Tissue motion tracking at the edges of a radiation treatment field using local optical flow analysis

17th International Conference on the Use of Computers in Radiation Therapy

物理学;计算机科学

Teo, P.T.^1,2 ; Pistorius, S.^1,2,3

CancerCare Manitoba, 675 McDermot Avenue, Winnipeg, MN, R3E 0V9, Canada^1

Department of Physics and Astronomy, University of Manitoba, Winnipeg, MN, R3T 2N2, Canada^2

Department of Radiology, University of Manitoba, Winnipeg, MN, R3A 1R9, Canada^3

关键词: Adaptive images;    Electronic portal images;    Motion accuracy;    Multileaf collimators;    Optical flow analysis;    Organ at risks;    Radiation treatments;    Velocity errors;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/489/1/012040/pdf
DOI  :  10.1088/1742-6596/489/1/012040

学科分类：计算机科学（综合）

来源: IOP

【 摘 要 】

This paper investigates the feasibility and accuracy of tracking the motion of an intruding organ-at-risk (OAR) at the edges of a treatment field using a local optical flow analysis of electronic portal images. An intruding OAR was simulated by modifying the portal images obtained by irradiating a programmable phantom's lung tumour. A rectangular treatment aperture was assumed and the edges of the beam's eye view (BEV) were partitioned into clusters/grids according to the width of the multi-leaf collimators (MLC). The optical flow velocities were calculated and the motion accuracy in these clusters was analysed. A velocity error of 0.4 ±1.4 mm/s with a linearity of 1.04 for tracking an object intruding at 10mm/s (max) was obtained.