EndometriosisPET-EndoNCT07523997
Imaging of Endometriosis With Total-body PET-CT (PET-Endo)
An observational study of Endometriosis, run by University of Edinburgh at 1 site in United Kingdom.
Trial 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'. Read more about this study
- Who is it for?
- Ages 18 to 60 years, women only
- Conditions the study is for
- Endometriosis
- What is being tested?
- PET/CT, PET/MRI and Buscopan 20 MG/ML Injectable Solution
- Type of treatment
- Injection or infusion
- How many people
- 30 participants
- Where
- 1 siteUnited Kingdom
- Study dates
- 8 Apr 2026to 31 Dec 2027
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
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 60 years
- Women only
- No healthy volunteers
- Adult
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.
Who may be able to join
- Chronic pelvic pain
- Clinical/radiological diagnosis of likely endometriosis and due to undergo confirmatory laparoscopy in the subsequent four months
Who cannot join
- 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)
Show all 10Show fewer
- 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
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United Kingdom1 site, 1 recruiting
- Recruiting
Centre for Reproductive Health, Institute for Regeneration and Repair, University of Edinburgh
Edinburgh, City Of Edinburgh, EH16 4UU
Lucy HR Whitaker, MD, etmt@ed.ac.uk
Lucy HR Whitaker, MD
About this study
Official title: Novel Non-invasive Imaging of Endometriosis Using Total-body PET-CT Programme (PET-Endo)
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.
Read more
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.
Read the detailed description
This will be an observational cohort study using a prospectively recruited cohorts for both cross-sectional and longitudinal comparison across the spectrum of endometriosis subtypes.
Up to 30 participants with a clinical/radiological diagnosis of likely endometriosis and due to undergo confirmatory laparoscopy in the subsequent four months will be recruited.
Data collected at baseline includes demographics, clinical history including previous imaging. Participants will complete the WERF EPHect questionnaire
Participants will attend two visits for imaging. They will undergo advanced imaging by total-body positron emission tomography and computed tomography (PET/CT), followed by PET/MRI for anatomical reconciliation of lesions and additional information about tracer dynamics. At one visit 68Ga-FAPI will be administered, and at the other 18F-GP1. IV buscopan will be given prior to the PET/MRI.
Following completion of imaging studies, participants will be invited to complete an online acceptability questionnaire, and complete and optional qualitative interview about their experience.
Subsequent surgical findings and associated histopathology will be correlated with tracer uptake
- Conditions
- Endometriosis
- Being tested
- PET/CT, PET/MRI, Buscopan 20 MG/ML Injectable Solution
- Keywords
- Endometriosis, PET-CT, PET-MRI
- Medical subject headings
- Endometriosis
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
PET/CTDiagnostic 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
PET/MRIDiagnostic 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
Buscopan 20 MG/ML Injectable SolutionDrug
Also called 20mg
IV injection prior to PET/MRI
| Study group | Role | What they receive |
|---|---|---|
| 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. Receives: Diagnostic Test: PET/CT; Diagnostic Test: PET/MRI; Drug: Buscopan 20 MG/ML Injectable Solution |
What is being measured
The primary outcome is the main question the study is designed to answer.
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.
Measured: 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
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.
The relative values for the two separate tracers GP1 (activated platelets) and FAPI (fibrosis) will be correlated with the macroscopic appearance of lesions of differing subtypes at surgery.
Measured: within 3 months post surgery
Acceptability of PET imaging for characterisation of endometriosis
Bespoke acceptability questionnaire will be administered following surgery. Acceptability of the overall study and specific aspects will be rated on a 5 point Likert scale, with free text options for further detail. Data will summarised despitative, with thematic analysis of free text where able. Additional acceptability data will be derived from qualitative interviews of a purposive sample of participants and analysed thematically.
Measured: within 3 months post surgery
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted13 Apr 2026
- Study start8 Apr 2026
- Primary completion1 Apr 2027 (estimated)
- Study completion31 Dec 2027 (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 University of EdinburghThe 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
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 30 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University of Edinburgh
- Sponsor type
- University, hospital or other
- Collaborators
- Life Molecular Imaging Ltd.
