Feasibility of Iodine-131 6β-Methyl-Iodo-19 Norcholesterol (NP-59) Scintigraphy to Complement Adrenal Venous Sampling in Management of Primary Aldosteronism: A Case Series

Jeongmin Lee,1 Jeonghoon Ha,2 Sang-Kuon Lee,3 Hye Lim Park,4 Sung-Hoon Kim,5 Dong-Jun Lim,2 Jung Min Lee,1 Sang-Ah Chang,1 Moo Il Kang,2 Min-Hee Kim1 1Division of Endocrinology and Metabolism, Department of Internal Medicine, Eunpyeong St. Mary’s Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea; 2Division of Endocrinology and Metabolism, Department of Internal Medicine, Seoul St. Mary’s Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea; 3Division of Pancreatobiliary Surgery, Department of Surgery, Seoul St. Mary’s Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea; 4Division of Nuclear Medicine, Department of Radiology, Eunpyeong St. Mary’s Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea; 5Division of Nuclear Medicine, Department of Radiology, Seoul St. Mary’s Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of KoreaCorrespondence: Min-Hee KimDivision of Endocrinology and Metabolism, Department of Internal Medicine, Eunpyeong St. Mary’s Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of KoreaTel +82-2-2030-4348Fax +82-2-2030-4641Email benedict@catholic.ac.krPurpose: Primary aldosteronism (PA) is mainly comprised of aldosterone-producing adenoma and bilateral idiopathic adrenal hyperplasia. Current guidelines recommend adrenal venous sampling (AVS) as a gold standard method to classify the subtypes. However, because of technical challenges in AVS including invasiveness of AVS and a wide range of success rate for cannulation, it is not uncommon that appropriate decisions could not be made depending on AVS. The aim of this study is to elucidate the proper role of I‑131‑6β‑iodomethyl‑norcholesterol (NP-59) scintigraphy in management of PA.Patients and Methods: Between January 2009 and October 2018, patients with PA were retrospectively reviewed for the study. Five patients were included in the study who had NP-59 scintigraphy with non-conclusive AVS results or without AVS. We described the clinical outcome of patients in whom clinical decisions were made according to NP-59 scintigraphy results.Results: Patients in the presenting cases were diagnosed for PA. AVS, the most reliable test to identify unilateral APA, were not applicable because of hypersensitivity to contrast dye (patient 1), and use of antiplatelet agents after acute cerebral infarction (patient 2). NP-59 scintigraphy was performed in patients 3 and 4 whose result of AVS and CT scan were inconsistent. In patient 5, who had bilateral adrenal adenomas (two in the left and one in the right adrenal gland), both unsuccessful catheterization and coexistence of cortisol overproduction made AVS results unreliable.Conclusion: Based on clinical outcomes of these case series, it is noticeable that NP-59 scintigraphy could play a substantial role in management of PA in selected cases.Keywords: hyperaldosteronism, angiography, aldosterone, radionuclide imaging