HERPET- A Novel PET Imaging Study of HER2 in Breast Cancer

Inclusion Criteria: 1. Female patients with a histological diagnosis of breast cancer with known HER2 status ((8 positive and 8 negative). 2. Written informed consent prior to admission in the study. 3. Target lesion diameter of ≥15mm that has not been previously irradiated. 4. Female patients aged ≥ 18 years of age. 5. For all patients: histologically confirmed locally advanced/metastatic breast cancer with a biopsy within the last 12 months confirming HER2 status by either immunohistochemistry (IHC), Silver In Situ Hybridization (SISH) or Fluorescent In Situ Hybridization (FISH). 6. ECOG performance status 0-2 7. Negative urine pregnancy test (within 2 hours prior to injection of imaging agent) in women of child bearing age and willingness to use contraception (barrier, abstinence, non-hormonal) for 3 weeks after injection of \[18F\]GE-226 8. Life expectancy \> 3 months 9. Adequate organ function as defined by * Hb≥10g/L * WBC≥3.0 x 109/L * PLT≥80 x 109/L * Serum creatinine ≤1.4mg/dl * SGOT and SGPT ≤2 x ULN * Total bilirubin ≤ 2 x ULN or 3.0 mg/dl in patients with Gilbert's syndrome 10. Patients must have been appropriately staged using FDG-PET within 42 days of study entry and additional imaging according to local standard of care Exclusion Criteria: 1. Pregnant or lactating women. 2. History of cardiac disease (myocardial infarction, arrhythmias requiring therapy, symptomatic valvular disease, cardiomyopathy, or pericarditis). 3. Evidence of significant medical condition or laboratory finding which, in the opinion of the Investigator, makes it undesirable for the patient to participate in the trial. 4. Participants with severe claustrophobia or who are unable to lie flat or fit into the scanner (≥350 lbs (160 Kg)). 5. Prior use within 14 days of enrolment or concurrent therapy with any other investigational agent. 6. Patients classified as radiation workers 7. Patients on therapeutic doses of anticoagulants, or with a raised prothrombin time