Department of Radiation Oncology, Shenzhen People's Hospital (The Second Clinical Medical College, Jinan University; The First Affiliated Hospital, Southern University of Science and Technology), Shenzhen, Guangdong, People's Republic of China.
Sichuan Provincial Center for Disease Control and Prevention, Center for AIDS/STD Control and Prevention, Chengdu, Sichuan, People's Republic of China.
Acta Oncol. 2023 Dec;62(12):1873-1879. doi: 10.1080/0284186X.2023.2275288. Epub 2023 Nov 25.
BACKGROUND/PURPOSE: Gastric dose parameters comparison for deep inspiration breath-hold (DIBH) or free breathing (FB) mode during radiotherapy (RT) for left-sided breast cancer patients (LSBCPs) has not been investigated before. This study aimed to analyze the impact of Active Breath Coordinator (ABC)-DIBH technique on the dose received by the stomach during RT for LSBCPs and to provide organ-specific dosimetric parameters.
The study included 73 LSBCPs. The dosimetric parameters of the stomach were compared between FB and DIBH mode. The correlation between the stomach volume and dosimetric parameters was analyzed.
Compared to FB mode, statistically significant reductions were observed in gastric dose parameters in ABC-DIBH mode, including Dmax (46.60 vs 17.25, < 0.001), D1cc (38.42 vs 9.60, < 0.001), Dmean (4.10 vs 0.80, < 0.001), V40Gy (0.50 vs 0.00, < 0.001), V30Gy (6.30 vs 0.00, < 0.001), V20Gy (20.80 vs 0.00, < 0.001), V10Gy (51.10 vs 0.77, < 0.001), and V5Gy (93.20 vs 9.60, < 0.001). ABC-DIBH increased the distance between the stomach and the breast PTV when compared to FB, from 1.3 cm to 2.8 cm ( < 0.001). Physiologic decrease in stomach volume was not found from FB to ABC-DIBH (415.54 cm vs 411.61 cm, = 0.260). The stomach volume showed a positive correlation with V40Gy (r = 0.289; < 0.05), V30Gy (r = 0.287; < 0.05), V20Gy (r = 0.343; < 0.05), V10Gy (r = 0.039; < 0.001), V5Gy (r = 0.439; < 0.001), Dmax (r = 0.269; < 0.05) and D1cc (r = 0.278; < 0.05) in FB mode. While in ABC-DIBH mode, most stomach dosimetric parameters were not correlated with gastric volume.
The implementation of ABC-DIBH in LSBCPs radiotherapy resulted in lower irradiation of the stomach. Larger stomach volume was associated with statistically significantly higher dose irradiation in FB mode. To reduce radiotherapy related side effects in FB mode, patients should be fast for at least 2 hours before the CT simulation and treatment.
背景/目的：对于左侧乳腺癌患者（LSBCP）放疗期间深吸气屏气（DIBH）或自由呼吸（FB）模式的胃剂量参数比较尚未进行研究。本研究旨在分析主动呼吸控制（ABC）-DIBH 技术对 LSBCP 放疗期间胃接受剂量的影响，并提供器官特异性剂量学参数。
该研究纳入了 73 例 LSBCP。比较了 FB 和 DIBH 模式下胃的剂量参数。分析了胃体积与剂量参数之间的相关性。
与 FB 模式相比，ABC-DIBH 模式下胃剂量参数有统计学意义的降低，包括 Dmax（46.60 比 17.25， < 0.001）、D1cc（38.42 比 9.60， < 0.001）、Dmean（4.10 比 0.80， < 0.001）、V40Gy（0.50 比 0.00， < 0.001）、V30Gy（6.30 比 0.00， < 0.001）、V20Gy（20.80 比 0.00， < 0.001）、V10Gy（51.10 比 0.77， < 0.001）和 V5Gy（93.20 比 9.60， < 0.001）。与 FB 相比，ABC-DIBH 增加了胃与乳腺 PTV 之间的距离，从 1.3 厘米增加到 2.8 厘米（ < 0.001）。从 FB 到 ABC-DIBH 没有发现胃体积的生理性下降（415.54 cm 比 411.61 cm， = 0.260）。胃体积与 V40Gy（r = 0.289； < 0.05）、V30Gy（r = 0.287； < 0.05）、V20Gy（r = 0.343； < 0.05）、V10Gy（r = 0.039； < 0.001）、V5Gy（r = 0.439； < 0.001）、Dmax（r = 0.269； < 0.05）和 D1cc（r = 0.278； < 0.05）在 FB 模式中呈正相关。而在 ABC-DIBH 模式下，大多数胃剂量参数与胃体积无关。
在 LSBCP 放疗中实施 ABC-DIBH 可降低胃的照射剂量。较大的胃体积与 FB 模式下更高的剂量照射有统计学意义上的相关性。为了减少 FB 模式下放疗相关的副作用，患者应在 CT 模拟和治疗前至少禁食 2 小时。
