Clinical application of stereotactic radiotherapy in treatment of lung cancer / 第三军医大学学报

ABSTRACT

Objective　To study the indication, contraindication and short-term clinical effects of stereotactic radiotherapy (X-knife) in lung cancer. Methods　A total of 56 cases (Treatment group) of lung cancer were treated with X-knife composing of the modern 3-D treatment planning system and the stereotactic body frame, and SL-75 accelerator. And another 53 cases only treated with routine external radiation served as the control. In treatment group, 42 cases received 50 Gy radiation, at 2 Gy per day, 5 d per week in the upper mediastinum, hilus of lung, below the primary focus first and then underwent X-knife for the primary focuses, and other 14 recurrent and metastatic cases received irradiation of 8-12 Gy per day, 5 d by X-knife alone. Results　The actually reexamination rate for 1, 3, 6, and 12 months after X-knife treatment in 78 focuses from 56 cases was 79.5% (62/78), 89.8% (70/78), 87.2% (68/78) and 78.2% (61/78) respectively. The focuses reappeared in 3 months after the treatment and the growth rates of focus in 3, 6, and 12 month after the treatment were 2.6% (2/78), 5.1% and 9% (7/78) respectively. There were 2 focuses received a second treatment with X-knife because no change after the first one. Both the 1-and 2-year survival rates of 36 cases of the primary lung cancer in the treatment group were higher than that of control group (89.1%, 53.9% and 77.4%, 39.6%). Conclusion　The stereotactic radiotherapy is of applicable and prospective in the treatment of lung cancer. The indications include ①As a boost dose in case when primary focus is less than 5 cm after the first external radiotherapy may reduce the exposure of lung tissue to x-ray and the occurrence of radiation pneumonia; ②Treatment for the recurrence after radiotherapy and operation; ③Radical treatment for the metastatic focus less than 5 cm. Attention must be paid to when multiple treatment is carried on the volume of the focus, the Karnofsky scores and the general condition when stereotactic radiotherapy combined with X-knife for lung cancer.