Sensitivity, Specificity and the Diagnostic Accuracy of PET/CT for Axillary Staging in Patients With Stage I-III Cancer: A Systematic Review of The Literature

Background/Aim: Axillary lymph node (ALN) status plays a key role in the staging of breast cancer. Positron Emission Tomography/Computed Tomography (PET/CT) using 18-Fluorodeoxyglucose ((18)FDG) can visualise ALN metastasis. However, its utility compared to current methods is unclear. We systematically reviewed the role of (18)FDG PET/CT in breast cancer staging. Materials and Methods: PubMed, Ovid and Cochrane were searched systematically up until August 2020. Included papers had true positive (TP), false positive (FP), true negative (TN) and false negative (FN) rates, sensitivity, specificity, accuracy, positive (PPV) and negative predictive value (NPV). Results: Nine studies (n=1486) were included, showing: i) sensitivity= 52 2%, ii) specificity=91.6%, iii) PPV=77 .8%, iv) NPV=77 .2, and v) accuracy=77 .3%. Conclusion: (18)FDG-PETICT has a low sensitivity but high specificity for ALN disease. Therefore, ultrasound-guided biopsy could be considered in a positive CT/PET. Modest accuracy prohibits the use of (18)FDG-PETICT alone in axillary staging. Prospective research using standardised protocols and quantitative cut-off points is warranted.