Role of ultrasound contrast agent in a tertiary cancer center: Experience in 75 patients with liver biopsy.

Abstract

e14671 Background: The sensitivity of B-mode ultrasound (US) in detecting hepatic lesions has been reported to be between 55-85%. A recently FDA approved US contrast agent has been shown to increase the detectability of liver lesions; yet, there is paucity of knowledge regarding its application in US guided biopsies. The aim of this study was to determine accuracy and applicability of contrast enhanced US (CEUS) guided biopsies of liver lesions in cancer patients. Methods: A prospective registry of 75 patients (M = 54%, F = 46%, Age: 63y±14), that underwent CEUS guided liver biopsy in 2017-2018, were retrospectively reviewed. The decision to apply US contrast was made based on pre-procedural and intra-procedural clinical findings. Lesions with negative biopsy results were reviewed in follow up imaging to determine any evidence of potential positive malignancy. Results: History of renal failure that precluded application of iodinated IV contrast was the main pre-procedural indication (17%). Intra-procedural indications included: poor visualization of lesions in B-mode US (78%), targeting enhancing part of lesions (necrotic, post ablation or cystic) (16%), and lesion selection (6%). Diameter of the lesions were ≤ 20mm in 46% of patients. Biopsy results were positive in 50 patients, and included 32% primary liver tumors (hepatocellular carcinoma and cholangiocarcinoma) and 68% metastasis (pancreas: 24%, breast: 12%, GI tract: 10%, lung: 8% and other: 14%). Of the 25 patients with negative biopsy results, 6 did not have follow up imaging and 3 were later found to have positive malignancy (Negative predictive value: 84%, accuracy: 96%). Genomic sequencing was established in 34% of the patients. Based on the biopsy/genomics results, patients underwent systemic treatment (56%), locoregional treatment (16%), combination (6%) or surgery (2%). 10% of patients selected hospice care and 10% lost follow up. Conclusions: CEUS increases the accuracy of US guided biopsies of focal liver lesions, by improving visualization, targeting viable parts and also in patients with renal failure, or small lesions. Findings from these biopsies could improve management of cancer patients by categorizing them into different treatment groups.