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Experimental and numerical studies on kV scattered x-ray imaging for real-time image guidance in radiation therapy.
Huang, Yanqi; Yang, Kai; Lai, Youfang; Liu, Huan; Shen, Chenyang; Zhong, Yuncheng; Shao, Yiping; Li, Xinhua; Liu, Bob; Jia, Xun.
Afiliación
  • Huang Y; Innovative Technology Of Radiotherapy Computations and Hardware (iTORCH) Laboratory, Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, TX, 75235, United States of America.
  • Yang K; Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, TX, 75235, United States of America.
  • Lai Y; Division of Diagnostic Imaging Physics, Department of Radiology, Massachusetts General Hospital, 55 Fruit Street, Boston, MA 02114, United States of America.
  • Liu H; Innovative Technology Of Radiotherapy Computations and Hardware (iTORCH) Laboratory, Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, TX, 75235, United States of America.
  • Shen C; Department of Physics, University of Texas Arlington, Arlington, TX, 76019, United States of America.
  • Zhong Y; Innovative Technology Of Radiotherapy Computations and Hardware (iTORCH) Laboratory, Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, TX, 75235, United States of America.
  • Shao Y; Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, TX, 75235, United States of America.
  • Li X; Innovative Technology Of Radiotherapy Computations and Hardware (iTORCH) Laboratory, Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, TX, 75235, United States of America.
  • Liu B; Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, TX, 75235, United States of America.
  • Jia X; Innovative Technology Of Radiotherapy Computations and Hardware (iTORCH) Laboratory, Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, TX, 75235, United States of America.
Phys Med Biol ; 66(4): 045022, 2021 02 11.
Article en En | MEDLINE | ID: mdl-33361559
ABSTRACT
Motion management is a critical component of image guided radiotherapy for lung cancer. We previously proposed a scheme using kV scattered x-ray photons for marker-less real-time image guidance in lung cancer radiotherapy. This study reports our recent progress using the photon counting detection technique to demonstrate potential feasibility of this method and using Monte Carlo (MC) simulations and ray-tracing calculations to characterize the performance. In our scheme, a thin slice of x-ray beam was directed to the target and we measured the outgoing scattered photons using a photon counting detector with a parallel-hole collimator to establish the correspondence between detector pixels and scatter positions. Image corrections of geometry, beam attenuation and scattering angle were performed to convert the raw image to the actual image of Compton attenuation coefficient. We set up a MC simulation system using an in-house developed GPU-based MC package modeling the image formation process. We also performed ray-tracing calculations to investigate the impacts of imaging system geometry on resulting image resolution. The experiment demonstrated feasibility of using a photon counting detector to measure scattered x-ray photons and generate the proposed scattered x-ray image. After correction, x-ray scattering image intensity and Compton scattering attenuation coefficient were linearly related, with R 2 greater than 0.9. Contrast to noise ratios of different objects were improved and the values in experimental results and MC simulation results agreed with each other. Ray-tracing calculations revealed the dependence of image resolution on imaging geometry. The image resolution increases with reduced source to object distance and increased collimator height. The study demonstrated potential feasibility of using scattered x-ray imaging as a real-time image guidance method in radiation therapy.
Asunto(s)

Texto completo: 1 Banco de datos: MEDLINE Asunto principal: Simulación por Computador / Radioterapia Guiada por Imagen Tipo de estudio: Diagnostic_studies / Guideline / Health_economic_evaluation / Prognostic_studies Límite: Humans Idioma: En Revista: Phys Med Biol Año: 2021 Tipo del documento: Article País de afiliación: Estados Unidos

Texto completo: 1 Banco de datos: MEDLINE Asunto principal: Simulación por Computador / Radioterapia Guiada por Imagen Tipo de estudio: Diagnostic_studies / Guideline / Health_economic_evaluation / Prognostic_studies Límite: Humans Idioma: En Revista: Phys Med Biol Año: 2021 Tipo del documento: Article País de afiliación: Estados Unidos