The roles of PET and CT/PET as preoperative studies

In breast cancer, FDG-PET has been used for detection, staging, and response monitoring; one of its main clinical applications is defining the extent of recurrent or metastatic disease [1]. We have reviewed the evidence regarding the roles of PET and CT/PET as preoperative studies in breast cancer.The review of the evidence shows that PET and CT/PET can contribute to patient diagnosis and management as preoperative studies in breast cancer in the following situations:1. Detection of primary breast cancer. When evaluating suspicious breast abnormalities, FDG-PET has a sensitivity of 80–100% and specificity of 75–100%. However, its role in primary tumor detection is not clear when compared with conventional imaging methods and remains to be determined [1].2. Prognostic value of FDG uptake in primary tumor. Most studies suggest that the level of FDG uptake in primary breast tumors carries clinical and biological information, and that a higher FDG uptake is correlated with more clinically aggressive tumors [1]. This information may help to stratify patients according to prognosis and risk for recurrence, and may help to tailor treatments to the individual patient.3. Axillary node staging. In this situation, FDG-PET had a sensitivity of 57–100% and specificity of 66–100%. FDG-PET underestimates the number of tumor-involved nodes compared with pathologic evaluation from conventional dissection. Therefore, FDG-PET should not replace axillary node sampling for routine staging of the axilla because even microscopic nodal involvement may be important for prognosis and treatment planning [1]. However, FDG-PET may be complementary to sentinel lymph node mapping and other standard axillary procedures in patients with more advanced tumors or equivocally palpable axillary nodes.4. Detection of locoregional and distant metastases. Functional imaging with FDG-PET is more accurate than CT for the detection of nodal involvement in the mediastinum; the sensitivity of FDG-PET was signif