Objectives: Somatostatin is an endocrine peptide hormone that regulates neurotransmission and cell proliferation by interacting with G protein-coupled somatostatin receptors (SSTRs). SSTRs are specific molecular targets of several radiotracers for neuroendocrine tumor (NET) imaging. Gallium-68 ( 68 Ga)-DOTA-TATE is widely used for positron emission tomography/computed tomography (PET/CT) imaging of SSTRs and has shown a higher affinity for SSTR2, the most common SSTR subtype found in NETs. We aimed to analyze the distribution pattern of 68 Ga-DOTA-TATE in normal subjects. Methods: A total of 617 consecutive 68 Ga-DOTA-TATE PET/CT whole-body scans performed in our department from May 2015 through April 2020 with known or suspected neuroendocrine malignancies, mostly to evaluate adrenal adenomas, were retrospectively analyzed by 2 nuclear medicine physicians. One hundred eighteen subjects without a diagnosis of NET, with no tracer avid lesion of NET on 68 Ga-DOTA-TATE PET/CT, and followed up for at least 6 months (average 2-3 years) without any biochemical, clinical, or imaging findings suggestive of NET were included in this study. Results: The highest uptake of 68 Ga-DOTA-TATE was noted in the spleen followed by the kidneys, adrenal glands, liver, stomach, small intestine, prostate gland, pancreas head, pancreas body, thyroid gland, and uterus, in descending order. Minimal to mild uptake was detected in the submandibular glands, parotid glands, thymus, muscles, bones, breast, lungs, and mediastinum. Conclusion: Our study shows the biodistribution pattern of 68 Ga-DOTA-TATE in normal subjects and the ranges of the maximum standard uptake value (SUV max ) and SUV mean values of 68Ga-DOTA-TATE obtained in several tissues for reliably identifying malignancy in 68 Ga-DOTA-TATE PET/CT studies.

Renal cell carcinoma (RCC) is the most common primary malignancy of the kidney. Approximately 35% of patients of RCC presents with distant metastasis at initial evaluation. CT and MRI are the mainstay imaging modalities. Distinguishing radiation necrosis from tumor progression after stereotactic radiosurgery is challenging. Herein, we present a case of a 43-year-old man with RCC who was treated with stereotactic radiosurgery for brain metastases. We want to emphasize the potential value of 68Ga-PSMA PET/CT imaging in the differential diagnosis and follow-up of tumor progression from radiation necrosis in RCC patients.

Von Hippel-Lindau (VHL) disease is an autosomal dominant hereditary cancer syndrome that is characterized by the presence of various malignant and benign tumors, including retinal and central nervous system hemangioblastomas. Hemangioblastomas are highly vascular tumors that can occur sporadically or within VHL disease. Herein, we present 68Ga-DOTATATE PET/CT findings of a unique case of suprasellar hemangioblastoma in a 52-year-old man with VHL disease.

Nasal-type extranodal natural killer/T-cell lymphoma is an aggressive rare type of lymphoma that mostly affects the nasal cavity and adjacent areas. However, some patients can present with distant nodal or extranodal involvement including the Waldeyer ring, gastrointestinal tract, genitourinary organs, lung, thyroid, skin, or adrenal glands. Herein, we present a unique case of extranodal natural killer/T-cell lymphoma with widespread cutaneous and subcutaneous involvement on 18 F-FDG PET/CT.

68Ga-DOTATATE PET/CT is an important tool for imaging neuroendocrine tumors, including skeletal metastases. However, false-positive results can occur in inflammatory pathologies such as sacral insufficiency fracture. We report the case of a 47-year-old man who was diagnosed with a neuroendocrine tumor of the pancreas. 68Ga-DOTATATE PET/CT showed 68Ga-DOTATATE uptake at the right side of the sacrum. Afterward, MRI made the diagnosis of sacral insufficiency fracture.