Evaluation of patient setup uncertainty of optical guided frameless system for intracranial stereotactic radiosurgery.
Evaluation of patient setup uncertainty of optical guided frameless system for intracranial stereotactic radiosurgery.
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DOI：
10.1120/jacmp.v11i2.3181
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发表时间：
2010-04-17
影响因子：
2.1
通讯作者：
Murphy KT
中科院分区：
文献类型：
--
作者：
Wang JZ;Rice R;Pawlicki T;Mundt AJ;Sandhu A;Lawson J;Murphy KT
自2006年以来，光学引导无框架系统（OFLS）已在我们的临床中用于颅内立体定向放射外科手术（SRS），因为它在基于IMRT的放射外科手术（IMRS）中特别有效，可以使用单一等中心入路同时治疗多个脑部病变。本研究报告了我们使用该系统对患者摆位准确性的回顾性分析。OFLS由带有基准标记的牙垫和红外摄像系统组成。为了测试可重复性，患者在咬合块构建后进行复位验证。放射外科计划完成后，等中心位置和图像被发送到光学引导计算机，在光学引导计算机中，根据CT扫描手动配准基准点。在治疗过程中，通过基准点上的摄像机读数监测和指导患者设置。此外，两个正交kV图像采集和使用作为等中心验证工具。此外，我们还分析了56例患者的复位和基准数字化数据。对所有患者进行了kV图像与参考图像的回顾性比较，以评价治疗时的实际患者摆位准确性。结果的直方图显示82.2%的患者有3D等位移（5.2%）。因此，对于研究中87.5%的患者，在光学引导下完成治疗，最大设置误差为2 mm，中位设置误差为0 mm。对于研究中其余12.5%的患者，等位移大于2 mm，治疗记录显示这些患者在正交kV图像引导下重新定位。研究发现，SRS治疗中的OFLS在与正交kV图像结合使用时具有可接受的准确性，并且使用正交kV图像作为验证工具确保了放射外科治疗中无框架定位的有效性。PACS编号：87.53.Ly、87.61.Tg、87.55.Qr、87.56. -v、29.20.Ej
The optically‐guided frameless system (OFLS) has been used in our clinic for intracranial stereotactic radiosurgery (SRS) since 2006, as it is especially effective in IMRT‐based radiosurgery (IMRS), which allows treating multiple brain lesions simultaneously using single isocenter approach. This study reports our retrospective analysis of patient setup accuracy using this system. The OFLS consists of a bite block with fiducial markers and an infra‐red camera system. To test reproducibility, patients are taken for reseat verification after bite block construction. Upon the completion of radiosurgery planning, the isocenter position(s) and images are sent to the optical guidance computer where fiducials are manually registered from the CT scan. During treatment, patient setup is monitored and guided by the camera readings on the fiducials. In addition, two orthogonal kV images are acquired and used as an isocenter verification tool. In addition, we have analyzed the reseat and fiducial digitization data of 56 patients. Retrospective comparison of kV images with reference images has been carried out for all the patients to evaluate actual patient setup accuracy at the time of treatment. The histogram of the findings shows that 82.2% of patients had 3D isodisplacement (; 5.2% had ). Hence, for 87.5 % of the patients in the study, treatments were finished under the optical guidance with a maximum setup error of 2 mm and the median setup error of 0 mm. For the remaining 12.5% of patients in the study, the isodisplacements were greater than 2 mm and the treatment records showed that those patients were repositioned, guided by the orthogonal kV‐images. It is found that the OFLS in the SRS treatment has acceptable accuracy when used in conjunction with orthogonal kV images, and the use of orthogonal kV images as a verification tool ensures the efficacy of frameless localization in the radiosurgery treatment. PACS numbers: 87.53.Ly, 87.61.Tg, 87.55.Qr, 87.56.‐v, 29.20.Ej