摘要
目的:研究MRI用于立体定向放射治疗(SRT)定位时误差的大小,明确MRI能否单独用于SRT定位。方法:模拟对病人的扫描方法,对特制体模进行固定和MRI扫描。在治疗计划系统上,测量x、y、z 3个方向靶点距离,并将结果与实际距离做比较,差别的绝对值即为该定位系统的误差。结果:相邻点x方向,误差0.2 ̄1.4 mm,平均0.9 mm;y方向误差0.3 ̄1.5 mm,平均0.9 mm。相对点x方向,误差0.3 ̄1.7 mm,平均0.9 mm;y方向,误差0.4 ̄1.8 mm,平均0.9 mm。各标记层面之间误差无显著性差别(P>0.05)。z方向误差0.3 ̄1.9 mm,平均1.0 mm。结论:本研究采用的立体定向定位系统和MRI扫描方法,用MRI进行影像采集制定SRT计划,对多数颅内和头颈部肿瘤的定位精度符合临床要求,但在将MRI进行SRT定位扫描时,必须作全面的检查和验证。
Objective: To measure the errors of magnetic resonance imaging ( MRI ) in the localization of stereotactic radiotherapy ( SRT ), and to confirm whether MRI can be used in the localization alone. Methods: A specially made phantom was used to acquire MRI images. In the treatment planning system, the distances between targets in x, y, and z directions were measured and compared with true values. The absolute values of the differences between the measured and true values were considered as the errors of the localization system. Results: The errors of adjacent points were in the range of 0.2 to 1.4 mm and 0.3 to 1.5 mm in x and y directions, respectively, and the average was 0.9 mm in beth x and y directions. The errors of opposite points were in the range of 0.3 to 1.7 mm and 0.4 to 1.8 mm in x and y directions, respectively, and the average was 0.9mm in beth x and y directions. There was no significant difference among 6 marked planes in beth x and y directions (P〉 0.05). Errors in z direction were in the range of 0.3 to 1.9 mm, and the average was 1.0 mm. Conclusion: MRI can be used alone in the localiz,ation of most brain tumors and head and neck tumors, but it is necessary to perform a comprehensive check when MRI is used in SRT localization.
出处
《中国医科大学学报》
CAS
CSCD
北大核心
2006年第5期540-542,共3页
Journal of China Medical University
关键词
立体定向放射治疗
磁共振成像
影像扭曲
stereotactic radiotherapy
magnetic resonance imaging
image distortion