Systematic Reviews
Copyright ©The Author(s) 2022. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Feb 21, 2022; 28(7): 745-754
Published online Feb 21, 2022. doi: 10.3748/wjg.v28.i7.745
Stereotactic radiotherapy and the potential role of magnetic resonance-guided adaptive techniques for pancreatic cancer
Tai Ermongkonchai, Richard Khor, Vijayaragavan Muralidharan, Niall Tebbutt, Kelvin Lim, Numan Kutaiba, Sweet Ping Ng
Tai Ermongkonchai, Richard Khor, Sweet Ping Ng, Department of Radiation Oncology, Olivia Newton-John Cancer Centre at Austin Health, Heidelberg 3084, Victoria, Australia
Vijayaragavan Muralidharan, Department of Surgery, Austin Health, Heidelberg 3084, Victoria, Australia
Niall Tebbutt, Department of Medical Oncology, Olivia Newton-John Cancer Centre at Austin Health, Heidelberg 3084, Victoria, Australia
Kelvin Lim, Numan Kutaiba, Department of Diagnostic Radiology, Austin Health, Heidelberg 3084, Victoria, Australia
Author contributions: Ermongkonchai T performed the literature search and wrote the manuscript; Khor R, Muralidharan V, Tebbutt N, Lim K, Kutaiba N and Ng SP performed editing and contributed to the quality of the manuscript.
Conflict-of-interest statement: No conflict-of-interest to be declared by authors of this article.
PRISMA 2009 Checklist statement: The authors have read the PRISMA 2009 Checklist, and the manuscript was prepared and revised according to the PRISMA 2009 Checklist.
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: Sweet Ping Ng, MBBS, PhD, Associate Professor, Department of Radiation Oncology, Olivia Newton-John Cancer Centre at Austin Health, 145 Studley Road, Heidelberg 3084, Victoria, Australia. sweetping.ng@austin.org.au
Received: September 13, 2021
Peer-review started: September 13, 2021
First decision: October 16, 2021
Revised: November 11, 2021
Accepted: January 22, 2022
Article in press: January 22, 2022
Published online: February 21, 2022
Abstract
BACKGROUND

Pancreatic cancer is a malignancy with one of the poorest prognoses amongst all cancers. Patients with unresectable tumours either receive palliative care or undergo various chemoradiotherapy regimens. Conventional techniques are often associated with acute gastrointestinal toxicities, as adjacent critical structures such as the duodenum ultimately limits delivered doses. Stereotactic body radiotherapy (SBRT) is an advanced radiation technique that delivers highly ablative radiation split into several fractions, with a steep dose fall-off outside target volumes.

AIM

To discuss the latest data on SBRT and whether there is a role for magnetic resonance-guided techniques in multimodal management of locally advanced, unresectable pancreatic cancer.

METHODS

We conducted a search on multiple large databases to collate the latest records on radiotherapy techniques used to treat pancreatic cancer. Out of 1229 total records retrieved from our search, 36 studies were included in this review.

RESULTS

Studies indicate that SBRT is associated with improved clinical efficacy and toxicity profiles compared to conventional radiotherapy techniques. Further dose escalation to the tumour with SBRT is limited by the poor soft-tissue visualisation of computed tomography imaging during radiation planning and treatment delivery. Magnetic resonance-guided techniques have been introduced to improve imaging quality, enabling treatment plan adaptation and re-optimisation before delivering each fraction.

CONCLUSION

Therefore, SBRT may lead to improved survival outcomes and safer toxicity profiles compared to conventional techniques, and the addition of magnetic resonance-guided techniques potentially allows dose escalation and conversion of unresectable tumours to operable cases.

Keywords: Magnetic resonance imaging, Pancreatic cancer, Radiotherapy, Stereotactic, Adaptive techniques

Core Tip: Locally advanced pancreatic cancer has very poor outcomes. These cases are treated with chemoradiotherapy regimens, but conventional radiotherapy techniques often yield minimal survival benefit while accruing significant toxicities. Stereotactic body radiotherapy (SBRT) is an advanced technique that is associated with improved survival outcomes and reduced toxicities compared to its predecessors. The addition of Magnetic resonance-guided techniques to SBRT provides excellent imaging that enables intra-treatment plan adaptations. This provides the possibility of dose escalation, which may be the key to achieving surgical resectability and thus potentially increasing the chances of cure.