Retrospective Study
Copyright ©The Author(s) 2020. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Jul 28, 2020; 26(28): 4151-4158
Published online Jul 28, 2020. doi: 10.3748/wjg.v26.i28.4151
Enhancement parameters of contrast-enhanced computed tomography for pancreatic ductal adenocarcinoma: Correlation with pathologic grading
Woorim Seo, Young Chul Kim, Seon Jeong Min, Sang Min Lee
Woorim Seo, Young Chul Kim, Seon Jeong Min, Department of Radiology, Hallym University Dongtan Sacred Heart Hospital, Gyeonggi-do 18450, South Korea
Sang Min Lee, Department of Radiology, Hallym University Sacred Heart Hospital, Gyeonggi-do 14068, South Korea
Author contributions: All the authors solely contributed to this paper; Kim YC, Seo W, Min SJ, and Lee SM substantially contributed to conception and design of the study, acquisition of data, or analysis and interpretation of data; Kim YC and Seo W contributed to drafting the article or making critical revisions related to important intellectual content of the manuscript; Kim YC, Min SJ and Lee SM finally approved of the version of the article to be published.
Supported by Central Medical Service Research Fund.
Institutional review board statement: The study was approved by the Hallym University Dongtan Sacred Heart Hospital ethics committee.
Informed consent statement: Informed written consent was obtained from the patient for publication of this report and any accompanying images.
Conflict-of-interest statement: The authors declare that they have 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
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:
Corresponding author: Young Chul Kim, MD, Associate Professor, Department of Radiology, Hallym University Dongtan Sacred Heart Hospital, 7 Keunjaebong-gil, Gyeonggi-do 18450, South Korea.
Received: April 6, 2020
Peer-review started: April 6, 2020
First decision: April 26, 2020
Revised: May 8, 2020
Accepted: July 15, 2020
Article in press: July 15, 2020
Published online: July 28, 2020
Research background

Pancreatic ductal adenocarcinoma (PDA) is a malignancy with a high mortality rate and short survival time. The conventional computed tomography (CT) has been worldwide used as a modality for diagnosis of PDA. Also, it has been widely accepted that CT enhancement pattern is related to tumor angiogenesis and pathologic grade of PDA.

Research motivation

Although there is other modality, like perfusion CT that provide information about vascularity and fibrosis in the diseased pancreas, it has a smaller FOV, requires additional radiation exposure, and processing time. So, if there is any CT parameter that can predict pathologic grade of PDA, it would be useful for predicting prognosis of PDA using conventional CT.

Research objectives

In this study, we aimed to evaluate the relationship between the pathologic grade of pancreatic ductal adenocarcinoma and the enhancement parameters of contrast-enhanced CT.

Research methods

In this retrospective study, 42 patients with PDA who underwent surgery after preoperative CT were selected. Two radiologists evaluated the CT images and calculated the value of attenuation at the aorta in the arterial phase and the pancreatic phase (VAarterial and VApancreatic) and of the tumor (VTarterial and VTpancreatic) by finding out four regions of interest. Ratio between the tumor and the aorta enhancement on the arterial phase and the pancreatic phase (TARarterial and TARpancreatic) was figured out through dividing VTarterial by VAarterial and VTpancreatic by VApancreatic. Tumor-to-aortic enhancement fraction (TAF) was expressed as the ratio of the difference between attenuation of the tumor on arterial and parenchymal images to that between attenuation of the aorta on arterial and pancreatic images.

Research results

A total of 42 PDAs were categorized into three groups: Well-differentiated (n = 13), moderately differentiated (n = 21), and poorly differentiated (n = 8). TAF differed significantly between the three groups (P = 0.034) but TARarterial (P = 0.164) and TARpancreatic (P = 0.339) did not. The value of TAF was statistically different among the three groups (P < 0.05).

Research conclusions

TAF was statistically different among the three pathologic grade groups. So, the TAF might be correlated with histological finding of PDA. Therefore, calculation of TAF using conventional CT might be useful in predicting the pathologic grade of PDA.

Research perspectives

The conventional CT has been useful modality for diagnosis of PDA. In our study, we suggest the CT enhancement parameter, TAF, could be used as a value for predicting pathologic grade of PDA. The pathologic grade is related to prognosis of PDA, then we can use conventional CT not only for diagnosis, but also for predicting pathologic grade and prognosis of PDA. Also, TAF may be obtained with conventional pancreatic CT, without additional radiation exposure and processing time, and is more useful for practical staging than perfusion CT parameters.