Recent developments in peptide-based SPECT radiopharmaceuticals for breast tumor targeting.

Breast cancer deaths occur mainly because of poor diagnosis in early stages that lead to tumor metastasis in advanced stages. Developing a high-sensitive early-stage breast cancer diagnostic tool based on single photon emission computer tomography (SPECT) and positron emission tomography (PET) are urgent. There are several evidences to demonstrate the prominent roles of specific receptors overexpression in tumor initiation and progression of breast cancer. Targeting of specific receptor with radiolabeled biomolecule is a suitable tool for early diagnosis of breast cancer. In recent years, investigators have paid their attention in the development of peptide-based radiopharmaceuticals due to their favorable pharmacokinetics that offer diagnostic applications for breast cancer imaging. Various characterizing techniques permit the preparation of variety of peptides that allow efficiently labeling with clinically useful SPECT radionuclides such as 99mTc, 123I and 111In without compromising biological properties. In this review, we focus on the recent developments in use of peptide-based SPECT radiopharmaceuticals for breast cancer targeting and imaging.