title: Stability of endoscopic ultrasound-guided fiducial marker placement for esophageal cancer target delineation and image-guided radiation therapy.
abstract: OBJECTIVE
  Fiducial markers have been integrated into the management of multiple malignancies to guide more precise delivery of radiation therapy (RT). Fiducials placed at the margins of esophageal tumors are potentially useful to facilitate both RT target delineation and image-guided RT (IGRT). In this study, we report on the stability of endoscopic ultrasound (EUS)-guided fiducial placement for esophageal cancers and utilization for radiation treatment planning and IGRT.
  
  
  METHODS
  An institutional review board-approved database was queried for patients treated for esophageal cancer with chemoradiotherapy (CRT). Patients included in the analysis had a diagnosis of esophageal cancer, were referred for treatment with CRT, and had fiducials placed under EUS guidance. Images acquired at time of radiation treatment planning, daily IGRT imaging, post-treatment restaging, and surveillance scans were analyzed to determine the stability of implanted markers.
  
  
  RESULTS
  We identified 60 patients who underwent EUS-guided fiducial marker placement near the margins of their esophageal tumors in preparation for RT treatment planning. A total of 105 fiducial markers were placed. At time of CT simulation, 99 markers were visualized. Fifty-seven patients had post-treatment imaging available for review. Of the 100 implanted fiducials in these 57 patients, 94 (94%) were visible at time of RT simulation. Eighty-eight (88%) fiducials were still present post-treatment imaging at a median of 107 days (range, 33-471 days) after implantation.
  
  
  CONCLUSIONS
  EUS-guided fiducial marker placement for esophageal cancer aids in target delineation for radiation planning and daily IGRT. Fiducial stability is reproducible and facilitates conformal treatment with image-guided RT techniques.
authors.affiliation: Department of Radiation Oncology, H. Lee Moffitt Cancer Center, Tampa, Florida. Electronic address: daniel.fernandez@moffitt.org.
authors.forename: Daniel C
authors.initials: DC
authors.lastname: Fernandez
authors.affiliation: Department of Radiation Oncology, H. Lee Moffitt Cancer Center, Tampa, Florida.
authors.forename: Sarah E
authors.initials: SE
authors.lastname: Hoffe
authors.affiliation: Gastrointestinal Tumor Program, H. Lee Moffitt Cancer Center, Tampa, Florida.
authors.forename: James S
authors.initials: JS
authors.lastname: Barthel
authors.affiliation: Gastrointestinal Tumor Program, H. Lee Moffitt Cancer Center, Tampa, Florida.
authors.forename: Shivakumar
authors.initials: S
authors.lastname: Vignesh
authors.affiliation: Gastrointestinal Tumor Program, H. Lee Moffitt Cancer Center, Tampa, Florida.
authors.forename: Jason B
authors.initials: JB
authors.lastname: Klapman
authors.affiliation: Gastrointestinal Tumor Program, H. Lee Moffitt Cancer Center, Tampa, Florida.
authors.forename: Cynthia
authors.initials: C
authors.lastname: Harris
authors.affiliation: Gastrointestinal Tumor Program, H. Lee Moffitt Cancer Center, Tampa, Florida.
authors.forename: Khaldoun
authors.initials: K
authors.lastname: Almhanna
authors.affiliation: Department of Radiation Oncology, H. Lee Moffitt Cancer Center, Tampa, Florida.
authors.forename: Matthew C
authors.initials: MC
authors.lastname: Biagioli
authors.affiliation: Gastrointestinal Tumor Program, H. Lee Moffitt Cancer Center, Tampa, Florida.
authors.forename: Kenneth L
authors.initials: KL
authors.lastname: Meredith
authors.affiliation: Department of Radiation Oncology, H. Lee Moffitt Cancer Center, Tampa, Florida.
authors.forename: Vladimir
authors.initials: V
authors.lastname: Feygelman
authors.affiliation: Department of Radiation Oncology, H. Lee Moffitt Cancer Center, Tampa, Florida.
authors.forename: Nikhil G
authors.initials: NG
authors.lastname: Rao
authors.affiliation: Department of Radiation Oncology, H. Lee Moffitt Cancer Center, Tampa, Florida.
authors.forename: Ravi
authors.initials: R
authors.lastname: Shridhar