主动呼吸控制与自由呼吸配合bodyfix固定装置用于胸部肿瘤SBRT对比研究

目的 初步比较主动呼吸控制(ABC)技术与自由呼吸(FB)模式配合bodyfix固定装置在胸部肿瘤立体定向放疗(SBRT)的差异。方法 随机选取 40例胸部肿瘤行SBRT患者,均分为ABC组和FB组。两组采用bodyfix固定装置固定后CBCT扫描图像与计划参考图像配准,得到左右、头脚、前后方向平移误差。校正摆位误差后SBRT同时逐弧行分次内CBCT并配准,直至治疗结束。结果 ABC组患者配准后左右、头脚、前后方向摆位误差分别为(0.25±0.21)、(0.28±0.21)、(0.21±0.24) cm,FB组的分别为(0.31±0.22)、(0.32±0.21)、(0.37±0.23) cm (均 P<0.05)。心 脏V30Gy、患侧 肺V20Gy、V30GyABC组患者明显低于FB组患者(0.31%∶7.35%、24.5%∶32.9%、19.5%∶25.8%,均 P<0.05)。结论 ABC技术配合bodyfix固定装置在胸部肿瘤SBRT中可能优于FB模式,建议大样本进一步研究。

Preliminary comparative study of active breathing coordinator and free breathing combined with bodyfix fixation device in stereotactic radiotherapy of thoracic tumors

Objective To compare the difference between active breathing coordinator (ABC) technique and free breathing (FB) mode combined with bodyfix stereotactic radiotherapy (SBRT) for chest tumors. Methods 40 thoracic tumor patients receiving SBRT were randomly selected and divided into the ABC technique group and FB model group. After fixation with bodyfix fixing devices in two groups, cone-beam CT (CBCT) scan images before each SBRT were matched with the plan reference images. The setup errors in the left-right (LR), superior-inferior (SI) and anterior-post (AP) directions were obtained. Then, the setup errors were corrected. SBRT was performed and split intra-fraction CBCT was conducted simultaneously, which was repeated until the end of treatment. Results In the ABC technique group, the setup errors in the LR, SI and AP directions were (0.25±0.21) cm,(0.28±0.21) cm, and (0.21±0.24) cm, significantly less compared with (0.31±0.22) cm,(0.32±0.21) cm and (0.37±0.23) cm in the FB model group (all P<0.05). The V30Gy of the heart, the V20Gy and V30Gy of the lung in the ABC technique group were significantly less than those in the FB model group (0.31%∶7.35%;24.5%∶32.9%;19.5%∶25.8%, all P<0.05). Conclusions ABC technique combined with bodyfix fixation device may be superior to FB mode in SBRT for chest tumors, which remains to be validated by subsequent studies with large samples.