Park Jeonghoon, Gagneur Justin D, Chungbin Suzanne J, Rong Yi, Lim Seng Boh, Chan Maria F
Department of Medical Physics, Memorial Sloan Kettering Cancer Center, Basking Ridge, New Jersey, USA.
Department of Radiation Oncology, Mayo Clinic, Phoenix, Arizona, USA.
J Appl Clin Med Phys. 2024 Mar;25(3):e14291. doi: 10.1002/acm2.14291. Epub 2024 Feb 2.
To present a modified calibration method to reduce signal drift due to table sagging in Respiratory Gating for Scanner (RGSC) systems with a wall-mounted camera.
Approximately 70 kg of solid water phantoms were evenly distributed on the CT couch, mimicking the patient's weight. New calibration measurements were performed at 9 points at the combination of three lateral positions, the CT isocenter and ±10 cm laterally from the isocenter, and three longitudinal locations, the CT isocenter and ±30 cm or ±40 cm from the isocenter. The new calibration was tested in two hospitals.
Implementing the new weighed calibration method at the extended distance yielded improved results during the DIBH scan, reducing the drift to within 1 from 3 mm. The extended calibration positions exhibited similarly reduced drift in both hospitals, reinforcing the method's robustness and its potential applicability across all centers.
This proposed solution aims to minimize the systematic error in radiation delivery for patients undergoing motion management with wall-mounted camera RGSC systems, especially in conjunction with a bariatric CT couchtop.
提出一种改进的校准方法，以减少在配备壁挂式摄像头的呼吸门控扫描系统（RGSC）中因检查床下垂导致的信号漂移。
在CT检查床上均匀分布约70千克的固体水模体，模拟患者体重。在三个横向位置（CT等中心以及等中心横向±10厘米处）与三个纵向位置（CT等中心以及等中心纵向±30厘米或±40厘米处）的组合下，于9个点进行新的校准测量。新校准方法在两家医院进行了测试。
在延长距离处实施新的加权校准方法，在深吸气屏气（DIBH）扫描期间产生了更好的结果，将漂移从3毫米减少到1毫米以内。在两家医院中，延长的校准位置均表现出类似程度的漂移减少，这增强了该方法的稳健性及其在所有中心的潜在适用性。
该提议的解决方案旨在最大限度地减少使用壁挂式摄像头RGSC系统进行运动管理的患者在放射治疗中的系统误差，尤其是在结合使用减重CT检查床面时。
