ABSTRACT
Obj ective In the body of stereotactic radiotherapy ( SBRT ) , using Cone Beam is the matc-hing precision of soft tissue and bone anatomy ,translation between evaluation organization and internal organiza-tion in the rotation of the lung cancer patients with tumor location error ,location correction .Methods Applica-tion varian companies in the United States has the airborne imaging system clinac -ix linear accelerator apparatus treatment of 8 cases of lung cancer patients .By CBCT and SBRT comparison before and after the treatment for each patient and evaluate internal instant translation and rotation of the body of the patients with SBRT postures , tumor location and tumor center of baseline shift score changes .Results Based on the difference between of the anatomy of the bone and soft tissue match position is 3.0 mm(0~8.3 mm).The patient′s tumor location in 3-d median change is 1.4 mm(0~12.2 mm)and 12.2 mm(0~13.2 mm).The median baseline offset between 3 d score is 2.2 mm(0~4.7 mm).The rest of the system error and random error about 1 °.Conclusion In Lung cancer SBRT transformation to improve treatment of lung tumor process , change the position of tumor center is mainly affected by the body′s internal organization instant translation and rotation .