LOCAL SETUP ERRORS IN IMAGE-GUIDED RADIOTHERAPY FOR HEAD AND NECK CANCER PATIENTS IMMOBILIZED WITH A CUSTOM-MADE DEVICE
LOCAL SETUP ERRORS IN IMAGE-GUIDED RADIOTHERAPY FOR HEAD AND NECK CANCER PATIENTS IMMOBILIZED WITH A CUSTOM-MADE DEVICE
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DOI：
10.1016/j.ijrobp.2010.07.1980
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发表时间：
2011-06-01
影响因子：
7
通讯作者：
Bendl, Rolf
中科院分区：
文献类型：
--
作者：
Giske, Kristina;Stoiber, Eva M.;Bendl, Rolf
目的：为了评估局部定位的不确定性，在分割放射治疗的头部和颈部癌症患者固定使用定制的固定装置，并讨论可能的患者纠正策略的效果，为这些uncertaints.Methods和材料：共有45个头部和颈部患者进行了定期控制计算机断层扫描扫描使用室内计算机断层扫描仪。通过应用刚性配准算法评估所有患者的局部和全局定位变化。在完整的靶区周围引入一个边界框和九个包含相关解剖结构的局部配准框。确定了立体定向设置和参考一个解剖局部配准框的变形的不确定性。使用我们的定制设备固定的患者的局部变形与以前发表的结果进行了比较。几个病人的定位校正策略进行了模拟，和残余的局部不确定性calculated.Results：在立体定向设置的病人解剖显示局部系统定位偏差1-4 mm。变形参考一个特定的解剖局部注册框是类似的报告变形评估与市售Aquaplast口罩固定的患者。包括旋转误差补偿的全局校正减小了剩余的局部平移误差。根据所选择的患者定位策略，其余的局部不确定性变化相当大。结论：即使使用精心设计的定制患者固定方法，头颈部患者也会发生局部变形。旋转误差校正大大降低了所需的裕度。所考虑的矫正策略均未实现完美对齐。因此，加权的解剖子区域，以获得最佳的校正向量，应在未来的研究。(C)2011 Elsevier Inc.
Purpose: To evaluate the local positioning uncertainties during fractionated radiotherapy of head-and-neck cancer patients immobilized using a custom-made fixation device and discuss the effect of possible patient correction strategies for these uncertainties.Methods and Materials: A total of 45 head-and-neck patients underwent regular control computed tomography scanning using an in-room computed tomography scanner. The local and global positioning variations of all patients were evaluated by applying a rigid registration algorithm. One bounding box around the complete target volume and nine local registration boxes containing relevant anatomic structures were introduced. The resulting uncertainties for a stereotactic setup and the deformations referenced to one anatomic local registration box were determined. Local deformations of the patients immobilized using our custom-made device were compared with previously published results. Several patient positioning correction strategies were simulated, and the residual local uncertainties were calculated.Results: The patient anatomy in the stereotactic setup showed local systematic positioning deviations of 1-4 mm. The deformations referenced to a particular anatomic local registration box were similar to the reported deformations assessed from patients immobilized with commercially available Aquaplast masks. A global correction, including the rotational error compensation, decreased the remaining local translational errors. Depending on the chosen patient positioning strategy, the remaining local uncertainties varied considerably.Conclusions: Local deformations in head-and-neck patients occur even if an elaborate, custom-made patient fixation method is used. A rotational error correction decreased the required margins considerably. None of the considered correction strategies achieved perfect alignment. Therefore, weighting of anatomic subregions to obtain the optimal correction vector should be investigated in the future. (C) 2011 Elsevier Inc.