Success rate of fiducial marker placement for treatment of esophageal or rectal cancers: a prospective multicenter study (FIDECHO study) (with video)

Abstract

Background and aims: EUS-guided placement of fiducial markers in patients with esophageal or rectal cancer who have been referred for radiation therapy lacks data regarding its feasibility and safety. The aim of this study was to assess the success rate of EUS-guided fiducial marker placement in these indications.

Methods: This prospective multicenter study enrolled patients with rectal or esophageal tumors who were treated between March 2017 and June 2021. The primary endpoint was the success of fiducial marker placement under EUS guidance utilizing the preloaded 22-gauge EchoTip Ultra Fiducial Needle (Cook Medical, Limerick, Ireland), defined by the ability to release fiducials at least at the proximal and distal ends of the tumor. Secondary endpoints were the adverse events, length of procedure, and fiducial markers remaining throughout radiation therapy.

Results: A total of 33 patients were included in this study, with a mean age of 64.2 ± 11.3 years; 66.7% were male. Twenty patients had rectal adenocarcinoma, and 13 had esophageal malignancies. The success rate of fiducial marker placement was 93.9%. Markers could only be released at the proximal end of the tumor in 2 cases. The average procedure time (±SD) was 12.5 ± 4.8 minutes. The number of fiducial markers placed for each patient was 3.8 ± .5. No adverse events were reported. At the end of radiotherapy, markers were still visible on imaging in all patients.

Conclusions: This prospective multicenter study highlights the safety and high success of the placement of fiducial markers under EUS guidance for rectal and esophageal tumors, with no adverse events and with a short procedure time. Fiducial markers remained in place over time during radiation therapy. (Clinical trial registration number: NCT03057288.).