Evaluation of [18F]Fluoroethyl Triazole Labelled [Tyr3]-Octreotate Analogues for the Imaging of Neuroendocrine Tumours.

Standardised uptake value (SUV) is a semiquantitative measurement of radiotracer uptake in tissue. It is a ratio that compares the activity concentration in a specific region of interest to the activity concentration in the whole body. SUVmax is the highest value of the SUV measured within a region of interest.

Time frame: Baseline (on the scan day over 4 hours)

Population: The FETONET study was designed to have 3 parts. Part C comprised a prospective non-inferiority study, combining the \[18F\]FET-βAG-TOCA PET/CT data (collected at the optimal time point) for participants enrolled into Part A and Part B and compared this to standard of care \[68Ga\]Ga-DOTA-peptide PET/CT imaging. This trial design was a prospective decision for the purposes of efficiency. A total of 285 lesions were detected within the 45 patients analysed using this imaging modality.

Effective dose is an estimate of the overall risk of potential harm from exposure to ionising radiation. ED takes into account, the absorbed dose to all organs of the body, the relative harm level of the radiation and the sensitivities of each organ to radiation. ED may help in understanding the risk of potential long-term health effects from radiation exposure, such as the risk of developing cancer later in life. The unit of measure for ED is millisievert per megabecquerel (mSv/MBq), which refers to the effective dose (amount of radiation absorbed by the body) per unit of activity administered.

Time frame: Baseline (on the day of the scan over 4 hours)

Population: Effective dose (ED) of \[18F\]-FET-βAG-TOCA in patients with histologically confirmed NETs.

Mean residence time (MRT) was used to characterise the biodistribution of \[18F\]-FET-βAG-TOCA throughout the body. Mean residence time is a pharmacokinetic/uptake parameter that describes the average length of time a radiotracer resides within the body, or a particular organ, before being eliminated. Understanding MRT helps researchers to determine how long a radiotracer remains in the system, which is crucial for drug dosing, therapeutic efficacy, and potential toxicity assessment.

Time frame: Baseline (on day of scan over 4 hours)

Population: The number of participants analysed differ within certain rows (breasts, ovaries, uterus and testes due to the anatomical differences between the participant groups.

The \[18F\]FET-βAG-TOCA and \[68Ga\]Ga-DOTA-peptide PET/CT scans were reviewed by independent imaging experts to obtain an objective inter-reader lesion detection rate. To avoid recall bias, the \[18F\]FET-βAG-TOCA and \[68Ga\]Ga-DOTA-peptide PET/CT scans for each subject were reviewed at less 4 weeks apart in random order Percentage of agreement, also known as percent agreement, is a simple method to measure inter-rater reliability (IRR), calculating the proportion of times raters agree without considering chance. It's calculated by dividing the number of agreements by the total number of ratings and multiplying by 100

Time frame: [68Ga]Ga-DOTA-peptide PET/CT imaging assessed within 6 months of the [18F]-FET-βAG-TOCA PET/CT scan.

Population: The FETONET study was designed to have 3 parts. Part C comprised a prospective non-inferiority study. \[18F\]FET-βAG-TOCA PET/CT data for the patients enrolled into Parts A and B of the FETONET study (45 patients) were compared to standard of care \[68Ga\]Ga-DOTA-peptide PET/CT imaging. This trial design was a prospective decision for the purposes of efficiency. All PET/CT scans analysed within Part C were reviewed by independent imaging experts to determine an inter-reader lesion detection rate.

To determine the clinical utility of \[18F\]-FET-βAG-TOCA-PET/CT compared with standard of care \[68Ga\]Ga-DOTA-peptide imaging. Standardised uptake value (SUV) is a semiquantitative measurement of radiotracer uptake in tissue. It is a ratio that compares the activity concentration in a specific region of interest to the activity concentration in the whole body. SUVmax is the highest value of the SUV measured within a region of interest. The median SUVmax of \[18F\]-FET-βAG-TOCA and \[68Ga\]-DOTA-peptide per anatomic region were calculated to determine diagnostic efficacy. Diagnostic efficacy is the ability of a test to correctly identify a disease or condition when it's present and correctly identify the absence of a disease when it's not present.

Time frame: [68Ga]Ga-DOTA-peptide PET/CT imaging performed within 6 months of the [18F]-FET-βAG-TOCA PET/CT scan.

Population: The FETONET study was designed to have 3 parts. Part C comprised a prospective non-inferiority study. \[18F\]FET-βAG-TOCA PET/CT data collected for patients enrolled into Parts A and B of the FETONET study were combined and compared to \[68Ga\]Ga-DOTA-peptide PET/CT (standard of care) imaging. This trial design was a prospective decision for the purposes of efficiency. A total of 285 lesions (45 patients) were detected using \[18F\]-FET-βAG-TOCA \& \[68Ga\]Ga-DOTA-peptide PET/CT imaging.