Neuroendocrine TumorsNCT04804371
Dual Tracer (68Ga-DOTATATE and 18F-FDG) PET Imaging in G2 & G3 Gastroenteropancreatic Neuroendocrine Tumors
A study testing F18-FDG in people with Neuroendocrine Tumors, run by University Health Network, Toronto at 1 site in Canada.
Trial summary
The variable clinical outcome of patients with G2 \& G3 well diff GEP-NETs makes the selection of an optimal treatment strategy challenging. Initial data suggests that high DOTATATE uptake and low FDG uptake are suggestive of low grade disease, with an indolent course. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Neuroendocrine Tumors
- What is being tested?
- F18-FDG
- Type of treatment
- Injection or infusion
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 40 participants
- Where
- 1 siteCanada
- Study dates
- 4 Mar 2021to 22 Feb 2027
- Phase
- Interventional
- 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 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Has provided written informed consent prior to any study-related procedures,
- Is a male or a female of 18 years of age or older.
- Patients who already had/scheduled for a 68Ga-DOTATATE PET/CT scan.
- Has a gastro entero-pancreatic neuroendocrine neoplasm confirmed by histological criteria. Patients with unknown primaries clinically thought to be from gastroenteropancreatic source shall be eligible.
- Has a well differentiated tumour Grade 2-3 (WHO 2017).
- Has a tumour with a proliferation index (Ki67 ≥3%) or in samples where the Ki67 antigen cannot be reliably quantified, a mitotic index ≥2 mitosis/10HPF (high power fields)
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- Treatment naïve patients and/or patient who have received any number of prior systemic therapy lines for metastatic disease and/or locally advanced inoperable tumor.
- Willing and able to comply with all study requirements, including timing and/or nature of required assessments.
- Women of child-bearing age will undergo a urine test to exclude pregnancy prior to PET.
Who cannot join
- Patients with known lung neuroendocrine tumours or other proven non gastroenteropancreatic histologies are not eligible.
- Patients with any known hypersensitivity to FDG.
- Has a well differentiated neuroendocrine tumour Grade 1 (WHO 2017).
- Has a poorly differentiated neuroendocrine carcinoma (WHO 2017).
- Mixed neuroendocrine and non-neuroendocrine cancer
- Has any mental condition rendering the patient unable to understand the nature, scope and possible consequences of the study, and/or evidence of an uncooperative attitude.
- Any patient who is pregnant.
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Combined 68Ga-DOTATATE and 18F-FDG PET/CT Imaging in Patients With Well-differentiated, G2-G3, Gastroenteropancreatic (GEP)-Neuroendocrine Tumors (NETs) - A Pilot Study
The variable clinical outcome of patients with G2 \& G3 well diff GEP-NETs makes the selection of an optimal treatment strategy challenging.
Initial data suggests that high DOTATATE uptake and low FDG uptake are suggestive of low grade disease, with an indolent course.
Read more
Conversely, low DT uptake and high FDG uptake are suggestive of high-grade/ aggressive disease.
G2/3 GEP NETs may be biologically diverse; clinically relevant cohort for dual-tracer PET imaging.
Our secondary objectives are
- To determine the distribution of PETNET scores derived from 18F-FDG \& 68Ga-DT PET in patients with G2 \& G3 well diff GEP-NETs.
- To determine the proportion of patients in whom the addition of 18F-FDG PET data results in a change in planned clinical management.
To assess intra-individual variability in SSTR expression \& glucose metabolism (as seen on DT and FDG PET) across different tumor sites within the same patient.
- To determine whether a correlation exists between tumor texture features on 68Ga-DT \& FDG PET to tumor grade and Ki 67 index.
- To assess for an association between tumor texture features on 68Ga-DT PET and glucose metabolism; and/or an association between tumor texture features on FDG PET and SSTR expression.
Read the detailed description
The variable clinical outcome of patients with G2 and G3 well differentiated GEP-NETs makes the selection of an optimal treatment strategy challenging.
A subject with 68Ga-DOTATATE uptake on all lesions without FDG uptake is likely to have low-grade, metabolically inactive disease, leading to an indolent disease course and may also be a predictive biomarker in subjects being considered for PRRT.
Conversely, avidity on 18F-FDG PET/CT and non-avidity on 68Ga-DOTATATE may indicate a high-grade NET, and would predict resistance to PRRT, suggesting that a more "aggressive" approach with systemic chemotherapy might be beneficial.
Therefore, the prospective assessment of PETNET score in patients with G2 or G3 GEP NETs, which may be biologically diverse is the most clinically relevant group for dual-tracer PET imaging.
Primary Objectives:
- To determine the distribution of PETNET scores derived from 18F-FDG and 68Ga-DOTATATE PET/CT in patients with G2 and G3 well differentiated GEP-NETs.
- To determine the proportion of patients in whom the addition of 18F-FDG PET/CT data results in a change in planned clinical management.
