6-iodomethylcholesterol and Adrenal-Gland-Diseases

To determine the efficacy of 131I-6-beta-iodomethylnorcholesterol (NP-59) adrenal scintigraphy in distinguishing benign from malignant euadrenal masses.. Case series of patients with incidentally discovered unilateral, euadrenal masses.. Referral-based nuclear medicine clinics at university and affiliated Veterans Administration medical centers.. Consecutive sample of 119 euadrenal patients with unilateral adrenal masses discovered on computed tomographic (CT) scans for reasons other than suspected adrenal disease.. Adrenal scintiscans done using 1 mCi of NP-59 intravenously, and gamma camera imaging 5 to 7 days later.. Mean lesion diameter was 3.3 +/- 1.9 cm (SD) (95% CI: 2.9 to 3.6 cm). In 76 patients, NP-59 uptake lateralized to the abnormal adrenal seen on CT scans (concordant imaging), and in all of these patients, a diagnosis of adenoma was made by needle-aspiration biopsy, adrenalectomy, or extended follow-up with repeat CT scans that were unchanged at 6 months or later. Twenty-six patients had absent or markedly reduced NP-59 uptake in the glands identified as abnormal on CT scans (discordant imaging). These adrenal masses proved to be metastatic malignancies in 19 patients, primary adrenal neoplasms other than adenoma in 4, and adrenal cysts in 3. Bilateral, symmetric accumulation of NP-59 was seen in 17 patients, in whom the adrenal masses were shown to be metastatic malignancies in 2, and adenomas in 6 (the lesions in these cases being 2 cm or less in diameter), and lesions not truly involving the adrenal in the rest (periadrenal metastases in 4 and pseudoadrenal masses in 5). Sensitivity was 76% (26 of 34 patients; CI, 58% to 88%); specificity, 100% (85 of 85 patients; CI, 95% to 100%), and accuracy, 93% (111 of 119 patients: CI, 88% to 98%).. Functional NP-59 scintigraphy can be used to accurately and noninvasively characterize many euadrenal masses; concordance of CT and NP-59 scans can be used to exclude the presence of a malignancy or other space-occupying adrenal lesion.

Topics: 19-Iodocholesterol; Adenoma; Adolescent; Adrenal Cortex; Adrenal Gland Diseases; Adrenal Gland Neoplasms; Adult; Aged; Aged, 80 and over; Cholesterol; Cysts; Diagnosis, Differential; Female; Humans; Iodine Radioisotopes; Male; Middle Aged; Predictive Value of Tests; Radionuclide Imaging; Tomography, X-Ray Computed

The exact localization of adrenal lesions can be achieved by noninvasive procedures. Whereas radiological methods reflect morphological changes, scintigraphy of adrenal cortex and medulla depends on function. - Radiolabeled 6 beta-methyl-19-norcholesterol is used for adrenocortical scintigraphy in primary aldosteronism, Cushing's syndrome and hyperandrogenism. By dexamethasone suppression a correct classification of adrenocortical lesions by scintigraphy can be observed in about 89% with a specificity of 86%. 123-I- and 131-I-metaiodobenzylguanidine is used for specific scintigraphy of the adrenal medulla. This method is a safe and reliable method for localization of adrenal and extraadrenal pheochromocytomas.

Topics: 19-Iodocholesterol; 3-Iodobenzylguanidine; Adrenal Gland Diseases; Adrenal Gland Neoplasms; Cholesterol; Cushing Syndrome; Dexamethasone; Humans; Hyperaldosteronism; Iodobenzenes; Pheochromocytoma; Radionuclide Imaging; Selenium; Succimer; Technetium; Technetium Tc 99m Dimercaptosuccinic Acid