Clinical Study on the Application of 18F-HER2 Affibody PET Imaging in HER2-Expressing Breast Cancer

This study is testing a new PET imaging agent called 18F-HER2 affibody that targets the HER2 protein, which is overexpressed in some breast cancers. Researchers want to see how accurately this scan can detect and locate HER2-expressing breast cancer tumors. **You may be eligible if...** - You are between 18 and 75 years old with an ECOG score of 0 or 1 - You have confirmed or suspected HER2-expressing breast cancer - Your expected survival is at least 12 weeks - You have at least one measurable lesion on imaging - You are willing to use effective contraception during the study and for 6 months after **You may NOT be eligible if...** - You have severe liver or kidney dysfunction - You are pregnant or breastfeeding - You are claustrophobic or have other conditions preventing a PET scan - You cannot lie flat for 30 minutes Talk to your doctor to see if this trial is right for you.