19-iodocholesterol and Adrenal-Cortex-Diseases

To assess the efficacy of 131I-6-beta-iodomethylnorcholesterol scintigraphy in the adrenocorticotropic hormone-independent Cushing syndrome and to compare this with computed tomography.. Retrospective analysis of case series from 1977 to 1987.. Referral to the Division of Nuclear Medicine at a tertiary-care university medical center.. Twenty-four patients with a pathologically-confirmed diagnosis of the adrenocorticotropic hormone-independent Cushing syndrome had 131I-6-beta-iodomethylnorcholesterol scintigraphy and, in most cases, computed tomography.. Using 131I-6-beta-iodomethylnorcholesterol scintigraphy, adenomas were accurately seen as focal, unilateral tracer uptake in 14 of 14 patients. In carcinoma, the classic scintigraphic pattern of bilateral nonvisualization was observed in 3 of 4 patients, with ipsilateral uptake of tracer in 1 patient with a histologically well-differentiated malignancy. Computed tomography done during the same interval depicted abnormal adrenals in all cases of adenoma and carcinoma. In cortical nodular hyperplasia, however, computed tomography identified abnormal pairs of adrenals in only one of four cases studied, whereas scintigraphy showed typical patterns of bilateral increased uptake in all of the cases.. 131I-6-beta-iodomethylnorcholesterol scintigraphy accurately shows the location and nature of adrenal dysfunction in the adrenocorticotropic hormone-independent Cushing syndrome and may be particularly useful in identifying the bilateral adrenal involvement in cortical nodular hyperplasia.

Topics: 19-Iodocholesterol; Adenoma; Adrenal Cortex; Adrenal Cortex Diseases; Adrenal Cortex Neoplasms; Carcinoma; Cholesterol; Cushing Syndrome; Evaluation Studies as Topic; Female; Humans; Hyperplasia; Iodine Radioisotopes; Male; Radionuclide Imaging; Retrospective Studies; Tomography, X-Ray Computed

Referral patterns from internists to departments of nuclear medicine or radiology are important determinants of whether adrenal glands are imaged by computed tomography (CT) or by radioisotope scintigraphy. To assist clinicians in making an informed choice, computed tomographic scans were compared with isotope scintigrams using 131I-19-iodocholesterol (19-IC) and 131I-6 beta-iodomethyl-19-norcholesterol (NP-59). In general, imaging techniques serve to localize diseases that are diagnosed on the basis of biochemical tests of adrenal function. Computed tomographic scanning and NP-59 scanning are of comparable diagnostic accuracy. Both are superior to 19-IC scanning in the diagnosis of Cushing's syndrome and primary aldosteronism. Computed tomographic scanning is faster and less expensive, and involves lower radiation doses to the patient than scintigraphy. Adrenocortical isotope scanning as a routine procedure has been superseded by computed tomographic scanning at the Mayo Clinic.

Topics: 19-Iodocholesterol; Adosterol; Adrenal Cortex; Adrenal Cortex Diseases; Adrenal Cortex Neoplasms; Adult; Aged; Cushing Syndrome; Female; Humans; Hyperaldosteronism; Male; Middle Aged; Radionuclide Imaging; Tomography, X-Ray Computed

In six normal dogs the adrenals could be visualized as separate areas of radioactivity at 7--10 days after injection of 20--40 muCi 131I-iodocholesterol per kg of body weight. Image analysis revealed uptake values of 0.15--0.3% of the injected dose. In five dogs with pituitary-dependent hyperadrenocorticism the adrenals became visible at 3--5 days after injection of the radiopharmaceutical, with uptake values of 0.38--2.2%. In six dogs with hyperadrenocorticism due to adrenocortical tumor the scintigraphy contributed to the diagnosis and the presurgical localization. The uptake values were within the normal range; the tumor could be observed at 3--10 days after injection. Additional findings on adrenal asymmetry and a case of fluctuating pituitary-dependent hyperadrenocorticism are discussed.

Topics: 19-Iodocholesterol; Adrenal Cortex Diseases; Adrenal Glands; Adrenocorticotropic Hormone; Animals; Cholesterol; Dogs; Iodine Radioisotopes; Pituitary-Adrenal System; Radionuclide Imaging; Stimulation, Chemical

Topics: 19-Iodocholesterol; Adrenal Cortex Diseases; Adult; Brain Diseases; Diagnosis, Differential; Female; Humans; Hypothalamus; Iodine Radioisotopes; Middle Aged; Pituitary Diseases; Radionuclide Imaging; Recurrence