EndometriosisEM-FAPINCT07876648
Prospective Trial of [18F]AlF-FAPI-74 for PET Imaging of Fibroblast Activation Protein in Patients With Endometriosis
A study testing [18F]AlF-FAPI-74 PET/CT in people with Endometriosis and Deep Infiltrating Endometriosis, run by Universitaire Ziekenhuizen KU Leuven at 1 site in Belgium.
Trial summary
The goal of this clinical trial is to learn whether [18F]AlF-FAPI-74 PET/CT can help detect endometriosis in adult women who are already scheduled for laparoscopy due to suspicion of deep infiltrating endometriosis or superficial peritoneal endometriosis. Read more about this study
- Who is it for?
- Ages 18 to 64 years, women only
- Conditions the study is for
- Endometriosis, Deep Infiltrating Endometriosis, Women
- What is being tested?
- [18F]AlF-FAPI-74 PET/CT
- Type of treatment
- Pill or oral medicine, Injection or infusion
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 64 participants
- Where
- 1 siteBelgium
- Study dates
- 30 Sep 2026to 31 Aug 2029
- Phase
- Interventional
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 64 years
- Women only
- No healthy volunteers
- Adult
Who may be able to join
- Voluntary written informed consent of the participant has been obtained prior to any screening procedures.
- At least 18 years of age at the time of signing the Informed Consent Form (ICF).
- At least one of the following to be eligible for the DE cohort: (i) Clinical suspicion of DE, defined as the presence of deep nodule(s) during vaginal examination determined by a clinician who is an expert in endometriosis. (ii) Diagnostic suspicion of DE, defined as an ultrasound and/or MRI that shows lesions suspicious for DE.
- At least one of the following to be eligible for the SPE cohort: (i) Clinical suspicion of SPE, defined as clinical symptoms suspicious of SPE determined by a clinician who is an expert in endometriosis. These clinical symptoms include dysmenorrhea, deep dyspareunia, dysuria, dyschezia, painful rectal bleeding or haematuria, shoulder tip pain, catamenial pneumothorax, cyclical cough/haemoptysis/chest pain, cyclical scar swelling and pain, fatigue, and infertility. (ii) Diagnostic suspicion of SPE, defined as an ultrasound and/or MRI that shows lesions suspicious for SPE.
- Planned laparoscopy for suspected endometriosis.
Who cannot join
- For SPE cohort: (i) Ultrasound and/or MRI with lesions suspicious of ovarian endometriosis and/or DE. (ii) Clinical symptoms suspicious of ovarian endometriosis and/or DE, determined by a clinician who is an expert in endometriosis.
- Prior abdominal surgery less than one year ago.
- Female who is pregnant, breastfeeding or is of childbearing potential and not using an adequate, highly effective contraceptive or no usage of contraception when sexually active are not accepted.
- Participant is mentally or legally incapacitated, does not understand the study design or is not willing or capable to undergo all study-specific procedures.
- Any disorder or condition, which in the Investigator's opinion might jeopardise the participant's safety or compliance with the protocol, or may influence the result of the study.
- Any prior or concomitant treatment(s) that might jeopardise the participant's safety or that would compromise the integrity of the Trial.
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- Participation in an interventional Trial with an investigational medicinal product (IMP) or device when the trial designs are not considered compatible by the study team.
- Participation in a clinical scientific study in the last 12 months with a radiation exposure caused by the experimental procedures greater than 1 mSv.
