Current state and future potential of radiopharmaceutical therapy in breast cancer.

Radiopharmaceutical therapy has been adopted with success in malignancies such as prostate cancer and neuroendocrine tumors. This approach often combines a diagnostic agent to measure and assess target availability prior to administering a parenteral radiotherapeutic agent against the same target. Emerging evidence and ongoing research suggest that this approach could have a beneficial impact in breast cancer treatment, with a number of different breast cancer-specific or tumor microenvironment targets. There are several agents under investigation, with the majority in early-phase trials. This narrative review will provide a brief introduction to radiopharmaceutical imaging and therapy for breast cancer, discuss emerging therapeutic targets under investigation in breast cancer, and discuss challenges with the implementation of radiopharmaceuticals in breast cancer.