Evaluation of [68Ga]Ga-NOTA-anti-HER2-sdAb PET/CT for Predicting Pathological Complete Response After Neoadjuvant Chemotherapy in HER2 Positive Early Breast Cancer

Inclusion Criteria: * Female aged 18 years or older * Histologically proven HER2-positive early breast cancer, defined as IHC 3+ or IHC 2+ with ISH amplification * Indication for neoadjuvant chemotherapy combined with anti-HER2 targeted therapy followed by surgery, as determined by a multidisciplinary tumor board * ECOG performance status of 0 or 1 * Affiliated to or beneficiary of a social protection scheme * Written informed consent signed prior to any study-specific procedure Exclusion Criteria: * Pregnant or breastfeeding women * Patient not treated with curative intent * History of ipsilateral breast cancer treated by surgery and/or radiotherapy * Lobular histology * Known contraindication or hypersensitivity to \[68Ga\]Ga-NOTA-anti-HER2-sdAb or any of its radiopharmaceutical excipients * Known contraindication or hypersensitivity to \[18F\]F-FDG or any of its radiopharmaceutical excipients * Concurrent enrollment in another clinical trial evaluating radiopharmaceuticals * Patient under guardianship, curatorship, or judicial protection * Patient deprived of liberty * Inability to understand the study or comply with trial constraints due to linguistic, psychological, or geographical barriers