Covington Elizabeth L, Stanley Dennis N, Lawson Ashanti, Hadley Scott, Moncion Alexander, Sullivan Rodney J, Fiveash John B, Popple Richard A
Department of Radiation Oncology, The University of Alabama at Birmingham, Birmingham, Alabama, USA.
Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan, USA.
J Appl Clin Med Phys. 2025 Jul;26(7):e70188. doi: 10.1002/acm2.70188.
To study the localization accuracy of two commercial surface imaging (SI) systems used for intrafraction motion monitoring during stereotactic radiosurgery (SRS) and quantify the difference in accuracy due to skin tone.
Using a publicly available CT dataset, anthropomorphic phantoms were 3D printed using filament in four skin tones: rose tan, light brown, medium brown, and dark brown (3DUniverse, Chicago, IL, USA). Three SI systems from two vendors were utilized to measure the SI-reported offsets of the stationary phantoms in various gantry and couch configurations to create SRS-like conditions, including when the gantry obscured one camera pod. At each position, approximately 5 s of offsets were averaged to obtain the SI-reported offset.
All SI systems reported larger offsets for all phantoms at non-zero couch angles. The medium brown and dark brown phantoms showed the largest magnitudes at non-zero couch angles, increasing further when a camera pod was obstructed. For two SI systems, the position of the phantom for medium and dark brown phantoms could not be resolved at certain gantry/couch positions, and offsets up to 5 mm were reported.
Characterization of SI systems using 3D-printed phantoms in a spectrum of skin tones can be used to determine the accuracy of SI tracking under treatment-like conditions. All SI systems showed decreased accuracy with darker skin-toned phantoms, which increased with an obstructed camera view.
研究两种用于立体定向放射治疗（SRS）期间分次内运动监测的商用表面成像（SI）系统的定位准确性，并量化因肤色导致的准确性差异。
使用公开可用的CT数据集，采用四种肤色（玫瑰棕、浅棕、中棕和深棕）的细丝3D打印拟人化体模（美国伊利诺伊州芝加哥市的3DUniverse公司）。利用来自两家供应商的三种SI系统，测量在各种机架和治疗床配置下静止体模的SI报告偏移量，以创建类似SRS的条件，包括当机架遮挡一个摄像头组件时的情况。在每个位置，对大约5秒的偏移量进行平均，以获得SI报告的偏移量。
所有SI系统均报告，在非零治疗床角度下，所有体模的偏移量更大。中棕和深棕体模在非零治疗床角度下显示出最大的偏移量，当一个摄像头组件被遮挡时，偏移量进一步增加。对于两种SI系统，在某些机架/治疗床位置无法分辨中棕和深棕体模的位置，报告的偏移量高达5毫米。
使用具有一系列肤色的3D打印体模对SI系统进行表征，可用于确定类似治疗条件下SI跟踪的准确性。所有SI系统均显示，肤色较深的体模准确性降低，且随着摄像头视野受阻而增加。
