Breast Cancer, Breast Diseases, Breast Neoplasms
Conditions
Keywords
68Ga-FAPI-46, ER+ breast cancer, PET/CT, PET/MRI
Brief summary
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.
Interventions
DIAGNOSTIC_TEST68Ga-FAPI-46 PET/CT and 68Ga-FAPI-46 PET/MRI
All participating patients will undergo an additional 68Ga-FAPI- 46 PET/CT and 68Ga-FAPI-46 PET/MRI scan prior to their breast cancer treatment.
Sponsors
Maastricht University Medical Center
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
DIAGNOSTIC
Masking
NONE
Intervention model description
Single-group, single-center pilot study
Eligibility
Sex/Gender
FEMALE
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
* 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.
Exclusion criteria
* Age \<18 * Pregnancy * Patients with secondary malignancies (except non-melanoma skin cancer) * No 18F-FDG PET/CT or 18F-FDG PET/MRI scan. * Contra-indications for PET/MRI such as pacemaker, aneurysm clips, metallic device in their body, severe claustrophobia, and severe obesity * Chronic inflammatory disease such as rheumatoid arthritis. * Patients with severe hepatic or renal impairment (eGFR ≤45mL/min/1.73m²) * Inability to provide informed consent.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| 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. | Patients will be followed from diagnosis until the additional imaging exams are performed, within 20 working days both PET exams will be performed. | 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. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| To explore the feasibility of taking biopsies in test-positive patients. | Patients will be followed from diagnosis until the additional imaging exams are performed, within 20 working days both PET exams will be performed. | The proportion of 68Ga-FAPI-46-positive 18F-FDG-negative lesions for which performing a biopsy is not feasible. |
Other
| Measure | Time frame | Description |
|---|---|---|
| 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. | Patients will be followed from diagnosis until the additional imaging exams are performed, within 20 working days both PET exams will be performed. | 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) |
| To investigate the differences in accuracy between 68Ga-FAPI-46 PET/CT versus 68Ga-FAPI-46 PET/MRI. | Patients will be followed from diagnosis until the additional imaging exams are performed, within 20 working days both PET exams will be performed. | Diagnostic performance will be compared between both exams (i.e. 68Ga-FAPI-46 PET/CT and 68Ga-FAPI-46 PET/MRI. |
Countries
Netherlands
Contacts
Primary ContactThiemo JA van Nijnatten, MD, PhD
Backup ContactLisa EHW Duijx, MSc
Outcome results
None listed