Somatostatin Receptor Imaging with⁶⁸Ga DOTATATE PET/CT: Clinical Utility, Normal Patterns, Pearls, and Pitfalls in Interpretation

Abstract

Gallium 68 ((68)Ga) 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA)-octreotate (DOTATATE, GaTate) positron emission tomography (PET)/computed tomography (CT) is an imaging technique for detecting and characterizing neuroendocrine tumors (NETs). GaTate, a somatostatin analog, has recently been accorded orphan drug status by the U.S. Food and Drug Administration, thereby increasing interest in and availability of this radiotracer. GaTate PET/CT allows whole-body imaging of cell surface expression of somatostatin receptors (SSTRs) and is rapidly evolving as the new imaging standard of reference for the detection and characterization of NETs. The authors discuss the normal appearance at GaTate PET/CT and the utility of this modality in a variety of these tumors, including gastrointestinal, pancreatic, and bronchial NETs as well as pheochromocytoma, paraganglioma, meningioma, and oncogenic osteomalacia. In addition, they discuss potential causes of false-positive findings, including pancreatic uncinate process activity, inflammation, osteoblastic activity, and splenosis. They also highlight the complementary role of 2-[fluorine-18]fluoro-2-deoxy-d-glucose (FDG) PET/CT, including the advantages of using both GaTate PET/CT and FDG PET/CT to evaluate sites of well- and poorly differentiated disease. The use of GaTate PET/CT together with FDG PET/CT allows identification of tumor heterogeneity, which provides prognostic information and can be pivotal in guiding biopsy. It also allows optimal patient management, including theranostic application of peptide receptor radionuclide therapy, and the restaging of patients following therapy.

Application of 68Ga-DOTA-TATE PET/CT in metastatic neuroendocrine tumor of gastrointestinal origin

“…The patient underwent a whole-body positron emission tomography-computed tomography (PET/CT) scan using Ga-DOTATATE injection) excision of the tumors from the small bowel, the mesenteric lymph nodes and the liver lesions. Subsequently pathological evaluation of all excised specimens revealed primary grade-I NET in the terminal ileum with metastases to the liver and mesenteric lymph nodes.Since the majority of NETs overexpress SST receptors, they can be effectively targeted and localized using radiolabeled SST analogs [1,2]. In the presented case 68Ga-DOTATATE PET/ CT accurately showed the extent of the disease and confidently revealed the location of the primary tumor, demonstrating the utility of PET/CT using 68 Ga-DOTA-conjugated peptides in the accurate management of patients with gastro-enteropancreatic NETs [3].…”

“…Since the majority of NETs overexpress SST receptors, they can be effectively targeted and localized using radiolabeled SST analogs [1,2]. In the presented case 68Ga-DOTATATE PET/ CT accurately showed the extent of the disease and confidently revealed the location of the primary tumor, demonstrating the utility of PET/CT using 68 Ga-DOTA-conjugated peptides in the accurate management of patients with gastro-enteropancreatic NETs [3].…”

Glomus tumor as a cause of oncogenic osteomalacia

“…GaTate, is a somatostatin analog, a radiotracer that is used in GaTate PET/CT, it allows whole-body imaging of cell surface expression of somatostatin receptors. The use of GaTate PET/CT together with FDG PET/CT allows identification of tumor (14). Heterogeneity, which provides prognostic information and can be pivotal in guiding biopsy.…”

Neuroendocrine Neoplasms: A Case Report with Complete Reverse Mismatch and the Correlation with Differentiation Rate

“…The present and future trend in oncological care heads towards personalizing treatments in order to reduce the side effects of current available therapies and individualizing management to each patient. And this is where the Nuclear Medicine Therapeutics is a cornerstone in achieving the objective [6][7][8][9][10][11][12][13][14][15][16][17].…”