Fractionated stereotactic radiotherapy for skull base tumors: analysis of treatment accuracy using a stereotactic mask fixation system.
Fractionated stereotactic radiotherapy for skull base tumors: analysis of treatment accuracy using a stereotactic mask fixation system.
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DOI：
10.1186/1748-717x-5-1
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发表时间：
2010-01-13
期刊：
影响因子：
--
通讯作者：
Enrici RM
中科院分区：
文献类型：
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作者：
Minniti G;Valeriani M;Clarke E;D'Arienzo M;Ciotti M;Montagnoli R;Saporetti F;Enrici RM
评估使用立体定向面罩固定系统进行分次立体定向放射治疗（FSRT）的准确性。16例接受FSRT治疗的患者参与了本研究。使用市售立体定向面罩固定系统（BrainLAB AG）进行患者固定。在FSRT之前和期间获得的系列CT扫描用于通过比较等中心位置来评估患者固定的准确性。采集每日射野成像，以确定每日患者位置变化。沿不同方向的位移误差沿着被计算为系统误差和随机误差的组合。基于定位和验证CT成像的平均等中心位移在横向方向上为0.1 mm（SD 0.3 mm），在前后方向上为0.1 mm（SD 0.4 mm），在头尾方向上为0.3 mm（SD 0.4 mm）。平均3D位移为0.5 mm（SD 0.4 mm），最大为1.4 mm。治疗期间未发现显著差异（P = 0.4）。通过456个前部和侧部射野图像计算的整体等中心位移在内外侧方向上为0.3 mm（SD 0.9 mm），在前后方向上为-0.2 mm（SD 1 mm），在头尾方向上为0.2 mm（SD 1.1 mm）。在头-尾方向观察到2.7 mm的最大位移，在任何方向上95%的位移< 2 mm。结果表明，CT验证扫描和射野成像评价的所提出的掩模系统的设置误差是最小的。等中心位置的再现性在其他立体定向系统报告的定位再现性的最佳范围内。
To assess the accuracy of fractionated stereotactic radiotherapy (FSRT) using a stereotactic mask fixation system. Sixteen patients treated with FSRT were involved in the study. A commercial stereotactic mask fixation system (BrainLAB AG) was used for patient immobilization. Serial CT scans obtained before and during FSRT were used to assess the accuracy of patient immobilization by comparing the isocenter position. Daily portal imaging were acquired to establish day to day patient position variation. Displacement errors along the different directions were calculated as combination of systematic and random errors. The mean isocenter displacements based on localization and verification CT imaging were 0.1 mm (SD 0.3 mm) in the lateral direction, 0.1 mm (SD 0.4 mm) in the anteroposterior, and 0.3 mm (SD 0.4 mm) in craniocaudal direction. The mean 3D displacement was 0.5 mm (SD 0.4 mm), being maximum 1.4 mm. No significant differences were found during the treatment (P = 0.4). The overall isocenter displacement as calculated by 456 anterior and lateral portal images were 0.3 mm (SD 0.9 mm) in the mediolateral direction, -0.2 mm (SD 1 mm) in the anteroposterior direction, and 0.2 mm (SD 1.1 mm) in the craniocaudal direction. The largest displacement of 2.7 mm was seen in the cranio-caudal direction, with 95% of displacements < 2 mm in any direction. The results indicate that the setup error of the presented mask system evaluated by CT verification scans and portal imaging are minimal. Reproducibility of the isocenter position is in the best range of positioning reproducibility reported for other stereotactic systems.