Intraoperative dynamic dosimetry for prostate implants Journal Article


Authors: Todor, D. A.; Zaider, M.; Cohen, G. N.; Worman, M. F.; Zelefsky, M. J.
Article Title: Intraoperative dynamic dosimetry for prostate implants
Abstract: This paper describes analytic tools in support of a paradigm shift in brachytherapy treatment planning for prostate cancer - a shift from standard pre-planning to intraoperative planning using dosimetric feedback based on the actual deposited seed positions within the prostate. The method proposed is guided by several desiderata: (a) bringing both planning and evaluation in the operating room (i.e. make post-implant evaluation superfluous) therefore making rectifications - if necessary - still achievable; (b) making planning and implant evaluation consistent by using the same imaging system (ultrasound); and (c) using only equipment commonly found in a hospital operating room. The intraoperative dosimetric evaluation is based on the fusion between ultrasound images and 3D seed coordinates reconstructed from fluoroscopic projections. Automatic seed detection and registration of the fluoroscopic and ultrasound information, two of the three key ingredients needed for the intraoperative dynamic dosimetry optimization (IDDO), are explained in detail. The third one, the reconstruction of 3D coordinates from projections, was reported in a previous article. The algorithms were validated using a custom-designed phantom with non-radioactive (dummy) seeds. Also, fluoroscopic images were taken at the conclusion of an actual permanent prostate implant and compared with data on the same patient obtained from radiographic-based post-implant evaluation. To offset the effect of organ motion the comparison was performed in terms of the proximity function of the two seed distributions. The agreement between the intra- and post-operative seed distributions was excellent.
Keywords: controlled study; treatment planning; image analysis; radiotherapy dosage; algorithms; prostate cancer; prostatic neoplasms; imaging system; hospitals; algorithm; image enhancement; subtraction technique; tumors; dosimetry; intraoperative period; echography; brachytherapy; radiography; radiometry; radiotherapy planning, computer-assisted; phantom; monitoring, intraoperative; radioisotope therapy; operating room; image reconstruction; fluoroscopy; radiotherapy, computer-assisted; imaging techniques; ultrasonics; implants (surgical); humans; male; priority journal; article; intraoperative dynamic dosimetry optimization (iddo)
Journal Title: Physics in Medicine and Biology
Volume: 48
Issue: 9
ISSN: 0031-9155
Publisher: IOP Publishing Ltd  
Date Published: 2003-05-01
Start Page: 1153
End Page: 1171
Language: English
DOI: 10.1088/0031-9155/48/9/306
PUBMED: 12765329
PROVIDER: scopus
DOI/URL:
Notes: Export Date: 12 September 2014 -- Source: Scopus
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  1. Dorin Aurel Todor
    4 Todor
  2. Michael J Zelefsky
    754 Zelefsky
  3. Michael F Worman
    10 Worman
  4. Gilad N Cohen
    181 Cohen
  5. Marco Zaider
    171 Zaider