The role of ultrasonography and FDG-PET in axillary lymph node staging of breast cancer

Abstract

[한글]

[영문]Background: The presence of axillary lymph node metastasis is the most important prognostic factor and an essential part of staging and prognosis of breast cancer.Purpose: To elucidate the usefulness and accuracy of the US, FDG-PET and combined analysis for axillary lymph node staging in breast cancer.Material and Methods: From January 2005 to December 2006, total 250 consecutive breast cancer patients who undertaken US, FDG?PET and sentinel lymph node biopsy (SLNB) before surgery were included. If axillary lymph nodes showed the length to width ratio ≤ 1.5 or cortical thickening ≥ 3mm or compression of the hilum on US, focal hot uptake (maximal standardized uptake value, SUVmax ≥ 2.0) in ipsilateral axilla on FDG-PET, it was considered as metastatic lymph node. In combined analysis of US and FDG-PET, the interpretation was considered positive if at least two of any of the criteria. Each imaging findings were compared with pathologic report that the presence of axillary lymph node metastasis, the number of metastatic lymph nodes and the T stage of breast mass.Results: Pathologically confirmed axillary lymph node metastasis was noted in 73 cases (29.2%). The mean number of metastatic lymph nodes in pathology was 3.1±3.2, and the size of breast cancer was 2.0±1.04cm. In the detection of lymph node metastasis, diagnostic accuracy of US was 78.8%, and that of FDG-PET was 76.4%. On combined US and FDG-PET, accuracy was improved (91.6%). The number of metastatic lymph nodes on pathology was correlated with the positivity of US and FDG?PET (p < 0.01).Conclusion: Combined evaluation of US and FDG-PET was a sensitive and accurate method for axillary lymph node staging in breast cancer.