- Participant has a known hypersensitivity to [18F]AlF-FAPI-74 or the used excipients.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Elena Lara Jimenez contact
Belgium1 site, 1 recruiting
- Recruiting
UZ Leuven
Leuven, 3000
Niloefar Ahmadi Bidakhvidi, +3216343715, niloefar.ahmadibidakhvidi@uzleuven.be
About this study
The goal of this clinical trial is to learn whether [18F]AlF-FAPI-74 PET/CT can help detect endometriosis in adult women who are already scheduled for laparoscopy due to suspicion of deep infiltrating endometriosis or superficial peritoneal endometriosis. The main aims are: (i) How well does [18F]AlF-FAPI-74 PET/CT identify endometriosis lesions compared with findings during laparoscopy? (ii) Can PET/CT identify additional lesions that may not be seen on ultrasound or MRI? (iii) Can ultra-high-resolution NeuroEXPLORER PET/CT improve the detection of small lesions compared with standard PET/CT? Participants will: (i) Receive an intravenous injection of [18F]AlF-FAPI-74 followed by a PET/CT scan before their planned laparoscopy. (ii) Undergo their planned laparoscopy, during which PET findings will be compared with the surgical findings and where tissue is removed with laboratory analysis. (iii) Optionally undergo an additional NeuroEXPLORER PET/CT scan after the same tracer injection. (iv) Optionally undergo a second [18F]AlF-FAPI-74 PET/CT if participants started gonadotropin-releasing hormone (GnRH) treatment after their first scan to investigate whether tracer uptake in endometriosis lesions changes during treatment.
- Conditions
- Endometriosis, Deep Infiltrating Endometriosis, Women, Superficial Peritoneal Endometriosis, Fibrosis
- Being tested
- [18F]AlF-FAPI-74 PET/CT
- Keywords
- [18F]AlF-FAPI-74 PET/CT, FAPI PET, Endometriosis, Superficial Peritoneal Endometriosis, Deep Infiltrating Endometriosis, Fibroblast Activation Protein, Fibroblast Activation Protein Inhibitor, Positron emission tomography, PET, Nuclear imaging, Prospective, [18F]-FAPI-74, NeuroEXPLORER
- Medical subject headings
- Endometriosis, Fibrosis
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
[18F]AlF-FAPI-74 PET/CTDiagnostic test
A [18F]AlF-FAPI-74 PET/CT will be performed at UZ Leuven before the participant's planned laparoscopy. Participants are required to fast for 4 hours before tracer administration but water is allowed. An intravenous line will be placed and [18F]AlF-FAPI-74 will be administered in one bolus (3.5 MBq/kg). PET/CT acquisition will start after 60 minutes. The CT will be a low dose CT with oral contrast. If there are no contraindications, 20 mg Buscopan may be administered shortly before imaging to reduce bowel movement.
Participants may optionally undergo an additional NeuroEXPLORER PET/CT scan on the same day after the same [18F]AlF-FAPI-74 administration, so no second tracer injection is required. Participants who start treatment with a GnRH (ant)agonist after their first scan may undergo a second [18F]AlF-FAPI-74 PET/CT to investigate changes in tracer uptake during hormonal treatment. Participants will be monitored for adverse events related to study procedures.
[18F]AlF-FAPI-74 PET/CTDiagnostic test
A [18F]AlF-FAPI-74 PET/CT will be performed at UZ Leuven before the participant's planned laparoscopy. Participants are required to fast for 4 hours before tracer administration but water is allowed. An intravenous line will be placed and [18F]AlF-FAPI-74 will be administered in one bolus (3.5 MBq/kg). PET/CT acquisition will start after 60 minutes. The CT will be a low dose CT with oral contrast. If there are no contraindications, 20 mg Buscopan may be administered shortly before imaging to reduce bowel movement.
Participants may optionally undergo an additional NeuroEXPLORER PET/CT scan on the same day after the same [18F]AlF-FAPI-74 administration, so no second tracer injection is required. Participants will be monitored for adverse events related to study procedures.
| Study group | Role | What they receive |
|---|---|---|
| Deep infiltrating endometriosis (DE) | Experimental | Not described Receives: Diagnostic Test: [18F]AlF-FAPI-74 PET/CT |
| Superficial peritoneal endometriosis (SPE) | Experimental | Not described Receives: Diagnostic Test: [18F]AlF-FAPI-74 PET/CT |
What is being measured
The primary outcome is the main question the study is designed to answer.
