[PET/CT in breast cancer: an update]

The authors discuss the various roles of 18F-FDG PET/CT in the management of breast cancer. Roles of new tracers such as F-18 fluoro-L-thymidine (a marker of cell proliferation), 18-fluoro-17-B-estradiol (marker of estrogen receptor) and sodium fluoride (marker of bone matrix) are also mentioned. There is little justification for the use of FDG-PET/CT in patient with clinically T1 (< or = 2 cm) N0 tumours. Notably, it cannot be used as a substitute to SLNB "sentinel lymph node biopsy" for axillary staging due to limited sensitivity for the detection of small metastases. The case is different in higher risk patients, and especially so in patients with locally advanced disease. FDG-PET/CT in these patients might depict lymph node involvement in the level III of Berg or in supraclavicular or internal mammary basins. It might also uncover occult distant metastases, notably, early osteomedullary infiltration. Thus, for these tumors, initial PET/CT can enable better intramodality treatment planning or a change in treatment. PET/CT as a whole-body examination is also very efficient in case of suspicion of recurrence. On the other hand, many studies show that this functional imaging could be used to assess early response to neoadjuvant chemotherapy or to chemotherapy of metastatic disease. 18FDG-PET/CT could thus become an unavoidable modality to answer various clinical situations.