Preliminary study on the relationship between the contrast-enhanced ultrasonography of liver metastasis and the differentiation degree of neuroendocrine tumors

Abstract

Objective To retrospectively analyze contrast-enhanced ultrasound (CEUS) manifestations of neuroendocrine tumors (NETs) liver metastases, and explore the relationship between CEUS parameters and differentiation of NETs. Methods From January 2014 to June 2018, 36 patients who had been performed CEUS due to liver metastasis of NETs with pathological diagnosis and immunohistochemical staining results were enrolled in this study. The CEUS findings of NETs liver metastases were summarized. According to the Ki-67 index, CgA results, and the stage G, the patients were divided into Ki-67>20% group and Ki-67≤20% group, CgA negative group and CgA positive group, and group G1+ G2 and group G3, respectively. The CEUS parameters of NETs liver metastases between the above groups were compared. Results In 36 lesions, during the arterial phase of CEUS, 66.7% (24/36) showed hyperenhancement, 16.7% (6/36) isoenhancement, 13.9% (5/36) rim-like enhancement, and 5.6% (2/36) hypoenhancement; During the portal phase, 13.9% (5/36) showed hyper or iso enhancement, 86.1% (31/36) showed hypoenhancement. The average washout time was (67.5±56.1)s, of which 5 (13.9%) lesions were washed out after 120 s. The mean starting washout time was statistically different between the CgA negative group and the positive group [(91.6±81.5)s vs (60.1±38.7)s, P=0.001]. There was no statistically significant difference in all observations between the group of Ki-67≤20% and >20%, group G1+ G2 and group G3(P>0.05). Conclusions CEUS of NETs liver metastasis has certain characteristics, among which hyperenhancement is its main enhancement mode, and some lesions have a longer wash out time. The relationship with the degree of differentiation needs further investigation. Key words: Ultrasonography; Contrast-enhanced ultrasound; Neuroendocrine neoplasms; Differentiation degree