Endoscopic ultrasound-guided fiducial marker insertion to guide radiotherapy in advanced esophageal carcinoma

Abstract

Background and Objectives:The role of endoscopic ultrasound (EUS)-guided fiducial marker insertion to guide radiotherapy for esophageal cancer is uncertain. The aim of this study is to evaluate the optimal method of performing the technique.Methods:This was a retrospective study of all patients who received EUS-guided fiducial marker insertion between March 2015 and November 2016. Gold fiducial markers of size 5 mm × 0.35 mm (VISICOIL, IBA Dosimetry, USA) were placed under EUS guidance either intratumorally or in the normal submucosa just proximal and distal to the tumor. Outcome parameters included tumor characteristics, migration rates, and tumor response rates.Results:During the study period, 25 patients received the procedure. The mean (standard deviation [S.D.]) age was 59.6 (10.2) years. The mean (S.D.) length and volume of the tumor were 6.7 (4.2) cm and 24.6 (15.8) ml, respectively, and 88% of the patients had Stage 3 disease. Twenty patients had markers inserted by endobronchial ultrasound (EBUS) and 60% in the submucosa. When comparing fiducials that were placed in the submucosa versus intratumorally, significantly, more fiducials had early (42.9% vs. 0%, P = 0.017) and late migration (100% vs. 0%, P < 0.001) in the intratumoral group. There were no differences in the stage of disease (P = 0.657), percentage of patients who completed radiotherapy (P = 0.299), and response rate (P = 0.515).Conclusions:In obstructing esophageal carcinomas, fiducial markers should be placed in the submucosa just proximal and distal to the tumor by EBUS.