Dr. Abdurrahman Yurtaslan Ankara Oncology Teachingand Research Hospital, 06200, Ankara, Turkey.
J Xray Sci Technol. 2022;30(6):1057-1066. doi: 10.3233/XST-221228.
Voluntary deep inspiration breath hold (v-DIBH) reduces cardiac dose during left-sided breast irradiation. The purpose of this study is to evaluate the reproducibility and variability of breath-hold level (BHL) using breath-hold curves and lateral kV setup images together.
MATERIAL/METHOD: A retrospective analysis of 30 left breast cancer patients treated using the v-DIBH technique in our department is performed. The BHL difference is measured from breath hold curves and lateral (LAT) kilo-Voltage (kV) setup images. The planning CT image and the selected treatment fraction data are collected. If the changes in BHL relate to the displacement of various bones in the kV setup, images are assessed. Furthermore, the maximum heart distance inside the treatment field is compared from LAT MV portal images.
The median and mean values of the BHL are nearly identical in different fractions (good reproducibility). However, the mean BHL values between planning and all measured fractions are statistically different; 16.3 vs. 20.8 mm for the planning and measured fractions (p < 0.001), which indicates that the variability of BHL is significantly different.
While reproducibility testing shows good agreement for inter-fractional breath-hold level, the variability between planning and fractions is relatively poor.
自愿深吸气屏气（v-DIBH）可降低左侧乳房放疗中的心脏剂量。本研究的目的是通过屏息曲线和侧千伏（kV）设置图像一起评估屏息水平（BHL）的可重复性和可变性。
材料/方法：对我科 30 例采用 v-DIBH 技术治疗的左侧乳腺癌患者进行回顾性分析。从屏息曲线和侧（LAT）千伏（kV）设置图像测量 BHL 差异。收集计划 CT 图像和选定的治疗分次数据。如果 BHL 的变化与 kV 设置中各种骨骼的位移有关，则评估图像。此外，还比较了 LAT MV 端口图像中治疗野内最大心脏距离。
不同分次的 BHL 中位数和平均值几乎相同（具有良好的可重复性）。然而，计划和所有测量分次的平均 BHL 值之间存在统计学差异；计划和测量分次分别为 16.3mm 和 20.8mm（p<0.001），这表明 BHL 的可变性差异显著。
虽然重复性测试显示分次间屏息水平的一致性良好，但计划与分次之间的可变性相对较差。
