IDEAL
Research type
Research Study
Full title
Image-Derived Enzymatic Adrenal Lateralisation of Primary Hyperaldosteronism (IDEAL)
IRAS ID
274695
Contact name
Robert Shortman
Contact email
Sponsor organisation
Joint Research Office of University College London & University College London Hospitals NHS FT
ISRCTN Number
ISRCTN58338025
Duration of Study in the UK
1 years, 11 months, 31 days
Research summary
Research Summary:
One of the most common causes of high blood pressure is primary hyperaldosteronism (PHA), a hormonal disorder that leads to overproduction of a hormone called aldosterone. Aldosterone usually balances sodium and potassium in the blood, however when too much of this hormone is produced more potassium is lost but the body retains the sodium. This imbalance can cause your body to hold too much water which in turn leads to a greater volume of blood and ultimately increased blood pressure.
One of the causes of PHA is a non-cancerous tumour that grows on the gland that produces aldosterone In these cases surgery to remove theses glands can substantially reduce blood pressure and medication requirements and may result in a complete cure (30-60% of cases).
Currently, methods of diagnosis for this tumour are inefficient and often inconclusive; screening, such as CT scans and adrenal vein sampling (AVS) is used. AVS is challenging, invasive, has a poor success rate and is often not feasible as it requires patients with high blood pressure to stop medication for several weeks.
We have developed a molecule that will target an enzyme which acts as the main regulator of aldosterone secretion. It is labelled with a radioactive substance that Is regularly used in PET scanning. Patients with increased levels of this enzyme from the adrenal glands should absorb more of the molecule. As the molecule is radioactive, this will be detected by a Positron Emission Tomography/Computed Tomography (PET/CT) scanner and can be viewed by a radiologist.
We have trialled this in animals and found that the radiolabelled substance does target expression of the correct enzyme and can be given in quantities that should not be harmful to humans.
We would like to use this tracer in patients that have an aldosterone producing tumour, to illustrate this effect in humans, and as the patients will go on to have surgery we can examine the adrenal tissue that has been removed to confirm that enzyme expression is related to uptake of the tracer.Lay summary of study results:
Image-Derived Enzymatic Adrenal Lateralisation of Primary Hyperaldosteronism (IDEAL) - Testing a Medical Scan with a New Dye to Detect Abnormal Hormone Production in the Adrenal Glands What was the study about?
Some people develop high blood pressure because they produce too much of a hormone called aldosterone, which is made in the adrenal glands. In many of these cases, only one of the two adrenal glands overproduces aldosterone. If doctors can identify which adrenal gland is affected, they can often cure the condition by removing it.
This study tested a medical scan known as PET/CT using a new dye called [18F]AldoView. The aim was to determine whether this scan could accurately detect adrenal glands that overproduce aldosterone and help decide which gland should be removed.
What did we do?
We scanned 17 patients who were scheduled to have surgery to remove one of their adrenal glands because they produced too much aldosterone. Study participants were given an injection of [18F]AldoView and then underwent a PET/CT scan to see where the dye accumulated in the body. This helped identify which adrenal glands that overproduced aldosterone.
We also examined the tissue from the surgically removed adrenal glands under a microscope and compared the findings with the scan images. Patients were followed up after surgery to monitor changes in their blood pressure and aldosterone levels.
What did we find?
- The scan was safe, with no side effects from the [18F]AldoView dye.
- It clearly showed which adrenal glands that were overproducing aldosterone.
- We found that the best time to take the scan was about 35–45 minutes after administration of the dye.
- The scan results closely matched those of adrenal vein sampling (AVS), a test already used in hospitals, but the scan was less invasive, is much quicker, and potentially easier to use.
- The scan results also aligned with laboratory tests on the removed adrenal glands, confirming the accuracy of the PET/CT scan with the [18F]AldoView dye.Why is this important?
This new scan could help doctors quickly and safely identify which adrenal gland is causing the problem. It may allow more patients to receive the correct surgery and reduce their need for blood pressure medication. Additionally, the scan has the potential to be more comfortable and accessible than current diagnostic tests.
What happens next?
We now plan to conduct a larger trial to confirm these findings and further investigate how the scan can help predict patient outcomes after surgery.REC name
London - Brent Research Ethics Committee
REC reference
21/LO/0521
Date of REC Opinion
2 Oct 2021
REC opinion
Further Information Favourable Opinion