Secondary Objectives:
- mTo determine whether there is intra-individual variability in somatostatin receptor expression and glucose metabolism (as seen on DOTATATE PET and FDG PET, respectively) across different tumor sites within the same patient.
- To determine whether a correlation exists between tumor texture features on 68Ga-DOTATATE PET and FDG PET to tumor grade and Ki67 index.
- To assess if an association exists between tumor texture features on 68Ga-DOTATATE PET and glucose metabolism; and/or an association between tumor texture features on FDG PET and somatostatin receptor expression.
- Conditions
- Neuroendocrine Tumors
- Being tested
- F18-FDG
- Medical subject headings
- Neuroendocrine Tumors
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
F18-FDGDrug
Evaluate FDG uptake
| Study group | Role | What they receive |
|---|---|---|
| 18F-FDG PETCT scan | Other | 18F-FDG tracer (5 MBq/kg body weight of FDG; up to 550 MBq) will be injected into the intravenous Receives: Drug: F18-FDG |
What is being measured
The primary outcome is the main question the study is designed to answer.
Discordance in tracer uptake:
Discordance in tracer uptake as assessed by PETNET score distribution: Proportion of patients with PETNET score of P1/P2 (no or low FDG uptake) vs those with P3-P5 (moderate or high FDG uptake).
Measured: 2 years
Impact to patient management:
Impact of the addition of FDG PET to patient management as assessed by rate of clinical management changed after the addition of 18F-FDG PET/CT to 68Ga-DOTATATE PET/CT.
Measured: 2 years
Secondary outcomes (3)
Intraindividual tumor heterogeneity:
Assessment of tumor heterogeneity by measuring the proportion of patients with variable PET NET score at different tumor sites (intraindividual variability).
Measured: 2 years
Tumor texture geatures as predictors of tumor grade:
To determine whether tumor texture features on PET correlate with tumor grade and/or Ki-67 index.
Measured: 2 years
Tumor texture features as predictors of tumor metabolism and somatostatin receptor expression:
To determine whether tumor texture features on 68Ga-DOTATATE PET correlate with glucose metabolism (as measured semiquantitatively with SUV on FDG PET); and/or whether tumor texture features on FDG PET correlate with somatostatin receptor expression (as measured semiquantitatively with SUV on 68Ga-DOTATATE PET).
Measured: 2 years
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted18 Mar 2021
- Study start4 Mar 2021
- Primary completion22 Feb 2027 (estimated)
- Study completion22 Feb 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Neuroendocrine TumorsStudies of the same condition, open and under way.
- More trials run by University Health Network, TorontoThe 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
- Not applicable
- Intervention model
- Single group
- Model description
- Histologically proven well diff GEP NET, G2-3, Ki 67 ≥3% (or mitotic index ≥2 mitosis/10HPF).
- Masking
- None (open label)
- Enrolment
- 40 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University Health Network, Toronto
- Sponsor type
- University, hospital or other
- Collaborators
- Canadian Neuroendocrine Tumour Society (CNETS)
- Responsible party
- Sponsor
- Investigators
- Ur Metser, MD, Principal investigator, University Health Network, Toronto
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04804371
- Sponsor's protocol ID
- 20-5920
- Status last verified
- Mar 2026
- First submitted
- 3 Mar 2021
- Last updated
- 23 Mar 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 23 Mar 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Combined 68Ga-DOTATATE and 18F-FDG PET/CT Imaging in Patients With Well-differentiated, G2-G3, Gastroenteropancreatic (GEP)-Neuroendocrine Tumors (NETs) - A Pilot Study
- ClinicalTrials.gov ID
- NCT04804371
- Acronym / sponsor ID
- 20-5920
- Conditions
- Neuroendocrine Tumors
- Study type
- Interventional
- Recruitment status
- Active, not recruiting
- Enrolment
- 40 participants (estimated)
- Lead sponsor
- University Health Network, TorontoUniversity, hospital or other
- Collaborators
- Canadian Neuroendocrine Tumour Society (CNETS)
- Study start
- 4 Mar 2021 (actual)
- Primary completion
- 22 Feb 2027 (estimated)
- Study completion
- 22 Feb 2027 (estimated)
- First posted
- 18 Mar 2021 (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.
The variable clinical outcome of patients with G2 \& G3 well diff GEP-NETs makes the selection of an optimal treatment strategy challenging.
Initial data suggests that high DOTATATE uptake and low FDG uptake are suggestive of low grade disease, with an indolent course.
Conversely, low DT uptake and high FDG uptake are suggestive of high-grade/ aggressive disease.
G2/3 GEP NETs may be biologically diverse; clinically relevant cohort for dual-tracer PET imaging.
Our secondary objectives are
- To determine the distribution of PETNET scores derived from 18F-FDG \& 68Ga-DT PET in patients with G2 \& G3 well diff GEP-NETs.
