SU-E-J-48：立体定向体部放疗肺/肝患者放疗中的实时图像引导定位

SU-E-J-48: Real Time Image Guided Localization in SBRT Lung/Liver Patients Radiation Treatment.

作者信息

Liu Y, Campbell J

机构信息

INTEGRIS Cancer Institute of Oklahoma, Oklahoma City, OK.

出版信息

Med Phys. 2012 Jun;39(6Part6):3663. doi: 10.1118/1.4734883.

DOI:10.1118/1.4734883

PMID:28517575

Abstract

PURPOSE

Stereotactic body radiation therapy (SBRT) lung/liver patientradiation treatment requires high precision of patient position and target localization. For SBRT lung/liver patients positioning, cone beam CT imaging has been widely used, generally with zero couch rotation. The purpose of this study is to implement Stereotactic radiation surgery (SRS) patient positioning technology to SBRT by expanding patient positioning with couch rotation.

METHODS

A Varian® Novlis Tx for SRS treatment wasused to treat SBRT lung/liver patients implementing CBCT. BrainLAB® X-ray imaging system in conjunction with optical guidance is primarily used for SRS patients. CBCT and X-ray imaging system were independently calibrated with 1.0 mm accuracy. The X-ray imaging system was implemented through BrainLAB® ExacTrac system with CBCT localized position at the initial zero position for the X-ray imaging system. For the other couch positions, X-ray images were fused with patient DRRs for positioning.

RESULTS

Based on daily imaging QA records for a period oftwo years, the longitudinal, vertical and lateral coordination between CBCT and X-ray imaging average 0.3+/-0.5, 0.2+/-0.5 and 0.5+/-0.5 mm. The shiftfrom the CBCT imaging isocenter to the X-ray imaging isocenter is 0.5+/-0.5 mm accuracy for a 24-month period of tracking. Patient position accuracy: After initially localizing the patient with CBCT at the zero couch position, the patient was positioned with the X-ray imaging system. The computed translational and rotational shift accuracy are 0.5+/-0.5 mm and0.4+/-0.3 degree respectively, based on 66 SBRT lung/liver patients couchrotations.

CONCLUSIONS

Accurate coordination of CBCT and X-ray imaging in conjunction with optical imaging guidance can be expanded to patient positioning with couch rotation. The X-ray imaging capability at rotated-couch positions improved the physician confidence level during SBRT lung/liver patients treatment.

摘要

目的

立体定向体部放射治疗（SBRT）肺部/肝脏患者的放射治疗需要患者位置和靶区定位的高精度。对于SBRT肺部/肝脏患者的定位，锥形束CT成像已被广泛使用，通常是在治疗床零旋转的情况下。本研究的目的是通过扩展带治疗床旋转的患者定位，将立体定向放射外科（SRS）患者定位技术应用于SBRT。

方法

使用一台用于SRS治疗的瓦里安Novalis Tx治疗实施CBCT的SBRT肺部/肝脏患者。BrainLAB X射线成像系统结合光学引导主要用于SRS患者。CBCT和X射线成像系统分别以1.0毫米的精度进行校准。X射线成像系统通过BrainLAB ExacTrac系统实施，CBCT在X射线成像系统的初始零位置定位。对于其他治疗床位置，将X射线图像与患者数字重建放射影像（DRR）进行融合以进行定位。

结果

根据两年期间的每日成像质量保证记录，CBCT和X射线成像之间的纵向、垂直和横向坐标平均分别为0.3±0.5、0.2±0.5和0.5±0.5毫米。在24个月的跟踪期内，从CBCT成像等中心到X射线成像等中心的偏移精度为0.5±0.5毫米。患者位置精度：在最初使用CBCT在治疗床零位置对患者进行定位后，使用X射线成像系统对患者进行定位。基于66例SBRT肺部/肝脏患者的治疗床旋转，计算得出的平移和旋转偏移精度分别为0.5±0.5毫米和0.4±0.3度。