The Future Role of PET Imaging in Metastatic Breast Cancer.

BACKGROUND: A variety of therapeutic approaches are employed to treat patients suffering from breast cancer. Likewise, a broad spectrum of imaging ligands has been introduced for noninvasive positron emission tomography/computed tomography (PET/CT) imaging to enable comprehensive tumor characterization and more accurate response evaluation.

SUMMARY: In recent years, novel radioactively labeled ligands have been developed for PET/CT imaging in metastatic breast cancer. One promising tracer is [18F]fluoroestradiol, which was recently approved by the Food and Drug Administration. It can be used for a whole-body assessment of estrogen receptor status. Another radionuclide currently under development is [68Ga]Ga-fibroblast-activation-protein inhibitor. In addition to new radionuclides, the field of application for existing tracers like [18F]fluorodeoxyglucose (FDG) was broadened. It has been shown that an early therapeutic response to various therapies can be detected by [18F]FDG PET/CT, which leads to early treatment optimization. Key Message: In this review, we highlighted new tracers and applications of PET/CT imaging as well as therapeutic approaches in patients with advanced breast cancer. Furthermore, we give an outlook on the application of artificial intelligence, immunoPET, and liquid biopsy.