Background: Markers placed at the borders of esophageal tumors are potentially useful to facilitate radiotherapy (RT) target delineation, which offers the possibility of image-guided RT.
Objective: To evaluate and compare the feasibility and technical benefit of endoscopy/EUS-guided marker placement of 3 different types of markers in patients with esophageal cancer referred for RT.
Design: Prospective, single-center, feasibility and comparative study.
Setting: Tertiary-care medical center.
Patients: Thirty patients with esophageal cancer who were referred for RT.
Interventions: Patients underwent endoscopy/EUS-guided implantation of 1 type of marker. A solid gold marker (SM) with fixed dimensions, a flexible coil-shaped gold marker (FM) with hand-cut length (2-10 mm), and a radiopaque hydrogel marker (HG) were used. Technical feasibility and adverse events were registered. CT scans and cone-beam CT scans (CBCT) acquired during RT were analyzed to determine and compare the visibility and continuous clear visibility of the implanted markers.
Main outcome measurements: Technical feasibility, technical benefit, and adverse events of 3 types of markers.
Results: A total of 101 markers were placed in 30 patients. Implantation was technically feasible in all patients without grade 3 to 4 adverse events. Two patients with asymptomatic mediastinitis and one with asymptomatic pneumothorax were seen. Visibility on CT scan of all 3 types of implanted markers was adequate for target delineation. Eighty percent of FMs remained continuously visible over the treatment period on CBCT, significantly better than SMs (63%) and HGs (11%) (P = .015). When we selected FMs ≥5 mm, 90.5% remained visible on CBCT between implantation and the end of RT.
Limitations: Single-center, nonrandomized design.
Conclusion: Endoscopy/EUS-guided fiducial marker placement for esophageal cancer is both safe and feasible and can be used for target volume delineation purposes on CT. Our results imply a significant advantage of FMs over SMs and HGs, regarding visibility and continuous clear visibility over the treatment period. (
Clinical trial registration number: NTR4724.).
Copyright © 2015 American Society for Gastrointestinal Endoscopy. Published by Elsevier Inc. All rights reserved.