Effectiveness of ¹³¹I nor-cholesterol Uptake per Unit Volume of Adrenal Adenoma in the Diagnosis of Aldosteronoma

Abstract

Diagnosis of adrenal adenomas for patients with primary aldosteronism is sometimes difficult only by referring to the visualization pattern in adrenocortical scintigraphy without regards to standard scintigraphy or suppression scintigraphy with dexamethasone. We studied if quantitative evaluation of the standard scintigraphy without dexamethasone suppression can be useful to diagnose aldosteronomas. Twenty-nine patients who had undergone adrenalectomy with different clinical manifestations (16 patients with primary aldosteronism, 6 patients with Cushing's syndrome and 7 patients without hormonal abnormality) were included in the study. Volume of the adrenocortical adenomas, ¹³¹I nor-cholesterol uptake of the adrenocortical adenomas, and ¹³¹I nor-cholesterol uptake per unit volume of the adrenocortical adenomas were compared between the 3 groups. The volume of adrenocortical adenomas in the patients with primary aldosteronism was significantly lower than those in the other two groups (Cushing's syndrome p<0.01, Non-hormonal abnormality p<0.01). No significant differences were found between the 3 groups in terms of ¹³¹I nor-cholesterol uptake of adrenocortical adenoma. The ¹³¹I nor-cholesterol uptake per unit volume of adrenocortical adenomas was significantly higher in the patients with primary aldosteronism than those in the other two groups (Cushing's syndrome p<0.001, Non-hormonal abnormality p<0.001). ¹³¹I nor-cholesterol uptake per unit volume of adenoma obtained from adrenocortical scintigraphy without dexamethasone suppression can be useful in the diagnosis of aldosteronoma.