18F-FDG Versus 68Ga-FAPI-46 as PET Tracer in ER-positive Breast Cancer.
Trial statusRecruiting
Trial phasePhase 2
Trial typeInterventional
Biological sexFemale
Age18+
SponsorMaastricht University Medical Center
About this trial
The extent of breast cancer is an important prognostic factor in patients diagnosed with this disease. Therefore, adequate staging at diagnosis is a requisite for optimal treatment. In all patients diagnosed with locally advanced breast cancer (LABC), distant staging using 18F-FDG PET/CT is recommended. However, the degree of metabolic uptake in the primary breast tumor is significantly lower in the ER+ subtype compared to HER2+ and triple negative breast cancer (TNBC). As a consequence, a suboptimal 18F-FDG uptake in ER+ breast cancer patients can potentially lead to missed distant metastases. Fibroblast-activating protein inhibitor (FAPI) is a recently developed radiotracer that binds to FAP, a stromal antigen overexpressed in more than 90% of epithelial-derived tumors and their metastases. Previous studies all show 68Ga-FAPI PET/CT to have a higher detection rate compared to 18F-FDG PET/CT. However, all previous studies were performed without considering breast cancer subtype. If the metabolic uptake by 68Ga-FAPI-46 is higher in ER+ breast cancer patients, more lesions will be detected, resulting in a more appropriate treatment for these patients. Therefore, in this pilot study, the investigators aim to compare the diagnostic performance of 18F-FDG with 68Ga-FAPI-46 as PET-tracer in ER+ breast cancer patients.
Eligibility criteria
This trial does not accept healthy volunteersQualifiers
Female patient with histopathologically proven ER+ breast cancer.
Diagnosed with locally advanced (primary tumor >5 cm and/or presence of axillary lymph node metastases) or recurrent breast cancer, or metastatic breast cancer for which 18F-FDG PET/CT or 18F-FDG PET/MRI staging is performed.
Willing and able to undergo the study procedures.
Has personally provided written informed consent.
Disqualifiers
Age <18
Pregnancy
Patients with secondary malignancies (except non-melanoma skin cancer)
No 18F-FDG PET/CT or 18F-FDG PET/MRI scan.
Trial design
Design model
Single group
Treatments tested in this trial
68Ga-FAPI-46 PET/CT and 68Ga-FAPI-46 PET/MRI
Diagnostic testAll participating patients will undergo an additional 68Ga-FAPI- 46 PET/CT and 68Ga-FAPI-46 PET/MRI scan prior to their breast cancer treatment.
Treatment groups
20 Participants
are divided into 1 treatment groupGroup A: Additional 68Ga-FAPI-46 PET/CT and PET/MRI examExperimental treatment 1 intervention
Trial outcomes
Primary outcomes
1
To determine essential input parameters for an adequate sample size calculation for a diagnostic study that compares the diagnostic accuracy of 18F-FDG and 68Ga-FAPI-46 as PET tracer in patients with ER+ breast cancer.
To investigate the proportion of discordant pairs: the number of lesions detected on 18F-FDG PET but not on 68Ga-FAPI-46 PET and the number of lesions detected on 68Ga-FAPI-46 PET but not on 18F-FDG PET.
Time frame
Patients will be followed from diagnosis until the additional imaging exams are performed, within 20 working days both PET exams will be performed.Secondary outcomes
1
To explore the feasibility of taking biopsies in test-positive patients.
The proportion of 68Ga-FAPI-46-positive 18F-FDG-negative lesions for which performing a biopsy is not feasible.
Time frame
Patients will be followed from diagnosis until the additional imaging exams are performed, within 20 working days both PET exams will be performed.Other outcomes
1
To provide preliminary estimates of the proportion of 68Ga-FAPI-46-positive and 18F-FDG-positive lesions confirmed as true positives and false positives verified by a histological biopsy (gold standard) in patients with ER+ breast cancer.
The proportion of 68Ga-FAPI-46-positive lesions and the proportion of 18F-FDG-positive lesions confirmed as true positives or false positives (verified by a biopsy, the gold standard)
Time frame
Patients will be followed from diagnosis until the additional imaging exams are performed, within 20 working days both PET exams will be performed.2
To investigate the differences in accuracy between 68Ga-FAPI-46 PET/CT versus 68Ga-FAPI-46 PET/MRI.
Diagnostic performance will be compared between both exams (i.e. 68Ga-FAPI-46 PET/CT and 68Ga-FAPI-46 PET/MRI.
Time frame
Patients will be followed from diagnosis until the additional imaging exams are performed, within 20 working days both PET exams will be performed.Sponsors and contacts
Click on the lead sponsor to view all of their trials.
Source ClinicalTrials.gov