- Responsible party
- Sponsor
- Investigators
- Lucy HR Whitaker, MD, Principal investigator, University of Edinburgh
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07523997
- Sponsor's protocol ID
- AC24225
- Other IDs
- MRC/IAA/017, UKRI3897, EPD/24/19
- Acronym
- PET-Endo
- Status last verified
- May 2026
- First submitted
- 2 Apr 2026
- Last updated
- 27 May 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided: Requests for anonymised data sharing will be considered on a case by case basis by the trial management team with appropriate data sharing contracts in place
Study at a glance
From the registry record, last updated by the sponsor on 27 May 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Novel Non-invasive Imaging of Endometriosis Using Total-body PET-CT Programme (PET-Endo)
- ClinicalTrials.gov ID
- NCT07523997
- Acronym / sponsor ID
- PET-Endo / AC24225
- Conditions
- Endometriosis
- Keywords
- Endometriosis, PET-CT, PET-MRI
- Study type
- Observational
- Recruitment status
- Recruiting
- Enrolment
- 30 participants (estimated)
- Lead sponsor
- University of EdinburghUniversity, hospital or other
- Collaborators
- Life Molecular Imaging Ltd.
- Study start
- 8 Apr 2026 (actual)
- Primary completion
- 1 Apr 2027 (estimated)
- Study completion
- 31 Dec 2027 (estimated)
- First posted
- 13 Apr 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
Detailed description
This will be an observational cohort study using a prospectively recruited cohorts for both cross-sectional and longitudinal comparison across the spectrum of endometriosis subtypes.
Up to 30 participants with a clinical/radiological diagnosis of likely endometriosis and due to undergo confirmatory laparoscopy in the subsequent four months will be recruited.
Data collected at baseline includes demographics, clinical history including previous imaging. Participants will complete the WERF EPHect questionnaire
Participants will attend two visits for imaging. They will undergo advanced imaging by total-body positron emission tomography and computed tomography (PET/CT), followed by PET/MRI for anatomical reconciliation of lesions and additional information about tracer dynamics. At one visit 68Ga-FAPI will be administered, and at the other 18F-GP1. IV buscopan will be given prior to the PET/MRI.
Following completion of imaging studies, participants will be invited to complete an online acceptability questionnaire, and complete and optional qualitative interview about their experience.
Subsequent surgical findings and associated histopathology will be correlated with tracer uptake
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Suspected endometriosis | – | Diagnostic Test: PET/CT, Diagnostic Test: PET/MRI, Drug: Buscopan 20 MG/ML Injectable SolutionWomen/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. |
Who may qualify
- Ages
- 18 to 60 years
- Sex
- Female only
- Healthy volunteers
- Not accepted
- Age groups
- Adult
- 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.
Key inclusion criteria (2 listed)
- Chronic pelvic pain
- Clinical/radiological diagnosis of likely endometriosis and due to undergo confirmatory laparoscopy in the subsequent four months
Key exclusion criteria (10 listed)
- 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
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| PET/CTHybrid 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 | Diagnostic test | Suspected endometriosis |
| PET/MRIHybrid 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 | Diagnostic test | Suspected endometriosis |
| Buscopan 20 MG/ML Injectable SolutionAlso: 20mgIV injection prior to PET/MRI | Drug | Suspected endometriosis |
Primary outcome
In vivo uptake of 18F-GP1 and 68Ga-FAPI in endometriosis
Time frame: within 3 months post surgery
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.
2 secondary outcomes
Non-invasive in vivo imaging-based characterisation of thrombosis and fibrosis characterisation in superficial, ovarian and deep endometriosis lesions
Time frame: within 3 months post surgery
Acceptability of PET imaging for characterisation of endometriosis
Time frame: within 3 months post surgery
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 27 May 2026.
- Individual participant dataSharing planned: Undecided. Requests for anonymised data sharing will be considered on a case by case basis by the trial management team with appropriate data sharing contracts in place
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Lucy HR Whitaker, MD principal investigator
University of Edinburgh
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Endometriosis, run by University of Edinburgh at 1 site in United Kingdom.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 2 inclusion and 10 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 27 May 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United Kingdom. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Lucy HR Whitaker, MD (01316518321, ETMT@ed.ac.uk), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
In vivo uptake of 18F-GP1 and 68Ga-FAPI in endometriosis (time frame: within 3 months post surgery). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 27 May 2026.