The Role of FDG-PET for Axillary Lymph Node Staging in Primary Breast Cancer

PET and PET/CT have revealed a good diagnostic accuracy in visualizing both primary cancer and metastatic lesions, and many clinical studies demonstrate that they can compete with the morphological conventional diagnostic modalities mainly in staging, detecting tumor relapses, evaluating tumor response to therapy and giving useful prognostic indications. Data about the usefulness of PET to stage axillary nodes in breast cancer patients are controversial, also considering that another nuclear medicine technique, the sentinel lymph nodes biopsy (SLNB) after localization with lymphoscintigraphy, is very reliable for this indication. It is well known that SLNB today is considered the standard nuclear medicine method for staging axilla. This chapter is focused on the diagnostic potential of PET in studying lymph node axillary metastases that are one the most important prognostic factors affecting the therapeutic strategies. The diagnostic results of the most important clinical trials carried out with FDG-PET in axillary staging of breast cancer patients have been examined and reported. However, the position of FDG-PET in studying the loco-regional lymph nodal involvement still has to be completely evaluated, since the main problem is the absence of long-term prospective studies able to evaluate the outcome of the patients after FDG-PET staging and treated or not with ALND according to FDG negative or positive uptake.