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Title: Automatic tracking of implanted fiducial markers in cone beam CT projection images

Abstract

Purpose: This paper describes a novel method for simultaneous intrafraction tracking of multiple fiducial markers. Although the proposed method is generic and can be adopted for a number of applications including fluoroscopy based patient position monitoring and gated radiotherapy, the tracking results presented in this paper are specific to tracking fiducial markers in a sequence of cone beam CT projection images. Methods: The proposed method is accurate and robust thanks to utilizing the mean shift and random sampling principles, respectively. The performance of the proposed method was evaluated with qualitative and quantitative methods, using data from two pancreatic and one prostate cancer patients and a moving phantom. The ground truth, for quantitative evaluation, was calculated based on manual tracking preformed by three observers. Results: The average dispersion of marker position error calculated from the tracking results for pancreas data (six markers tracked over 640 frames, 3840 marker identifications) was 0.25 mm (at iscoenter), compared with an average dispersion for the manual ground truth estimated at 0.22 mm. For prostate data (three markers tracked over 366 frames, 1098 marker identifications), the average error was 0.34 mm. The estimated tracking error in the pancreas data was < 1 mm (2 pixels) inmore » 97.6% of cases where nearby image clutter was detected and in 100.0% of cases with no nearby image clutter. Conclusions: The proposed method has accuracy comparable to that of manual tracking and, in combination with the proposed batch postprocessing, superior robustness. Marker tracking in cone beam CT (CBCT) projections is useful for a variety of purposes, such as providing data for assessment of intrafraction motion, target tracking during rotational treatment delivery, motion correction of CBCT, and phase sorting for 4D CBCT.« less

Authors:
; ;  [1]
  1. Christie Medical Physics and Engineering, The Christie NHS Foundation Trust, Manchester M20 4BX, United Kingdom and Manchester Academic Health Science Centre, University of Manchester, Manchester M20 4BX (United Kingdom)
Publication Date:
OSTI Identifier:
22098780
Resource Type:
Journal Article
Journal Name:
Medical Physics
Additional Journal Information:
Journal Volume: 39; Journal Issue: 3; 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; BEAMS; COMPUTERIZED TOMOGRAPHY; CORRECTIONS; DISPERSIONS; FLUOROSCOPY; GROUND TRUTH MEASUREMENTS; IMAGE PROCESSING; NEOPLASMS; PANCREAS; PROSTATE; RADIOTHERAPY; RANDOMNESS; SAMPLING; SORTING

Citation Formats

Marchant, T. E., Skalski, A., Matuszewski, B. J., AGH University of Science and Technology, al. A. Mickiewicza 30, Krakow 30-059, and School of Computing, Engineering and Physical Sciences, University of Central Lancashire, Preston PR1 2HE. Automatic tracking of implanted fiducial markers in cone beam CT projection images. United States: N. p., 2012. Web. doi:10.1118/1.3684959.
Marchant, T. E., Skalski, A., Matuszewski, B. J., AGH University of Science and Technology, al. A. Mickiewicza 30, Krakow 30-059, & School of Computing, Engineering and Physical Sciences, University of Central Lancashire, Preston PR1 2HE. Automatic tracking of implanted fiducial markers in cone beam CT projection images. United States. doi:10.1118/1.3684959.
Marchant, T. E., Skalski, A., Matuszewski, B. J., AGH University of Science and Technology, al. A. Mickiewicza 30, Krakow 30-059, and School of Computing, Engineering and Physical Sciences, University of Central Lancashire, Preston PR1 2HE. Thu . "Automatic tracking of implanted fiducial markers in cone beam CT projection images". United States. doi:10.1118/1.3684959.
@article{osti_22098780,
title = {Automatic tracking of implanted fiducial markers in cone beam CT projection images},
author = {Marchant, T. E. and Skalski, A. and Matuszewski, B. J. and AGH University of Science and Technology, al. A. Mickiewicza 30, Krakow 30-059 and School of Computing, Engineering and Physical Sciences, University of Central Lancashire, Preston PR1 2HE},
abstractNote = {Purpose: This paper describes a novel method for simultaneous intrafraction tracking of multiple fiducial markers. Although the proposed method is generic and can be adopted for a number of applications including fluoroscopy based patient position monitoring and gated radiotherapy, the tracking results presented in this paper are specific to tracking fiducial markers in a sequence of cone beam CT projection images. Methods: The proposed method is accurate and robust thanks to utilizing the mean shift and random sampling principles, respectively. The performance of the proposed method was evaluated with qualitative and quantitative methods, using data from two pancreatic and one prostate cancer patients and a moving phantom. The ground truth, for quantitative evaluation, was calculated based on manual tracking preformed by three observers. Results: The average dispersion of marker position error calculated from the tracking results for pancreas data (six markers tracked over 640 frames, 3840 marker identifications) was 0.25 mm (at iscoenter), compared with an average dispersion for the manual ground truth estimated at 0.22 mm. For prostate data (three markers tracked over 366 frames, 1098 marker identifications), the average error was 0.34 mm. The estimated tracking error in the pancreas data was < 1 mm (2 pixels) in 97.6% of cases where nearby image clutter was detected and in 100.0% of cases with no nearby image clutter. Conclusions: The proposed method has accuracy comparable to that of manual tracking and, in combination with the proposed batch postprocessing, superior robustness. Marker tracking in cone beam CT (CBCT) projections is useful for a variety of purposes, such as providing data for assessment of intrafraction motion, target tracking during rotational treatment delivery, motion correction of CBCT, and phase sorting for 4D CBCT.},
doi = {10.1118/1.3684959},
journal = {Medical Physics},
issn = {0094-2405},
number = 3,
volume = 39,
place = {United States},
year = {2012},
month = {3}
}