What is it?
Breast PET uses an injection of a short-lived radioactive sugar (18FDG) into the body to detect metabolically active lesions such as cancer. PET, or more often PET-CT, is commonly used to stage the whole body in patients with larger breast cancers or suspected recurrence. Newer technologies can provide detailed PET images of the breasts to assess local extent of breast cancer.
How it works
The radioactive sugar accumulates in cancer cells in the breast and emits high-energy positron radiation that is detected and analyzed. For one such system, the patient is seated and the breast is gently stabilized; positioning is otherwise like mammography (Fig. PET-1).
Breast PET is generally considered a diagnostic test used to determine the extent of cancer within the breasts, and can be used as an alternative to breast MRI for that purpose [1, 2]. In women with newly diagnosed breast cancer being treated with chemotherapy prior to surgery, breast PET can also help monitor response to treatment. In addition, breast PET may help distinguish recurrence of cancer from scar in women who have been previously treated for breast cancer. Uncommonly, it can be used for problem solving (Fig. PET-3). It is a relatively new modality and not widely available.
Breast PET exposes the patient to a moderately high whole body radiation dose and is not used for screening . The very back part of the breast near the chest wall and the axillary lymph nodes are better evaluated with MRI.
1. Berg WA, Madsen KS, Schilling K, et al. Breast cancer: Comparative effectiveness of positron emission mammography and MR imaging in presurgical planning for the ipsilateral breast. Radiology 2011; 258:59-72
2. Narayanan D, Berg WA. Use of breast-specific PET scanners and comparison with MR imaging. Magn Reson Imaging Clin N Am 2018; 26:265-272
3. Narayanan D, Berg WA. Dedicated breast gamma camera imaging and breast PET: Current status and future directions. PET Clin 2018; 13:363-381