Radiation Physics Laboratory, Sydney Medical School, The University of Sydney, Sidney, NSW, Australia.
School of Mathematical and Physical Sciences, The University of Newcastle, Newcastle, NSW, Australia; Department of Radiation Oncology, Calvary Mater Newcastle, Newcastle, NSW, Australia.
Int J Radiat Oncol Biol Phys. 2016 Mar 1;94(3):628-36. doi: 10.1016/j.ijrobp.2015.11.017. Epub 2015 Nov 18.
To assess the impact of an audiovisual (AV) biofeedback on intra- and interfraction tumor motion for lung cancer patients.
Lung tumor motion was investigated in 9 lung cancer patients who underwent a breathing training session with AV biofeedback before 2 3T magnetic resonance imaging (MRI) sessions. The breathing training session was performed to allow patients to become familiar with AV biofeedback, which uses a guiding wave customized for each patient according to a reference breathing pattern. In the first MRI session (pretreatment), 2-dimensional cine-MR images with (1) free breathing (FB) and (2) AV biofeedback were obtained, and the second MRI session was repeated within 3-6 weeks (mid-treatment). Lung tumors were directly measured from cine-MR images using an auto-segmentation technique; the centroid and outlier motions of the lung tumors were measured from the segmented tumors. Free breathing and AV biofeedback were compared using several metrics: intra- and interfraction tumor motion consistency in displacement and period, and the outlier motion ratio.
Compared with FB, AV biofeedback improved intrafraction tumor motion consistency by 34% in displacement (P=.019) and by 73% in period (P<.001). Compared with FB, AV biofeedback improved interfraction tumor motion consistency by 42% in displacement (P<.046) and by 74% in period (P=.005). Compared with FB, AV biofeedback reduced the outlier motion ratio by 21% (P<.001).
These results demonstrated that AV biofeedback significantly improved intra- and interfraction lung tumor motion consistency for lung cancer patients. These results demonstrate that AV biofeedback can facilitate consistent tumor motion, which is advantageous toward achieving more accurate medical imaging and radiation therapy procedures.
评估视听（AV）生物反馈对肺癌患者肿瘤内和肿瘤间运动的影响。
对 9 例肺癌患者进行了研究，这些患者在 2 次 3T 磁共振成像（MRI）检查前进行了带 AV 生物反馈的呼吸训练。呼吸训练旨在使患者熟悉 AV 生物反馈，该反馈根据参考呼吸模式为每位患者定制引导波。在第一次 MRI 检查（预处理）中，获得了（1）自由呼吸（FB）和（2）AV 生物反馈的二维电影-MR 图像，并且在 3-6 周内重复进行了第二次 MRI 检查（中期治疗）。使用自动分割技术直接从电影-MR 图像测量肺肿瘤；从分割的肿瘤中测量肺肿瘤的质心和离群运动。使用几个指标比较了自由呼吸和 AV 生物反馈：位移和周期内和内肿瘤运动的一致性，以及离群运动的比例。
与 FB 相比，AV 生物反馈在位移方面提高了 34％的分运动一致性（P=.019），在周期方面提高了 73％（P<.001）。与 FB 相比，AV 生物反馈在位移方面提高了 42％的间运动一致性（P<.046），在周期方面提高了 74％（P=.005）。与 FB 相比，AV 生物反馈减少了 21％的离群运动比（P<.001）。
这些结果表明，AV 生物反馈显著改善了肺癌患者的肿瘤内和肿瘤间运动一致性。这些结果表明，AV 生物反馈可以促进一致的肿瘤运动，这有利于实现更准确的医学成像和放射治疗程序。
