Molecular Imaging in Breast Cancer

Breast cancer (BC) is the most common cancer among females with more than 2 million new cases diagnosed worldwide in 2018. Although the prognosis in the majority of cases in the early stages combined with appropriate treatment is positive, there are still about 30% of patients who will develop locoregional diseases and distant metastases. Molecular imaging is very important in the diagnosis, staging, follow-up, and radiotherapy planning. Additionally, it is useful in characterizing lesions, prognosis, and therapy response in BC patients. Nuclear medicine imaging modalities (SPECT and PET) are of indispensable importance in diagnosis (positron emission mammography), staging (sentinel lymph node detection), and follow-up with¹⁸F-FDG and tumor characterization. Among many available PET tracers, the most commonly used are ¹⁸F-FLT, ¹⁸F-FES, ¹⁸F-FDHT, ⁶⁴Cu DOTA trastuzumab (bevacizumab), ⁶⁸Ga-PSMA, ⁶⁸Ga-RM2 (gastrin-releasing peptide receptor), ¹⁸F-fluorooctreotide (SSTR), and ⁶⁸Ga-TRAP (RGD)-3αvβ3-integrin. Molecular imaging helps in evaluation of tumor heterogeneity, allowing a shift from one-size-fits-all-approach to era of personalized medicine and precision oncology.