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Title: Automated detection of a prostate Ni-Ti stent in electronic portal images

Abstract

Planning target volumes (PTV) in fractionated radiotherapy still have to be outlined with wide margins to the clinical target volume due to uncertainties arising from daily shift of the prostate position. A recently proposed new method of visualization of the prostate is based on insertion of a thermo-expandable Ni-Ti stent. The current study proposes a new detection algorithm for automated detection of the Ni-Ti stent in electronic portal images. The algorithm is based on the Ni-Ti stent having a cylindrical shape with a fixed diameter, which was used as the basis for an automated detection algorithm. The automated method uses enhancement of lines combined with a grayscale morphology operation that looks for enhanced pixels separated with a distance similar to the diameter of the stent. The images in this study are all from prostate cancer patients treated with radiotherapy in a previous study. Images of a stent inserted in a humanoid phantom demonstrated a localization accuracy of 0.4-0.7 mm which equals the pixel size in the image. The automated detection of the stent was compared to manual detection in 71 pairs of orthogonal images taken in nine patients. The algorithm was successful in 67 of 71 pairs of images. Themore » method is fast, has a high success rate, good accuracy, and has a potential for unsupervised localization of the prostate before radiotherapy, which would enable automated repositioning before treatment and allow for the use of very tight PTV margins.« less

Authors:
; ; ; ;  [1];  [2];  [3];  [3];  [3]
  1. Department of Medical Physics, Aalborg Hospital, University of Aarhus, Aalborg (Denmark)
  2. (CVMT), Aalborg University, Aalborg (Denmark)
  3. (Denmark)
Publication Date:
OSTI Identifier:
20853828
Resource Type:
Journal Article
Resource Relation:
Journal Name: Medical Physics; Journal Volume: 33; Journal Issue: 12; Other Information: DOI: 10.1118/1.2369466; (c) 2006 American Association of Physicists in Medicine; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
62 RADIOLOGY AND NUCLEAR MEDICINE; ACCURACY; ALGORITHMS; CARCINOMAS; IMAGES; MORPHOLOGY; NICKEL ALLOYS; PHANTOMS; PROSTATE; RADIOTHERAPY; TITANIUM ALLOYS

Citation Formats

Carl, Jesper, Nielsen, Henning, Nielsen, Jane, Lund, Bente, Larsen, Erik Hoejkjaer, Computer Vision and Media Technology Laboratory, Department of Medical Physics, Aalborg Hospital, University of Aarhus, Aalborg, Department of Oncology, Aalborg Hospital, Aalborg, and Department of Urology, Aalborg Hospital, Aalborg. Automated detection of a prostate Ni-Ti stent in electronic portal images. United States: N. p., 2006. Web. doi:10.1118/1.2369466.
Carl, Jesper, Nielsen, Henning, Nielsen, Jane, Lund, Bente, Larsen, Erik Hoejkjaer, Computer Vision and Media Technology Laboratory, Department of Medical Physics, Aalborg Hospital, University of Aarhus, Aalborg, Department of Oncology, Aalborg Hospital, Aalborg, & Department of Urology, Aalborg Hospital, Aalborg. Automated detection of a prostate Ni-Ti stent in electronic portal images. United States. doi:10.1118/1.2369466.
Carl, Jesper, Nielsen, Henning, Nielsen, Jane, Lund, Bente, Larsen, Erik Hoejkjaer, Computer Vision and Media Technology Laboratory, Department of Medical Physics, Aalborg Hospital, University of Aarhus, Aalborg, Department of Oncology, Aalborg Hospital, Aalborg, and Department of Urology, Aalborg Hospital, Aalborg. Fri . "Automated detection of a prostate Ni-Ti stent in electronic portal images". United States. doi:10.1118/1.2369466.
@article{osti_20853828,
title = {Automated detection of a prostate Ni-Ti stent in electronic portal images},
author = {Carl, Jesper and Nielsen, Henning and Nielsen, Jane and Lund, Bente and Larsen, Erik Hoejkjaer and Computer Vision and Media Technology Laboratory and Department of Medical Physics, Aalborg Hospital, University of Aarhus, Aalborg and Department of Oncology, Aalborg Hospital, Aalborg and Department of Urology, Aalborg Hospital, Aalborg},
abstractNote = {Planning target volumes (PTV) in fractionated radiotherapy still have to be outlined with wide margins to the clinical target volume due to uncertainties arising from daily shift of the prostate position. A recently proposed new method of visualization of the prostate is based on insertion of a thermo-expandable Ni-Ti stent. The current study proposes a new detection algorithm for automated detection of the Ni-Ti stent in electronic portal images. The algorithm is based on the Ni-Ti stent having a cylindrical shape with a fixed diameter, which was used as the basis for an automated detection algorithm. The automated method uses enhancement of lines combined with a grayscale morphology operation that looks for enhanced pixels separated with a distance similar to the diameter of the stent. The images in this study are all from prostate cancer patients treated with radiotherapy in a previous study. Images of a stent inserted in a humanoid phantom demonstrated a localization accuracy of 0.4-0.7 mm which equals the pixel size in the image. The automated detection of the stent was compared to manual detection in 71 pairs of orthogonal images taken in nine patients. The algorithm was successful in 67 of 71 pairs of images. The method is fast, has a high success rate, good accuracy, and has a potential for unsupervised localization of the prostate before radiotherapy, which would enable automated repositioning before treatment and allow for the use of very tight PTV margins.},
doi = {10.1118/1.2369466},
journal = {Medical Physics},
number = 12,
volume = 33,
place = {United States},
year = {Fri Dec 15 00:00:00 EST 2006},
month = {Fri Dec 15 00:00:00 EST 2006}
}