CBCT影像扫描系统与Sentinel激光扫描系统对摆位误差测量结果的比较研究

Comparison of CBCT imaging system and Sentinel laser scan system for measurement of setup errors

目的比较CBCT影像系统和Sentinel激光扫描系统对胸腹部肿瘤患者摆位误差测量结果的优劣。方法选取19例胸腹部肿瘤IMRT患者,放疗前行CBCT扫描,扫描的同时进行Sentinel激光扫描系统扫描并成像,得出x、y、z三个线性方向和u,v,w(绕x轴、y轴和z轴)的三个旋转方向的摆位误差值,并对两种测量结果行配对t检验。结果用CBCT每例患者摆位验证需114 s,而Sentinel仅需5 s。测量结果显示,两组数据线性误差在z轴(上下方向)存在差异(t=-4.243,P<0.05),旋转误差在v方向(绕y轴方向)上存在差异(t=5.667,P<0.05),其它方向差异不大。结论 CBCT对胸腹部肿瘤患者摆位误差的测量结果大部分优于Sentinel激光扫描系统,CBCT能对患者治疗摆位进行较为准确测量及校正,可作为治疗前的摆位校正依据。Sentinel激光扫描系统应用直观、简便、耗时短、可实时追踪,适合在患者位置校正后进行辅助监测。

Objective To measure the setup errors with CBCT imaging system and Sentinel laser scan system for the patient with thoracic and abdominal tumors and investigate the accuracy and practicality of them.Methods 19 patients with thoracic and abdominal tumors were included in this study,the first step took the CBCT images,then took the laser images while CBCT scanning. After this,we acquired the setup errors in x,y,z,u,v,w axies. The data of setup errors were compared with paired t-test. Results It took 114 s to complete the validating for each patient by CBCT system,while Sentinel system only needs 5s. The measurement results showed that two groups of data of linear error in the z axis,and rotating error in the v axis,the other direction had little difference. Conclusions The measurement results of setup errors for patients with thoracic and abdominal tumors show that CBCT is mostly better than Sentinel. CBCT can do better in accurate measurement and correction of the positioning treatment patients,it can be used as position adjustment basis before the treatment. Because of macroscopic,homely,spare time,Sentinel can be used easily as real-time monitoring after position correction by CBCT.