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

Objectives Primary: * To determine the uptake in tumour lesions and normal tissue of \[18F\]GE-226 and compare the difference between patients with HER2 positive and HER2 negative lesions. Uptake will be quantified by semi-quantitative (SUV, AUC) and fully quantitative parameters (Ki in the case of irreversible uptake, and binding potential in the case of reversible uptake) * To determine the optimal imaging time point for \[18F\]GE-226 Secondary: * To determine the safety and toxicity of \[18F\]GE-226 PET in humans * To determine if \[18F\]GE-226 can distinguish between HER2 amplified and HER2 non-amplified breast tumours * To determine the metabolism of \[18F\]GE-226 in human subjects Exploratory: • To explore circulating biomarkers that may be related to \[18F\]GE-226 uptake and to investigate if treatment modulates \[18F\]GE-226 Endpoints Secondary: * Safety and toxicity of \[18F\]GE-226 measured by adverse events from administration of \[18F\]GE-226 injection throughout the study period, and clinically significant changes from baseline measurements in serum biochemistry, haematology, coagulation, immunology, urinalysis, vital signs, ECG, injection site and physical examination findings. * The association between \[18F\]GE-226 tumour uptake and standard HER2 pathological testing (HER2 amplified and HER2 non-amplified breast tumours) * Proportion of metabolised \[18F\]GE-226 at scheduled time-points compared to baseline * Normal tissue uptake of \[18F\]GE-226 will be quantified in the appropriate regions depending on the field of view. Exploratory: • To perform preliminary biodistribution analysis, to compare \[18F\]GE- 226 uptake to \[18F\]FDG uptake in tumour lesion