title: Fiducial placement for stereotactic radiation by using EUS: feasibility when using a marker compatible with a standard 22-gauge needle.
abstract: BACKGROUND
  Stereotactic radiation by using fiducial markers permits higher doses of radiation while reducing the exposure of uninvolved, adjacent structures. EUS has been used to deploy fiducials, although a 19-gauge needle has traditionally been required.
  
  
  OBJECTIVE
  To report a new technique and the feasibility of deploying a fiducial compatible with a 22-gauge needle under EUS guidance.
  
  
  METHODS
  Single-center, case series.
  
  
  METHODS
  Tertiary care referral center.
  
  
  METHODS
  Thirteen patients with primary or metastatic cancer referred for stereotactic radiation.
  
  
  METHODS
  EUS-guided placement of a single fiducial marker that is compatible with a 22-gauge EUS-FNA needle.
  
  
  METHODS
  Technical success and complications.
  
  
  RESULTS
  Thirteen patients referred for EUS-guided placement of a fiducial marker were identified in the endoscopic database. Targeted lesions measured 27 +/- 13 mm (range 8-50) x 21 +/- 10 mm (range 6-42). All fiducials were successfully deployed, 9 using a transgastric and 4 using a transduodenal approach. There were no EUS-associated complications. Two patients did not proceed to radiation therapy as a result of interval peritoneal metastasis. However, all fiducials were visible on the roentogram. Eleven of 13 patients (85%) required placement of 1 fiducial, whereas 2 patients (15%) required 2 fiducials.
  
  
  CONCLUSIONS
  Uncontrolled feasibility study with limited sample size and follow-up.
  
  
  CONCLUSIONS
  EUS-guided placement of a fiducial using a 22-gauge needle is technically feasible and may permit greater access compared with the 19-gauge needle technique.
authors.affiliation: Division of Gastroenterology, Department of Medicine, Alvin J. Siteman Cancer Center, Washington University School of Medicine, St. Louis, Missouri, USA.
authors.forename: Tarek
authors.initials: T
authors.lastname: Ammar
authors.forename: Gregory A
authors.initials: GA
authors.lastname: Coté
authors.forename: Kimberly M
authors.initials: KM
authors.lastname: Creach
authors.forename: Cara
authors.initials: C
authors.lastname: Kohlmeier
authors.forename: Parag J
authors.initials: PJ
authors.lastname: Parikh
authors.forename: Riad R
authors.initials: RR
authors.lastname: Azar
mesh_terms: D019160:Endosonography / Q000295:instrumentation / Q000379:methods*; D004867:Equipment Design; D005240:Feasibility Studies; D005770:Gastrointestinal Neoplasms / Q000532:radiotherapy*; D006801:Humans; D009339:Needles; D010534:Peritoneal Neoplasms / Q000556:secondary; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted