Department of Radiation Oncology, University of California Irvine, Orange, CA, USA.
Department of Radiation Oncology, The Permanente Medical Group, Santa Clara, CA, USA.
J Appl Clin Med Phys. 2020 Jun;21(6):73-82. doi: 10.1002/acm2.12867. Epub 2020 Apr 6.
Surface guided radiation therapy (SGRT) is increasingly being adopted for use in radiation treatment delivery for Head and Neck (H&N) cancer patients. This study investigated the improvement of patient setup accuracy and reduction of setup time for SGRT compared to a conventional setup. A total of 60 H&N cancer patients were retrospectively included. Patients were categorized into three groups: oral cavity, oropharynx and nasopharynx/sinonasal sites with 20 patients in each group. They were further separated into two (2) subgroups, depending on whether they were set up with the aid of SGRT. The Align-RT™ system was used for SGRT in this work. Positioning was confirmed by daily kV-kV imaging in conjunction with weekly CBCT scans. Translational and rotational couch shifts along with patient setup times were recorded. Imaging setup time, which was defined as the elapsed time from the acquisition of the first image set to the end of the last image set, was recorded. Average translational shifts were larger in the non-SGRT group. Vertical shifts showed the most significant reduction in the SGRT group for both oropharynx and oral cavity groups. Pitch corrections were significantly higher in the SGRT group for oropharynx patients and higher pitch corrections were also observed in the SGRT groups of oral cavity and nasopharynx/sinonasal patients. The average setup time when SGRT guidance was employed was shorter for all three treatment sites although this did not reach statistical significance. The largest time reduction between the SGRT and non-SGRT groups was seen in the nasopharynx/sinonasal group. This study suggests that the use of SGRT decreases the magnitude of translational couch shifts during patient setup. However, the rotational corrections needed were generally higher with SGRT group. When SGRT was employed, a definite reduction in patient setup time was observed for nasopharynx/sinonasal and hypopharynx cancer patients.
表面引导放射治疗（SGRT）越来越多地被应用于头颈部（H&N）癌症患者的放射治疗。本研究旨在探讨 SGRT 与传统摆位相比，在改善患者摆位准确性和减少摆位时间方面的优势。共回顾性纳入 60 例 H&N 癌症患者。患者分为三组：口腔、口咽和鼻咽/鼻旁窦部位，每组 20 例。根据是否采用 SGRT 辅助摆位，将每组进一步分为两个亚组。本研究采用 Align-RT™系统进行 SGRT。通过每日千伏级（kV）kV 成像和每周锥形束 CT（CBCT）扫描来确认定位。记录了横向和纵向床移动以及患者摆位时间。将定义为从第一组图像采集到最后一组图像采集结束的时间间隔作为成像摆位时间进行记录。非 SGRT 组的平均横向移动较大。对于口咽和口腔组，SGRT 组的垂直移动减少最显著。对于口咽患者，SGRT 组的俯仰校正显著更高，对于口腔和鼻咽/鼻旁窦组的患者，也观察到更高的俯仰校正。在所有三个治疗部位，当使用 SGRT 引导时，平均摆位时间更短，尽管这没有达到统计学意义。SGRT 和非 SGRT 组之间的最大时间减少见于鼻咽/鼻旁窦组。本研究表明，SGRT 可减少患者摆位过程中的横向床移动幅度。然而，SGRT 组通常需要更高的旋转校正。当使用 SGRT 时，鼻咽/鼻旁窦和下咽癌症患者的患者摆位时间明显减少。
