PET/CT using FDG (18F-fluorodeoxyglucose) is mainly employed for staging and assessment of lymph node involvement in breast cancer patient. It also assists in determining surgery extent, the need for neoadjuvant treatment, and predicting prognosis. PET/CT is essential for early differentiation between true recurrence and postsurgical or radiation-related changes. PET/CT is useful in assessing treatment response by evaluating tumor metabolic activity. It determines the effectiveness of systemic therapies like chemotherapy or targeted agents. A significant decrease in FDG uptake after neoadjuvant chemotherapy indicates a higher likelihood of achieving a pathological complete response (pCR) and improved survival outcomes. For radiation therapy planning, PET/CT aids in target volume delineation and optimal radiation dose determination. PET/CT excels in detecting distant metastases in organs like the lungs, liver, and bones. It outperforms conventional methods in bone metastasis detection, offering anatomical localization and lesion characterization. Lastly, positron emission mammography (PEM) is a specialized imaging technique that uses a small PET device optimized for breast imaging. PEM offers higher spatial resolution, reduced radiation exposure, and is particularly valuable for detecting and characterizing primary breast lesions for surgical planning or prechemotherapy evaluation. Thus, PET/CT is a versatile tool in breast cancer management, providing crucial functional and anatomical information.