Taweesak WannachaleeAdina F. TurcuIrina BancosMouhammed Amir HabraAnca M. AvramHubert H. ChuangSteven G. WaguespackRichard J. AuchusUniversity of Michigan Medical SchoolUniversity of Michigan, Ann ArborUniversity of Texas MD Anderson Cancer CenterFaculty of Medicine, Siriraj Hospital, Mahidol UniversityMayo Clinic2020-01-272020-01-272019-08-01Clinical Endocrinology. Vol.91, No.2 (2019), 288-29413652265030006642-s2.0-85067353207https://repository.li.mahidol.ac.th/handle/123456789/50118© 2019 John Wiley & Sons Ltd Objectives: Localization of ectopic ACTH-secreting tumours causing Cushing syndrome (ECS) is essential for clinical management, yet often difficult. [68Ga]-DOTATATE PET/CT ([68Ga]-DOTA-(Tyr3)-octreotate)] is an FDA-approved high-resolution diagnostic tool for imaging neuroendocrine tumours. Data on the clinical utility of [68Ga]-DOTATATE in patients with ECS, however, are scarce. The objectives of this study were to determine the efficacy for ECS localization and the clinical benefit of [68Ga]-DOTATATE imaging. Method: We conducted a retrospective review of all cases with ECS evaluated with [68Ga]-DOTATATE from November 2016 through October 2018 at three referral centres. The clinical benefit of [68Ga]-DOTATATE was based on detection of new tumours and resultant changes in management. Results: Over the study period, 28 patients with ECS underwent [68Ga]-DOTATATE: 17 for identification of the primary tumour and 11 during follow-up. [68Ga]-DOTATATE identified the suspected primary ECS in 11/17 patients (65%). Of these, nine patients underwent surgery: eight with confirmed ECS (5 bronchial, 1 thymic, 1 pancreatic and 1 metastatic neuroendocrine tumour of unknown primary origin) and one patient with a false-positive scan (adrenal gland). Of the 11 patients with ECS who underwent [68Ga]-DOTATATE evaluation during follow-up, the study led to changes in clinical management in 7/11 (64%) patients. Conclusions: [68Ga]-DOTATATE is sensitive in detecting primary and metastatic ECS, often identifies occult tumours after conventional imaging, and impacts clinical care in the majority of patients.Mahidol UniversityBiochemistry, Genetics and Molecular BiologyMedicineArticleSCOPUS10.1111/cen.14008