Abstract
1172
Objectives: With the recent FDA approval of 68Ga-DOTATATE, the demand for PET-CT imaging of Neuroendocrine Tumors (NETs) has increased. This trend will be further fueled by the imminent FDA approval of 177Lu- DOTATATE for therapy. Many patients come to Nuclear Medicine for 68Ga-DOTATATE PET with recent MRI obtained during the work-up of NET. Accordingly, this educational exhibit will utilize 68Ga-DOTATATE PET-CT and correlative MRI to: 1) Familiarize the viewer with expected patterns of disease progression across the heterogeneous classes of NETs, including primary and metastatic NET in the brain, lungs, small and large bowel, pancreas, liver, bones, and skin. 2) Highlight MRI sequences that are particularly useful to aid in anatomic localization of NET involvement and, 3) Familiarize the viewer with common pitfalls in 68Ga-DOTATATE PET-CT imaging and potential problem-solving strategies using correlative MRI.
Methods: Consecutive 68Ga-DOTATATE PET-CTs performed between 4/4/17 and 1/4/18 were reviewed. Illustrative cases with correlative MRI were chosen to demonstrate expected patterns of NET disease spread, particular MRI sequences to aid in image interpretation, and problem-solving strategies for common 68Ga-DOTATATE PET-CT pitfalls.
Results: Of 106 68Ga-DOTATATE PET-CTs reviewed, 38 had correlative MRI for the evaluation of NET. These cases provide illustrative examples of well-differentiated and poorly-differentiated neuroendocrine tumor (primary small bowel, pancreas, and anus), carcinoid (lungs, small bowel, appendix, and rectum), Merkel cell carcinoma, paraganglioma, pheochromocytoma, and primary pancreatic adenocarcinoma with neuroendocrine features. Metastases were identified in the brain, liver, bones, lymph nodes, bladder, and direct invasion of venous structures. This collection of cases also included examples of 68Ga-DOTATATE uptake due to benign etiologies, such as meningioma, parathyroid adenoma, adrenal adenoma, physiologic uptake in the uncinate process, prostatitis, and degenerative disk disease. In addition, special considerations in MEN1 and VHL are illustrated. Conclusion: As 68Ga-DOTATATE PET-CT becomes increasingly used for evaluation of NETs, the Nuclear Medicine physician must be familiar with expected patterns of disease progression in all types of NETs, as well as develop an understanding of correlative MRI findings that can aid in more refined interpretation of 68Ga-DOTATATE PET-CT. Review of 68Ga-DOTATATE PET-CT with correlative MRIs in this exhibit will increase the viewer’s confidence in interpretation of 68Ga-DOTATATE PET-CT for NETs.
