Diagnostic accuracy and clinical utility of axillary ultrasound in the evaluation of axillary lymph node status in early breast cancer patients

Purpose Axillary ultrasound (AUS) is a standard procedure in the preoperative clinical identification of axillary metastatic lymph node (LN) involvement and thereby guides local and systemic therapy decisions in early breast cancer (EBC) patients. However, the interpretation of AUS findings remains highly subjective, as a systematic definition for positive LN in AUS has not been established yet. The aim of this study was to assess AUS performance in the detection and exclusion of LN metastases by evaluating standardized sonographic criteria.

Material and methods In a retrospective monocenter study n = 622 EBC patients were included who underwent both AUS plus any type of axillary surgery, i.e. sentinel lymph node dissection and/or (completing) axillary lymph node dissection. For all patients, AUS image documentation of the most suspicious LN was saved during the initial diagnostic process and then re-evaluated using pre-defined criteria for LN positivity. Main outcome measures were sensitivity, specificity, accuracy, Youden-index (YI) and diagnostic odds ratio (DOR) of the examined criteria.

Results Sensitivity and specificity of AUS were 53.3 % [46.4; 60.1] and 93.6 % [90.8; 95.8] whereas accuracy of 79.7 % [76.4; 82.8], YI of 0.469 [0.398; 0.540] and a DOR of 16.75 [10.37; 27.05] were observed.

Conclusion AUS performance in clinical practice is currently not sufficient for accurately identifying or excluding axillary metastatic disease. Although systematic criteria previously recommended in literature were easily applicable and interrater-reliable, their application did not substantially improve accuracy.

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Publication History

Article published online:
07 October 2020