6-iodomethylcholesterol and Cushing-Syndrome

The aim of this study was three-fold: 1) to quantify [131I]-6beta-iodomethyl-norcholesterol ([131I]-NP-59) adrenal uptake trend in patients with incidentalomas, 2) to identify a specific uptake trend (TREND) capable of characterising pre-clinical Cushing syndrome (PC-CS) patients, 3) to assess the clinical availability of TREND as a prognostic factor of late clinical outcome in a cohort of patients with bilateral adrenal adenomas.. Fifty-seven consecutive patients were examined using three-head SPECT at 24, 48, 72 hours following intravenous injection of [131I ]-NP-59. On the basis of the absence or presence of hormonal abnormalities, the selected population was classified as GR1 or GR2, respectively. Adrenal glands were classified into 4 groups taking into account both the patient group (GR1, GR2) and the presence (+) or absence (-) of the adenoma (AD) on CT scan. Using ROI technique, adrenal-liver uptake ratio (A/L) was estimated bilaterally at 24, 48 and 72 hours. For each adrenal group, mean [131I]-NP-59 uptake trends were derived.. TREND was significantly different between GR1/AD+ and GR2/AD+. Among GR2/AD+ patients, TREND correctly identified PC-CS with a global accuracy of 74%. Two patients with bilateral incidentaloma developed an overt CS. In both patients, TREND correctly identified the hyperfunctioning adrenal, thus permitting an effective sparing adrenalectomy.. TREND seems to be a parameter which closely reflects adrenal physiological behaviour, especially in the case of bilateral adrenal involving. The possibility to quantify even contralateral adrenal uptake as standardised index provides additional useful information about normal adrenal parenchyma and, indirectly, about adenoma functional autonomy.

Topics: 19-Iodocholesterol; Adenoma; Adrenal Cortex Neoplasms; Cushing Syndrome; Female; Humans; Image Interpretation, Computer-Assisted; Male; Metabolic Clearance Rate; Middle Aged; Radiopharmaceuticals; Reference Values; Reproducibility of Results; Sensitivity and Specificity; Tomography, Emission-Computed, Single-Photon

The goal of this study was to evaluate the clinical reliability of the (131)I-6 beta-iodomethyl-norcholesterol ((131)I-NP-59) uptake semiquantitative evaluation method we propose for the characterization of adrenocortical masses in a selected population of patients with disease clinically classified as subclinical (SC) and preclinical (PC) Cushing's syndrome (CS) according to Reincke's definition.. Forty-seven consecutive patients with incidentally discovered unilateral adrenal masses were examined by a triple-head SPECT system after intravenous injection of (131)I-NP-59. Abdominal SPECT was performed at 24, 48, 72, and, in selected cases, 96 h after tracer injection. Connected with adrenals and liver, a standard elliptic region of interest (ROI) was manually drawn, taking care to avoid the gallbladder region. The adrenal ROI integral count, obtained by summing the 24-, 48-, and 72-h counting values, was normalized by the hepatic integral count. Subsequently, the adrenal percentage of relative uptake (UPT%) was computed.. Discriminant analysis was performed on the variables UPT%, adrenocorticotropic hormone (ACTH) serum concentration, and CT mass dimension (CTMD) to determine the variable, or combination thereof, best discriminating between the SC-CS and PC-CS groups. Compared with both ACTH and CTMD variables, univariate analysis confirmed the UPT% variable as the most significant to discriminate between these 2 clinical groups. In fact, UPT% alone correctly classified 8 of 9 patients in the SC-CS group and 20 of 22 patients in the PC-CS group with 95% positive and 80% negative predictive values and with overall accuracy, sensitivity, and specificity equal to 90%, 91%, and 89%, respectively. When all 3 variables were submitted to stepwise discriminant analysis, the derived classification matrix, after cross-validation, correctly classified 9 of 9 patients in the SC-CS group and 18 of 22 patients in the PC-CS group with 100% positive and 69% negative predictive values and with overall accuracy, sensitivity, and specificity equal to 87%, 82%, and 100%, respectively.. According to these initial results, use of the proposed semiquantitative approach associated with both laboratory screening for cortisol production and CTMD measure seems to be able to increase the clinical diagnostic accuracy of PC-CS. This approach could be used in the follow-up of adrenal mass function every time hormonal or clinical features are suggestive of adrenocortical hyperfunction.

Topics: 19-Iodocholesterol; Adrenal Cortex; Adrenal Gland Neoplasms; Adult; Aged; Cushing Syndrome; Diagnosis, Differential; Female; Humans; Male; Middle Aged; Radiopharmaceuticals; Reproducibility of Results; Sensitivity and Specificity; Tomography, Emission-Computed, Single-Photon

Topics: 19-Iodocholesterol; Adrenal Gland Neoplasms; Adrenocorticotropic Hormone; Asymptomatic Diseases; Cushing Syndrome; Dexamethasone; Female; Humans; Hydrocortisone; Incidental Findings; Iodine Radioisotopes; Middle Aged; Neoplasms, Multiple Primary; Radionuclide Imaging; Radiopharmaceuticals; Tomography, X-Ray Computed; Watchful Waiting

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

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

Thirty-three adrenal scintigrams in 30 patients were reviewed to determine the utility of this noninvasive imaging technique. It was found to be very accurate in distinguishing bilateral from unilateral hyperfunction in patients who have clinical and biochemical evidence of adrenal cortical hyperfunction. The technique proved correct in 12 of 12 cases of Cushing's syndrome and 14 of 19 cases of hyperaldosteronism. Specific clinical questions were also answered in three miscellaneous cases.

Topics: 19-Iodocholesterol; Adrenal Glands; Adult; Aged; Cushing Syndrome; Female; Humans; Hyperaldosteronism; Male; Middle Aged; Radionuclide Imaging

Topics: 19-Iodocholesterol; Adosterol; Adrenal Glands; Adult; Aged; Cholesterol; Cushing Syndrome; Evaluation Studies as Topic; Female; Humans; Hyperaldosteronism; Infant; Iodine Radioisotopes; Male; Middle Aged; Radionuclide Imaging; Sterols