Review
Copyright ©The Author(s) 2017. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Clin Oncol. Jun 10, 2017; 8(3): 214-229
Published online Jun 10, 2017. doi: 10.5306/wjco.v8.i3.214
Magnetic resonance imaging for diagnosis and neoadjuvant treatment evaluation in locally advanced rectal cancer: A pictorial review
Gulgun Engin, Rasul Sharifov
Gulgun Engin, Oncology Institute, Istanbul University, 34390 Capa, Istanbul, Turkey
Rasul Sharifov, Department of Radiology, Faculty of Medicine, Bezmialem Vakif University, 34093 Fatih, Istanbul, Turkey
Author contributions: Engin G designed and wrote the paper; Sharifov R performed MRI.
Conflict-of-interest statement: Authors declare no conflict of interests for this article.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (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/
Correspondence to: Gulgun Engin, MD, Oncology Institute, Istanbul University, Millet Street, 34390 Capa, Istanbul, Turkey. gengin@istanbul.edu.tr
Telephone: +90-212-4142000 Fax: +90-212-5348078
Received: January 28, 2017
Peer-review started: February 10, 2017
First decision: March 27, 2017
Revised: May 4, 2017
Accepted: May 18, 2017
Article in press: May 20, 2017
Published online: June 10, 2017
Abstract

High-resolution pelvic magnetic resonance imaging (MRI) is the primary method for staging rectal cancer. MRI is highly accurate in the primary staging of rectal cancer; however, it has not proven to be effective in re-staging, especially in complete response evaluation after neoadjuvant therapy. Neoadjuvant chemoradiotherapy produces many changes in rectal tumors and on adjacent area, as a result, local tumor extent may not be accurately determined. However, adding diffusion-weighted sequences to the standard approach can improve diagnostic accuracy. In this pictorial review, an overview of the situation of MRI in the staging and re-staging of rectal cancer is exhibited as a pictorial assay. An experience- and literature-based discussion of limitations and difficulties in interpretation are also presented.

Keywords: Rectal cancer, Locally advanced, Magnetic resonance imaging, Staging, Neoadjuvant treatment

Core tip: Accurate staging and circumferential resection margin evaluation significantly impacts determining optimal treatment scheme. Preoperative magnetic resonance imaging (MRI) is highly accurate; however, it has yet to be proved as effective in re-staging. The adding of diffusion-weighted sequences to standard T2-weighted MRI can positively affect its diagnostic accuracy.