Improved detection of liver metastasis using Kupffer-phase imaging in contrast-enhanced harmonic EUS in patients with pancreatic cancer (with video)

Abstract

Background and aims: Kupffer-phase imaging visualized by perfluorobutane (Sonazoid) distribution into normal liver tissues upon phagocytosis by Kupffer cells potentially aids in improving detection of liver metastasis compared with fundamental B-mode EUS (FB-EUS). However, the diagnostic performance of Kupffer-phase imaging in contrast-enhanced harmonic EUS (CH-EUS) remains unclear. Hence, this study aimed to evaluate the usefulness of CH-EUS-based Kupffer-phase imaging for diagnosing liver metastasis from pancreatic cancer.

Methods: We retrospectively analyzed consecutive patients with pancreatic cancer who underwent contrast-enhanced CT (CE-CT) and FB-EUS, followed by CH-EUS, from 2011 to 2017. The diagnostic ability of CH-EUS against that of CE-CT and FB-EUS for metastasis in the left liver lobe was compared. Subsequently, the influences of CH-EUS on the determination of clinical stage and patient management for pancreatic cancer were assessed.

Results: We enrolled 426 patients with pancreatic cancer. Metastasis in the left liver lobe was present in 27.2% of patients. The diagnostic accuracy of CE-CT, FB-EUS, and CH-EUS was 90.6%, 93.4%, and 98.4%, respectively. The sensitivity and diagnostic accuracy of CH-EUS for metastasis in the left liver lobe were significantly higher than those of FB-EUS or CE-CT. The sensitivity of CH-EUS for detecting small liver metastasis (<10 mm) was considerably higher than that of CE-CT or FB-EUS (P < .001). In 2.1% of patients, only CH-EUS could detect a single distant metastasis of the left liver lobe, thereby upgrading the tumor staging and altering the clinical management.

Conclusions: CH-EUS-based Kupffer-phase imaging increased the detectability of metastasis in the left liver lobe. This technique could be a reliable pretreatment imaging modality for clinical decision-making in patients with pancreatic cancer.