Ga-68 DOTATATE PET/CT in the Evaluation of Paragangliomas and Other Indeterminate Lesions in the Head and Neck

BACKGROUND AND PURPOSE: Paragangliomas (PGLs) are rare neuroendocrine tumors with imaging features that can overlap with other entities. This study hypothesizes that given overexpression of somatostatin receptor (SSTR) 2, PGLs can be differentiated on Ga-68 DOTATATE positron emission tomography/computed tomography (PET/CT) from other benign or malignant lesions. MATERIALS AND METHODS: Ninety-six patients with known tumors of the head and neck who underwent Ga-68 DOTATATE PET/CT from May 2017 to December 2021 were retrospectively reviewed from a single institution. Of these, 43 patients had histopathological confirmation and 66 positive lesions were discovered on PET/CT. For each lesion, the SUV max, the SUV lesion to liver ratio, and the SUV lesion to spleen ratio were analyzed. RESULTS: PGLs (n = 37) showed the most intense uptake, and the mean of SUVmax was 69.3 (range 3.7–225.9). Metastatic PGL and metastasis from other neuroendocrine tumors (n = 13) demonstrated intermediate uptake, the mean of SUVmax was 15.16 (range 2.3–40.3). Meningiomas (n = 3) had intermediate uptake, and the mean of SUVmax was 12.37 (range 2.5–19.4). One patient with esthesioneuroblastoma had 5 lesions in the head and neck, and the mean of SUVmax was 18.9 (range 6.9–49.4). Schwannomas (n = 4) had very low uptake, and the mean of SUVmax was 1.75 (range 1.1–2.2). Other rare cases with low uptake included 1 each of osteosarcoma, acinic cell carcinoma, ectopic thyroid tissue, and plasmacytoma, and the mean of SUVmax was 4.75 (range 2.3–6.1). CONCLUSIONS: Ga-68 DOTATATE PET/CT can be a useful adjunct in differentiating tumors in the head and neck. PGLs demonstrate the highest uptake. Meningioma, esthesioneuroblastoma, and neuroendocrine tumor metastasis have intermediate uptake. Schwannomas and other rare tumors exhibit low uptake.