Physics·Technique·Biology
Development and application of three-dimensional point cloud radiotherapy real-time monitoring system based on depth camera
Li Chunying, Lu Zhengda, Zhang Sai, Sun Jiawei, Gao Liugang, Xie Kai, Lin Tao, Sui Jianfeng, Ni Xinye
Published 2023-02-15
Cite as Chin J Radiat Oncol, 2023, 32(2): 145-151. DOI: 10.3760/cma.j.cn113030-20211214-00516
Abstract
ObjectiveTo develop the real-time radiotherapy monitoring system of three-dimensional (3D) point cloud by using depth camera and verify its feasibility.
MethodsTaking 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).
ResultsIn 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.
ConclusionThe 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.
Key words:
Depth camera; Three-dimensional point cloud; Radiotherapy real-time monitoring; Radiotherapy six-dimensional error
Contributor Information
Li Chunying
Department of Radiotherapy, Changzhou No.2 People's Hospital, the Affiliated Hospital of Nanjing Medical University, Changzhou 213003, China
Lu Zhengda
School of Biomedical Engineering and Information, Nanjing Medical University, Nanjing 210000, China
Zhang Sai
Department of Radiotherapy, Changzhou No.2 People's Hospital, the Affiliated Hospital of Nanjing Medical University, Changzhou 213003, China
Sun Jiawei
Department of Radiotherapy, Changzhou No.2 People's Hospital, the Affiliated Hospital of Nanjing Medical University, Changzhou 213003, China
Gao Liugang
Department of Radiotherapy, Changzhou No.2 People's Hospital, the Affiliated Hospital of Nanjing Medical University, Changzhou 213003, China
Xie Kai
Department of Radiotherapy, Changzhou No.2 People's Hospital, the Affiliated Hospital of Nanjing Medical University, Changzhou 213003, China
Lin Tao
Department of Radiotherapy, Changzhou No.2 People's Hospital, the Affiliated Hospital of Nanjing Medical University, Changzhou 213003, China
Sui Jianfeng
Department of Radiotherapy, Changzhou No.2 People's Hospital, the Affiliated Hospital of Nanjing Medical University, Changzhou 213003, China
Ni Xinye
Department of Radiotherapy, Changzhou No.2 People's Hospital, the Affiliated Hospital of Nanjing Medical University, Changzhou 213003, China
