI and LR directions,respectively.The suggested expanding margins of CTV to PTV were9.6,10.0and5.3mm in the AP,SI and LR directions according to the setup errors.The setup errors in the AP direction of peripheral lesions and in the SI direction of inferior,right and metastatic lesions were relatively larger(P=0.007,0.008,0.000and0.000)..Conclusion:In patients with malignant lung tumors receiving SBRT,the setup errors were more obvious in the SI and AP directions.Tumor motion management techniques including CBCT,breathholding technique are required to reduce the setup error in patients with lung tumors receiving SBRT.
作者
王焱
蔡钢
陆维
许青
WANG Yan;CAI Gang;LU Wei;XU Qing(Department of Radiation Oncology, Fudan University Shanghai Cancer Center, Department of Oncology, Shanghai Medical College, Fudan University Shanghai 200032, China;Department of Radiation Oncology, Ruijin Hospital, Shanghai Jiao Tong University School of Medical, Shanghai 200025, China)
出处
《中国癌症杂志》
CAS
CSCD
北大核心
2017年第6期501-504,共4页
China Oncology
关键词
锥形束CT
立体定向放疗
肺部肿瘤
摆位误差
Cone-beam CT
Stereotactic body radiotherapy
Lung neoplasms
Setup error