Evaluate diagnostic performance of [18F]AlF-FAPI-74 PET/CT as a non-invasive tool to diagnose deep infiltrating endometriosis and/or superficial peritoneal endometriosis, in comparison with laparoscopic findings in women with suspected endometriosis
Correlating the locations of endometriotic lesions on [18F]AlF-FAPI-74 PET/CT and the locations of endometriotic lesions detected during laparoscopy.
Measured: From enrollment until laparoscopy (up to 1 month after the last [18F]AlF-FAPI-74 PET/CT)
Frequency of serious adverse device effects (SADEs) related to NeuroEXPLORER PET/CT
The number of participants experiencing one or more serious adverse device effects (SADEs) during NeuroEXPLORER PET/CT will be recorded.
Measured: From enrollment until laparoscopy (up to 1 month after the last NeuroEXPLORER PET/CT)
Secondary outcomes (15)
Sensitivity, specificity, positive and negative predictive value and accuracy of [18F]AlF-FAPI-74 PET/CT for detecting endometriosis
Sensitivity, specificity, positive predictive value, negative predictive value, accuracy of [18F]AlF-FAPI-74 PET/CT in detecting endometriotic lesions using laparoscopic findings as the reference standard.
Measured: From enrollment until laparoscopy (up to 1 month after the last [18F]AlF-FAPI-74 PET/CT)
Semi-quantitative uptake measurements
Semi-quantitative uptake measurements (maximal standardized uptake value (SUVmax), average SUV (SUVmean), peak SUV (SUVpeak) of endometriotic lesions on [18F]AlF-FAPI-74 PET/CT.
Measured: From enrollment until laparoscopy (up to 1 month after the last [18F]AlF-FAPI-74 PET/CT)
Lesion-to-background uptake values
Endometriotic lesion-to-background uptake values (SUV lesion divided by SUV background) for [18F]AlF-FAPI-74 PET/CT, using following background organs: liver, lung, gluteus muscle, mediastinal bloodpool, bowel, bone marrow (L4 if no abnormal uptake).
Measured: From enrollment until laparoscopy (up to 1 month after the last [18F]AlF-FAPI-74 PET/CT)
FAP-positive endometriotic burden
Total FAP-positive endometriotic burden, defined as the sum of the volumes of all lesions deemed to be endometriotic in nature.
Measured: From enrollment until laparoscopy (up to 1 month after the last [18F]AlF-FAPI-74 PET/CT)
Additional lesions after unblinding
Number of additional endometriotic lesions recorded after unblinding of the surgeon during laparoscopy.
Measured: From enrollment until laparoscopy (up to 1 month after the last [18F]AlF-FAPI-74 PET/CT)
Sensitivity, specificity, positive predictive value, negative predictive value and accuracy of MRI for detecting endometriosis
Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of MRI in detecting endometriotic lesions, in patients in which MRI is available, and comparison with [18F]AlF-FAPI-74 PET/CT, laparoscopy and if available ultrasound.
Measured: From enrollment until laparoscopy (up to 1 month after the last [18F]AlF-FAPI-74 PET/CT)
Sensitivity, specificity, positive predictive value, negative predictive value and accuracy of ultrasound for detecting endometriosis
Sensitivity, specificity, positive predictive value, negative predictive value and accuracy of ultrasound in detecting endometriotic lesions, in patients in which ultrasound is available, and comparison with [ 18F]AlF-FAPI-74 PET/CT, laparoscopy and if available MRI.
Measured: From enrollment until laparoscopy (up to 1 month after the last [18F]AlF-FAPI-74 PET/CT)
Number of participants with a change in clinical management following review of [18F]AlF-FAPI-74 PET/CT findings
The number and proportion of participants with a change in planned clinical management attributable to the [18F]AlF-FAPI-74 PET/CT findings, as documented by the treating clinical team, will be recorded. The type of management change will also be documented.
