ADRENAL IMAGING WITH IODOMETHYL-NORCHOLESTEROL (I-131) IN PRIMARY ALDOSTERONISM

  • 1 January 1979
    • journal article
    • research article
    • Vol. 20  (1) , 7-10
Abstract
Patients (20) with primary aldosteronism (PAl) underwent dexamethasone suppression (DS) imaging with 6.beta.-[131I]-iodomethyl-19-norcholesterol (NP-59): to establish the value of the adrenal scan in distinguishing aldosteronomas from bilateral hyperplasia, to determine its ability to locate aldosteronomas when present and to compare the efficacy of NP-59 in this current series against that reported previously with NM-145 [19-[131I]-iodocholesterol] in PAl. Of 20 patients, 10 had an aldosteronoma, 5 had histologically confirmed hyperplasia and 5 had presumed hyperplasia. With NP-59, 9 of 10 tumors were correctly located (90%), correct distinction between tumor and hyperplasia was possible in 90% and a locating DS scan was specific for tumor in 90%. In a combined series of different patients with PAl imaged with NM-145, 21 of 25 tumors were correctly located (84%), tumor was distinguished from hyperplasia in 86% and the specificity of the localizing scan was 92%. The imaging delay required from tracer injection to attainment of an interpretable scan averaged 2.7 days with NP-59 and 4.8 days with NM-145. No significant differences were noted in the clinical results achieved with these 2 agents. The preferred agent is NP-59 since the study can be completed with less average time delay than is possible with NM-145.