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©The Author(s) 2017. Published by Baishideng Publishing Group Inc. All rights reserved.
Real time endoscopic ultrasound elastography and strain ratio in the diagnosis of solid pancreatic lesions
Hussein Okasha, Shaimaa Elkholy, Ramy El-Sayed, Mohamed-Naguib Wifi, Mohamed El-Nady, Walid El-Nabawi, Waleed A El-Dayem, Mohamed I Radwan, Ali Farag, Yahya El-sherif, Emad Al-Gemeie, Ahmed Salman, Mohamed El-Sherbiny, Ahmed El-Mazny, Reem E Mahdy
Hussein Okasha, Shaimaa Elkholy, Mohamed Naguib Wifi, Mohamed El-Nady, Ali Farag, Ahmed Salman, Mohamed El-Sherbiny, Ahmed El-Mazny, Internal Medicine Department, Cairo University, Cairo 11311, Egypt
Ramy El-Sayed, Waleed A El-Dayem, Mohamed I Radwan, Department of Tropical Medicine, Zagazig University, Elsharkiah 44519, Egypt
Walid El-Nabawi, Internal Medicine Department, Beni Suef University, Beni Suef 71515, Egypt
Yahya El-sherif, Tropical Medicine Department, El Manial Specialized Hospital, Cairo University, Cairo 11311, Egypt
Emad Al-Gemeie, Pathology Department, National Cancer Institute, Cairo University, Cairo 11311, Egypt
Reem E Mahdy, Internal Medicine Department, Assiut University, Assiut 71515, Egypt
Author contributions: Okasha H is the main endosongrapher who performed all the cases and participated in the study design; Elkholy S, Mahdy RE and El-Sayed R participated in Manuscript writing and data analysis; Wifi MN, El-Nady M, El-Dayem WA and Radwan MI participated in design and oversight of the study; El-Nabawi W, Farag A and El-sherif Y participated in design of the study and data collection; Salman A, El-Sherbiny M and El-Mazny A were involved with data collection, and follow up of the patients; Al-Gemeie E is the main histopathologist who performed histopathological analysis for the specimens; all the above mentioned authors have read and approved the final manuscript.
Institutional review board statement: The study was reviewed and approved by the institutional review boards of Zagazig University, Egypt (ZU-IRB#2516).
Informed consent statement: All study participants, or their legal guardian, provided written consent prior to study enrollment.
Conflict-of-interest statement: The authors of this manuscript having no conflicts of interest to disclose.
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: Shaimaa Elkholy, MD, Lecturer, Department of Internal Medicine, Faculty of Medicine, Cairo University, Kasralainy street Cairo, Cairo 11311, Egypt.
shaimaa.elkholy@cu.edu.eg
Telephone: +2-10-60407761 Fax: +2-37-493563
Received: February 26, 2017
Peer-review started: February 28, 2017
First decision: April 11, 2017
Revised: May 10, 2017
Accepted: June 9, 2017
Article in press: July 9, 2017
Published online: August 28, 2017
Processing time: 182 Days and 22.7 Hours
AIM
To evaluate the accuracy of the elastography score combined to the strain ratio in the diagnosis of solid pancreatic lesions (SPL).
METHODS
A total of 172 patients with SPL identified by endoscopic ultrasound were enrolled in the study to evaluate the efficacy of elastography and strain ratio in differentiating malignant from benign lesions. The semi quantitative score of elastography was represented by the strain ratio method. Two areas were selected, area (A) representing the region of interest and area (B) representing the normal area. Area (B) was then divided by area (A). Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy were calculated by comparing diagnoses made by elastography, strain ratio and final diagnoses.
RESULTS
SPL were shown to be benign in 49 patients and malignant in 123 patients. Elastography alone had a sensitivity of 99%, a specificity of 63%, and an accuracy of 88%, a PPV of 87% and an NPV of 96%. The best cut-off level of strain ratio to obtain the maximal area under the curve was 7.8 with a sensitivity of 92%, specificity of 77%, PPV of 91%, NPV of 80% and an accuracy of 88%. Another estimated cut off strain ratio level of 3.8 had a higher sensitivity of 99% and NPV of 96%, but with less specificity, PPV and accuracy 53%, 84% and 86%, respectively. Adding both elastography to strain ratio resulted in a sensitivity of 98%, specificity of 77%, PPV of 91%, NPV of 95% and accuracy of 92% for the diagnosis of SPL.
CONCLUSION
Combining elastography to strain ratio increases the accuracy of the differentiation of benign from malignant SPL.
Core tip: This prospective study included 172 patients with solid pancreatic lesions (SPL) to evaluate the value of combining the elastography score to strain ratio for differentiating benign from malignant lesions. Adding both elastography to strain ratio resulted in a sensitivity of 98%, specificity of 77%, positive predictive value (PPV) of 91%, negative predictive value (NPV) of 95% and accuracy of 92% for the diagnosis of SPL. The best cut-off level of strain ratio was 7.8 with a sensitivity of 92%, specificity of 77%, PPV of 91%, NPV of 80% and an accuracy of 88%. So, adding both diagnostic tools increases the yielding of diagnosis.
