Lobular Breast cancer staging with 18F-fluorodeoxyglucose positron emission tomography (18F-FDG PET) is not optimal due to the poor accumulation of 18F-FDG in the tumour. Through better sensitivity (and specificity), 68Ga-FAPI-46-46 PET should provide a more accurate staging of lobular breast cancer than 18F-FDG PET.
Research hypothesis : Through better sensitivity (and specificity), 68Ga-FAPI-46-46 PET should provide a more accurate staging of lobular breast cancer than 18F-FDG PET. Participants with lobular breast carcinoma will then undergo 18F-FDG and 68Ga-FAPI-46 PET scan. Primary objective of the study is to compare the sensitivity of 68Ga-FAPI-46 with the sensitivity of 18F-FDG in the detection of lobular breast carcinoma lesions, measured by positron emission tomography (PET). These results will be compared with the histological data collected before or during surgery (conventional histological data and immunohistochemical labeling of FAPα on the sample obtained), clinical follow-up and any results of additional examinations carried out within the usual clinical follow-up of the patients. Comparison of primary tumor and metastases uptake of 68Ga-FAPI-46 with the uptake of 18F-FDG, radiomic study of 68Ga-FAPI-46 PET and comparative radiomic study of 68Ga-FAPI-46 PET and 18F-FDG PET and comparison of the specificity of 68Ga-FAPI-46 with the specificity of 18F-FDG after a 12-month follow-up will also be performed as secondary objectives.
Study Type
INTERVENTIONAL
Allocation
NA
Purpose
DIAGNOSTIC
Masking
NONE
Enrollment
40
68Ga-FAPI-46 is a radiotracer for the detection of Fibroblast Activation Protein (FAP) in cancer patients. 68Ga-FAPI-46 will be administered intravenously at a dose of 2MBq/kg. Patients will be scanned 60 minutes after administration of 68Ga-FAPI-46.
Centre Hospitalier Princesse Grace
Monaco, Monaco
Number of positive tumor lesions, i.e. confirmed by additional imaging, histopathology/biopsy or response to treatment (on imaging or clinical assessment)
Number of positive tumor lesions of 68Ga-FAPI-46 PET scan in comparison with 18F-FDG PET scan
Time frame: Up to 12 months
SUVmaxFAPI and SUVmaxFDG for each target (Standardized Uptake Value)
Comparison of 68Ga-FAPI-46 and 18F-FDG Standardized Uptake Value in the primary tumor and possible metastases
Time frame: Up to 21 days
SUVmaxFAPI/reference and SUVmaxFDG/reference activity ratios
Comparison of (SUVmaxFAPI/reference) and (SUVmaxFDG/reference) activity ratios. For the primary tumour, the reference activity will be measured in either the periphery of the lesion or on a homologous healthy tissue. For a vertebral metastasis, the reference activity will be measured in an adjacent healthy vertebra.
Time frame: Up to 21 days
MTVFAPI and MTVFDG (Metabolic Tumor Volume)
Comparison of MTVFAPI and MTVFDG in the primary tumor and possible metastases
Time frame: Up to 21 days
Number of discrepancies between FAPI and FDG PET scans
Discrepancies (discordant pairs) between 68Ga-FAPI-46 PET scan and 18F-FDG PET scan will be analyzed
Time frame: Up to 21 days
Correlation between PET scan and FAPα labeling
Correlation between PET scan results and measurement of the FAPα labeling density on the biopsy
Time frame: Up to 12 months
Correlation between PET scan and breast histology
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Correlation between PET scans results and standard measurements in breast histology: OR (estrogen receptors), PR (progesterone receptors), HER2 (Human Epidermal Growth Factor Receptor-2), Ki-67 antigen, Ecadherin
Time frame: Up to 12 months
Specificity comparison
Specificity of 68Ga-FAPI-46 PET scan will be compared to 18F-FDG PET scan specificity
Time frame: 12 months
Correlation between tumor lesion radiomics and histological characteristics
1st order characteristics reflecting the distribution of gray levels determined by radiomics study of 68Ga-FAPI PET scan and 18F-FDG PET scan
Time frame: 12 months
Molecular biology analysis of tumor samples
Bioinformatics analysis of tumor sample celullar composition in terms of fibroblasts expressing FAP protein after total RNA extraction.
Time frame: 12 months