By InvitationNot Applicable

Use of [18F]FET PET-MRI to Improve Detection of Pituitary Adenomas in Cushing's Disease

Netherlands, Switzerland43 participantsStarted 2025-10-22

Plain-language summary

In ACTH-dependent hypercortisolism it is important to distinguish between Cushing's disease (CD), with ACTH production by a pituitary neuroendocrine tumour (PitNET) and Cushing's syndrome (CS), with ectopic ACTH production. Bilateral inferior petrosal sinus sampling (IPSS) is the gold standard for this distinction, with a diagnostic accuracy of 98%. However, IPSS is an invasive procedure and an indi-rect diagnostic method, rarely providing reliable data on the exact location of the PitNET. This has a major impact on the therapeutic approach, short and long-term remission rates, and other outcomes. Hybrid Positron-emission tomography-Magnetic Resonance Imaging (PET-MRI) using O-(2-\[18F\]-fluo-roethyl)-L-tyrosine (\[18F\]FET) is promising in this respect. Recent data published by our research group demonstrate a a sensitivity of 100% a high accuracy in in the precise localization of ACTH-secreting PitNETs. We hypothesize that \[18F\]FET PET-MRI could become the new non-invasive diagnostic stand-ard, but data regarding a direct comparison between the diagnostic impact of \[18F\]FET PET-MRI versus IPSS in the differentiation between CD and ectopic CS are lacking. In addition, there are currently no other reliable biomarkers to distinguish the two disorders. The investigators hypothesize that the ACTH-dependent biomarker copeptin could be a valuable addition in this regard. The aim of this prospective diagnostic study is to compare the diagnostic accuracy of \[18F\]FET-PET-MRI and IPSS in differentiating CD from ectopic CS in patients with ACTH-dependent hypercortisolism.

Who can participate

Age range

18 Years

Sex

ALL

See this in plain English?

AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.

Inclusion Criteria: * Age ≥18 years * Biochemically confirmed ACTH-dependent hypercortisolism, defined as: * Non-suppressed ACTH levels plus minimal 2 of the following: * Overnight 1mg dexamethasone suppression test \> 50 nmol/L * Elevated late night salivary cortisol (min. 2/3 measurements) * Elevated 24-hours urinary free cortisol (min. 2 measurements) * Pituitary microadenoma (\< 10mm) OR negative / inconclusive findings on standard MRI of the pituitary sella-region. * Indication for further evaluation with IPSS Exclusion Criteria: * Non-ACTH dependent hypercortisolism * Pituitary macroadenoma (≥ 10mm) * Suspicion of Pseudo-Cushing's disease (e.g. due to alcohol use disorder, PCO's, obesity, de-pression) according to standard work up / guidelines * use of glucocorticosteroids * Impaired renal function, defined as eGFR (MDRD) \<30ml/min/1,73 m2. An exception can be made in consultation with the treating physician. * Impaired Liver function * Pregnancy/breastfeeding. For the latter, temporary discontinuation may be considered. * Known allergic reaction to therapeutic radiopharmaceuticals.

Questions worth asking your doctor

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1Based on my diagnosis and history, is this trial worth exploring for me — or is there a standard treatment we should try first?
2What does this trial's phase tell us about how much is already known about its safety and benefit?
3What would taking part actually involve for me — visits, tests, time, and travel?
4What are the known and possible risks or side effects I should weigh, and how would they be monitored?
5If this trial isn't the right fit, what other options or trials would you suggest I look into?

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Questions for the trial coordinator

The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.

1What does taking part actually involve week to week — how many visits, where, and how long does each one take?
2What costs are covered by the study, and what might I have to pay for myself, including travel, parking, or time off work?
3What happens during screening, and what happens if the study team confirms I don't meet the criteria after those tests?
4Who pays for the scans, blood work, and other tests the trial requires — the study, my insurance, or me?
5How will being in the trial affect my regular care, and will my own doctor stay informed and involved?
6Can I leave the trial at any point if I change my mind, and what would happen to my care if I do?

A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.

What they're measuring

Comparison of the proportion of correct distinctions between CD and ectopic CS in patients with ACTH-dependent hypercortisolism using [18F]FET PET-MRI versus IPSS

Timeframe: Patients will receive standard surgical or radiotherapeutic treatment. The study will collect follow-up data 3-6 months post-treatment without influencing clinical management or requiring study-specific visits.

Trial details

NCT IDNCT07108244

SponsorUniversity Hospital, Basel, Switzerland

Sponsor typeOTHER

Study typeINTERVENTIONAL

Primary completion2029-07-30

View on ClinicalTrials.gov More Cushing Disease trials