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Title: Feasibility of low-dose single-view 3D fiducial tracking concurrent with external beam delivery

Abstract

Purpose: In external-beam radiation therapy, existing on-board x-ray imaging chains orthogonal to the delivery beam cannot recover 3D target trajectories from a single view in real-time. This limits their utility for real-time motion management concurrent with beam delivery. To address this limitation, the authors propose a novel concept for on-board imaging based on the inverse-geometry Scanning-Beam Digital X-ray (SBDX) system and evaluate its feasibility for single-view 3D intradelivery fiducial tracking. Methods: A chest phantom comprising a posterior wall, a central lung volume, and an anterior wall was constructed. Two fiducials were placed along the mediastinal ridge between the lung cavities: a 1.5 mm diameter steel sphere superiorly and a gold cylinder (2.6 mm length x 0.9 mm diameter) inferiorly. The phantom was placed on a linear motion stage that moved sinusoidally. Fiducial motion was along the source-detector (z) axis of the SBDX system with {+-}10 mm amplitude and a programmed period of either 3.5 s or 5 s. The SBDX system was operated at 15 frames per second, 100 kVp, providing good apparent conspicuity of the fiducials. With the stage moving, detector data were acquired and subsequently reconstructed into 15 planes with a 12 mm plane-to-plane spacing using digital tomosynthesis.more » A tracking algorithm was applied to the image planes for each temporal frame to determine the position of each fiducial in (x,y,z)-space versus time. A 3D time-sinusoidal motion model was fit to the measured 3D coordinates and root mean square (RMS) deviations about the fitted trajectory were calculated. Results: Tracked motion was sinusoidal and primarily along the source-detector (z) axis. The RMS deviation of the tracked z-coordinate ranged from 0.53 to 0.71 mm. The motion amplitude derived from the model fit agreed with the programmed amplitude to within 0.28 mm for the steel sphere and within -0.77 mm for the gold seed. The model fit periods agreed with the programmed periods to within 7%. Conclusions: Three dimensional fiducial tracking with approximately 1 mm or better accuracy and precision appears to be feasible with SBDX, supporting its use to guide radiotherapy.« less

Authors:
; ; ;  [1]
  1. Department of Medical Physics, University of Wisconsin-Madison, Madison, Wisconsin 53705 (United States)
Publication Date:
OSTI Identifier:
22098824
Resource Type:
Journal Article
Journal Name:
Medical Physics
Additional Journal Information:
Journal Volume: 39; Journal Issue: 4; Other Information: (c) 2012 American Association of Physicists in Medicine; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0094-2405
Country of Publication:
United States
Language:
English
Subject:
62 RADIOLOGY AND NUCLEAR MEDICINE; ACCURACY; ALGORITHMS; BEAMS; CAVITIES; CHAINS; CHEST; GOLD; LUNGS; MANAGEMENT; PHANTOMS; RADIATION DOSES; RADIOTHERAPY; THREE-DIMENSIONAL CALCULATIONS; X RADIATION

Citation Formats

Speidel, Michael A., Wilfley, Brian P., Hsu, Annie, Hristov, Dimitre, Triple Ring Technologies, Inc., 39655 Eureka Drive, Newark, California 94560, and Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California 94305-5847. Feasibility of low-dose single-view 3D fiducial tracking concurrent with external beam delivery. United States: N. p., 2012. Web. doi:10.1118/1.3697529.
Speidel, Michael A., Wilfley, Brian P., Hsu, Annie, Hristov, Dimitre, Triple Ring Technologies, Inc., 39655 Eureka Drive, Newark, California 94560, & Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California 94305-5847. Feasibility of low-dose single-view 3D fiducial tracking concurrent with external beam delivery. United States. https://doi.org/10.1118/1.3697529
Speidel, Michael A., Wilfley, Brian P., Hsu, Annie, Hristov, Dimitre, Triple Ring Technologies, Inc., 39655 Eureka Drive, Newark, California 94560, and Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California 94305-5847. 2012. "Feasibility of low-dose single-view 3D fiducial tracking concurrent with external beam delivery". United States. https://doi.org/10.1118/1.3697529.
@article{osti_22098824,
title = {Feasibility of low-dose single-view 3D fiducial tracking concurrent with external beam delivery},
author = {Speidel, Michael A. and Wilfley, Brian P. and Hsu, Annie and Hristov, Dimitre and Triple Ring Technologies, Inc., 39655 Eureka Drive, Newark, California 94560 and Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California 94305-5847},
abstractNote = {Purpose: In external-beam radiation therapy, existing on-board x-ray imaging chains orthogonal to the delivery beam cannot recover 3D target trajectories from a single view in real-time. This limits their utility for real-time motion management concurrent with beam delivery. To address this limitation, the authors propose a novel concept for on-board imaging based on the inverse-geometry Scanning-Beam Digital X-ray (SBDX) system and evaluate its feasibility for single-view 3D intradelivery fiducial tracking. Methods: A chest phantom comprising a posterior wall, a central lung volume, and an anterior wall was constructed. Two fiducials were placed along the mediastinal ridge between the lung cavities: a 1.5 mm diameter steel sphere superiorly and a gold cylinder (2.6 mm length x 0.9 mm diameter) inferiorly. The phantom was placed on a linear motion stage that moved sinusoidally. Fiducial motion was along the source-detector (z) axis of the SBDX system with {+-}10 mm amplitude and a programmed period of either 3.5 s or 5 s. The SBDX system was operated at 15 frames per second, 100 kVp, providing good apparent conspicuity of the fiducials. With the stage moving, detector data were acquired and subsequently reconstructed into 15 planes with a 12 mm plane-to-plane spacing using digital tomosynthesis. A tracking algorithm was applied to the image planes for each temporal frame to determine the position of each fiducial in (x,y,z)-space versus time. A 3D time-sinusoidal motion model was fit to the measured 3D coordinates and root mean square (RMS) deviations about the fitted trajectory were calculated. Results: Tracked motion was sinusoidal and primarily along the source-detector (z) axis. The RMS deviation of the tracked z-coordinate ranged from 0.53 to 0.71 mm. The motion amplitude derived from the model fit agreed with the programmed amplitude to within 0.28 mm for the steel sphere and within -0.77 mm for the gold seed. The model fit periods agreed with the programmed periods to within 7%. Conclusions: Three dimensional fiducial tracking with approximately 1 mm or better accuracy and precision appears to be feasible with SBDX, supporting its use to guide radiotherapy.},
doi = {10.1118/1.3697529},
url = {https://www.osti.gov/biblio/22098824}, journal = {Medical Physics},
issn = {0094-2405},
number = 4,
volume = 39,
place = {United States},
year = {Sun Apr 15 00:00:00 EDT 2012},
month = {Sun Apr 15 00:00:00 EDT 2012}
}