%0 Journal Article %T Molecular Imaging Probes for Diagnosis and Therapy Evaluation of Breast Cancer %A Qingqing Meng %A Zheng Li %J International Journal of Biomedical Imaging %D 2013 %I Hindawi Publishing Corporation %R 10.1155/2013/230487 %X Breast cancer is a major cause of cancer death in women where early detection and accurate assessment of therapy response can improve clinical outcomes. Molecular imaging, which includes PET, SPECT, MRI, and optical modalities, provides noninvasive means of detecting biological processes and molecular events in vivo. Molecular imaging has the potential to enhance our understanding of breast cancer biology and effects of drug action during both preclinical and clinical phases of drug development. This has led to the identification of many molecular imaging probes for key processes in breast cancer. Hormone receptors, growth factor receptor, and angiogenic factors, such as ER, PR, HER2, and VEGFR, have been adopted as imaging targets to detect and stage the breast cancer and to monitor the treatment efficacy. Receptor imaging probes are usually composed of targeting moiety attached to a signaling component such as a radionuclide that can be detected using dedicated instruments. Current molecular imaging probes involved in breast cancer diagnosis and therapy evaluation are reviewed, and future of molecular imaging for the preclinical and clinical is explained. 1. Introduction Breast cancer is a major cause of mortality in women worldwide. In the US, approximately 40,000 women die of breast cancer every year and about 1 in 8 women will be diagnosed with breast cancer over the course of her lifetime. Although mammography remains a key imaging method for screening of breast cancer, the overall accuracy of this test is low [1, 2], particularly in the setting of fibrocystic breast disease and dense breast tissue in young women. There remains a great demand for the ability to define the extent of disease, to monitor treatment response and to predict tumor behavior in breast cancer patients in which molecular imaging may play an important role. Molecular imaging, including positron emission tomography (PET), single-photon emission computed tomography (SPECT), magnetic resonance imaging (MRI), optical imaging, and ultrasound, provides noninvasive in vivo information on important biological and molecular events, which can ultimately lead to improved early detection and characterization of therapy response. The goal of molecular imaging is to detect and quantify biological processes at the cellular and subcellular levels in living subjects. Molecular changes in tissue and organ from functional molecular imaging can be used for comparing to traditional imaging which usually gives only anatomic information. With advancements in instrumentation and introduction of %U http://www.hindawi.com/journals/ijbi/2013/230487/