Retrospective Cohort Study
Copyright ©The Author(s) 2025. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Methodol. Dec 20, 2025; 15(4): 106591
Published online Dec 20, 2025. doi: 10.5662/wjm.v15.i4.106591
Preoperative marking of the proximal resection margin in esophageal cancer with a surgical fiducial marker: First experiences
Trygve U Solstad, Andreas W Mucha, August A Olsen, Hanne Grossjohann, Michael P Achiam
Trygve U Solstad, Andreas W Mucha, August A Olsen, Hanne Grossjohann, Michael P Achiam, Department of Digestive Diseases, Transplantation and General Surgery, Copenhagen University Hospital Rigshospitalet, København 2100, Denmark
Michael P Achiam, Department of Clinical Medicine, University of Copenhagen, Copenhagen 2100, Hovedstaden, Denmark
Author contributions: Solstad TU, Achiam MP, and Olsen AA initiated and designed the study; Solstad TU, Mucha AW, Grossjohann H, and Achiam MP acquired the data and performed the research; Solstad TU, Mucha AW, Olsen AO, and Achiam MP analyzed and interpreted the data; Solstad TU, Mucha AW, and Olsen AO drafted the manuscript; Solstad TU, Mucha AW, Grossjohann H, Olsen AO, and Achiam MP revised and contributed to the final manuscript. All authors have read and approved the final manuscript.
Supported by Nanovi A/S provided twenty vials of BioXmark® along with financial support for the evaluation of the implementation of the fiducial marker.
Institutional review board statement: As BioXmark® was implemented as a standard supplement to the standard operating procedure for esophagectomies at Rigshospitalet, the study did not constitute a clinical trial or experimental research requiring prior ethics committee approval. Instead, it was classified as a quality assurance initiative.
Informed consent statement: As BioXmark® was implemented as a standard supplement to the standard operating procedure for esophagectomies at Rigshospitalet, the study did not constitute a clinical trial or experimental research requiring prior ethics committee approval. Instead, it was classified as a quality assurance initiative.
Conflict-of-interest statement: The authors declare no conflict of interest.
STROBE statement: The authors have read the STROBE Statement—checklist of items, and the manuscript was prepared and revised according to the STROBE Statement—checklist of items.
Data sharing statement: The data that support the findings of this study are available on reasonable request from the corresponding author. The data are not publicly available due to privacy or ethical restrictions.
Open Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: https://creativecommons.org/Licenses/by-nc/4.0/
Corresponding author: Trygve U Solstad, MD, Researcher, Department of Digestive Diseases, Transplantation and General Surgery, Copenhagen University Hospital Rigshospitalet, Inge Lehmannsvej 7, København 2100, Denmark. trygve.ulvund.solstad.01@regionh.dk
Received: March 4, 2025
Revised: April 12, 2025
Accepted: June 10, 2025
Published online: December 20, 2025
Processing time: 156 Days and 0.5 Hours
Abstract
BACKGROUND

Neoadjuvant therapy can reduce the size of gastroesophageal tumors to the extent that they are no longer macroscopically visible. This may increase the risk of microscopic-positive resection margins. One potential method to reduce this uncertainty could be the preoperative endoscopic marking of proximal tumor margins with BioXmark®, a novel liquid fiducial marker. This study aimed to report the initial experiences of the first ten patients marked with BioXmark®.

AIM

To evaluate the visibility of BioXmark® on ultrasound after preoperative marking of the proximal resection line of an esophageal tumor.

METHODS

The circumference of the esophagus was endoscopically marked preoperatively with a fiducial marker in four quadrants, 5 cm proximal to the tumor. During the surgery, the surgeon’s proposed proximal resection line was marked. Next, an ultrasound probe was used to identify the previously placed fiducial markers, and its placement was marked. The difference between the surgeon’s proposed resection line and the fiducial marker was measured intraoperatively and subsequently examined with respect to the resection margin and status.

RESULTS

BioXmark® was implanted in ten patients, 5 cm proximal to the tumor. The surgeon’s proposed resection line was positioned 2-6 cm proximally to the surgical marker line. Technical success of injecting the fiducial marker was achieved in all ten patients. In six patients, the marker was successfully identified intraoperatively on ultrasound. No peri- or postoperative adverse events related to BioXmark® implantation were found.

CONCLUSION

Excellent technical success with the implantation of the fiducial surgical marker was achieved, but limited intraoperative visibility on ultrasound was achieved. Further studies are required to optimize its clinical application.

Keywords: BioXmark®; Gastroesophageal junction cancer; Gastroesophageal surgery; Surgical oncology; Fiducial marker

Core Tip: This study explores the use of the liquid fiducial marker BioXmark® to enhance precision in cancer surgery. BioXmark® was injected 5 cm proximal to the tumor duringpreoperative nasal gastroscopy. The injected BioXmark® was subsequently identified in vivo using perioperative ultrasound. By improving intraoperative visualization of tumor margins, fiducial markers may increase resection precision and the likelihood of achieving an R0 resection, potentially reducing patient morbidity and mortality. The marker's technical feasibility and safety were demonstrated, although further studies are required to optimize its visibility and clinical application.