Retrospective Study
Copyright ©The Author(s) 2017. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Jan 14, 2017; 23(2): 275-285
Published online Jan 14, 2017. doi: 10.3748/wjg.v23.i2.275
Pancreatic neuroendocrine neoplasms: Magnetic resonance imaging features according to grade and stage
Riccardo De Robertis, Sara Cingarlini, Paolo Tinazzi Martini, Silvia Ortolani, Giovanni Butturini, Luca Landoni, Paolo Regi, Roberto Girelli, Paola Capelli, Stefano Gobbo, Giampaolo Tortora, Aldo Scarpa, Paolo Pederzoli, Mirko D’Onofrio
Riccardo De Robertis, Department of Radiology, Casa di Cura Pederzoli, 37019 Peschiera del Garda, Italy
Riccardo De Robertis, Giampaolo Tortora, Course in Inflammation, Immunity and Cancer, University of Verona, 37134 Verona, Italy
Sara Cingarlini, Luca Landoni, Paola Capelli, Giampaolo Tortora, Aldo Scarpa, Mirko D’Onofrio, Verona Comprehensive Cancer Network, Department of Medical Oncology, G.B. Rossi Hospital, University of Verona, 37134 Verona, Italy
Paolo Tinazzi Martini, Department of Radiology, Casa di Cura Pederzoli, 37019 Peschiera del Garda, Italy
Silvia Ortolani, Department of Oncology, Casa di Cura Pederzoli, 37019 Peschiera del Garda, Italy
Giovanni Butturini, Paolo Regi, Roberto Girelli, Paolo Pederzoli, Department of Pancreatic Surgery, Casa di Cura Pederzoli, 37019 Peschiera del Garda, Italy
Stefano Gobbo, Department of Pathology, Casa di Cura Pederzoli, 37019 Peschiera del Garda, Italy
Author contributions: De Robertis R designed and performed the research and wrote the paper; D’Onofrio M designed the research and supervised the report; Cingarlini S, Tinazzi Martini P, Ortolani S, Butturini G, Landoni L, Regi P, Girelli R, Capelli P, Gobbo S, Tortora G, Scarpa A, Pederzoli P provided clinical advice and supervised the report.
Institutional review board statement: This study was approved by our institutional review board and the requirement for informed patient consent was waived due to the retrospective nature of the study.
Informed consent statement: Patients were not required to give informed consent to the study because the analysis used anonymous clinical data that were obtained after each patient agreed to MR examinations by written consent.
Conflict-of-interest statement: We have no financial relationships to disclose.
Data sharing statement: No additional data are available.
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: Riccardo De Robertis, MD, Department of Radiology, Casa di Cura Pederzoli, via Monte Baldo 24, 37019 Peschiera del Garda, Italy. riccardo.derobertis@hotmail.it
Telephone: +39-45-6449111 Fax: +39-45-6449223
Received: September 1, 2016
Peer-review started: September 2, 2016
First decision: October 20, 2016
Revised: November 7, 2016
Accepted: December 8, 2016
Article in press: December 8, 2016
Published online: January 14, 2017
Processing time: 132 Days and 22.1 Hours
Abstract
AIM

To describe magnetic resonance (MR) imaging features of pancreatic neuroendocrine neoplasms (PanNENs) according to their grade and tumor-nodes-metastases stage by comparing them to histopathology and to determine the accuracy of MR imaging features in predicting their biological behavior.

METHODS

This study was approved by our institutional review board; requirement for informed patient consent was waived due to the retrospective nature of the study. Preoperative MR examinations of 55 PanNEN patients (29 men, 26 women; mean age of 57.6 years, range 21-83 years) performed between June 2013 and December 2015 were reviewed. Qualitative and quantitative features were compared between tumor grades and stages determined by histopathological analysis.

RESULTS

Ill defined margins were more common in G2-3 and stage III-IV PanNENs than in G1 and low-stage tumors (P < 0.001); this feature had high specificity in the identification of G2-3 and stage III-IV tumors (90.3% and 96%, 95%CI: 73.1-97.5 and 77.7-99.8). The mean apparent diffusion coefficient value was significantly lower in G2-3 and stage III-IV lesions compared to well differentiated and low-stage tumors (1.09 × 10-3 mm2/s vs 1.45 × 10-3 mm2/s and 1.10 × 10-3 mm2/s vs 1.53 × 10-3 mm2/s, P = 0.003 and 0.001). Receiving operator characteristic analysis determined optimal cut-offs of 1.21 and 1.28 × 10-3 mm2/s for the identification of G2-3 and stage III-IV tumors, with sensitivity and specificity values of 70.8/80.7% and 64.5/64% (95%CI: 48.7-86.6/60-92.7 and 45.4-80.2/42.6-81.3).

CONCLUSION

MR features of PanNENs vary according to their grade of differentiation and their stage at diagnosis and could predict the biological behavior of these tumors.

Keywords: Pancreatic neuroendocrine tumor; World Health Organization classification 2010; Diffusion-weighted imaging; European Neuroendocrine Tumor Society staging system; Magnetic resonance imaging

Core tip: This study aimed to describe magnetic resonance imaging features of pancreatic neuroendocrine neoplasms by comparing them to histopathology and to determine the accuracy in predicting tumor grade and biological behavior. Beside vascular infiltration and liver metastases, ill-defined margins had high specificity for the identification of G2-3 and stage III-IV tumors (90.3% and 96%, respectively). Lesion size above 17.5 mm had a 91.7% sensitivity in the identification of G2-3 tumors; apparent diffusion coefficient values below 1.21 and 1.28 × 10-3 mm2/s had high sensitivity (70.8% and 80.7%) for the identification of G2-3 and stage III-IV tumors.