Research on photogrammetry-based positioning of heavy ion radiotherapy and tumor target monitoring

Abstract

Heavy ion therapy is currently recognized as the most advanced cancer radiotherapy approach in the world. This article introduces a high-precision and non-contact measurement method based on close-range photogrammetry combined with a 3D control network of a laser tracker, which is used to guide the positioning and real-time target area monitoring for patients undergoing heavy ion radiotherapy. By the precise connection between the 3D control network of the laser tracker and the digital photogrammetry device, we position the photogrammetry system absolutely at the treatment isocenter, measuring the feature points of the target area on the patient's body surface. After that, the seven-parameter solution model is combined with the feature points to accurately determine the tumor position, as well as displaying its real-time location changes in the form of relative position to the treatment isocenter shown as six-degree-of-freedom parameters during radiotherapy, so that the patient may be guided to achieve a more reliable and efficient positioning. The research and design on the dual-camera close-range photogrammetry patient monitoring system has provided insights in the course of radiotherapy. That is to say, by monitoring the feature points on the patient's body surface, a real-time display of tumor displacement and a warning system for out-of-tolerance variances are established, controlling the treatment bed to stay on the tumor. This method could ensure the irradiation precision for the patient during the treatment and protect normal tissues from radiation exposure, optimizing the treatment outcome. Multiple patient positioning simulations have verified that the measurement precision of our photogrammetry-based method can meet the requirements of heavy ion radiotherapy patient positioning.

KEYWORDS:

• Heavy ion radiotherapy
• photogrammetry
• 3D control network
• patient positioning
• target area monitoring

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Notes on contributors

W. J. Chen

W. J. Chen, Ph.D., senior engineer at the Institute of Modern Physics, Chinese Academy of Sciences, engaged in heavy ion accelerator survey and alignment research, recent representative articles published include A new alignment method for HIMM magnetic field measurement system and Alignment of heavy ion therapy center vertical terminal, etc.

Y. Q. Yang

Y. Q. Yang is a researcher at the Institute of Modern Physics, Chinese Academy of Sciences. She is engaged in the mechanical design and research of heavy ion accelerators. Recent representative works include the development of the Lanzhou heavy ion accelerator cooling storage ring kicking magnet power supply and other articles.

Y. J. Zheng

Y. J. Zheng is an engineer from the Institute of Modern Physics, Chinese Academy of Sciences. He is engaged in the mechanical design and research of heavy ion accelerators. His recent representative works include articles on the vibration of the magnets scanned by the ground simulation device of the space environment.

B. Zhang

B. Zhang is a professor-level engineer at the Institute of Modern Physics, Chinese Academy of Sciences. He is engaged in the mechanical design and research of heavy ion accelerators. His recent representative works include articles on the calibration and survey and alignment of cryogenic superconducting components.

S. M. Wang

S. M. Wang, a senior engineer at the Institute of Modern Physics, Chinese Academy of Sciences, is engaged in the research of heavy ion accelerator survey and alignment. His recent representative works include the installation and alignment of the deflection magnet of the HIRFL micro-beam irradiation device, and the survey and alignment of the main ring magnet of the cooling storage ring.

J. D. Yuan

J. D. Yuan is a senior engineer at the Institute of Modern Physics, Chinese Academy of Sciences. He is engaged in the research of heavy ion accelerator survey and alignment. The representative work recently published is an overview of the application of tension wire technology in accelerator survey and alignment, and the low temperature survey and alignment technology of ADS injector II Cry Module, etc

G. Z. Sun

G. Z. Sun is an engineer at the Institute of Modern Physics, Chinese Academy of Sciences. He is engaged in the research on the survey and alignment of heavy ion accelerators. His recently published representative works include the research on rationalization of the target position of the alignment element.

X. D. Zhang

X. D. Zhang, engineer at the Institute of Modern Physics, Chinese Academy of Sciences, engaged in the research of survey and alignment of heavy ion accelerators.

L. S. Yan

L. S. Yan, engineer at the Institute of Modern Physics, Chinese Academy of Sciences, engaged in the research of survey and alignment of heavy ion accelerators.