title: A novel use of endoscopic clips in the treatment planning for radiation therapy (XRT) of esophageal cancer.
abstract: OBJECTIVE
  To determine if the placement of metal endoclips improves radiotherapy (XRT) planning for esophageal cancer.
  
  
  BACKGROUND
  XRT is an important modality in the treatment and palliation of esophageal cancer. Accurate simulation of the radiation field ensures optimal therapy while limiting toxicity.
  
  
  METHODS
  Patients with esophageal carcinoma underwent EGD and endoscopic mucosal clip placement at the proximal and distal margins of the tumor. At XRT simulation the radiation oncologist simulated the field based on barium study, CT scan, and endoscopy report. A second radiation oncologist then assessed the ease of identification of the clips/margins of the tumor, shift in the field isocenter, and change in the radiation field width and length because of the metal clips.
  
  
  RESULTS
  Seven patients with cancer of the esophagus had endoscopic clips placed followed by XRT simulation. The clips could be identified in all 7 patients. Simulation with the use of clips caused a shift in the field isocenter with a mean longitudinal shift (y-axis) of 3.5 cm (range, 1-6 cm) and a mean lateral shift (x-axis) of 0.33 cm (range, 0-1 cm).
  
  
  CONCLUSIONS
  Endoscopically placed mucosal metal clips can aid field simulation when planning radiation therapy in patients with esophageal cancer.
authors.affiliation: Division of Gastroenterology, University Hospitals of Cleveland, Case Western Reserve University, Cleveland, OH 44118, USA.
authors.forename: Patrick R
authors.initials: PR
authors.lastname: Pfau
authors.forename: Huong
authors.initials: H
authors.lastname: Pham
authors.forename: Rod
authors.initials: R
authors.lastname: Ellis
authors.forename: Ananya
authors.initials: A
authors.lastname: Das
authors.forename: Gerard
authors.initials: G
authors.lastname: Isenberg
authors.forename: Amitabh
authors.initials: A
authors.lastname: Chak
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002277:Carcinoma / Q000473:pathology / Q000532:radiotherapy*; D019160:Endosonography; D004867:Equipment Design; D004938:Esophageal Neoplasms / Q000175:diagnosis / Q000532:radiotherapy*; D004945:Esophagoscopy; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D020266:Radiotherapy, Conformal / Q000295:instrumentation*; D015203:Reproducibility of Results; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome