Dynamic enhanced CT: is there a difference between liver metastases of gastroenteropancreatic neuroendocrine tumor and adenocarcinoma.

Yong Cui,Xiao-Ting Li,Lei Tang,Shun-Yu Gao,Zhong-Wu Li,Ying-Shi Sun,Ying Li,Hui-Ci Zhu,Kun Cao,Jie Li

doi:10.18632/oncotarget.22554

Yong Cui, Xiao-Ting Li + Show 8 more

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https://doi.org/10.18632/oncotarget.22554

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Abstract

This study proposed to evaluate the feasibility of dynamic enhanced CT in differentiation of liver metastases of gastroenteropancreatic well-differentiated neuroendocrine tumors (GEP NETs) from GEP adenocarcinomas based on their characteristic features. CT images of 23 well-differentiated (G1 or G2) GEP NETs and 23 GEP adenocarcinomas patients with liver metastases were retrospectively reviewed. The distribution type, shape, intra-tumoral neovascularity, enhancement on hepatic artery phase, dynamic enhancement pattern and lymphadenopathy were subjective analyzed. Meanwhile, the size, number, CT value of tumor and adjacent normal liver parenchyma were measured and the metastasis-to-liver ratios were calculated objectively. Compared with GEP adenocarcinomas, the liver metastases of GEP NETs more frequently demonstrated a hyper enhancement on hepatic artery phase, washout dynamic enhancement pattern, absence of lymphadenopathy and higher metastasis-to-liver ratios on both hepatic artery phase and portal venous phase (P=0.017, P<0.001, P =0.038, P <0.001 and P =0.008, respectively). Logistic regression analysis showed that the dynamic enhancement pattern (P=0.012), and the metastasis-to-liver ratios on hepatic artery phase (P=0.009) were independent CT predictors for liver metastases of GEP NETs. The sensitivity and specificity of combing the two predictors in differentiation of liver metastases of GEP adenocarcinomas from GEP NET were 82.6% (19 of 23) and 91.3% (21 of 23), respectively. CT features are helpful in differentiating liver metastases of well-differentiated GEP NETs from that of GEP adenocarcinomas.

Highlights

Gastroenteropancreatic neuroendocrine tumors (GEP Neuroendocrine tumors (NETs)) arise from the diffuse endocrine system of gastrointestinal tract and pancreatic islet cells [1]
This study proposed to evaluate the feasibility of dynamic enhanced computed tomography (CT) in differentiation of liver metastases of gastroenteropancreatic well-differentiated neuroendocrine tumors (GEP NETs) from GEP adenocarcinomas based on their characteristic features
Differences in tumor sizes were not statistically significant (Z=-1.143, P = 0.253). Both of the metastasis-to-liver ratios on hepatic artery phase and portal venous phase were higher in the GEP NETs liver metastases (1.15±0.33, 0.81±0.27) compared with GEP adenocarcinomas (0.77±0.20, 0.64±0.15) with statistically significant differences (t=4.774, P

Summary

Introduction

Gastroenteropancreatic neuroendocrine tumors (GEP NETs) arise from the diffuse endocrine system of gastrointestinal tract and pancreatic islet cells [1]. Metastatic NETs show an optimistic long-term outcomes (5-year survival > 50%) after aggressive surgical or effective non-surgical treatment options such as somatostatin analogues, peptide receptor radiotherapy, and intra-arterial therapies [5,6,7]. Adenocarcinomas of GEP are the most common primary tumor of liver metastases. In patients with liver metastases from GEP adenocarcinomas, acceptable 5-year overall survival only achieved after the resection of colorectal liver metastasis [8]. For the liver metastases of other primary tumor such as gastric cancer or pancreatic cancer, the long-term outcomes are still poor [9]. Considering that there is a definite survival benefit of local treatments or surgical for metastatic NETs, the differentiation of liver metastases between the GEP NETs and GEP adenocarcinomas may be clinically noteworthy

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