title: Safety and efficacy of ultrasound-guided fiducial marker implantation for CyberKnife radiation therapy.
abstract: OBJECTIVE
  To evaluate the safety and technical success rate of an ultrasound-guided fiducial marker implantation in preparation for CyberKnife radiation therapy.
  
  
  METHODS
  We retrospectively reviewed 270 percutaneous ultrasound-guided fiducial marker implantations in 77 patients, which were performed from June 2008 through March 2011. Of 270 implantations, 104 were implanted in metastatic lymph nodes, 96 were in the liver, 39 were in the pancreas, and 31 were in the prostate. During and after the implantation, major and minor procedure-related complications were documented. We defined technical success as the implantation enabling adequate treatment planning and CT simulation.
  
  
  RESULTS
  The major and minor complication rates were 1% and 21%, respectively. One patient who had an implantation in the liver suffered severe abdominal pain, biloma, and pleural effusion, which were considered as major complication. Abdominal pain was the most common complication in 11 patients (14%). Among nine patients who had markers inserted in the prostate, one had transient hematuria for less than 24 hours, and the other experienced transient voiding difficulty. Of the 270 implantations, 261 were successful (97%). The reasons for unsuccessful implantations included migration of fiducial markers (five implantations, 2%) and failure to discriminate the fiducial markers (three implantations, 1%). Among the unsuccessful implantation cases, six patients required additional procedures (8%).
  
  
  CONCLUSIONS
  The symptomatic complications following ultrasound-guided percutaneous implantation of fiducial markers are relatively low. However, careful consideration of the relatively higher rate of migration and discrimination failure is needed when performing ultrasound-guided percutaneous implantations of fiducial markers.
authors.affiliation: Department of Radiology, Soonchunhyang University Seoul Hospital, Seoul 140-743, Korea.
authors.forename: Jae Hyun
authors.initials: JH
authors.lastname: Kim
authors.forename: Seong Sook
authors.initials: SS
authors.lastname: Hong
authors.forename: Jung Hoon
authors.initials: JH
authors.lastname: Kim
authors.forename: Hyun Jeong
authors.initials: HJ
authors.lastname: Park
authors.forename: Yun-Woo
authors.initials: YW
authors.lastname: Chang
authors.forename: A Ram
authors.initials: AR
authors.lastname: Chang
authors.forename: Seok-Beom
authors.initials: SB
authors.lastname: Kwon
mesh_terms: D000328:Adult; D000368:Aged; D004869:Equipment Safety; D005260:Female; D057918:Fiducial Markers / Q000009:adverse effects; D006801:Humans; D008297:Male; D008875:Middle Aged; D016634:Radiosurgery / Q000379:methods*; D012189:Retrospective Studies; D012307:Risk Factors; D018084:Ultrasonography, Interventional