Evaluation of 68Ga-DOTANOC PET/CT imaging in a large exclusive population of pancreatic neuroendocrine tumors

Abstract

Purpose: To evaluate the diagnostic accuracy of 68Ga-DOTANOC PET/CT imaging in a large exclusive population of pancreatic neuroendocrine tumors (NETs). Methods: Data of 141 (mean age 46.2 ± 15.2 years) patients who underwent 178 68Ga-DOTANOC PET/CT studies for diagnosis/staging (n = 88) and restaging (n = 90) of pancreatic NET were retrospectively analyzed. PET/CT results were compared to conventional imaging (CIM) when available (n = 86). Histopathology and/or clinical/imaging follow-up (minimum 6 months) were used as reference standard. Conclusions: 68Ga-DOTANOC PET/CT is useful for diagnosis/staging and restaging of patients with pancreatic NET. It demonstrates more lesions compared to CIM and is more specific. Results: The overall sensitivity, specificity, and accuracy of 68Ga-DOTANOC PET/CT were 85.7%, 79.1%, and 84.8%. The corresponding values were 73%, 50%, and 70.4% for diagnosis/staging groups and 98.6%, 100%, and 98.8% for restaging groups. The accuracy was significantly higher for restaging as compared to diagnosis/staging (P < 0.0001) and in non-insulinoma tumors than insulinomas (P < 0.0001). The SUVmax of primary tumors was significantly higher than metastatic lesions overall (P = 0.001), as well as in diagnosis/staging (P = 0.041) and restaging (P = 0.0003) subgroups. When available, CIM was less specific than 68Ga-DOTANOC PET/CT (P < 0.001) and showed fewer lesions.