Stereotactic radiotherapy of extracranial targets:: CT-simulation and accuracy of treatment in the stereotactic body frame
Stereotactic radiotherapy of extracranial targets:: CT-simulation and accuracy of treatment in the stereotactic body frame
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DOI：
10.1016/s0167-8140(00)00226-7
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发表时间：
2000-11-01
影响因子：
5.7
通讯作者：
Flentje, M
中科院分区：
文献类型：
--
作者：
Wulf, J;Hädinger, U;Flentje, M
背景和目的：由斯德哥尔摩Karolinska医院的Blomgren和Lax设计的立体定向体架（SBF）中的设置准确度评价和靶点再现性分析。分析了不同类型靶点的靶点偏离风险。材料与方法：对30例原发性或转移性周围型肺癌、肝转移瘤、腹部和盆腔肿瘤复发或骨转移瘤患者的32个靶点进行SBF治疗。通过CT模拟和端口电影评估设置精度和目标移动性。通过匹配CT切片，比较等中心水平的靶区轮廓、骨性结构和身体轮廓，以SBF的立体定向坐标作为外部参考系统进行治疗计划和模拟。结果：以骨性结构为代表的摆位精度的标准差（SD）纵向为3.5 mm，前后向为2.2 mm，横向为3.9 mm。目标再现性显示校正前纵向SD为4.4 mm，ap为3.4 mm，横向SD为3.3 mm。目标偏差与骨骼的相关性范围从33%（软组织目标）到100%（骨骼）。结论：如果在每次治疗前进行CT模拟以纠正较大的目标偏差或设置错误，则PTV定义的5 mm安全裕度是足够的。相对于骨结构的等中心验证仅对骨目标安全，但对软组织目标不安全。(C)2000爱思唯尔科学爱尔兰有限公司保留所有权利。
Background and purpose: Evaluation of set-up accuracy and analysis of target reproducibility in the stereotactic body frame (SBF), designed by Blomgren and Lax from Karolinska Hospital, Stockholm. Different types of targets were analyzed for the risk of target deviation. The correlation of target deviation to bony structures was analyzed to evaluate the value of bones as reference structures for isocenter verification.Materials and methods: Thirty patients with 32 targets were treated in the SBF for primary or metastatic peripheral lung cancer, liver metastases, abdominal and pelvic tumor recurrences or bone metastases. Set-up accuracy and target mobility were evaluated by CT-simulation and port films. The contours of the target at isocenter level, bony structures and body outline were compared by matching the CT-slices for treatment planning and simulation using the stereotactic coordinates of the SBF as external reference system. The matching procedure was performed by using a 3D treatment planning program.Results: Set-up accuracy represented by bony structures revealed standard deviations (SD) of 3.5 mm in longitudinal, 2.2 mm in anterior-posterior and 3.9 mm in lateral directions. Target reproducibility showed a SD of 4.4 mm in longitudinal, 3.4 mm ap and 3.3 mm in lateral direction prior to correction. Correlation of target deviation to bones ranged from 33% (soft tissue targets) to 100% (bones).Conclusion: A security margin of 5 mm for PTV definition is sufficient, if CT simulation is performed prior to each treatment to correct larger target deviations or set-up errors. Isocenter verification relative to bony structures is only safe for bony targets but not for soft tissue targets. (C) 2000 Elsevier Science Ireland Ltd. All rights reserved.