- To determine the proportion of patients in whom the addition of 18F-FDG PET data results in a change in planned clinical management.
To assess intra-individual variability in SSTR expression \& glucose metabolism (as seen on DT and FDG PET) across different tumor sites within the same patient.
- To determine whether a correlation exists between tumor texture features on 68Ga-DT \& FDG PET to tumor grade and Ki 67 index.
- To assess for an association between tumor texture features on 68Ga-DT PET and glucose metabolism; and/or an association between tumor texture features on FDG PET and SSTR expression.
Detailed description
The variable clinical outcome of patients with G2 and G3 well differentiated GEP-NETs makes the selection of an optimal treatment strategy challenging.
A subject with 68Ga-DOTATATE uptake on all lesions without FDG uptake is likely to have low-grade, metabolically inactive disease, leading to an indolent disease course and may also be a predictive biomarker in subjects being considered for PRRT.
Conversely, avidity on 18F-FDG PET/CT and non-avidity on 68Ga-DOTATATE may indicate a high-grade NET, and would predict resistance to PRRT, suggesting that a more "aggressive" approach with systemic chemotherapy might be beneficial.
Therefore, the prospective assessment of PETNET score in patients with G2 or G3 GEP NETs, which may be biologically diverse is the most clinically relevant group for dual-tracer PET imaging.
Primary Objectives:
- To determine the distribution of PETNET scores derived from 18F-FDG and 68Ga-DOTATATE PET/CT in patients with G2 and G3 well differentiated GEP-NETs.
- To determine the proportion of patients in whom the addition of 18F-FDG PET/CT data results in a change in planned clinical management.
Secondary Objectives:
- mTo determine whether there is intra-individual variability in somatostatin receptor expression and glucose metabolism (as seen on DOTATATE PET and FDG PET, respectively) across different tumor sites within the same patient.
- To determine whether a correlation exists between tumor texture features on 68Ga-DOTATATE PET and FDG PET to tumor grade and Ki67 index.
- To assess if an association exists between tumor texture features on 68Ga-DOTATATE PET and glucose metabolism; and/or an association between tumor texture features on FDG PET and somatostatin receptor expression.
Study design
- Primary purpose
- Diagnosis
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
- Model description
- Histologically proven well diff GEP NET, G2-3, Ki 67 ≥3% (or mitotic index ≥2 mitosis/10HPF).
| Arm | Type | Receives |
|---|---|---|
| 18F-FDG PETCT scan | Other | Drug: F18-FDG18F-FDG tracer (5 MBq/kg body weight of FDG; up to 550 MBq) will be injected into the intravenous |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (9 listed)
- Has provided written informed consent prior to any study-related procedures,
- Is a male or a female of 18 years of age or older.
- Patients who already had/scheduled for a 68Ga-DOTATATE PET/CT scan.
- Has a gastro entero-pancreatic neuroendocrine neoplasm confirmed by histological criteria. Patients with unknown primaries clinically thought to be from gastroenteropancreatic source shall be eligible.
- Has a well differentiated tumour Grade 2-3 (WHO 2017).
Key exclusion criteria (7 listed)
- Patients with known lung neuroendocrine tumours or other proven non gastroenteropancreatic histologies are not eligible.
- Patients with any known hypersensitivity to FDG.
- Has a well differentiated neuroendocrine tumour Grade 1 (WHO 2017).
- Has a poorly differentiated neuroendocrine carcinoma (WHO 2017).
- Mixed neuroendocrine and non-neuroendocrine cancer
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 |
|---|---|---|
| F18-FDGEvaluate FDG uptake | Drug | 18F-FDG PETCT scan |
Primary outcome
Discordance in tracer uptake:
Time frame: 2 years
Discordance in tracer uptake as assessed by PETNET score distribution: Proportion of patients with PETNET score of P1/P2 (no or low FDG uptake) vs those with P3-P5 (moderate or high FDG uptake).
Impact to patient management:
Time frame: 2 years
Impact of the addition of FDG PET to patient management as assessed by rate of clinical management changed after the addition of 18F-FDG PET/CT to 68Ga-DOTATATE PET/CT.
3 secondary outcomes
Intraindividual tumor heterogeneity:
Time frame: 2 years
Tumor texture geatures as predictors of tumor grade:
Time frame: 2 years
Tumor texture features as predictors of tumor metabolism and somatostatin receptor expression:
Time frame: 2 years
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 23 Mar 2026.
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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. This study is not recruiting at the moment.
Ur Metser, MD principal investigator
University Health Network, Toronto
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing F18-FDG in people with Neuroendocrine Tumors, run by University Health Network, Toronto at 1 site in Canada.
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 9 inclusion and 7 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: under way, not looking for participants, as of the sponsor's last update on 23 Mar 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 Canada. 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?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Discordance in tracer uptake: (time frame: 2 years). The study lists 2 primary outcomes in all. 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 23 Mar 2026.