Efficacy of Contrast-Enhanced Harmonic Endoscopic Ultrasound for Pancreatic Solid Tumors with a Combination of Qualitative and Quantitative Analyses: A Prospective Pilot Study

Image evaluation of contrast-enhanced harmonic endoscopic ultrasound (CEH-EUS) and additional time-intensity curve (TIC) analysis enable qualitative and quantitative analyses of pancreatic tumor based on real-time perfusion imaging.

To evaluate the efficacy of CEH-EUS with a combination of qualitative and quantitative analyses of pancreatic solid tumors.

Patients were scheduled to undergo EUS-guided fine needle aspiration (FNA) for pancreatic solid tumors were prospectively enrolled between 11/2016 and 12/2018 and underwent CEH-EUS. The vascular and enhancement patterns were qualitatively evaluated and heterogeneous enhancement was defined to be indicative of malignancy. The echo intensity change during 60 s in the tumor was quantitatively evaluated by time intensity curve analysis.

In total, 100 patients were enrolled in this study. The final diagnoses were malignant lesions in 87 patients and benign legions in 13 patients. There were four categories of enhancement and patterns: hypovascular with heterogeneous, hypovascular with homogeneous, hypervascular heterogeneous, and hypervascular homogeneous enhancement. The diagnostic capability of qualitative analysis was the sensitivity, specificity, and accuracy of 89%, 62%, and 85%, respectively. With respect to time intensity curve analysis, the time to peak of malignant lesions was significantly shorter than those of benign lesions (P = 0.0009) with an optimal cutoff value of 12.81 s on the receiver operating characteristic curve analysis. With the combination of qualitative and quantitative analyses, the sensitivity, specificity, and accuracy were improved to 100%, 54%, and 94%, respectively.

CEH-EUS with combined qualitative and quantitative analyses for pancreatic tumors might be useful as a complement for EUS-FNA. The UMIN Clinical Trials Registry (UMIN000025192).