HER2-expression PET Imaging in Metastatic Breast Cancer

This clinical study is designed for female patients with metastatic breast cancer, focusing on understanding the HER2 protein's expression in cancer cells. It aims to explore how a specific imaging technique, using a tracer called [68Ga]Ga-ABY-025, might predict the effectiveness of HER2-targeting treatments. The study targets women whose tumors are known to be non-HER2 positive or have an unknown HER2 status. It includes those whose disease has progressed after previous chemotherapy or within six months of completing treatment for primary breast cancer. This study is crucial as it could lead to better-targeted treatments for patients with this type of cancer, potentially improving outcomes. Participants in the study will first undergo a special scan called HER2-PET and a tumor biopsy, which helps determine the presence and extent of HER2 proteins. If the HER2 protein is present in the tumor biopsy, patients will receive treatment with a drug called T-DXd. The effectiveness of this treatment is evaluated with a follow-up HER2-PET scan after 9-12 weeks. An additional HER2-PET scan and biopsy may be done if the disease progresses while on T-DXd. This process helps researchers evaluate the treatment's impact and potentially predict the responsiveness of such therapies in managing metastatic breast cancer.