HER2 PET Imaging in Breast Cancer Patients Using [68GA]ABY-025

Inclusion Criteria: 1. Subject is \> 18 years of age 2. Histologically or cytologically confirmed diagnosis of breast adenocarcinoma ≥ 3 cm determined by ultrasound, or locally advanced breast cancer (LABC: T3-4NxMx or TxN2-3Mx) 3. HER2-positiv breast cancer first recurrence 4. HER2-positiv breast cancer primary metastatic 5. HER2 status has been determined on biopsy material from the primary tumour and found to be HER2-positive, defined as a DAKO HercepTest™ score of 3+ or else 2+ and FISH positive 6. \[18F\]FDG PET/ceCT performed within 7 days before administration of IMP 7. ECOG performance status of =\< 2 8. Hematological, liver and renal function test results within the following limits: * White blood cell count: \> 2.0 x 10\^9/L * Haemoglobin: \> 5.0 mmol/L * Platelets: \> 50.0 x 10\^9/L * ALT, ALP: =\< 3 times Upper Limit of Normal * Bilirubin =\< 2.0 times Upper Limit of Normal * Serum creatinine: Within Normal Limits 9. A negative pregnancy test (serum beta-HCG) at screening for all subjects of childbearing potential 10. Subject is capable to undergo the diagnostic investigations to be performed in the study 11. Informed consent Exclusion Criteria: * 1\. Known hypersensitivity to Dotarem® 2. Active known autoimmune disease or history of autoimmune disease 3. Active serious infection according to investigator evaluation 4. Known HIV positive or chronically active hepatitis B or C 5. Administration of other investigational medicinal product within 30 days of screening 6. Pregnant or breast-feeding 7. Women capable of childbearing not using a sufficient non-hormonal method of birth control 8. Other primary malignancies (including primary brain tumors) within the last 5 years before inclusion, with exception of sufficiently treated in situ carcinoma of the cervix, squamous carcinoma of the skin or sufficiently controlled limited basal cell carcinoma of the skin 9. Signs of any other disease, metabolic or psychological dysfunction, findings at physical examination or laboratory findings, which give reasonable suspicion of a disease or condition that would contraindicate use of the IMP, could influence the patient's compliance with the study routines or involves an increased risk for treatment-related complications.