First-in-human Evaluation of [18F]CETO

After receiving oral and written information about the study and its potential risks, all participants provided written informed consent. All participants underwent a screening visit 1-28 days before their [18F]CETO PET/CT. At the screening visit their medical history was obtained, including besides information of previous disease(s) and medication, also a clinical examination, WHO performance status, height, weight, pulse rate and blood pressure, blood chemistry and haematology.

Right before the PET/CT investigation a baseline assessment was performed including:

• A physical examination according to Modified Early Warning Score (MEWS)
• 12-lead electrocardiogram (ECG)
• Any concomitant medications was recorded
• Medical history - occurrence of any new symptoms and events since the screening visit
• Hematology (International Normalized Ratio (INR) in patients with antiocoagulant treatment).
• Pregnancy test in women.
• Assessment of injection site monitored by visual inspection (rash and phlebitis)

Participants received on average 0,76 mikrograms (range 0,1-1.37 mikrograms) of administered mass of CETO in conjunction to the PET/CT investigation.

Potential adverse events were monitored closely during, and after the administration of [18F]CETO, with access to emergency medicine resources.

Each participant remained for observation at least 3 hours after administration of [18F]CETO and the following assessments were performed:

• Blood withdrawn for additional post-scan chemical analysis.
• Assessment of injection site monitored by visual inspection (rash and phlebitis).
• MEWS

The ten first participants were evaluated for serious adverse events/adverse events (SAE/AEs) the day after (approximately 24 hours after) performing the [18F]CETO PET due to the short half-life of the radionuclide used, fluorine- 18 (T1/2= 109.5 min). Safety reporting was assessed by use of clinical Adverse Events and Common Toxicity Criteria (CTC), laboratory and non-laboratory toxicities.

Inclusion criteria

• Patients diagnosed with adrenal incidentalomas with an concurrent overproduction of aldosterone or cortisol or no concurrent hormone production, or patients diagnosed with adrenocortical carcinoma
• For healthy volunteers inclusion criteria included no known diseases, no ongoing medication and no known adrenal anomalies.

Exclusion criteria

for patients and healthy volunteers:

• pregnancy, age below 18, claustrophobia