Abstract：Objective To evaluate the importance of the application of ExacTrac 6D image-guidance system
in non-coplanar arcs stereotactic radiosurgery treatment of stereotactic radiotherapy surgery (SRS) based on
comparing the setup error before and after the reset. Methods From August 2014 to December 2015, a total of
89 brain metastases patients who were treated with SRS were chosen to perform the research. Firstly, the X-ray
imaging device of ExacTrac system was used to shoot 2 X-ray images on the target area before treatment and
after the table were rotated to a fixed angle, respectively. Then, they were separately matched with the X-ray
images that were automatic processed based on the CT data. In this case, the X, Y, Z direction of 3 translation
and rotation errors (6D error) of the former were gained. In the following, a key reset placement correction
was performed. Finally, ExacTrac 6D image-guidance system were utilized to validate the 6D error of
the patients’ position. Results Before the treatment when the table placed in 0° angle, three linear error
was less than 1.0 mm and 3 rotation error was less than 0.5° after using the X-ray images to guide a key
reset, which satisfied the requirement of the SRS radiotherapy. Meanwhile, the 6D errors were much
smaller than the positioning error correction before, the differences were significant (P<0.05). When the
table was rotated to the setting angle, the use of verification images could adequately reduce the error
associated with intrafraction patient movement in all 3 translations and rotations. The differences were
significant (P<0.05). Conclusion Application of ExacTrac 6D image-guidance system in non-coplanar
arcs stereotactic radiosurgery treatment is feasible. In addition, it can obviously reduce the positioning
error caused by rotating the table during frameless stereotactic radiosurgery.
张平a，罗龙辉a，戴鹏a，
周巧敏a，吴伟a，黄庆b. ExacTrac 6D影像精确引导系统在脑转移瘤SRS中的应用[J]. 中国医疗设备, 2017, 32(5): 40-43.
ZHANG Pinga, LUO Long-huia,
DAI Penga, ZHOU Qiao-mina,
WU Weia, HUANG Qingb. Application of ExacTrac 6D Image-Guidance System in Stereotactic
Radiotherapy Surgery Treatment of Brain Metastasis. China Medical Devices, 2017, 32(5): 40-43.
