Prospective Comparison of Diagnostic Accuracy Between Contrast-enhanced Harmonic and Conventional EUS-guided Fine-needle Biopsy in Solid Pancreatic Lesions

Overview

Endoscopic ultrasonography (EUS)-guided fine-needle aspiration/biopsy (FNA/B) is used to collect biopsy samples from many organs throughout the digestive tract and is useful in diagnosing solid pancreatic lesions (SPLs). The reported diagnostic accuracy of EUS-FNA for SPLs is 85-89.4%, the sensitivity is 82-94.7%, and the specificity is 100%. One randomized controlled trial reported that the fanning technique of FNA was superior to the standard approach because fewer passes were required to establish the diagnosis. However, in many cases, like SPLs with the presence of fibrosis and necrosis background, four or more needle passes are still needed to obtain sufficient biopsy samples. There is a potential risk of tumor seeding associated with multiple needle punctures. Therefore, it is important to minimize the number of needle passes. Contrast-enhanced harmonic EUS (CEH-EUS) using sonazoid (Daiichi-Sankyo, Tokyo, Japan) is useful to visualize parenchymal perfusion in the pancreas and characterize of SPLs. Because the necrotic or fibrotic area within the SPLs were appeared as non-enhanced area, CEH-EUS could help us to avoid puncture the non-enhancing area hence increased the diagnostic accuracy. Katana et al. reported that conventional EUS-FNA has lower sensitivity (72.9%) for pancreatic adenocarcinoma with non-enhanced areas compared to with enhanced areas (94.3%) on CEH-EUS. Therefore, it would be difficult to obtain sufficient biopsy samples through unenhanced areas of SPLs.

According to the study result by Katana et al., fanning technique in SPLs with avascular areas had a negative impact on diagnostic accuracy of FNA. Because of the retrospective basis of their study, a prospective study is warranted to answer whether CEH-EUS-guided FNA/B is superior to conventional EUS-guided FNA/B with fanning technique in SPLs. The main objective of this randomized trial therefore was to determine whether CEH-EUS-guided sampling to avoid non-enhanced areas within a mass lesion result in more rapid diagnosis requiring fewer FNA/B passes than the conventional EUS-guided FNA/B with fanning needle throughout the mass is targeted.