Imaging of Endometriosis With Total-body PET-CT (PET-Endo)

NCT07523997 | Not Yet Recruiting

• 4 other identifiers: AC24225MRC/IAA/017UKRI3897EPD/24/19
• Study Type: observational
• Target: 30
• Locations: 1 country
• Sites: 1

Brief Summary

Endometriosis is a disease that affects 1 in 10 women and is associated with debilitating pain and infertility. Endometriosis is where cells similar to those lining the womb (the 'endometrium') grow elsewhere in the body, forming 'lesions'. Most commonly the lesions grow on the lining of the pelvic cavity, called 'peritoneal' endometriosis. Lesions can also grow on the ovary, this is called 'ovarian' endometriosis, or form nodules, called 'deep' endometriosis. At present the only way to confidently identify endometriosis is through surgery, this exposes patient to the risks of surgery and contributes to the diagnostic delay associated with endometriosis. PET/CT is a specialist scan that is commonly used to identify cancers which cannot be seen on other types of scans. PET/CT uses a 'tracer', a substance given into a vein which then temporarily accumulates in areas of disease. This project will determine if a new specialist scan, total body PET/CT, and novel tracers that were developed for other conditions can be used to identify some of the key pathways in endometriosis: bleeding and scarring. Being able to identify these processes in endometriosis lesions and being able to track how they change over time would improve our understanding of endometriosis. The investigators also want to know if these pathways are different between superficial, deep and ovarian endometriosis, and what the impact is of the hormones related to the menstrual cycle. In this study up to 30 people who have suspected endometriosis and are already due to undergo diagnostic surgery will be asked to undergo two total-body PET/CT scans in Edinburgh, one at one visit and one another visit. Participants will also have a PET/MRI scan at visit. Participants will have a different tracer at each visit. The investigators will then compare the scan findings with their subsequent surgical findings.

Conditions

Endometriosis

Keywords

Endometriosis; PET-CT; PET-MRI

Outcome Measures

Primary Outcomes (1)

• In vivo uptake of 18F-GP1 and 68Ga-FAPI in endometriosis

  Tracer uptake will be quantified by determining standardized uptake values (SUVs) and tissue to background ratio (TBR) in areas of increased uptake within the abdomen. This will correlated with surgical findings, specifically presence and location of endometriosis lesions.

  within 3 months post surgery

Secondary Outcomes (2)

• Non-invasive in vivo imaging-based characterisation of thrombosis and fibrosis characterisation in superficial, ovarian and deep endometriosis lesions

  within 3 months post surgery

• Acceptability of PET imaging for characterisation of endometriosis

  within 3 months post surgery

Study Arms (1)

Suspected endometriosis

Women/those assigned female at birth (aged ≥18 years) with chronic pelvic pain and a clinical/radiological diagnosis of likely endometriosis and due to undergo confirmatory laparoscopy in the subsequent four months.

Diagnostic Test: PET/CT; Diagnostic Test: PET/MRI; Drug: Buscopan 20 MG/ML Injectable Solution

Interventions

PET/CT DIAGNOSTIC_TEST

Hybrid positron emission tomography and computed tomography will be performed after intravenous administration of the 68Ga-FAPI or the 18F-GP1 radiotracer and images centred on the pelvis. Attenuation-correction CT will be performed before acquisition of PET data

Suspected endometriosis

PET/MRI DIAGNOSTIC_TEST

Hybrid PET/MRI will be performed on a 3T scanner with T1 mapping immediately after the PET/CT with images acquired centred on the pelvis after injection of buscopan

Suspected endometriosis

Buscopan 20 MG/ML Injectable Solution DRUG

IV injection prior to PET/MRI

Also known as: 20mg

Suspected endometriosis

Eligibility Criteria

• Age: 18 Years - 60 Years
• Sex: female
• Healthy Volunteers: No
• Age Groups: Adult (18-64)
• Sampling Method: Non-Probability Sample

Study Population

30 patients in NHS Lothian with clinically diagnosed endometriosis due to undergo confirmatory laparoscopy in the subsequent four months will be recruited. All subjects recruited for the study will be able to withdraw from the study at any time. The patients will be referred to the study by their treating physicians to investigate clinically diagnosed endometriosis. We will not recruit or enroll healthy volunteers in this study.

You may qualify if:

• Chronic pelvic pain
• Clinical/radiological diagnosis of likely endometriosis and due to undergo confirmatory laparoscopy in the subsequent four months

You may not qualify if:

• Inability or unwilling to give informed consent
• Actively trying to conceive, pregnant or breastfeeding
• Post menopausal (no periods for \>12 months and not taking hormonal treatments to prevent periods or bilateral oophorectomy performed)
• Previous hysterectomy
• Confirmed or suspected pelvic malignancy
• Contraindication to MRI (ferromagnetic material in the body, metallic device implantation or claustrophobia)
• Contraindication to buscopan (e.g. glaucoma, unstable cardiac disease, arrythmias, myasthenia, previous hypersensitivity to buscopan)
• Taking part in a CTIMP or interventional non-CTIMP study
• Previous severe pelvic inflammatory disease
• Previous peritonitis

Sponsors & Collaborators

• Life Molecular Imaging Ltd: collaborator
• University of Edinburgh: lead

Study Sites (1)

Centre for Reproductive Health, Institute for Regeneration and Repair, University of Edinburgh

Edinburgh, City of Edinburgh, EH16 4UU, United Kingdom

Location

MeSH Terms

Conditions

Endometriosis

Interventions

Positron Emission Tomography Computed Tomography; Butylscopolammonium Bromide

Condition Hierarchy (Ancestors)

Genital Diseases, Female; Female Urogenital Diseases; Female Urogenital Diseases and Pregnancy Complications; Urogenital Diseases; Genital Diseases

Intervention Hierarchy (Ancestors)

Positron-Emission Tomography; Tomography, Emission-Computed; Image Interpretation, Computer-Assisted; Diagnostic Imaging; Diagnostic Techniques and Procedures; Diagnosis; Tomography, X-Ray Computed; Multimodal Imaging; Radiographic Image Enhancement; Image Enhancement; Photography; Radiography; Tomography, X-Ray; Radionuclide Imaging; Tomography; Diagnostic Techniques, Radioisotope; Quaternary Ammonium Compounds; Amines; Organic Chemicals; Scopolamine Derivatives; Tropanes; Azabicyclo Compounds; Aza Compounds; Alkaloids; Heterocyclic Compounds; Bridged Bicyclo Compounds, Heterocyclic; Heterocyclic Compounds, Bridged-Ring

Study Officials

• Lucy HR Whitaker, MD

  University of Edinburgh

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Lucy HR Whitaker, MD

CONTACT

01316518321; ETMT@ed.ac.uk

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: PROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: April 2, 2026
• First Posted: April 13, 2026
• Study Start: April 1, 2026
• Primary Completion (Estimated): April 1, 2027
• Study Completion (Estimated): December 31, 2027
• Last Updated: April 13, 2026

Record last verified: 2026-04

Locations

GB (1)