Department of Radiation Oncology, University of California San Diego, La Jolla, California.
Department of Radiation Oncology, University of California San Diego, La Jolla, California.
Pract Radiat Oncol. 2012 Jan-Mar;2(1):54-62. doi: 10.1016/j.prro.2011.04.005. Epub 2011 Dec 20.
To evaluate the initial clinical experience with a frameless and maskless technique for stereotactic radiosurgery using minimal patient immobilization and real-time patient motion monitoring during treatment. We focus on the evaluation of the patient treatment process.
The study considered the first 23 patients treated with this technique. Head positioning was achieved with a patient-specific head mold made out of expandable foam that conforms to the patient's head. The face of the patient is left open for maximal comfort and so that motion of a region of interest consisting of the forehead, nose, eyes, and temporal bones can be monitored during treatment using a video surface imaging system (VisionRT Inc, London, UK). Initial setup of the patient was performed with the surface imaging system using the surface of the patient obtained from the treatment planning computed tomographic (CT) scan. The initial setup was confirmed and finalized with cone-beam CT (CBCT) prior to treatment. The shifts for final setup based on the CBCT and the duration of all the steps in the treatment process were recorded. Patients were monitored during treatment with surface imaging, and a beam hold-off was initiated when the patient's motion exceeded a prespecified tolerance.
The average total setup time including surface imaging and CBCT was 26 minutes, while the portion corresponding to surface imaging was 14 minutes. The average treatment time from when the patient was placed on the treatment table until the last treatment beam was 40 minutes. Eight (35%) patients needed repositioning during the treatment. The average shifts identified from CBCT after initial setup with surface imaging were 1.85 mm in the anterior-posterior direction, and less than 1.0 mm in the lateral and superior-inferior directions. The longest treatment times (including beam hold-offs) happened for patients who fell asleep on the treatment table and were moving involuntarily.
The frameless and maskless treatment using minimal immobilization and surface imaging has proven to be reasonably fast for routine clinical use. We observed that patient compliance is important. An additional degree of semi-rigid immobilization would be helpful for patients who fall asleep and involuntarily move during the procedure.
评估一种无框架、无面罩的立体定向放射外科技术的初步临床经验，该技术在治疗过程中采用最小的患者固定和实时患者运动监测。我们专注于评估患者的治疗过程。
该研究考虑了前 23 名接受该技术治疗的患者。头部定位采用可膨胀泡沫制成的患者专用头模来实现，该头模与患者头部贴合。患者的面部保持开放，以获得最大的舒适度，并使用视频表面成像系统（VisionRT Inc，英国伦敦）在治疗过程中监测包括额头、鼻子、眼睛和颞骨在内的感兴趣区域的运动。使用从治疗计划计算机断层扫描（CT）扫描中获得的患者表面，通过表面成像系统对患者进行初始设置。在治疗前，使用锥形束 CT（CBCT）对初始设置进行确认和最终确定。记录基于 CBCT 的最终设置的移位以及治疗过程中所有步骤的持续时间。在治疗过程中，使用表面成像对患者进行监测，当患者的运动超过预设容限时，会启动束流暂停。
包括表面成像和 CBCT 的平均总设置时间为 26 分钟，而与表面成像对应的部分为 14 分钟。从患者被放置在治疗台上到最后一个治疗束的平均治疗时间为 40 分钟。在治疗过程中有 8 名（35%）患者需要重新定位。在初始设置后使用 CBCT 识别的平均移位在前后方向上为 1.85 毫米，在左右和上下方向上小于 1.0 毫米。最长的治疗时间（包括束流暂停）发生在在治疗台上入睡且不由自主移动的患者身上。
使用最小固定和表面成像的无框架、无面罩治疗对于常规临床应用来说已经相当快了。我们观察到患者的依从性很重要。对于在手术过程中入睡和不由自主移动的患者，增加一定程度的半刚性固定会有所帮助。
