Automatic segmentation of radiographic fiducial and seeds from X-ray images in prostate brachytherapy

Nathanael Kuo, Anton Deguet, Danny Y. Song, Everette C. Burdette, Jerry L. Prince, Junghoon Lee

Research output: Contribution to journalArticlepeer-review

12 Scopus citations


Prostate brachytherapy guided by transrectal ultrasound is a common treatment option for early stage prostate cancer. Prostate cancer accounts for 28% of cancer cases and 11% of cancer deaths in men with 217,730 estimated new cases and 32,050 estimated deaths in 2010 in the United States alone. The major current limitation is the inability to reliably localize implanted radiation seeds spatially in relation to the prostate. Multimodality approaches that incorporate X-ray for seed localization have been proposed, but they require both accurate tracking of the imaging device and segmentation of the seeds. Some use image-based radiographic fiducials to track the X-ray device, but manual intervention is needed to select proper regions of interest for segmenting both the tracking fiducial and the seeds, to evaluate the segmentation results, and to correct the segmentations in the case of segmentation failure, thus requiring a significant amount of extra time in the operating room. In this paper, we present an automatic segmentation algorithm that simultaneously segments the tracking fiducial and brachytherapy seeds, thereby minimizing the need for manual intervention. In addition, through the innovative use of image processing techniques such as mathematical morphology, Hough transforms, and RANSAC, our method can detect and separate overlapping seeds that are common in brachytherapy implant images. Our algorithm was validated on 55 phantom and 206 patient images, successfully segmenting both the fiducial and seeds with a mean seed segmentation rate of 96% and sub-millimeter accuracy.

Original languageEnglish (US)
Pages (from-to)64-77
Number of pages14
JournalMedical Engineering and Physics
Issue number1
StatePublished - Jan 2012


  • Fiducial
  • Non-isocentric C-arm
  • Overlapping seeds
  • Prostate brachytherapy
  • Seed localization
  • Segmentation
  • X-ray

ASJC Scopus subject areas

  • Biophysics
  • Biomedical Engineering


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