E2497. Patterns of 68Ga Dotatate PET Uptake in Patient With Neuroendocrine Tumors
68Ga-Dotatate PET scan has become especially important in localization and treatment plan for neuroendocrine tumors (NET) which are rare and difficult to manage tumors. The incidence of NET is currently about 6.98 per 100,000 per year. This is thought to be due to improved detection on imaging as well as availability of advance therapy. The gastrointestinal tract, pancreas and the bronchopulmonary tracts are the most common sites of primary tumors.
Recognition of normal physiological uptake is important to reduce false positive results and to enhance appropriate patient selection for peptide receptor radionuclide therapy (PRRT).
We seek to demonstrate common NET manifestation on 68GalliumDotatate PET scan and common physiological uptakes which may be mistaken for disease entities.
Materials and Methods:
Following intravenous administration of 4.0-5.4mCi of 68GaDotatate, each patient was imaged at about 60minutes +/-10minutes with a GE Discovery 690 Elite in 3D mode PETCT scanner. Images of 17 patients were reviewed. Clinical information was also reviewed to confirm biopsy findings for those who had surgery. Following deidentification of the images on PACS, we present some of the images which include the physiological uptakes, primary tumors and site of metastasis.
A total of 17 consecutive 68GaDotatate scan images were reviewed. Subjects have a mean age of 56.9 years and comprise of 9 (52.9%) females and 8 (47.1%) males. Common site of primary lesions are terminal ileum 5(29.4%), pancreas 3(17.6%), duodenum 2(11.7%), adrenal gland 2(11.7%), left main bronchus 1(5.9%), stomach 1(5.9%), 3 (17.6%) had no positive lesions. Majority of lesions are well differentiated neuroendocrine tumors which account for 10(58.6%) Others are, poorly differentiated NET 1(5.9%), pheochromocytoma 2(11.8%) and gastrinoma 1(5.9%). Physiologic uptake was seen in the pituitary gland, thyroid, liver, adrenal glands, pancreas, prostate, uterus. A patient who had splenectomy was seen to have multiple splenules with significant uptake.
There is variation in the manifestation of 68Ga-Dotatate uptake in NET and physiological distribution in nonpathological tissues. The understanding of this is important for image specialists to make accurate calls and reduce waste.