我们回顾性地研究了表面导引放射治疗（SGRT）技术下，由Sentinel/Catalyst系统完成的深吸气屏气（DIBH）放射治疗在进行区域淋巴结照射（RNI）的右侧乳腺癌患者中剂量学和定位精度，旨在澄清其临床应用价值和相关问题。在满足剂量容积规定的情况下，比较了四个风险器官（OARs）的剂量学指标，即心脏、右冠状动脉（RCA）、右肺和肝脏。同时，根据呼吸门控的主要点的不同位置，将患者分为剑突某侧（EXP）、胸骨中部（SM）和左侧乳房壁（LBW）三组。对三组的CBCT定位误差数据进行了对比研究，比较了不同门控窗口高度对右侧肺容积增加的影响。与自由呼吸（FB）相比，DIBH降低了心脏和RCA的最大剂量，分别为739.3 ± 571.2 cGy和509.8 ± 403.8 cGy（p <0.05）。在平均剂量方面，肝脏变化最大（916.9 ± 318.9 cGy到281.2 ± 150.3 cGy，p <0.05）。EXP组的AP方向定位误差为3.6 ± 4.5 mm，是三组中最高的。EXP、SM和LBW组的右侧肺容积增加分别为72.3％、69.9％和67.2％（p = 0.08），对应的屏气高度分别为13.5 ± 3.7 mm、10.3 ± 2.4 mm和9.6 ± 2.8 mm（p <0.05）。SGRT技术的DIBH放射治疗可以更好地保护RNI的右侧乳腺癌患者的四个OARs。不同的呼吸门控主要点有不同的定位精度和屏气高度。

We retrospectively studied the dosimetry and setup accuracy of deep inspiration breath-hold (DIBH) radiotherapy in right-sided breast cancer patients with regional nodal irradiation (RNI) who had completed treatment based on surface-guided radiotherapy (SGRT) technology by Sentinel/Catalyst system, aiming to clarify the clinical application value and related issues.Dosimetric indicators of four organs at risk (OARs), namely the heart, right coronary artery (RCA), right lung, and liver, were compared on the premise that the planning target volume met dose-volume prescription requirements. Meanwhile, the patients were divided into the edge of the xiphoid process (EXP), sternum middle (SM), and left breast wall (LBW) groups according to different positions of respiratory gating primary points. The CBCT setup error data of the three groups were contrasted for the treatment accuracy study, and the effects of different gating window heights on the right lung volume increases were compared among the three groups.Compared with free breath (FB), DIBH reduced the maximum dose of heart and RCA by 739.3 ± 571.2 cGy and 509.8 ± 403.8 cGy, respectively (p < 0.05). The liver changed the most in terms of the mean dose (916.9 ± 318.9 cGy to 281.2 ± 150.3 cGy, p < 0.05). The setup error of the EXP group in the anterior-posterior (AP) direction was 3.6 ± 4.5 mm, which is the highest among the three groups. The right lung volume increases in the EXP, SM, and LBW groups were 72.3%, 69.9%, and 67.2%, respectively (p = 0.08), and the corresponding breath-holding heights were 13.5 ± 3.7 mm, 10.3 ± 2.4 mm, and 9.6 ± 2.8 mm, respectively (p < 0.05).SGRT-based DIBH radiotherapy can better protect the four OARs of right-sided breast cancer patients with RNI. Different respiratory gating primary points have different setup accuracy and breath-hold height.© 2023 The Authors. Journal of Applied Clinical Medical Physics published by Wiley Periodicals, LLC on behalf of The American Association of Physicists in Medicine.