Evaluation of axillary status in breast cancer. CT-based determination of sentinel lymph node size.

Purpose: To determine whether the location and size of sentinel lymph nodes (SLN) on CT are predictive of the axillary lymph node status in patients with breast cancer.
Material and Methods: Forty patients with confirmed breast cancer underwent 5-mm CT of both breasts and axillae and the most inferior lymph node in the affected axilla was designated the SLN. Based on CT assessment of the axillary lymph node status, 22 (55%) patients then underwent dye- and gamma probe (DGP)-guided SLN biopsy followed by axillary dissection; 18 (45%) underwent dissection without prior SLN biopsy. The localization and status of the SLN determined on CT and by DGP-guided biopsy were compared. Biopsied and excised nodes were subjected to histopathologic examinations.
Results: All SLN identified on CT were close to the lateral thoracic artery and their localization corresponded well with SLN identified by the DGP-guided method. The positive predictive value of CT diagnosis was 100%. Histopathologic examination of excised nodes confirmed that none of the SLN biopsies was false-negative.
Conclusion: Our CT criteria were highly accurate for identification and diagnostic assessment of SLN and useful for evaluating the axillary status in patients with breast cancer.