Radioisotope diagnostics of endogenous ACTH-dependent hypercorticism: a review

Abstract

INTRODUCTION: The literature review presents the possibilities of existing methods of radionuclide diagnosis of endogenous ACTH-dependent hypercorticism, which includes Itsenko-Cushing’s disease and ectopic ACTH syndrome. The similar clinical picture of these pathologies significantly complicates their differential diagnosis. Localization of corticotropinoma, especially in patients with persistent Cushing’s disease, and ectopic focus of ACTH hyperproduction also causes difficulties.OBJECTIVE: To analyze the available foreign and domestic literature to determine the possibilities of radionuclide imaging methods in the diagnosis of endogenous ACTH-dependent hypercorticism.MATERIALS AND METHODS: A search of scientifiс publications and clinical recommendations in the information and analytical systems PudMed and elibrary over the past twenty years, dedicated to the diagnosis of Itsenko-Cushing’s disease and ectopic ACTH syndrome using radioisotope diagnostic methods by keywords «Itsenko-Cushing’s disease», «ectopic ACTH syndrome», «radionuclide diagnostics», «scintigraphy», «SPECT», «PET».RESULTS: The presented review demonstrated the broad possibilities and prospects of using modern radioisotope imaging methods in the diagnosis of endogenous ACTH-dependent hypercorticism. Radionuclide imaging methods make it possible to conduct a study in the «whole body» mode, which makes it possible to detect not only the primary tumor focus, but also metastases in patients with ectopic ACTH syndrome in one study. In addition, the use of scintigraphy or positron emission tomography with labeled somatostatin analogues makes it possible to predict the effectiveness of treatment of formations producing adrenocorticotropic hormone with somatostatin analogues, which is important when planning antitumor therapy.CONCLUSION: The use of radioisotope diagnostic methods significantly increases the accuracy of topical diagnosis of a tumor focus, allows for an assessment of the prevalence of the tumor process and the selection of patients for antitumor therapy using somatostatin analogues.