Development and application of three-dimensional point cloud radiotherapy real-time monitoring system based on depth camera
10.3760/cma.j.cn113030-20211214-00516
- VernacularTitle:基于深度相机的三维点云放疗实时监测系统的研发与应用
- Author:
Chunying LI
1
;
Zhengda LU
;
Sai ZHANG
;
Jiawei SUN
;
Liugang GAO
;
Kai XIE
;
Tao LIN
;
Jianfeng SUI
;
Xinye NI
Author Information
1. 南京医科大学附属常州第二人民医院放疗科，常州 213003
- Keywords:
Depth camera;
Three-dimensional point cloud;
Radiotherapy real-time monitoring;
Radiotherapy six-dimensional error
- From:
Chinese Journal of Radiation Oncology
2023;32(2):145-151
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To develop the real-time radiotherapy monitoring system of three-dimensional (3D) point cloud by using depth camera and verify its feasibility.Methods:Taking the depth camera coordinate system as the world coordinate system, the conversion relationship between the simulation CT coordinate system and the world coordinate system was obtained from the calibration module. The patient's simulation CT point cloud was transformed into the world coordinate system through the above relationship, and registered with the patient's surface point cloud obtained in real-time manner by the depth camera to calculate the six-dimensional (6D) error, and complete the positioning verification and fractional internal position error monitoring in radiotherapy. Mean and standard deviation of 6D calculation error, Hausdorff distance of point cloud after registration and the running time of each part of the program were calculated to verify the feasibility of the system. Fifteen real patients were selected to calculate the 6D error between the system and cone beam CT (CBCT).Results:In the phantom experiment, the errors of the system in the x, y and z axes were (1.292±0.880)mm, (1.963±1.115)mm, (1.496±1.045)mm, respectively, and the errors in the rotation, pitch and roll directions were 0.201°±0.181°, 0.286°±0.326°, 0.181°±0.192°, respectively. For real patients, the translational error of the system was within 2.6 mm, the rotational error was approximately 1°, and the program run at 1-2 frames/s. The precision and speed met the radiotherapy requirement. Conclusion:The 3D point cloud radiotherapy real-time monitoring system based on depth camera can automatically complete the positioning verification before radiotherapy, real-time monitoring of body position during radiotherapy, and provide error visual feedback, which has potential clinical application value.
