Feasibility of real-time gold markers tracking by a double-anode-target X-ray tube CBCT(PDF)
《中国医学物理学杂志》[ISSN:1005-202X/CN:44-1351/R]
- Issue:
- 2022年第9期
- Page:
- 1094-1100
- Research Field:
- 医学放射物理
- Publishing date:
Info
- Title:
- Feasibility of real-time gold markers tracking by a double-anode-target X-ray tube CBCT
- Author(s):
- HU Mi1; HU Yimin2; QUAN Hong1
- 1. School of Physics and Technology,Wuhan University, Wuhan 430000, China 2. Department of Radiotherapy, Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100021, China
- Keywords:
- Keywords: double-anode-target X-ray tube coordinate reconstruction gold marker real-time tracking
- PACS:
- R812
- DOI:
- DOI:10.3969/j.issn.1005-202X.2022.09.007
- Abstract:
- Abstract: Objective To explore the optimal target spacing of a novel double-anode-target X-ray tube, and to realize real-time CBCT image-guided radiotherapy by proposing an algorithm for real-time gold markers tracking based on this innovated tube. Methods The phantom with pre-implanted gold markers was put on the treatment couch of Elekta Synergy linear accelerator, and the kV-X-ray zero-degree projection images of the gold markers were obtained by the CBCT configured by the accelerator. At the same gantry angle, the phantom on the treatment couch was translated, so that it is in an equidistant symmetrical position with a spacing of 2 to 12 mm, and two kV-X-ray zero-degree projection images of the gold marks were obtained. Then the 2D projected coordinates of the gold markers were extracted from the overlayed projection images, and the corresponding 2D projected coordinates of the markers were backprojected to the simulated double-anode-target positions. Finally, the geometric principle of the intersection of two projection lines was used to reconstruct the 3D coordinates of the gold markers in the phantom for realizing the tracking of the gold markers in the target area. Results When the phantom was located at a symmetrical position with a spacing of 2 to 12 mm on the couch, it corresponded to two parallel X-rays of a double-anode-target X-ray tube with a target spacing of 2 to 12 mm. When the symmetrical distance of the phantom was no more than 7 mm, the 2D projected coordinates of the gold markers could not be successfully read out from the overlayed projection images, and there was no way to reconstruct their 3D coordinates. Only when the phantom was in a symmetrical position with a spacing of 8 mm or larger than 8 mm, the 2D projected coordinates of the gold markers were detectable, with a detection precision of (±0.176, ±0.140) mm, and the precision of reconstructed 3D coordinates reached (±0.242, ±0.392, ±1.036) mm. Conclusion The 3D coordinates of the gold markers can be accurately reconstructed according to the double-anode-target X ray tube images, when the double-anode-target spacing was equal to or larger than 8 mm.
Last Update: 2022-09-27