Diagnostic performance of fluorodeoxyglucose-positron emission tomography/computed tomography combined with ultrasonography-guided fine needle aspiration cytology for identifying axillary lymph node status in patients with breast cancer.

AIM: The aim of this study was to assess the diagnostic performance of fluorodeoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT) in combination with ultrasonography-guided fine needle aspiration cytology (US-guided FNAC) for the preoperative diagnosis of axillary lymph node (ALN) metastases in patients with breast cancer.

MATERIALS AND METHODS: A total of 318 patients with breast cancer were recruited retrospectively. Some of the cases that underwent neoadjuvant chemotherapy (NAC) were included. The sensitivity and specificity of FDG-PET/CT were calculated. We assessed the relationship between the combined results for US-guided FNAC with FDG-PET/CT and the pathological ALN status.

RESULTS: A total of 271 patients underwent FDG-PET/CT. Of these patients, 41 underwent US-guided FNAC. The sensitivity and the specificity of FDG-PET/CT for the cases without NAC were 18.5%, 97.1%, respectively. The sensitivity in cases with NAC was 68.2%. As a whole, the sensitivity was 40.8%. ALN metastasis was detected using US-guided FNAC in a case with a negative FDG uptake in the ALN. The T stage was T2 in the case and the FDG uptake at the primary site was poor.

CONCLUSION: FDG-PET/CT has a good specificity for ALN metastasis, although its sensitivity is limited, especially in early-stage cases. In cases with a negative FDG uptake in the ALN, US-guided FNAC may play a role in the detection of lymph node metastasis when the primary tumor size is large and the FDG uptake in the primary tumor is low.