此研究的目的是评估涉及野放射治疗下受累区域在呼吸自由、腹式深吸气屏气与胸式深呼气屏气情况下的肺和心脏剂量。使用25位乳腺癌患者的腹式深吸气屏气、胸式深呼气屏气和呼吸自由的计算机断层扫描图像模拟了食管癌患者的情况。辐射区域设定为累及区，通过一致性标准勾画出靶区和危险器官。进行涉及野放射治疗模式优化，并评估肺和心脏剂量。腹式深吸气屏气下的肺部V20 Gy剂量、V40 Gy剂量和V30 Gy剂量均低于呼吸自由和胸式深呼气屏气下。胸式深呼气屏气下的心脏所有剂量指数均低于呼吸自由，而腹式深吸气屏气下的心脏V10 Gy剂量低于呼吸自由。然而，腹式深吸气屏气下的心脏Dmean剂量与胸式深呼气屏气相当。相比呼吸自由和胸式深呼气屏气，腹式深吸气屏气对肺部具有明显的剂量优势，并且心脏Dmean剂量与胸式深呼气屏气相当。因此，在进行胸式深呼气屏气放射治疗时，在不涉及预防区域的情况下，建议采用腹式深吸气屏气。

The purpose of this study was to evaluate the lung and heart doses in volumetric-modulated arc therapy (VMAT) using involved-field irradiation in patients with middle-to-lower thoracic esophageal cancer during free breathing (FB), abdominal deep inspiratory breath-hold (A-DIBH), and thoracic DIBH (T-DIBH) images.Computed tomography images of A-DIBH, T-DIBH, and FB from 25 patients with breast cancer were used to simulate patients with esophageal cancer. The irradiation field was set at an involved-field, and target and risk organs were outlined according to uniform criteria. VMAT optimization was performed, and lung and heart doses were evaluated.A-DIBH had a lower lung V20 Gy than FB and a lower lung V40 Gy, V30 Gy, V20 Gy than T-DIBH. The heart all dose indices were lower in T-DIBH than FB, and the heart V10 Gy was lower in A-DIBH than FB. However, the heart Dmean was comparable with A-DIBH and T-DIBH.A-DIBH had significant dose advantages for lungs compared to FB and T-DIBH, and the heart Dmean was comparable to T-DIBH. Therefore, when performing DIBH, A-DIBH is suggested for radiotherapy in patients with middle-to-lower thoracic esophageal cancer, excluding irradiation of the prophylactic area.