Molecular Imaging of HER2 Expression in Breast Cancer Using 99mTc-HE3-G3

Overall goal of the project: To determine HER2 expression level in primary breast cancer and possibly in axillary lymph node metastases before neoadjuvant trastuzumab therapy. Phase I. Distribution of 99mTc-HE3-G3 in patients with primary breast cancer. The study should evaluate distribution of 99mTc-HE3-G3 in patients with primary HER2-positive and HER2-negative breast cancer. The primary objective are: 1. To assess distribution of 99mTc-HE3-G3 in normal tissues and in tumours over time; 2. To evaluate dosimetry of 99mTc-HE3-G3; 3. To obtain initial information concerning safety and tolerability of 99mTc-HE3-G3 after single intravenous injection: The secondary objective are: 1\. To compare the tumour imaging data with the concerning HER2 expression obtained by immunohistochemistry (IHC) or fluorescent in situ hybridisation (FISH) analysis of biopsy samples: Methodology: Open-label, exploratory, single centre study. The subjects will receive a single injection of the labelled tracer.