A novel endoscopic marker for radiological localization and image-guided radiotherapy in esophageal and gastric cancers

Background and Aims: Radiotherapy is an accepted modality in the treatment of esophageal cancers and is currently being evaluated in conjunction with chemotherapy for the neoadjuvant treatment of gastric cancers. Our aim was to assess whether a novel endoscopically inserted marker can be used to improve radiological assessment of the primary cancer and allow for image-guided radiotherapy. Methods: A phase II feasibility study was conducted at a tertiary-care center. Twenty-six consecutive adult patients with esophagogastric cancers underwent endoscopic marking of the tumor margins with a novel radiopaque marker (mixture of lipiodol and n-butyl 2-cyanoacrylate). The main outcome measure was the successful insertion of the marker based on a combination of radiological, endoscopic, and histological assessment. Results: A total of 92 markers were inserted in 26 patients. Twenty-two (88%) had follow-up imaging to assess the 81 markers inserted, 79 of which (97.5%) were visible. There were no postprocedural adverse events noted in our cohort. Radiological assessment of tumor size improved such that it was in line with the endoscopic evaluation after marker placement in 18 of 21 patients (85.7%) who had appropriate follow-up radiology imaging. Ten patients (38.5%) from our cohort underwent image-guided radiotherapy (IGRT) by using the endoscopically inserted markers. Conclusion: Within the limitations of our small pilot study, endoscopic placement of our novel marker was successful in the majority of our cohort without significant adverse events. Marker placement resulted in improved radiological localization in the majority of our cohort and allowed for IGRT.