The relationship of I-131 6 beta-iodomethyl-19-norcholesterol (NP-59) adrenal cortical uptake to indices of androgen secretion in women with hyperandrogenism.

Dexamethasone suppression (DS) adrenal cortical scintigraphy has been shown to be useful in the detection of the adrenal pathology in women with hyperandrogenism. However, a relationship between adrenal cortical uptake of I-131 6 beta-iodomethylnorcholesterol (NP-59) and the level of adrenal androgen secretion has not been established. A retrospective analysis of DS adrenal scintiscans has been performed on 39 women with hirsutism and hyperandrogenism. In 14 patients with normal patterns of imaging, in vivo adrenal gland iodocholesterol uptake, calculated using a semi-operator-independent-computer algorithm, did not correlate with the excretion of urinary 17-ketosteroids (17-KS). In contrast, in 20 patients demonstrating abnormal bilateral early imaging patterns, adrenal gland NP-59 uptake correlated significantly with the level of urinary 17-KS excretion (r = 0.65, P less than 0.05). To date seven of these 20 patients have had confirmatory procedures documenting the adrenal glands as contributing sites of androgen secretion. A similar correlation with urinary 17-KS excretion was seen in five other patients with unilateral imaging patterns (r = 0.94, P less than 0.005), due to androgen-secreting adrenal cortical adenomas. No correlation between adrenal NP-59 uptake and plasma testosterone or dehydroepiandrosterone sulphate levels was observed in any of the groups. Thus, adrenal gland uptake of NP-59 under DS reflects a measure of androgen secretion in women with androgen excess.