Initial Staging of Lobular Breast Carcinoma: Head to Head Comparison of 68Ga-FAPI-46 and 18F-FDG PET/CT

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.

Inclusion Criteria: * Age greater than or equal to 18 years * ECOG from 0 to 2 * Histological diagnosis of Lobular Carcinoma of the breast based on a breast biopsy * Patient naïve to any treatment for lobular breast carcinoma * Women of childbearing age should have an adequate method of contraception * Patient having voluntarily accepted to participate in the study and signed the informed consent * Minimum tumor stage IIA * Sufficient histological material in the biopsy or the surgical specimen, if the biopsy is insufficient Exclusion Criteria: * PET scan contraindications: severe claustrophobia, unbalanced diabetes during 18F-FDG PET scans (fasting capillary blood sugar ≥ 11 mmol) * Hormone therapy started * 18F-FDG PET scan \> 21 days * Pregnant women, parturients and nursing mothers * Persons deprived of liberty by a judicial or administrative decision * Persons admitted to a health or social establishment for purposes other than research * Adults who are the subject of a legal protection measure or who are unable to express their consent