Recruiting

PET Imaging with [18F]AlF-FAPI-74 and Hyoscine Butylbromide in Patients Suspected of Endometriosis

Verified siteRegistered drugNo placebo

Clinical Trials Concierge

Prefer not to search? Our Concierge searches the trials for you.

What is this trial about?

A plain-language summary of the goals, design and what participants do

endometriosis is a condition in which tissue similar to the lining of the uterus grows outside the uterus, often causing pain and fertility problems. In this study an experimental imaging substance called [18F]AlF-FAPI-74 is injected into a vein and a special whole‑body scan called PET/CT is performed. This scan creates detailed pictures that show areas where the abnormal tissue is active, helping doctors see the disease without surgery.

The purpose of the study is to find out whether this new scan can accurately identify deep or superficial endometriosis compared with the current standard method, which is a small‑incision surgical examination known as laparoscopy. Participants will have the injection and scan, and later will undergo the routine surgical procedure so the two sets of findings can be compared. Additional routine imaging tests such as MRI or ultrasound may also be done if they are already part of the patient’s care.

After the initial scan, participants may have a second scan if they start hormone‑blocking medication (often called a GnRH‑agonist or GnRH‑antagonist) to see how the disease changes. Throughout the study, safety is monitored and any side effects are recorded. The overall aim is to determine if this non‑invasive imaging approach can help doctors diagnose and manage endometriosis more effectively.

The research process

The trial runs in 7 steps – from screening to follow-up. Each step says what happens and what the team monitors.

Step 1
Initial visit and preparation
After joining the study, you will attend an initial visit where basic health information is recorded and the schedule for the imaging procedures is confirmed.
You will be informed that a short medication called buscopan will be given to help reduce movement of the intestines during the scan.
Step 2
Administration of background medication
On the day of the scan, a healthcare professional will inject buscopan at a dose of 20 mg (20 milligrams) directly into a vein (intravenous injection).
This single dose is given only once before the imaging test.
Step 3
Injection of imaging tracer
Immediately after the buscopan injection, you will receive an injection of the tracer [18f]alf-fapi-74 at a dose of 600 MBq (600 megabecquerels) through a vein.
The tracer is a radioactive substance that highlights areas of fibroblast activation protein, which are associated with endometriosis.
Step 4
Uptake period
After the tracer is injected, you will wait for a short period to allow the substance to travel through your body and bind to the target tissue.
The exact waiting time is determined by the imaging team and is required for optimal image quality.
Step 5
Pet/ct scan
You will then undergo a pet/ct examination, which combines a positron emission tomography (pet) scan and a computed tomography (ct) scan.
The scan creates detailed pictures of the pelvis to show where the tracer has accumulated, indicating possible endometriotic lesions.
Step 6
Laparoscopic comparison
Within a short time after the pet/ct scan, you will have a routine laparoscopic procedure, which is a minimally invasive surgery used to directly view the pelvic organs.
Findings from the laparoscopy are compared with the images from the pet/ct scan to assess the diagnostic performance of the tracer.
Step 7
Optional second scan for gnrh medication users
If you start treatment with a gnrh medication (a hormone therapy used for endometriosis), the study may include a second pet/ct scan after the medication has been initiated.
This second scan follows the same steps as the first scan (steps 2–5) and allows comparison of lesion number, tracer uptake, and other measurements before and after the hormone therapy.

Who can join the trial?

8 criteria

You must give a voluntary written permission (informed consent) to join the study.
You must be at least 18 years old when you sign the consent form.
You must be a woman who is being evaluated for endometriosis.
You must have a planned laparoscopy (a small‑incision surgery used to look inside the abdomen) to investigate suspected endometriosis.
For the deep infiltrating endometriosis (DE) group, you need either:
- A doctor who specializes in endometriosis finds deep nodules during a vaginal exam, or
- An ultrasound or MRI scan shows areas that look like deep infiltrating endometriosis.
- For the superficial peritoneal endometriosis (SPE) group, you need either:
  - Symptoms that a specialist thinks are typical of superficial endometriosis, such as painful periods, pain during sex, painful urination, painful bowel movements, unusual bleeding, shoulder pain, lung‑related pain that follows the cycle, fatigue, or difficulty getting pregnant, or
  - An ultrasound or MRI scan shows areas that look like superficial endometriosis.

