Abstract
2139
Objectives: Neuroendocrine tumors (NETs) can hide within the body due to their minimal side effects and ability to mirror the side effects of other common diseases. Patients battling with NETs often undergo multiple diagnostic procedures before a true diagnosis can be found. Gallium-68 Dotatate is a positron emission tomography (PET) agent used in the detection of somatostatin receptor 2 (SSTR-2) positive neuroendocrine tumors (NET). The purpose of this study is to introduce the positive clinical outcomes we have seen with Gallium-68 Dotatate.
Methods: In collaboration with our Nuclear Medicine physicians, several Ga-68 Dotatate studies were reviewed. 4 clinical case studies will be presented which include comparisons to I-123 MIBG, In-111 pentetreotide, and F-18 FDG.
Results: Patient 1 presented with 2 meningiomas on the right hemisphere found on FDG PET, the Ga-68 Dotatate study revealed a small en plaque meningioma on the left hemisphere which was missed on a prior MR. Patient 2 presented with a primary endobronchial carcinoid tumor with known metastatic disease. The Ga-68 Dotatate revealed axial and appendicular bone disease along with increased metastatic disease compared to F-18 FDG. Patient 3 presented with neuroendocrine pathology found in the lymphatic system during an exploratory laparotomy. Dedicated CT and In-111 Penteteotide study discovered a large mesenteric mass but no metastatic disease. The patient underwent chemo and followed up with a Ga-68 Dotatate study which was positive for metastatic disease. Patient 3 underwent surgery to remove the metastatic disease. Post resection, the Ga-68 Dotatate study found continued SSTR-2 neuroendocrine avidity. Patient 4 presented with metastatic paraganglioma and underwent an I-123 MIBG study which found 2 masses in the chest wall. Two days later a Ga-68 Dotatate study found innumerable focal uptake within the lymphatic system, liver, axial and appendicular skeleton which were not reported on the MIBG or recent CT. Conclusion: Ga-68 Dotatate has given hope to doctors and patients who have encountered the battles of neuroendocrine tumors. Patients with somatostatin receptor 2 positive neuroendocrine tumors who receive a PET scan with Ga-68 Dotatate display an increased sensitivity and specificity of metastatic uptake when compared to F18-FDG, In-111 pentetreotide, and I-123 MIBG. With the aid of the Ga-68 Dotatate PET studies, physicians have greater confidence in evaluating patients with NETs when comparing to CT or MRI. Increased imaging sensitivity and specificity for a previously difficult disease to asses has led to faster and better outcomes for patients. Ga-68 Dotatate has been an effective tool for assessing tumor progression in response to therapies/surgeries.