The Clinical Impact of [ 68 Ga]-DOTATATE PET/CT for the Diagnosis and Management of Ectopic Adrenocorticotropic Hormone - Secreting Tumours

Clin Endocrinol (Oxf). 2019 Aug;91(2):288-294. doi: 10.1111/cen.14008. Epub 2019 Jun 12.


Objectives: Localization of ectopic ACTH-secreting tumours causing Cushing syndrome (ECS) is essential for clinical management, yet often difficult. [68 Ga]-DOTATATE PET/CT ([68 Ga]-DOTA-(Tyr3 )-octreotate)] is an FDA-approved high-resolution diagnostic tool for imaging neuroendocrine tumours. Data on the clinical utility of [68 Ga]-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 [68 Ga]-DOTATATE imaging.

Method: We conducted a retrospective review of all cases with ECS evaluated with [68 Ga]-DOTATATE from November 2016 through October 2018 at three referral centres. The clinical benefit of [68 Ga]-DOTATATE was based on detection of new tumours and resultant changes in management.

Results: Over the study period, 28 patients with ECS underwent [68 Ga]-DOTATATE: 17 for identification of the primary tumour and 11 during follow-up. [68 Ga]-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 [68 Ga]-DOTATATE evaluation during follow-up, the study led to changes in clinical management in 7/11 (64%) patients.

Conclusions: [68 Ga]-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.

Keywords: CT; Cushing syndrome; [68Ga]-DOTATATE PET; ectopic ACTH secretion; somatostatin receptor; tumour localization.

Publication types

  • Multicenter Study
  • Research Support, N.I.H., Extramural

MeSH terms

  • Adrenocorticotropic Hormone / metabolism*
  • Adult
  • Cushing Syndrome / diagnosis
  • Cushing Syndrome / diagnostic imaging
  • Cushing Syndrome / therapy*
  • Female
  • Follow-Up Studies
  • Gallium Radioisotopes / metabolism
  • Humans
  • Male
  • Middle Aged
  • Neuroendocrine Tumors / diagnosis
  • Neuroendocrine Tumors / metabolism
  • Neuroendocrine Tumors / therapy*
  • Organometallic Compounds / metabolism*
  • Positron Emission Tomography Computed Tomography / methods*
  • Referral and Consultation / statistics & numerical data
  • Retrospective Studies
  • Sensitivity and Specificity


  • Gallium Radioisotopes
  • Organometallic Compounds
  • Adrenocorticotropic Hormone
  • gallium Ga 68 dotatate