Objective: This study aimed to compare the diagnostic performance of 68Ga-DOTANOC PET/CT with 18F-FDG PET/CT in the patients with gastroenteropancreatic neuroendocrine tumors (GEP-NETs).
Patients and Methods: Data of 51 patients with definite histological diagnosis of GEP-NET who underwent both 68Ga-DOTA-NOC PET-CT and 18F-FDG PET-CT within a span of 15 days were selected for this retrospective analysis. Sensitivity, specificity, and predictive values were calculated for 68Ga-DOTA-NOC PET-CT and 18F-FDG PET-CT, and results were compared both on patientwise and regionwise analysis.
Results: 68Ga-DOTA-NOC PET-CT is superior to 18F-FDG PET-CT on patientwise analysis (P < 0.0001). On regionwise analysis, 68Ga-DOTA-NOC PET-CT is superior to 18F-FDG PET-CT only for lymph node metastases (P < 0.003). Although 68Ga-DOTA-NOC PET-CT detected more liver and skeletal lesions compared with 18F-FDG PET-CT, the difference was not statistically significant. In addition, the results of combined imaging helped in selecting candidates who would undergo the appropriate mode of treatment, whether octreotide therapy or conventional chemotherapy
Conclusions: 68Ga-DOTA-NOC PET-CT seems to be superior to 18F-FDG PET-CT for imaging GEP-NETs. However, their role seems to be complementary because combination of 68Ga-DOTA-NOC PET-CT and 18F-FDG PET-CT in such patients helps demonstrate the total disease burden and segregate them to proper therapeutic groups.