Department of Radiology, German Cancer Research Center, Heidelberg, Germany.
Strahlenther Onkol. 2011 Jul;187(7):426-32. doi: 10.1007/s00066-011-2201-2. Epub 2011 Jun 27.
To investigate prostate movement during deep breathing and contraction of abdominal musculature by means of dynamic MRI and analyze implications for image-guided radiotherapy of prostate cancer.
A total of 43 patients and 8 healthy volunteers were examined with MRI. Images during deep respiration and during contraction of abdominal musculature (via a coughing maneuver) were obtained with dynamic two-dimensional (2D) balanced SSFP; 3 frames/s were obtained over an acquisition time of 15 s. Images were acquired in sagittal orientation to evaluate motion along both the craniocaudal (cc)-axis and anteroposterior (ap)-axis. Prostate motion was quantified semi-automatically using dedicated software tools.
Respiratory induced mean cc-axis displacement of the prostate was 2.7 ± 1.9 (SD) mm (range, 0.5-10.6 mm) and mean ap-axis displacement 1.8 ± 1.0 (SD) mm (range, 0.3-10 mm). In 69% of the subjects, breathing-related prostate movements were found to be negligible (< 3 mm). The prostate displacement for abdominal contraction was significantly higher: mean cc-axis displacement was max. 8.4 ± 6.7 (SD) mm (range, 0.6-27 mm); mean anteroposterior movement was 8.3 ± 7.7 (SD) mm (range, 0.7-26 mm).
Dynamic MRI is an excellent tool for noninvasive real-time imaging of prostate movement. Further investigations regarding possible applications in image-guided radiotherapy, e.g., for individualized planning and in integrated linac/MRI systems, are warranted.
通过动态 MRI 研究前列腺在深呼吸和腹部肌肉收缩时的运动，并分析其对前列腺癌图像引导放疗的影响。
共 43 例患者和 8 例健康志愿者接受 MRI 检查。通过动态二维（2D）平衡稳态自由进动（SSFP）采集在深呼吸和腹部肌肉收缩（咳嗽动作）时的图像，采集时间为 15 秒，共获得 3 个时相。采集矢状位图像以评估沿头尾（cc）轴和前后（ap）轴的运动。使用专用软件工具半自动量化前列腺运动。
呼吸引起的前列腺 cc 轴平均位移为 2.7 ± 1.9（SD）mm（范围，0.5-10.6 mm），ap 轴平均位移为 1.8 ± 1.0（SD）mm（范围，0.3-10 mm）。在 69%的受试者中，呼吸相关的前列腺运动可忽略不计（<3mm）。腹部收缩引起的前列腺位移明显更高：cc 轴最大平均位移为 8.4 ± 6.7（SD）mm（范围，0.6-27 mm）；ap 轴平均移动为 8.3 ± 7.7（SD）mm（范围，0.7-26 mm）。
动态 MRI 是一种用于非侵入性实时成像前列腺运动的优秀工具。进一步的研究对于图像引导放疗中的可能应用是必要的，例如个体化计划和集成直线加速器/MRI 系统。
