Prostate gland motion assessed with cine-magnetic resonance imaging (cine-MRI)
Prostate gland motion assessed with cine-magnetic resonance imaging (cine-MRI)
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DOI：
10.1016/j.ijrobp.2003.10.017
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发表时间：
2005-06-01
影响因子：
7
通讯作者：
Martinez, AA
中科院分区：
文献类型：
--
作者：
Ghilezan, MJ;Jaffray, DA;Martinez, AA
目的：为了量化前列腺运动在放射治疗过程中使用电影磁共振成像（eine-MRI）的时间框架相比，预期在图像引导的放射治疗治疗session（20-30 min）。材料和方法：6例患者接受放射治疗的前列腺癌成像3天，在治疗过程中（第1，3和5周）。在1小时的MRI会话期间，以6秒的间隔在3个矢状面通过前列腺采集了400张图像。已使用11个解剖学兴趣点（POI）来表征前列腺/骨性骨盆/腹壁移位。已经确定了11个POI中的每个POI的运动轨迹和标准偏差。随着时间的推移位移的概率也calculated.Results：患者被分为2组，根据直肠充盈状态：满与空直肠。全直肠组POI的位移（标准差）范围为0.98至1.72 mm，空直肠组为0.68至1.04 mm。位置的低标准差（2 mm或更小）表明这些偏移的发生频率较低。对直肠壁运动最敏感的前列腺POI是中后部，全直肠组的标准差为1.72 mm，空直肠组为0.79 mm（p = 0.0001）。这POI有一个10%的概率移动超过3毫米的时间范围内类似于1分钟，如果直肠是满的vs.类似于20分钟，如果直肠是empty.Conclusion：运动的前列腺和精囊在一个时间范围内类似于一个标准的治疗会话减少相比，interfraction的研究报告。前列腺运动的最重要的预测因素是直肠充盈的状态。对于直肠排空的患者，在初始成像后20分钟内，预计前列腺移位< 3 mm（90%）。这不是病人的情况下提出了完整的直肠。在放射治疗中确定适当的分次内边缘以适应位置靶向中的时间依赖性不确定性是在线图像引导模型的正在进行的调查的主题。(c)2005年爱思唯尔公司
Purpose: To quantify prostate motion during a radiation therapy treatment using cine-magnetic resonance imaging (eine-MRI) for time frames comparable to that expected in an image-guided radiation therapy treatment session (20-30 min).Materials and Methods: Six patients undergoing radiation therapy for prostate cancer were imaged on 3 days, over the course of therapy (Weeks 1, 3, and 5). Four hundred images were acquired during the 1-h MRI session in 3 sagittal planes through the prostate at 6-s intervals. Eleven anatomic points of interest (POIs) have been used to characterize prostate/bony pelvis/abdominal wall displacement. Motion traces and standard deviation for each of the 11 POIs have been determined. The probability of displacement over time has also been calculated.Results: Patients were divided into 2 groups according to rectal filling status: full vs. empty rectum. The displacement of POIs (standard deviation) ranged from 0.98 to 1.72 mm for the full-rectum group and from 0.68 to 1.04 mm for the empty-rectum group. The low standard deviations in position (2 mm or less) would suggest that these excursions have a low frequency of occurrence. The most sensitive prostate POI to rectal wall motion was the midposterior with a standard deviation of 1.72 mm in the full-rectum group vs. 0.79 mm in the empty-rectum group (p = 0.0001). This POI has a 10% probability of moving more than 3 mm in a time frame of similar to 1 min if the rectum is full vs. similar to 20 min if the rectum is empty.Conclusion: Motion of the prostate and seminal vesicles during a time frame similar to a standard treatment session is reduced compared to that reported in interfraction studies. The most significant predictor for intrafraction prostate motion is the status of rectal filling. A prostate displacement of < 3 mm (90%) can be expected for the 20 min after the moment of initial imaging for patients with an empty rectum. This is not the case for patients presenting with full rectum. The determination of appropriate intrafraction margins in radiation therapy to accommodate the time-dependent uncertainty in positional targeting is a topic of ongoing investigations for the on-line image guidance model. (c) 2005 Elsevier Inc.