Prospective Study
Copyright ©The Author(s) 2020. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. May 28, 2020; 26(20): 2657-2668
Published online May 28, 2020. doi: 10.3748/wjg.v26.i20.2657
Role of dynamic perfusion magnetic resonance imaging in patients with local advanced rectal cancer
Davide Ippolito, Silvia Girolama Drago, Anna Pecorelli, Cesare Maino, Giulia Querques, Ilaria Mariani, Cammillo Talei Franzesi, Sandro Sironi
Davide Ippolito, Silvia Girolama Drago, Anna Pecorelli, Cesare Maino, Giulia Querques, Ilaria Mariani, Cammillo Talei Franzesi, Department of Diagnostic Radiology, H. S. Gerardo Monza, San Gerardo Hospital, University of Milano-Bicocca, Monza 20900, Italy
Sandro Sironi, Department of Diagnostic Radiology, Papa Giovanni XXIII Hospital, University of Milano-Bicocca, Bergamo 20110, Italy
Author contributions: All authors equally contributed to this paper with conception and design of the study, literature review and analysis, drafting and critical revision and editing, and final approval of the final version.
Institutional review board statement: The study was ethically approved by the San Gerardo Hospital Ethics Committee.
Clinical trial registration statement: This study is registered at “San Gerardo Hospital” trial registry. The registration identification number is EP 15673/19.
Informed consent statement: Informed consent was obtained from all patients.
Conflict-of-interest statement: All the authors are aware of the content of the manuscript and have no conflict of interest.
Data sharing statement: There are no additional data available.
CONSORT 2010 statement: The authors have read the CONSORT 2010 Statement, and the manuscript was prepared and revised according to the CONSORT 2010 Statement.
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: Davide Ippolito, MD, Adjunct Professor, Staff Physician, Department of Diagnostic Radiology, H. S. Gerardo Monza, San Gerardo Hospital, University of Milano-Bicocca, Via Pergolesi 33, Monza 20900, Italy. davide.atena@tiscalinet.it
Received: January 14, 2020
Peer-review started: January 14, 2020
First decision: February 29, 2020
Revised: April 30, 2020
Accepted: May 13, 2020
Article in press: May 13, 2020
Published online: May 28, 2020
Processing time: 134 Days and 21.8 Hours
Abstract
BACKGROUND

The management of rectal cancer patients is mainly based on the use of the magnetic resonance imaging (MRI) technique as a diagnostic tool for both staging and restaging. After treatment, to date, the evaluation of complete response is based on the histopathology assessment by using different tumor regression grade (TRG) features (e.g., Dworak or Mandard classifications). While from the radiological point of view, the main attention for the prediction of a complete response after chemotherapy treatment focuses on MRI and the potential role of diffusion-weighted images and perfusion imaging represented by dynamic-contrast enhanced MRI. The main aim is to find a reliable tool to predict tumor response in comparison to histopathologic findings.

AIM

To investigate the value of dynamic contrast-enhanced perfusion-MRI parameters in the evaluation of the healthy rectal wall and tumor response to chemo-radiation therapy in patients with local advanced rectal cancer with histopathologic correlation.

METHODS

Twenty-eight patients with biopsy-proven rectal adenocarcinoma who underwent a dynamic contrast-enhanced MR study performed on a 1.5T MRI system (Achieva, Philips), before (MR1) and after chemoradiation therapy (MR2), were enrolled in this study. The protocol included T1 gadolinium enhanced THRIVE sequences acquired on axial planes. A dedicated workstation was used to generate color permeability maps. Region of interest was manually drawn on tumor tissue and normal rectal wall, hence the following parameters were calculated and statistically analyzed: Relative arterial enhancement (RAE), relative venous enhancement (RVE), relative late enhancement (RLE), maximum enhancement (ME), time to peak and area under the curve (AUC). Perfusion parameters were related to pathologic TRG (Mandard's criteria; TRG1 = complete regression, TRG5 = no regression).

RESULTS

Ten tumors (36%) showed complete or subtotal regression (TRG1-2) at histology and classified as responders; 18 tumors (64%) were classified as non-responders (TRG3-5). Perfusion MRI parameters were significantly higher in the tumor tissue than in the healthy tissue in MR1 (P < 0.05). At baseline (MR1), no significant difference in perfusion parameters was found between responders and non-responders. After chemo-radiation therapy, at MR2, responders showed significantly (P < 0.05) lower perfusion values [RAE (%) 54 ± 20; RVE (%) 73 ± 24; RLE (%): 82 ± 29; ME (%): 904 ± 429] compared to non-responders [RAE (%): 129 ± 45; RVE (%): 154 ± 39; RLE (%): 164 ± 35; ME (%): 1714 ± 427]. Moreover, in responders group perfusion values decreased significantly at MR2 [RAE (%): 54 ± 20; RVE (%): 73 ± 24; RLE (%): 82 ± 29; ME (%): 904 ± 429] compared to the corresponding perfusion values at MR1 [RAE (%): 115 ± 21; RVE (%): 119 ± 21; RLE (%): 111 ± 74; ME (%): 1060 ± 325]; (P < 0.05). Concerning the time-intensity curves, the AUC at MR2 showed significant difference (P = 0.03) between responders and non-responders [AUC (mm2 × 10-3) 121 ± 50 vs 258 ± 86], with lower AUC values of the tumor tissue in responders compared to non-responders. In non-responders, there were no significant differences between perfusion values at MR1 and MR2.

CONCLUSION

Dynamic contrast perfusion-MRI analysis represents a complementary diagnostic tool for identifying vascularity characteristics of tumor tissue in local advanced rectal cancer, useful in the assessment of treatment response.

Keywords: Rectal neoplasm; Chemotherapy; Radiotherapy; Tumor staging; Treatment response; Magnetic resonance imaging

Core tip: The management of rectal cancer has changed in the past years. The possibility to achieve a complete response after chemo-radiotherapy and the results of non-surgical management of the disease (“watch and wait” approach) highlighted the need to obtain an accurate assessment of complete response. In this setting, dynamic-contrast-enhanced magnetic resonance imaging, which provides valuable information about the degree of angiogenesis, is considered a promising functional tool. This study aimed to assess dynamic-contrast enhanced-parameters differences between the tumor tissue and the healthy rectal wall, both before and after chemo-radiotherapy, and to find a possible correlation with pathological findings and TNM stage.