¹³¹I-6β-Iodomethyl-19-Norcholesterol SPECT/CT for Primary Aldosteronism Patients with Inconclusive Adrenal Venous Sampling and CT Results

Abstract

The 2 main causes of primary aldosteronism (PA) are aldosteroneproducing adenoma (APA) and idiopathic adrenal hyperplasia (IAH). Dexamethasone-suppression 131 I-6b-iodomethyl-19-norcholesterol (NP-59) adrenal scintigraphy can assess the functioning of the adrenal cortex. This study evaluated the diagnostic usefulness of NP-59 SPECT/CT in differentiating APA from IAH and in predicting postadrenalectomy clinical outcome for PA patients who had inconclusive adrenal venous sampling (AVS) and CT results. Methods: We retrospectively reviewed the 31 adrenal lesions of 27 patients (age range, 33-71 y; mean age 6 SD, 50.4 6 10.9 y) who had been clinically confirmed (by saline infusion and captopril tests) to have PA, had inconclusive CT and AVS test results, and had undergone NP-59 imaging before adrenalectomy. The accuracy of NP-59 imaging was determined by comparison with histopathologic findings. Results: NP-59 SPECT/ CT gave us 18 true-positive, 3 false-positive, 6 true-negative, and 4 false-negative results. Compared with planar imaging, SPECT/CT significantly improved diagnostic accuracy and prognostic predicting ability (P 5 0.0390 and P 5 0.0141, respectively). The NP-59 results were negative for 7 of the 23 patients with unilateral adrenal lesions, and none of these 7 patients had shown postsurgical clinical improvement. Conclusion: NP-59 SPECT/CT is an effective imaging tool for differentiating APA from IAH in PA patients whose CT and AVS results are inconclusive. Our results suggest that patients with presurgically negative NP-59 results should be treated medically and that noninvasive NP-59 SPECT/CT may be suited for use as the first lateralization modality after CT in patients with clinically confirmed PA.

Aldosterone Induces Tissue Inhibitor of Metalloproteinases-1 Expression and Further Contributes to Collagen Accumulation

“…The following criteria were used to diagnose PA: (1) aldosterone/ renin ratio >35 or urine aldosterone amount ≥12 μg/24 hours and a TAIPAI score of >60%, and postsaline loading plasma aldosterone concentration >10 ng/dL (the TAIPAI score was developed from our database using age, sex, plasma renin activity, body mass index, serum potassium, and estimated glomerular filtration rate to identify the patients with an area under a receiver operating characteristic curve of 0.904), 21 and (2) lateralization of aldosterone secretion at adrenal venous sampling or during dexamethasone suppression NP-59 single-photon emission computerized tomography/computerized tomography, 22 or (3) adenoma on a computerized tomographic scan.…”

Myelolipomatous Adrenal Adenoma and Adrenal Scintigraphy: A Case Presentation and Review of Literature

“…The technique is particularly suited if adrenal vein sampling (AVS) is inconclusive [7]. In a most recent retrospective chart review done at a single center, it was seen that adrenal cortical scintigraphy positivity was highly predictive in determining the outcome of subclinical Cushing's [8].…”

“…Adrenal scintigraphy with NP-59 (with concomitant SPECT/CT) is an imaging technique that can help in distinguishing between aldosterone-producing adenoma (APA) and idiopathic adrenal hyperplasia (IAH) [7]. The technique is particularly suited if adrenal vein sampling (AVS) is inconclusive [7].…”

A patient with concurrent primary aldosteronism and Page kidney

“…One year later, persistent hypertension in this age and blood pressure higher than 140/90 mmHg even on three anti-hypertensive medications including calcium channel blockers, alpha blockers, and ACE inhibitors raised the suspicion of PA. Though the screening ARR was high to 84 ng/dl per ng/ml/h (ARR cut-off is [35 in TAI-PAI database [2,5]) and the confirmatory test via captopril suppression unveiled suspicious PA (PAC 12.1 ng/dl), the subtype differentiating test by NP-59 SPECT/CT was negative. Hypertension could be only confidently attributed to Page phenomenon.…”

“…Primary aldosteronism (PA), characterized by hypertension, hypokalemia, low renin status and unsuppressed aldosterone secretion from the adrenal glands, has been increasingly recognized after the ratio of aldosterone-torenin (ARR) has been adopted as the first-line screening tool [1,2]. Besides, in recent published data, the overall prevalence of PA has reached 11.2% among newly diagnosed hypertensive patients in referred tertiary centers and has turned to be the most prevalent secondary hypertension [1,3].…”