Automated daily breath hold stability measurements by real-time imaging in radiotherapy of breast cancer
Automated daily breath hold stability measurements by real-time imaging in radiotherapy of breast cancer
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DOI：
10.1016/j.radonc.2016.02.012
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发表时间：
2016-04-01
影响因子：
5.7
通讯作者：
van Asselen, Bram
中科院分区：
文献类型：
--
作者：
de Boer, Hans C. J.;van den Bongard, Desiree J. G.;van Asselen, Bram
背景和目的：屏气越来越多地用于左侧乳腺癌放疗中的心脏保护。我们已经开发出一种快速自动化的方法来验证屏气稳定性，在每个治疗fraction.Material和方法：我们评估了504例患者屏气治疗。中度深吸气屏气是听觉引导的。在单次屏气中输送内侧和外侧大切向场片段，并使用EPID采集这些场的动态回放。在每帧中自动检测胸壁位置，并确定胸壁运动的全范围（RTWM）。结果：2.8%的患者出现屏气不稳，其中2.8%的患者出现屏气不稳，其余患者均未出现屏气不稳。然而，这一频率从最初6个月的9.5%下降到随后16个月的1.6%。97%正确屏气的患者表现出良好的稳定性：平均RTWM为0.9 +/- 0.5 mm。屏气深度的可重复性得到以下证实：（1）在一个片段内，内侧和外侧野胸壁位置之间的差异很小;（2）屏气患者的摆位误差与右侧患者无显著差异。结论：我们已经开发并临床应用了一种成像工具，以自动确定在射束输送期间每个治疗部分中屏气的稳定性。(C)2016爱思唯尔爱尔兰有限公司版权所有。
Background and purpose: Breath hold is increasingly used for cardiac sparing in left-sided breast cancer irradiation. We have developed a fast automated method to verify breath hold stability in each treatment fraction.Material and methods: We evaluated 504 patients treated with breath hold. Moderate deep inspiration breath hold was audio-guided. Medial and lateral large tangential field segments were delivered in a single breath hold and movieloops of these fields were acquired with an EPID. The thoracic wall position was automatically detected in each frame and the full range of thoracic wall motion (RTWM) was determined. If the RTWM >4 mm more than 3 times, the patient was excluded from breath hold treatment if further coaching did not yield improvement.Results: Unstable breath hold was observed in 2.8% of the patients. However, this frequency dropped from 9.5% in the first 6 months to 1.6% in the subsequent 16 months. The 97% of patients with proper breath hold showed excellent stability: the average RTWM was 0.9 +/- 0.5 mm. The reproducibility of the breath hold depth was confirmed by (1) the small difference between the thoracic wall positions in the medial and lateral fields within one fraction and (2) the setup errors of breath hold patients showed no significant differences with those of right-sided breast patients.Conclusions: We have developed and clinically applied an imaging tool to automatically determine stability of breath holds in each treatment fraction during beam delivery. (C) 2016 Elsevier Ireland Ltd. All rights reserved.