Observational Study
Copyright ©The Author(s) 2021. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Nov 14, 2021; 27(42): 7387-7401
Published online Nov 14, 2021. doi: 10.3748/wjg.v27.i42.7387
Long-term clinical outcomes of lipiodol marking using standard gastroscopy for image-guided radiotherapy of upper gastrointestinal cancers
Kim Hay Be, Richard Khor, Daryl Lim Joon, Ben Starvaggi, Michael Chao, Sweet Ping Ng, Michael Ng, Leonardo Zorron Cheng Tao Pu, Marios Efthymiou, Rhys Vaughan, Sujievvan Chandran
Kim Hay Be, Leonardo Zorron Cheng Tao Pu, Marios Efthymiou, Rhys Vaughan, Sujievvan Chandran, Department of Gastroenterology and Hepatology, Austin Health, Heidelberg 3084, Victoria, Australia
Richard Khor, Daryl Lim Joon, Ben Starvaggi, Michael Chao, Sweet Ping Ng, Department of Radiation Oncology, Austin Health, Heidelberg 3084, Victoria, Australia
Richard Khor, Sweet Ping Ng, School of Cancer Medicine, La Trobe University, Melbourne 3086, Victoria, Australia
Michael Chao, Sweet Ping Ng, Marios Efthymiou, Rhys Vaughan, Sujievvan Chandran, Medicine, Dentistry and Health Sciences, University of Melbourne, Parkville 3010, Victoria, Australia
Michael Ng, Genesis Care, East Melbourne 3002, Victoria, Australia
Author contributions: Be KH, Zorron Cheng Tao Pu L, Khor R, Lim Joon D, Chandran S, Efthymiou M and Vaughan R conceptualized and designed the study; all authors were involved in data collection, analyses, or both; all authors were involved in the interpretation of the results; Be KH, Zorron Cheng Tao Pu L, Khor R and Chandran S drafted the manuscript; Lim Joon D, Ng SP, Efthymiou M and Vaughan R carried the critical revision of the article for important intellectual content; and all authors read and approved the final version of the manuscript.
Institutional review board statement: The study was reviewed and approved by the Austin Health Institutional Review Board (Approval No. LNR/18/Austin/254).
Informed consent statement: Informed consent was waived.
Conflict-of-interest statement: Dr. BE on behalf of all authors has nothing to disclose.
Data sharing statement: No additional data are available.
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.
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: http://creativecommons.org/Licenses/by-nc/4.0/
Corresponding author: Kim Hay Be, MBBS, Doctor, Department of Gastroenterology and Hepatology, Austin Health, 145 Studley Road, Heidelberg 3084, Victoria, Australia. kim.be@austin.org.au
Received: July 5, 2021
Peer-review started: July 5, 2021
First decision: July 13, 2021
Revised: July 26, 2021
Accepted: October 27, 2021
Article in press: October 27, 2021
Published online: November 14, 2021
ARTICLE HIGHLIGHTS
Research background

Further studies are warranted to determine the long-term outcomes of liquid fiducial-based image-guided radiotherapy (IGRT) in the treatment of oesophagogastric cancers.

Research motivation

Based on a cohort of 31 patients who had undergone lipiodol fiducial implantation through standard gastroscopy and received radiotherapy, fiducial-based IGRT was possible in 87.1%. Our cohort had an overall survival (OS) of 19 mo and progression-free survival (PFS) of 13 mo.

Research objectives

52 patients were referred for liquid fiducial placement within the study period. A total of 51 patients underwent liquid fiducial implantation. Of these a total of 31 patients received radiotherapy. Twenty-seven out of the 31 patients were able to have liquid fiducial-based IGRT (LF-IGRT) while four had standard-IGRT (S-IGRT). There were no complications after endoscopic implantation of liquid fiducials in our cohort. The cohort OS post-radiotherapy was 19 mo (range 0 to 87 mo). Whilst the PFS post-adiotherapy was 13 mo (range 0 to 74 mo).

Research methods

A retrospective cohort study of consecutive adults with oesophagogastric cancers referred for liquid fiducial placement before definitive/neo-adjuvant or palliative IGRT between 2013 and 2021 at a tertiary hospital in Melbourne, Australia was conducted. Up to four liquid fiducials were inserted per patient, each injection consisting of 0.2-0.5mL of a 1:1 mixture of iodized oil (Lipiodol; Aspen Pharmacare) and n-butyl 2-cyanoacrylate (Histoacryl®; B. Braun). A 23-gauge injector (Cook Medical) was used for the injection. All procedures were performed by or under the supervision of a gastroenterologist. LF-IGRT consisted of computer-assisted direct matching of the fiducial region on cone-beam computerized tomography (CBCT) at the time of radiotherapy. Patients received S-IGRT if fiducial visibility was insufficient, consisting of bone match as a surrogate for tumor position. Radiotherapy was delivered to 54Gy in 30 fractions for curative patients and up to 45Gy in 15 fractions for palliative treatments.

Research results

To assess the long-term outcomes of liquid fiducial-guided IGRT in a cohort of oesophageal and gastric cancer patients.

Research conclusions

We believe this to be the largest observational cohort study of its kind, adding to the limited body of knowledge on the long-term outcomes of F-IGRT for gastrooesophageal tumors using liquid fiducials.

Research perspectives

IGRT has significantly improved the precision in which radiotherapy is delivered in cancer treatment. Typically, IGRT uses bony landmarks and key anatomical structures to locate the tumor. Recent studies have demonstrated the feasibility of peri-tumor fiducials in enabling even more accurate delineation of target and normal tissue. The use of gold coils as fiducials in gastrointestinal tumors has been extensively studied. However, placement requires expertise and specialized endoscopic ultrasound equipment. This article reports the long-term outcomes of using a standard gastroscopy to inject liquid fiducials for the treatment of oesophageal and gastric tumors with IGRT.