11C-metomidate positron emission tomography after dexamethasone suppression for detection of small adrenocortical adenomas in primary aldosteronism

• Published in: Langenbeck's archives of surgery Vol. 395; no. 7; pp. 963 - 967
• Main Authors: Hennings, J., Sundin, A., Hägg, A., Hellman, P.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer-Verlag 01.09.2010
• Subjects: Abdominal Surgery; Administration, Oral; Adrenocortical Adenoma - diagnostic imaging; Adrenocortical Adenoma - drug therapy; Adrenocortical Adenoma - pathology; Adult; Aged; Biopsy, Needle; Cardiac Surgery; Dexamethasone - therapeutic use; Dose-Response Relationship, Drug; Drug Administration Schedule; Etomidate - analogs & derivatives; Female; Follow-Up Studies; General Surgery; Humans; Hyperaldosteronism - diagnostic imaging; Hyperaldosteronism - drug therapy; Hyperaldosteronism - pathology; Immunohistochemistry; Male; Medicin och hälsovetenskap; Medicine; Medicine & Public Health; Middle Aged; Neoplasm Staging; Original Article; Positron-Emission Tomography - methods; Sampling Studies; Thoracic Surgery; Traumatic Surgery; Treatment Outcome; Tumor Burden - drug effects; Vascular Surgery; Dexamethasone; Metomidate; Primary aldosteronism; Adrenal; Suppression; PET
• ISSN: 1435-2443; 1435-2451; 1435-2451
• DOI: 10.1007/s00423-010-0681-7

Purpose To evaluate whether dexamethasone suppression treatment can improve 11 C-metomidate positron emission tomography (MTO-PET) detection of small adrenocortical adenomas in primary aldosteronism (PA). Materials and methods Eleven patients with proven PA and two patients with non-hyperfunctioning adrenocortical incidentalomas and small adrenocortical tumours observed on CT underwent MTO-PET before and 3 days after administration of oral dexamethasone suppression treatment. Small “hot-spot” regions of interest comprising 4 pixels (SUVhs) and 1 pixel (SUVmax) were placed in the tumour area with the highest radioactivity concentration and their respective standardised uptake values (SUV) were recorded. Results All tumours were detected and categorised as adrenocortical by MTO-PET. SUVhs as well as SUVmax were higher in PA compared to nonfunctional adenomas. Normal adrenal cortex was suppressed after dexamethasone ( p  < 0.05), but tumour SUV was not significantly decreased after suppression in either PA or nonfunctional tumours ( p  > 0.05). However, these changes caused no significant increase in the tumour-to-normal adrenal ratio ( p  > 0.05). Conclusion MTO-PET is a highly sensitive method for detecting and categorising even small adrenocortical tumours in PA. In this series, dexamethasone-suppressed MTO-PET was unable to increase the tumour-to-normal adrenal ratio to further facilitate detection of small adenomas in PA as an alternative to adrenal venous sampling.