Who cannot join the trial?

10 criteria

Had abdominal surgery (an operation on the belly area) within the past year.
Is pregnant, breast‑feeding, or could become pregnant and is not using a reliable birth‑control method.
Is mentally or legally unable to understand the study or cannot follow all required procedures.
Has any health problem that the doctor believes could put your safety at risk or affect the study results.
Is taking any medication or treatment that might affect safety or the accuracy of the study.
Is currently participating in another trial with an experimental medicine or device that is not compatible with this study.
Participated in another research study with a radiation dose greater than 1 mSv (a small measure of radiation) in the last 12 months.
Has a known hypersensitivity (allergy) to the imaging agent [18F]AlF‑FAPI‑74 or its ingredients.
Has ultrasound or MRI images showing lesions that look like ovarian endometriosis or deep infiltrating endometriosis.
Has clinical symptoms that suggest ovarian endometriosis or deep infiltrating endometriosis, as judged by an expert clinician.

Clinical Trials Concierge

Prefer not to search? Our Concierge searches the trials for you.

Tell us about your condition – we search every trial in Europe and connect you with the right site.

We usually reply within a few days

Verified sites

All sites with verified contact details – recruitment status may not be available; ask directly

Katholieke Universiteit te Leuven
Responsive
Leuven, Belgium

Trial locations

Where you can join this trial

Countries are shaded by recruitment status. Click a recruiting country to ask about joining there.

Recruiting

Not finding your country?

Not sure what to do next?

Joining a clinical trial can seem overwhelming. We guide you step by step, so you know exactly what to expect and how we support you through the process.

See the full process and FAQ

Investigated drugs

Buscopan
is a medication that contains hyoscine butylbromide. In this study it is given by injection into a vein. The drug works by relaxing smooth muscles in the gut, which can help reduce cramping and make the abdominal area easier to examine during imaging procedures. It is used in the trial as a background medication to improve comfort and image quality.
[AL[18F]F]FAPI-74
is a special imaging agent that contains a tiny amount of a radioactive material called fluorine‑18. It is injected into a vein before a PET/CT scan. The agent seeks out a protein called fibroblast activation protein, which is often found in endometriosis tissue. By lighting up these areas on the scan, doctors can see where endometriosis lesions are located without needing surgery. This tracer is the main test product being evaluated in the trial.

What is already known about the treatment

Buscopan 20 mg/1 ml solution for injection - It is given by a single intravenous injection as a clear liquid that is poured into a vein. Hyoscine butylbromide is an approved drug that has been used for many years to relieve smooth‑muscle cramps in the abdomen and urinary tract. It works by blocking muscarinic receptors, which stops the muscles from contracting too strongly. The medication belongs to the antispasmodic (anticholinergic) class of drugs. [AL[18F]F]FAPI-74 - This investigational agent is supplied as a sterile solution for intravenous injection and is used in a PET scan to highlight areas where fibroblast activation protein is present. It is not yet approved for routine clinical use but is being studied in research trials for imaging conditions such as endometriosis. The compound carries a radioactive fluorine‑18 atom that binds specifically to fibroblast activation protein, allowing the scanner to see active tissue. It is classified as a radiopharmaceutical PET tracer targeting fibroblast activation protein.

Investigated diseases

endometriosis - Endometriosis is a condition in which tissue that resembles the lining of the uterus grows on organs outside the uterus, such as the ovaries, pelvic lining, or bowel. This tissue continues to respond to the monthly hormonal cycle, swelling and bleeding each month. Over time the repeated bleeding can cause small pockets of blood to collect, leading to scar tissue and adhesions that may pull organs together. The lesions can become deeper and spread, often resulting in increasing pelvic discomfort, painful periods, and pain during intercourse. Symptoms may gradually intensify as more tissue is affected.