Clinical value of 18F-FDG PET/CT imaging in non-functional pancreatic neuroendocrine neoplasms / 中华核医学与分子影像杂志

ABSTRACT

Objective:To analyze 18F-FDG PET/CT imaging features of non-functional pancreatic neuroendocrine neoplasms (NF-pNENs) and investigate its correlation with pathology and prognosis. Methods:A total of 35 cases (17 males, 18 females; age (51±12) years) of pathologically confirmed NF-pNENs who underwent pretherapeutic 18F-FDG PET/CT from January 2011 to July 2017 in Peking Union Medical College Hospital were retrospectively enrolled. Clinical data were collected and patients were followed up. PET/CT parameters including number and maximum diameter of lesions, SUV max and pancreatic tumor-to-liver ratio (T/L) were measured. Mann-Whitney U test and Kruskal-Wallis rank sum test, Spearman correlation analysis were used to analyze the data. Results:Among the included 35 NF-pNENs patients (G1, n=6; G2, n=21; G3, n=8) with maximum diameter of 3.0(2.1, 6.1) cm and SUV max of 5.5(4.0, 8.9), 32 were positive in PET/CT. There were 1 patient with cystic, 2 with calcification and 3 with dilatation of pancreaticobiliary duct. Among 10 patients with metastases, 8 revealed multiple liver metastases. There was statistical difference of T/L among G1-G3 tumor (1.23(0.60, 2.00), 3.05(1.80, 4.00), 3.90(1.90, 7.60); H=8.29, P=0.016), but there were no statistical differences of SUV max or maximum diameter among G1-G3 tumor ( H values 4.34, 3.37, P values 0.114, 0.186). There was a significant correlation between T/L (2.78(1.48, 3.94)) and Ki-67 index (8.0(3.0, 20.0); rs=0.631, P<0.001). Among 27 patients with available follow-up results, T/L in patients with complete remission or stable disease ( n=20) was statistically lower than that in patients with progressive disease or death ( n=7) (2.1(1.2, 3.2) vs 7.5(3.4, 13.4); z=-3.37, P=0.001). Conclusions:18F-FDG PET/CT can detect primary and metastatic lesions of NF-pNENs. T/L can better reflect the proliferative activity based on Ki-67 index than SUV max and it may be favorable on prognostic value.