Comparison of 68Ga-DOTA-NOC and 18F-DOPA PET/CT in patients with neuroendocrine tumours (NETs)

407 Objectives 68Ga-DOTA-NOC and 18F-DOPA PET/CT are two imaging modalities used in the evaluation of neuroendocrine tumours. Accurate assessment of disease status is crucial for the management of NET. 68Ga-DOTA peptides also provide additional data on receptor status that are crucial for targeted radionuclide therapy. At present, there is limited data regarding their role in NET. Here is our initial experience using 68Ga-DOTA-NOC and 18F-DOPA PET/CT imaging in these patients. Methods Twenty-eight patients with NET (18 carcinoids, 4 medullary thyroid carcinomas, 5 MEN Syndromes and 1 Insulinoma) were prospectively enrolled and scheduled for 68Ga-DOTA-NOC and 18F-DOPA PET/CT. The duration interval between the two investigations was not more than 3 weeks. Wherever possible, tissue diagnosis was attempted either by FNAC or by excision biopsy. Results obtained with both tracers were compared with each other, with other conventional diagnostic procedures (CT, ultrasound) and with follow-up (clinical, imaging). Results 68Ga-DOTA-NOC identified 24/25 positive cases in either the primary or the metastatic tumour site, while 18F-DOPA was positive in 16/25 of these patients. On a lesions basis, 68Ga-DOTA-NOC identified more lesions than 18F-DOPA (124 vs 45), especially at liver. Conclusions 68Ga-DOTA-NOC proved to be superior to 18F-DOPA PET/CT in evaluation of NETs. In case of Insulinoma 18F-DOPA was superior to 68Ga-DOTA-NOC