Use of Contrast-Enhanced Endoscopic-Ultrasound (CE-EUS) and Endoscopic-Ultrasound Elastography (EUS-E) Improves Diagnostic Performance of EUS-Guided Tissue Acquisition in Solid Pancreatic Masses Arising in Presence of Chronic Pancreatitis

Aims: Ancillary techniques for improving diagnostic accuracy of Endoscopic-ultrasound guided-tissue acquisition (EUS-TA) for solid pancreatic masses, especially in the setting of chronic pancreatitis are still evolving. Current study aimed at evaluating the role of contrast-enhanced EUS (CE-EUS) and EUS-elastography (EUS-E) in improving diagnostic performances of EUS-TA for solid pancreatic masses.

Materials and Methods: Prospectively maintained database of consecutive patients with solid pancreatic masses undergoing EUS-TA using either standard B-mode-EUS alone or CE-EUS guidance from July 2022 to December 2023 were analyzed. Outcome measures were (1) comparison of diagnostic performance between two modalities in all solid pancreatic masses and (2) comparison of diagnostic performance when pancreatic mass was present with chronic pancreatitis. Strain ratio obtained by EUS-E was recorded for masses where CE-EUS was used. Diagnostic performance of use of combined strain ratio and enhancement pattern was also analyzed.

Results: A total of 94 patients underwent EUS-TA, out of which 62 underwent B-mode-EUS guided TA alone and 32 underwent additional CE-EUS guided-TA. Overall for differential diagnosis, B-mode-EUS performed similar to CE-EUS (diagnostic accuracy 93.5 vs. 96.88%, sensitivity 90 vs. 96%, specificity 100 vs. 100%). To diagnose malignant lesion in background of chronic pancreatitis (n = 30), when compared to B-mode, CE-EUS had higher diagnostic accuracy (90.91% vs. 78.96%, p = 0.0083), higher sensitivity (83.33% vs. 50%, p < 0.0001) with similar specificity, similar positive predictive value and similar negative predictive value ([Table 1]). Use of combined EUS-E and CE-EUS in 32 patients showed that presence of combination of strain ratio above 6.24 and hypo-enhancement pattern on CE-EUS had sensitivity of 85% and specificity of 100% for predicting pancreatic adenocarcinoma. When this combination was used in pancreatic masses with chronic pancreatitis (n = 11), sensitivity increased to 100% for predicting pancreatic adenocarcinoma.

Conclusion: Advanced-EUS modalities including contrast-enhancement and elastography should be used while performing EUS-TA for pancreatic masses arising in the background of chronic pancreatitis as it improves diagnostic performance over B-mode EUS.

Table 1 Comparison of diagnostic performance of standard B-mode EUS and CE-EUS-guided tissue acquisition for differential diagnosis of solid pancreatic masses with sub-group analysis of pancreatic masses with chronic pancreatitis

	In all pancreatic masses (n = 94)			Pancreatic masses with chronic pancreatic (n = 30)
Diagnostic performance	B-Mode EUS (n = 62)	CE-EUS (n = 32)	p-Value	B-Mode EUS (n = 19)	CE-EUS (n = 11)	p-Value
Diagnostic accuracy (%)	93.55	96.88	0.31	78.95	90.91	0.0083
Sensitivity (%)	90	96	0.09	50	83.33	<0.0001
Specificity (%)	100	100	0.99	100	100	0.99
Positive predictive value (%)	100	100	0.99	100	100	0.99
Negative predictive Value (%)	84.62	87.50	0.54	73.33	83.33	0.08

Abbreviations: EUS, endoscopic ultrasound; CE-EUS, contrast enhanced endoscopic ultrasound.

Publication History

Article published online:
22 April 2024