title: Segmentation of iodine brachytherapy implants in fluoroscopy.
abstract: OBJECTIVE
  In prostate brachytherapy, intraoperative dosimetry would allow for evaluation of the implant quality while the patient is still in treatment position. Such a mechanism, however, requires 3-D visualization of the deposited seeds relative to the prostate. It follows that accurate and robust seed segmentation is of critical importance in achieving intraoperative dosimetry.
  
  
  METHODS
  Implanted iodine brachytherapy seeds are segmented via a region-based implicit active contour model. Overlapping seed groups are then resolved using a template-based declustering technique.
  
  
  RESULTS
  Ground truth seed coordinates were obtained through manual segmentation. A total of 57 clinical C-arm images from 10 patients were used to validate the proposed algorithm. This resulted in two failed images and a 96.0% automatic detection rate with a corresponding 2.2% false-positive rate in the remaining 55 images. The mean centroid error between the manual and automatic segmentations was 1.2 pixels.
  
  
  CONCLUSIONS
  Robust and accurate iodine seed segmentation can be achieved through the proposed segmentation workflow.
authors.affiliation: Queen's University, Kingston, Canada.
authors.forename: Eric
authors.initials: E
authors.lastname: Moult
authors.forename: Gabor
authors.initials: G
authors.lastname: Fichtinger
authors.forename: W James
authors.initials: WJ
authors.lastname: Morris
authors.forename: Septimiu E
authors.initials: SE
authors.lastname: Salcudean
authors.forename: Ehsan
authors.initials: E
authors.lastname: Dehghan
authors.forename: Pascal
authors.initials: P
authors.lastname: Fallavollita
mesh_terms: D000465:Algorithms; D001918:Brachytherapy / Q000379:methods*; D005471:Fluoroscopy / Q000379:methods*; D006801:Humans; D021621:Imaging, Three-Dimensional; D007457:Iodine Radioisotopes / Q000627:therapeutic use*; D008297:Male; D011471:Prostatic Neoplasms / Q000532:radiotherapy*; D011879:Radiotherapy Dosage
chemical_list: D007457:Iodine Radioisotopes