The Correlation Between [68Ga]DOTATATE PET/CT and Cell Proliferation in Patients With GEP-NENs.

Abstract

Objectives of the study are to analyze the correlation between [68Ga]DOTATATE positron emission tomography (PET)/X-ray computed tomography (CT) measurements and various biological characteristics of gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs), and to determine optimal cutoff value of SUVmax (standard uptake value) to differentiate neuroendocrine tumors (NETs) and neuroendocrine cancers (NECs). Of the GEP-NEN cases (73 males, 53 females; age 18-77years) with pathologically proven primary and/or metastatic lesions, 126 were studied. All of the short axes of lesions were larger than 0.5cm in order to avoid the partial volume effect. Patients fasted for 6h before the PET/CT scans. The dose of [68Ga]DOTATATE was 100-200MBq and the acquisition began at 1h after injection. The lesion with the highest SUVmax in each patient was analyzed. In the total sample, the sensitivity of [68Ga]DOTATATE was 69.05%. The sensitivities were significantly different among G1, G2, and G3 groups (72.22%, 91.53%, and 40.82%, respectively; p < 0.01). The SUVmax of the G3 group was lowest. We also found that the sensitivity and SUVmax were significantly higher (p < 0.05) in patients with pancreatic NENs (Pan-NENs) than in patients with gastrointestinal NENs (Gi-NENs) and unknown primary NENs (Up-NENs). A significant negative correlation between SUVmax and Ki-67 was found (r = - 0.429, p < 0.01). Using SUVmax to differentiate neuroendocrine tumors (NETs) and neuroendocrine cancers (NECs), the area under the ROC curve (AUC) was 0.771 and the cutoff value of SUVmax was 11.25 (sensitivity 79.2%, specificity 65.3%). However, Pan-NENs did not show any statistical significance results in correlation and ROC analysis. [68Ga]DOTATATE PET/CT results showed a negative correlation with GEP-NEN cell proliferation and were complementary to Ki-67. Pan-NENs were different from Gi-NENs and Up-NENs when compared to somatostatin receptor expression.