title: A more efficient, radiation-free alternative to systematic chest x-ray for the detection of embolized seeds to the lung.
abstract: OBJECTIVE
  To evaluate the efficacy of a seed-migration detector and to compare its performance to fluoroscopy and postoperative chest radiographs.
  
  
  METHODS
  A gamma scintillation survey meter was converted to a seed-migration detector by adding a shield on the probe detection window. The detector response to three (125)I seed activities was characterized for different source-to-detector distances in water. The detector was used to perform a chest evaluation on 737 patients at their first postoperative visit. When the detector showed positive activity, seed migration was confirmed by taking a chest radiograph and by looking at the region with fluoroscopy.
  
  
  RESULTS
  One hundred and three patients (14.0%) presented at least one embolized seed. This accounts for 123 of the 39,887 seeds. Eighty-seven, 12, and 4 patients had respectively one, two, and three seed embolization. Compared with the seed-migration detector, detection based on fluoroscopy would have led to 13 false-negative detections (of 103, or 12.6%), and the radiograph would have resulted in 31 or 30.1%. More important, standard chest X-ray would have required a survey and extra radiation dose to lung to 100% of the patients, rather than the 14% who required it.
  
  
  CONCLUSIONS
  The usual recommendation to perform chest radiographs at the first follow-up visit to scan lungs for embolized seeds should be revised because of the high false-negative rate. Scintillator-based gamma counter detector provides superior detection sensitivity and should be adopted as a standard of practice. Chest X-ray could be limited to documenting cases of positive migration.
authors.affiliation: Département de radio-oncologie et Centre de recherche en cancérologie de l'Université Laval, Hôtel-Dieu de Québec, Québec, Canada. janelle.morrier@mail.chuq.qc.ca
authors.forename: Janelle
authors.initials: J
authors.lastname: Morrier
authors.forename: Mario
authors.initials: M
authors.lastname: Chrétien
authors.forename: André-Guy
authors.initials: AG
authors.lastname: Martin
authors.forename: Eric
authors.initials: E
authors.lastname: Vigneault
authors.forename: Luc
authors.initials: L
authors.lastname: Beaulieu
mesh_terms: D001918:Brachytherapy / Q000009:adverse effects* / Q000295:instrumentation; D002138:Calibration; D005188:False Negative Reactions; D005471:Fluoroscopy; D005548:Foreign-Body Migration / Q000150:complications / Q000000981:diagnostic imaging*; D015902:Gamma Cameras; D006801:Humans; D007457:Iodine Radioisotopes; D008168:Lung; D008297:Male; D011446:Prospective Studies; D011471:Prostatic Neoplasms / Q000532:radiotherapy; D011655:Pulmonary Embolism / Q000000981:diagnostic imaging* / Q000209:etiology; D011877:Radionuclide Imaging
chemical_list: D007457:Iodine Radioisotopes