Measured: From enrollment until laparoscopy (up to 1 month after the last [18F]AlF-FAPI-74 PET/CT)
Patient-reported responses to a study-specific questionnaire on the psychological impact of [18F]AlF-FAPI-74 PET/CT
Psychological impact of the [18F]AlF-FAPI-74 PET/CT procedure will be assessed using a study-specific questionnaire completed before and after the scan procedure. The questionnaire evaluates e.g. anxiety, concerns about the procedure, discomfort, or personnel. Responses will be scored according to the predefined questionnaire scoring system.
Measured: From enrollment until laparoscopy (up to 1 month after the last [18F]AlF-FAPI-74 PET/CT)
Intra- and interreader agreement for detection and localization of endometriosis lesions on [18F]AlF-FAPI-74 PET/CT
Two PET readers will independently identify and localize suspicious endometriosis lesions on [18F]AlF-FAPI-74 PET/CT. Intra- and interobserver agreement will be determined using the GWET agreement coefficient (AC) or intraclass correlation coefficients (ICC).
Measured: From enrollment until laparoscopy (up to 1 month after the last [18F]AlF-FAPI-74 PET/CT)
Adverse events
Adverse events associated with [18F]AlF-FAPI-74 PET/CT.
Measured: From tracer administration until 30 days after tracer administration
FAP IHC correlation
Correlation of [18F]AlF-FAPI-74 biodistribution with FAP tissue expression as measured by immunohistochemistry (IHC).
Measured: From enrollment until laparoscopy (up to 1 month after the last [18F]AlF-FAPI-74 PET/CT)
Change in [18F]AlF-FAPI-74 PET/CT findings after initiation of GnRH therapy
Evolution of [18F]AlF-FAPI-74 PET/CT scans in patients initiating GnRH-agonist or GnRH-antagonist medication and receiving 2 [18F]AlF-FAPI-74 PET/CT (prior and post initiation of GnRH-agonist or GnRH-antagonist medication): (i) number of lesion; (ii) uptake; (iii) endometriotic lesion-to-background value; (iv) correlation with laparoscopy and if available MRI and/or ultrasound.
Measured: From enrollment until laparoscopy (up to 1 month after the last [18F]AlF-FAPI-74 PET/CT)
Frequency of adverse device effects (ADEs) associated with NeuroEXPLORER PET/CT
The number of participants experiencing one or more adverse device effects (ADEs) during NeuroEXPLORER PET/CT will be recorded.
Measured: From enrollment until laparoscopy (up to 1 month after the last NeuroEXPLORER PET/CT)
Patient Reported Outcome Measures (PROM) to capture the perspective and satisfaction of the NeuroEXPLORER PET/CT
Patient Reported Outcome Measures (PROM) to capture the perspective and satisfaction of the NeuroEXPLORER PET/CT. This will be scored on a 0-10 Likert scale on the dimensions of "Investigation smoothness", "satisfaction with the scanning procedure" and "comfortable positioning during the examination".
Measured: From enrollment until laparoscopy (up to 1 month after the last NeuroEXPLORER PET/CT)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted15 Oct 2026
- Study start30 Sep 2026
- Primary completion31 Aug 2029 (estimated)
- Study completion31 Aug 2029 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for EndometriosisStudies of the same condition, open and under way.
- More trials run by Universitaire Ziekenhuizen KU LeuvenThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Diagnosis
- Allocation
- Non-randomised
- Intervention model
- Single group
- Model description
- Prospective, non-randomized, single center, multi-cohort, interventional phase II trial. The two cohorts include: deep infiltrating endometriosis (DE) and superficial peritoneal endometriosis (SPE).
- Masking
- None (open label)
- Enrolment
- 64 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Universitaire Ziekenhuizen KU Leuven
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Niloefar Ahmadi Bidakhvidi, Universitaire Ziekenhuizen KU Leuven
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07876648
- Sponsor's protocol ID
- S71544
- Other IDs
- 2026-525272-25-00, EUDAMED_CIV-25-06-053398
- Acronym
- EM-FAPI
- Status last verified
- Oct 2026
- First submitted
- 24 Sep 2026
- Last updated
- 19 Oct 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No