SFEBES2023 Oral Communications Adrenal and Cardiovascular (6 abstracts)
1UCL, London, United Kingdom. 2UCLH, London, United Kingdom. 3Queen Mary University of London, London, United Kingdom
Background: Primary aldosteronism (PA) is the most common potentially curable cause of secondary hypertension and is a risk factor for cardiovascular morbidity and mortality. For patients with unilateral disease adrenalectomy can be curative. However, PA remains substantially underdiagnosed due the complex diagnostic pathway required to identify patients with unilateral disease, and the difficulties in accurate lateralization of the affected adrenal gland. Specific and selective imaging of aldosterone synthase with PET-CT could provide a non-invasive readout of aldosterone production from both adrenals and allow patients with suspected PA to be better stratified for surgery or medical intervention. To achieve this, we have developed [18F]AldoView the first highly selective aldosterone synthase PET tracer. Here we report the results of the first-in-human imaging with [18F]AldoView.
Methods: The PET ligand is a highly selective antagonist of aldosterone synthase with fluoride in its primary structure which enables labelling without structural modifications. [18F]AldoView was synthesized in accordance with Good Manufacturing Practice. Four patients (1F,3M) diagnosed with PA (RAA, saline infusion confirmatory test) with unilateral excessive aldosterone secretion confirmed by cross sectional imaging and Adrenal Venous Sampling were imaged with [18F]AldoView PET-CT prior to adrenalectomy.
Results: [18F]AldoView showed rapid clearance from background tissues and substantial uptake in the abnormal adrenal gland. The adrenal lateralisation index, measured as the SUVmax ratio between the two adrenals 35-45 min post-injection, was 6:1, 11:1, 4:1, and 7:1, suggesting it is markedly more selective relative to results reported with alternative PET tracers. Patients tolerated [18F]AldoView well and had no side effects.
Conclusion: PET/CT imaging with [18F]AldoView in this preliminary report of the first four patients has provided highly promising results and suggests that this highly selective tracer has potential to improve the stratification of patients with unilateral PA.