Can HER2 Targeted PET/CT Imaging Identify Unsuspected HER2 Positive Breast Cancer Metastases, Which Are Amenable to HER2 Targeted Therapy?

Some breast cancer cells make a protein called Human Epidermal Growth factor receptor 2 (HER2). Patients with HER2 positive (HER2+) breast cancer receive medicine that attacks HER2, which helps these patients live longer. Some HER2 negative (HER2-) breast cancer patients also benefit from medicines that attack HER2, but we do not know why or which patients will benefit. This study uses a new imaging method, HER2-targeted PET/CT, to identify patients that may benefit from medicines that attack HER2. This is experimental.